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freebsd-skq/sys/kern/kern_ktrace.c

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/* -> /*- for copyright notices, minor format tweaks as necessary
2005-01-06 23:35:40 +00:00
/*-
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
* Copyright (c) 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)kern_ktrace.c 8.2 (Berkeley) 9/23/93
*/
Use __FBSDID().
2003-06-11 00:56:59 +00:00
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
Converted two options over to the new scheme: USER_LDT and KTRACE.
1996-01-03 21:42:35 +00:00
#include "opt_ktrace.h"
Introduce support for Mandatory Access Control and extensible kernel access control. Instrument the ktrace write operation so that it invokes the MAC framework's vnode write authorization check. Obtained from: TrustedBSD Project Sponsored by: DARPA, NAI Labs
2002-08-01 01:07:03 +00:00
#include "opt_mac.h"
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
#include <sys/param.h>
Fix up some sloppy coding practices: - Delete redundant declarations. - Add -Wredundant-declarations to Makefile.i386 so they don't come back. - Delete sloppy COMMON-style declarations of uninitialized data in header files. - Add a few prototypes. - Clean up warnings resulting from the above. NB: ioconf.c will still generate a redundant-declaration warning, which is unavoidable unless somebody volunteers to make `config' smarter.
1994-08-18 22:36:09 +00:00
#include <sys/systm.h>
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
#include <sys/fcntl.h>
#include <sys/kernel.h>
#include <sys/kthread.h>
Undo part of the tangle of having sys/lock.h and sys/mutex.h included in other "system" header files. Also help the deprecation of lockmgr.h by making it a sub-include of sys/lock.h and removing sys/lockmgr.h form kernel .c files. Sort sys/*.h includes where possible in affected files. OK'ed by: bde (with reservations)
2001-05-01 08:13:21 +00:00
#include <sys/lock.h>
#include <sys/mutex.h>
Introduce support for Mandatory Access Control and extensible kernel access control. Instrument the ktrace write operation so that it invokes the MAC framework's vnode write authorization check. Obtained from: TrustedBSD Project Sponsored by: DARPA, NAI Labs
2002-08-01 01:07:03 +00:00
#include <sys/mac.h>
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
#include <sys/malloc.h>
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
#include <sys/namei.h>
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
#include <sys/proc.h>
#include <sys/unistd.h>
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
#include <sys/vnode.h>
#include <sys/ktrace.h>
Convert the allproc and proctree locks from lockmgr locks to sx locks.
2001-03-28 11:52:56 +00:00
#include <sys/sx.h>
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
#include <sys/sysctl.h>
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
#include <sys/syslog.h>
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
#include <sys/sysproto.h>
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
Last major round (Unless Bruce thinks of somthing :-) of malloc changes. Distribute all but the most fundamental malloc types. This time I also remembered the trick to making things static: Put "static" in front of them. A couple of finer points by: bde
1997-10-12 20:26:33 +00:00
static MALLOC_DEFINE(M_KTRACE, "KTRACE", "KTRACE");
Distribute and statizice a lot of the malloc M_* types. Substantial input from: bde
1997-10-11 18:31:40 +00:00
Converted two options over to the new scheme: USER_LDT and KTRACE.
1996-01-03 21:42:35 +00:00
#ifdef KTRACE
Completed function declarations and/or added prototypes.
1995-12-02 18:58:56 +00:00
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
#ifndef KTRACE_REQUEST_POOL
#define KTRACE_REQUEST_POOL 100
#endif
struct ktr_request {
struct ktr_header ktr_header;
Merge kern_ktrace.c:1.102, ktrace.h:1.30 from HEAD to RELENG_6: Replace ktr_buffer pointer in struct ktr_header with a ktr_unused intptr_t. The buffer length needs to be written to disk as part of the trace log, but the kernel pointer for the buffer does not. Add a new ktr_buffer pointer to the kernel-only ktrace request structure to hold that pointer. This frees up an integer in the ktrace record format that can be used to hold the threadid, although older ktrace files will have a garbage ktr_buffer field (or more accurately, a kernel pointer value). Space requested by: davidxu
2005-11-16 08:11:06 +00:00
void *ktr_buffer;
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
struct ucred *ktr_cred;
struct vnode *ktr_vp;
union {
struct ktr_syscall ktr_syscall;
struct ktr_sysret ktr_sysret;
struct ktr_genio ktr_genio;
struct ktr_psig ktr_psig;
struct ktr_csw ktr_csw;
} ktr_data;
STAILQ_ENTRY(ktr_request) ktr_list;
};
static int data_lengths[] = {
0, /* none */
offsetof(struct ktr_syscall, ktr_args), /* KTR_SYSCALL */
sizeof(struct ktr_sysret), /* KTR_SYSRET */
0, /* KTR_NAMEI */
sizeof(struct ktr_genio), /* KTR_GENIO */
sizeof(struct ktr_psig), /* KTR_PSIG */
sizeof(struct ktr_csw), /* KTR_CSW */
0 /* KTR_USER */
};
static STAILQ_HEAD(, ktr_request) ktr_todo;
static STAILQ_HEAD(, ktr_request) ktr_free;
Make a SYSCTL_NODE static
2005-02-10 12:23:29 +00:00
static SYSCTL_NODE(_kern, OID_AUTO, ktrace, CTLFLAG_RD, 0, "KTRACE options");
- Add a kern.ktrace sysctl node. - Rename kern.ktrace_request_pool tunable/sysctl to kern.ktrace.request_pool. - Add a variable to control the max amount of data to log for genio events. This variable is tunable via the tunable/sysctl kern.ktrace.genio_size and defaults to one page.
2002-09-11 20:49:55 +00:00
Consistently use the BSD u_int and u_short instead of the SYSV uint and ushort. In most of these files, there was a mixture of both styles and this change just makes them self-consistent. Requested by: bde (kern_ktrace.c)
2003-08-07 15:04:27 +00:00
static u_int ktr_requestpool = KTRACE_REQUEST_POOL;
- Add a kern.ktrace sysctl node. - Rename kern.ktrace_request_pool tunable/sysctl to kern.ktrace.request_pool. - Add a variable to control the max amount of data to log for genio events. This variable is tunable via the tunable/sysctl kern.ktrace.genio_size and defaults to one page.
2002-09-11 20:49:55 +00:00
TUNABLE_INT("kern.ktrace.request_pool", &ktr_requestpool);
Consistently use the BSD u_int and u_short instead of the SYSV uint and ushort. In most of these files, there was a mixture of both styles and this change just makes them self-consistent. Requested by: bde (kern_ktrace.c)
2003-08-07 15:04:27 +00:00
static u_int ktr_geniosize = PAGE_SIZE;
- Add a kern.ktrace sysctl node. - Rename kern.ktrace_request_pool tunable/sysctl to kern.ktrace.request_pool. - Add a variable to control the max amount of data to log for genio events. This variable is tunable via the tunable/sysctl kern.ktrace.genio_size and defaults to one page.
2002-09-11 20:49:55 +00:00
TUNABLE_INT("kern.ktrace.genio_size", &ktr_geniosize);
SYSCTL_UINT(_kern_ktrace, OID_AUTO, genio_size, CTLFLAG_RW, &ktr_geniosize,
0, "Maximum size of genio event payload");
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
static int print_message = 1;
struct mtx ktrace_mtx;
Replace the ktrace queue's semaphore with a condition variable instead as it is slightly more efficient since we already have a mutex to protect the queue. Ktrace originally used a semaphore more as a proof of concept.
2004-02-26 19:30:22 +00:00
static struct cv ktrace_cv;
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
static void ktrace_init(void *dummy);
static int sysctl_kern_ktrace_request_pool(SYSCTL_HANDLER_ARGS);
Consistently use the BSD u_int and u_short instead of the SYSV uint and ushort. In most of these files, there was a mixture of both styles and this change just makes them self-consistent. Requested by: bde (kern_ktrace.c)
2003-08-07 15:04:27 +00:00
static u_int ktrace_resize_pool(u_int newsize);
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
static struct ktr_request *ktr_getrequest(int type);
static void ktr_submitrequest(struct ktr_request *req);
static void ktr_freerequest(struct ktr_request *req);
static void ktr_loop(void *dummy);
static void ktr_writerequest(struct ktr_request *req);
static int ktrcanset(struct thread *,struct proc *);
static int ktrsetchildren(struct thread *,struct proc *,int,int,struct vnode *);
static int ktrops(struct thread *,struct proc *,int,int,struct vnode *);
static void
ktrace_init(void *dummy)
{
struct ktr_request *req;
int i;
mtx_init(&ktrace_mtx, "ktrace", NULL, MTX_DEF | MTX_QUIET);
Replace the ktrace queue's semaphore with a condition variable instead as it is slightly more efficient since we already have a mutex to protect the queue. Ktrace originally used a semaphore more as a proof of concept.
2004-02-26 19:30:22 +00:00
cv_init(&ktrace_cv, "ktrace");
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
STAILQ_INIT(&ktr_todo);
STAILQ_INIT(&ktr_free);
for (i = 0; i < ktr_requestpool; i++) {
Back out M_* changes, per decision of the TRB. Approved by: trb
2003-02-19 05:47:46 +00:00
req = malloc(sizeof(struct ktr_request), M_KTRACE, M_WAITOK);
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
STAILQ_INSERT_HEAD(&ktr_free, req, ktr_list);
}
Some kernel threads try to do significant work, and the default KSTACK_PAGES doesn't give them enough stack to do much before blowing away the pcb. This adds MI and MD code to allow the allocation of an alternate kstack who's size can be speficied when calling kthread_create. Passing the value 0 prevents the alternate kstack from being created. Note that the ia64 MD code is missing for now, and PowerPC was only partially written due to the pmap.c being incomplete there. Though this patch does not modify anything to make use of the alternate kstack, acpi and usb are good candidates. Reviewed by: jake, peter, jhb
2002-10-02 07:44:29 +00:00
kthread_create(ktr_loop, NULL, NULL, RFHIGHPID, 0, "ktrace");
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
}
SYSINIT(ktrace_init, SI_SUB_KTRACE, SI_ORDER_ANY, ktrace_init, NULL);
static int
sysctl_kern_ktrace_request_pool(SYSCTL_HANDLER_ARGS)
{
struct thread *td;
Consistently use the BSD u_int and u_short instead of the SYSV uint and ushort. In most of these files, there was a mixture of both styles and this change just makes them self-consistent. Requested by: bde (kern_ktrace.c)
2003-08-07 15:04:27 +00:00
u_int newsize, oldsize, wantsize;
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
int error;
/* Handle easy read-only case first to avoid warnings from GCC. */
if (!req->newptr) {
mtx_lock(&ktrace_mtx);
oldsize = ktr_requestpool;
mtx_unlock(&ktrace_mtx);
Consistently use the BSD u_int and u_short instead of the SYSV uint and ushort. In most of these files, there was a mixture of both styles and this change just makes them self-consistent. Requested by: bde (kern_ktrace.c)
2003-08-07 15:04:27 +00:00
return (SYSCTL_OUT(req, &oldsize, sizeof(u_int)));
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
}
Consistently use the BSD u_int and u_short instead of the SYSV uint and ushort. In most of these files, there was a mixture of both styles and this change just makes them self-consistent. Requested by: bde (kern_ktrace.c)
2003-08-07 15:04:27 +00:00
error = SYSCTL_IN(req, &wantsize, sizeof(u_int));
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
if (error)
return (error);
td = curthread;
- Add a td_pflags field to struct thread for private flags accessed only by curthread. Unlike td_flags, this field does not need any locking. - Replace the td_inktr and td_inktrace variables with equivalent private thread flags. - Move TDF_OLDMASK over to the private flags field so it no longer requires sched_lock.
2003-06-09 17:38:32 +00:00
td->td_pflags |= TDP_INKTRACE;
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
mtx_lock(&ktrace_mtx);
oldsize = ktr_requestpool;
newsize = ktrace_resize_pool(wantsize);
mtx_unlock(&ktrace_mtx);
- Add a td_pflags field to struct thread for private flags accessed only by curthread. Unlike td_flags, this field does not need any locking. - Replace the td_inktr and td_inktrace variables with equivalent private thread flags. - Move TDF_OLDMASK over to the private flags field so it no longer requires sched_lock.
2003-06-09 17:38:32 +00:00
td->td_pflags &= ~TDP_INKTRACE;
Consistently use the BSD u_int and u_short instead of the SYSV uint and ushort. In most of these files, there was a mixture of both styles and this change just makes them self-consistent. Requested by: bde (kern_ktrace.c)
2003-08-07 15:04:27 +00:00
error = SYSCTL_OUT(req, &oldsize, sizeof(u_int));
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
if (error)
return (error);
Bound the number of iterations a thread can perform inside ktr_resize_pool(); this eliminates a potential livelock. Return ENOSPC only if we encountered an out-of-memory condition when trying to increase the pool size. Reviewed by: jhb, bde (style)
2003-11-11 09:09:26 +00:00
if (wantsize > oldsize && newsize < wantsize)
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
return (ENOSPC);
return (0);
}
- Add a kern.ktrace sysctl node. - Rename kern.ktrace_request_pool tunable/sysctl to kern.ktrace.request_pool. - Add a variable to control the max amount of data to log for genio events. This variable is tunable via the tunable/sysctl kern.ktrace.genio_size and defaults to one page.
2002-09-11 20:49:55 +00:00
SYSCTL_PROC(_kern_ktrace, OID_AUTO, request_pool, CTLTYPE_UINT|CTLFLAG_RW,
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
&ktr_requestpool, 0, sysctl_kern_ktrace_request_pool, "IU", "");
Consistently use the BSD u_int and u_short instead of the SYSV uint and ushort. In most of these files, there was a mixture of both styles and this change just makes them self-consistent. Requested by: bde (kern_ktrace.c)
2003-08-07 15:04:27 +00:00
static u_int
ktrace_resize_pool(u_int newsize)
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
{
struct ktr_request *req;
Bound the number of iterations a thread can perform inside ktr_resize_pool(); this eliminates a potential livelock. Return ENOSPC only if we encountered an out-of-memory condition when trying to increase the pool size. Reviewed by: jhb, bde (style)
2003-11-11 09:09:26 +00:00
int bound;
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
mtx_assert(&ktrace_mtx, MA_OWNED);
print_message = 1;
Bound the number of iterations a thread can perform inside ktr_resize_pool(); this eliminates a potential livelock. Return ENOSPC only if we encountered an out-of-memory condition when trying to increase the pool size. Reviewed by: jhb, bde (style)
2003-11-11 09:09:26 +00:00
bound = newsize - ktr_requestpool;
if (bound == 0)
return (ktr_requestpool);
if (bound < 0)
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
/* Shrink pool down to newsize if possible. */
Bound the number of iterations a thread can perform inside ktr_resize_pool(); this eliminates a potential livelock. Return ENOSPC only if we encountered an out-of-memory condition when trying to increase the pool size. Reviewed by: jhb, bde (style)
2003-11-11 09:09:26 +00:00
while (bound++ < 0) {
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
req = STAILQ_FIRST(&ktr_free);
if (req == NULL)
return (ktr_requestpool);
STAILQ_REMOVE_HEAD(&ktr_free, ktr_list);
ktr_requestpool--;
mtx_unlock(&ktrace_mtx);
free(req, M_KTRACE);
mtx_lock(&ktrace_mtx);
}
else
/* Grow pool up to newsize. */
Bound the number of iterations a thread can perform inside ktr_resize_pool(); this eliminates a potential livelock. Return ENOSPC only if we encountered an out-of-memory condition when trying to increase the pool size. Reviewed by: jhb, bde (style)
2003-11-11 09:09:26 +00:00
while (bound-- > 0) {
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
mtx_unlock(&ktrace_mtx);
req = malloc(sizeof(struct ktr_request), M_KTRACE,
Back out M_* changes, per decision of the TRB. Approved by: trb
2003-02-19 05:47:46 +00:00
M_WAITOK);
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
mtx_lock(&ktrace_mtx);
STAILQ_INSERT_HEAD(&ktr_free, req, ktr_list);
ktr_requestpool++;
}
return (ktr_requestpool);
}
static struct ktr_request *
ktr_getrequest(int type)
{
struct ktr_request *req;
struct thread *td = curthread;
struct proc *p = td->td_proc;
int pm;
- Add a td_pflags field to struct thread for private flags accessed only by curthread. Unlike td_flags, this field does not need any locking. - Replace the td_inktr and td_inktrace variables with equivalent private thread flags. - Move TDF_OLDMASK over to the private flags field so it no longer requires sched_lock.
2003-06-09 17:38:32 +00:00
td->td_pflags |= TDP_INKTRACE;
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
mtx_lock(&ktrace_mtx);
if (!KTRCHECK(td, type)) {
mtx_unlock(&ktrace_mtx);
- Add a td_pflags field to struct thread for private flags accessed only by curthread. Unlike td_flags, this field does not need any locking. - Replace the td_inktr and td_inktrace variables with equivalent private thread flags. - Move TDF_OLDMASK over to the private flags field so it no longer requires sched_lock.
2003-06-09 17:38:32 +00:00
td->td_pflags &= ~TDP_INKTRACE;
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
return (NULL);
}
req = STAILQ_FIRST(&ktr_free);
if (req != NULL) {
STAILQ_REMOVE_HEAD(&ktr_free, ktr_list);
req->ktr_header.ktr_type = type;
Add a new userland-visible ktrace flag KTR_DROP and an internal ktrace flag KTRFAC_DROP to track instances when ktrace events are dropped due to the request pool being exhausted. When a thread tries to post a ktrace event and is unable to due to no available ktrace request objects, it sets KTRFAC_DROP in its process' p_traceflag field. The next trace event to successfully post from that process will set the KTR_DROP flag in the header of the request going out and clear KTRFAC_DROP. The KTR_DROP flag is the high bit in the type field of the ktr_header structure. Older kdump binaries will simply complain about an unknown type when seeing an entry with KTR_DROP set. Note that KTR_DROP being set on a record in a ktrace file does not tell you anything except that at least one event from this process was dropped prior to this event. The user has no way of knowing what types of events were dropped nor how many were dropped. Requested by: phk
2003-03-13 18:31:15 +00:00
if (p->p_traceflag & KTRFAC_DROP) {
req->ktr_header.ktr_type |= KTR_DROP;
p->p_traceflag &= ~KTRFAC_DROP;
}
- Cache a reference to the credential of the thread that starts a ktrace in struct proc as p_tracecred alongside the current cache of the vnode in p_tracep. This credential is then used for all later ktrace operations on this file rather than using the credential of the current thread at the time of each ktrace event. - Now that we have multiple ktrace-related items in struct proc that are pointers, rename p_tracep to p_tracevp to make it less ambiguous. Requested by: rwatson (1)
2003-03-13 18:24:22 +00:00
KASSERT(p->p_tracevp != NULL, ("ktrace: no trace vnode"));
KASSERT(p->p_tracecred != NULL, ("ktrace: no trace cred"));
req->ktr_vp = p->p_tracevp;
VREF(p->p_tracevp);
req->ktr_cred = crhold(p->p_tracecred);
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
mtx_unlock(&ktrace_mtx);
microtime(&req->ktr_header.ktr_time);
req->ktr_header.ktr_pid = p->p_pid;
Merge kern_ktrace.c:1.103, ktrace.h:1.31 from HEAD to RELENG_6: Reuse ktr_unused field in ktr_header structure as ktr_tid; populate ktr_tid as part of gathering of ktr header data for new ktrace records. The continued use of intptr_t is required for file layout reasons, and cannot be changed to lwpid_t at this point. Reviewed by: davidxu Approved by: re (scottl)
2006-02-14 00:02:01 +00:00
req->ktr_header.ktr_tid = td->td_tid;
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
bcopy(p->p_comm, req->ktr_header.ktr_comm, MAXCOMLEN + 1);
Merge kern_ktrace.c:1.102, ktrace.h:1.30 from HEAD to RELENG_6: Replace ktr_buffer pointer in struct ktr_header with a ktr_unused intptr_t. The buffer length needs to be written to disk as part of the trace log, but the kernel pointer for the buffer does not. Add a new ktr_buffer pointer to the kernel-only ktrace request structure to hold that pointer. This frees up an integer in the ktrace record format that can be used to hold the threadid, although older ktrace files will have a garbage ktr_buffer field (or more accurately, a kernel pointer value). Space requested by: davidxu
2005-11-16 08:11:06 +00:00
req->ktr_buffer = NULL;
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
req->ktr_header.ktr_len = 0;
} else {
Add a new userland-visible ktrace flag KTR_DROP and an internal ktrace flag KTRFAC_DROP to track instances when ktrace events are dropped due to the request pool being exhausted. When a thread tries to post a ktrace event and is unable to due to no available ktrace request objects, it sets KTRFAC_DROP in its process' p_traceflag field. The next trace event to successfully post from that process will set the KTR_DROP flag in the header of the request going out and clear KTRFAC_DROP. The KTR_DROP flag is the high bit in the type field of the ktr_header structure. Older kdump binaries will simply complain about an unknown type when seeing an entry with KTR_DROP set. Note that KTR_DROP being set on a record in a ktrace file does not tell you anything except that at least one event from this process was dropped prior to this event. The user has no way of knowing what types of events were dropped nor how many were dropped. Requested by: phk
2003-03-13 18:31:15 +00:00
p->p_traceflag |= KTRFAC_DROP;
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
pm = print_message;
print_message = 0;
mtx_unlock(&ktrace_mtx);
if (pm)
printf("Out of ktrace request objects.\n");
- Add a td_pflags field to struct thread for private flags accessed only by curthread. Unlike td_flags, this field does not need any locking. - Replace the td_inktr and td_inktrace variables with equivalent private thread flags. - Move TDF_OLDMASK over to the private flags field so it no longer requires sched_lock.
2003-06-09 17:38:32 +00:00
td->td_pflags &= ~TDP_INKTRACE;
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
}
return (req);
}
A Major staticize sweep. Generates a couple of warnings that I'll deal with later. A number of unused vars removed. A number of unused procs removed or #ifdefed.
1995-12-14 08:32:45 +00:00
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
static void
ktr_submitrequest(struct ktr_request *req)
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
{
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
mtx_lock(&ktrace_mtx);
STAILQ_INSERT_TAIL(&ktr_todo, req, ktr_list);
Replace the ktrace queue's semaphore with a condition variable instead as it is slightly more efficient since we already have a mutex to protect the queue. Ktrace originally used a semaphore more as a proof of concept.
2004-02-26 19:30:22 +00:00
cv_signal(&ktrace_cv);
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
mtx_unlock(&ktrace_mtx);
- Add a td_pflags field to struct thread for private flags accessed only by curthread. Unlike td_flags, this field does not need any locking. - Replace the td_inktr and td_inktrace variables with equivalent private thread flags. - Move TDF_OLDMASK over to the private flags field so it no longer requires sched_lock.
2003-06-09 17:38:32 +00:00
curthread->td_pflags &= ~TDP_INKTRACE;
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
}
static void
ktr_freerequest(struct ktr_request *req)
{
crfree(req->ktr_cred);
If we fail to write to a vnode during a ktrace write, then we drop all other references to that vnode as a trace vnode in other processes as well as in any pending requests on the todo list. Thus, it is possible for a ktrace request structure to have a NULL ktr_vp when it is destroyed in ktr_freerequest(). We shouldn't call vrele() on the vnode in that case. Reported by: bde
2002-08-01 13:35:38 +00:00
if (req->ktr_vp != NULL) {
mtx_lock(&Giant);
vrele(req->ktr_vp);
mtx_unlock(&Giant);
}
Merge kern_ktrace.c:1.102, ktrace.h:1.30 from HEAD to RELENG_6: Replace ktr_buffer pointer in struct ktr_header with a ktr_unused intptr_t. The buffer length needs to be written to disk as part of the trace log, but the kernel pointer for the buffer does not. Add a new ktr_buffer pointer to the kernel-only ktrace request structure to hold that pointer. This frees up an integer in the ktrace record format that can be used to hold the threadid, although older ktrace files will have a garbage ktr_buffer field (or more accurately, a kernel pointer value). Space requested by: davidxu
2005-11-16 08:11:06 +00:00
if (req->ktr_buffer != NULL)
free(req->ktr_buffer, M_KTRACE);
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
mtx_lock(&ktrace_mtx);
STAILQ_INSERT_HEAD(&ktr_free, req, ktr_list);
mtx_unlock(&ktrace_mtx);
}
static void
ktr_loop(void *dummy)
{
struct ktr_request *req;
struct thread *td;
struct ucred *cred;
/* Only cache these values once. */
td = curthread;
cred = td->td_ucred;
for (;;) {
mtx_lock(&ktrace_mtx);
Replace the ktrace queue's semaphore with a condition variable instead as it is slightly more efficient since we already have a mutex to protect the queue. Ktrace originally used a semaphore more as a proof of concept.
2004-02-26 19:30:22 +00:00
while (STAILQ_EMPTY(&ktr_todo))
cv_wait(&ktrace_cv, &ktrace_mtx);
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
req = STAILQ_FIRST(&ktr_todo);
STAILQ_REMOVE_HEAD(&ktr_todo, ktr_list);
KASSERT(req != NULL, ("got a NULL request"));
Remove support for synchronous ktrace requests now that none exist anymore. They were an ugly, gross hack.
2002-09-11 20:58:10 +00:00
mtx_unlock(&ktrace_mtx);
/*
* It is not enough just to pass the cached cred
* to the VOP's in ktr_writerequest(). Some VFS
* operations use curthread->td_ucred, so we need
* to modify our thread's credentials as well.
* Evil.
*/
td->td_ucred = req->ktr_cred;
ktr_writerequest(req);
td->td_ucred = cred;
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
ktr_freerequest(req);
}
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
}
Remove the MPSAFE keyword from the parser for syscalls.master. Instead introduce the [M] prefix to existing keywords. e.g. MSTD is the MP SAFE version of STD. This is prepatory for a massive Giant lock pushdown. The old MPSAFE keyword made syscalls.master too messy. Begin comments MP-Safe procedures with the comment: /* * MPSAFE */ This comments means that the procedure may be called without Giant held (The procedure itself may still need to obtain Giant temporarily to do its thing). sv_prepsyscall() is now MP SAFE and assumed to be MP SAFE sv_transtrap() is now MP SAFE and assumed to be MP SAFE ktrsyscall() and ktrsysret() are now MP SAFE (Giant Pushdown) trapsignal() is now MP SAFE (Giant Pushdown) Places which used to do the if (mtx_owned(&Giant)) mtx_unlock(&Giant) test in syscall[2]() in */*/trap.c now do not. Instead they explicitly unlock Giant if they previously obtained it, and then assert that it is no longer held to catch broken system calls. Rebuild syscall tables.
2001-08-30 18:50:57 +00:00
/*
* MPSAFE
*/
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
void
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
ktrsyscall(code, narg, args)
Make sure syscall arguments properly aligned in ktrace records. Make syscall return value a register_t. Based on a patch from Hidetoshi Shimokawa. Mostly reviewed by: Hidetoshi Shimokawa and Bruce Evans.
1999-06-16 18:37:01 +00:00
int code, narg;
register_t args[];
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
{
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
struct ktr_request *req;
struct ktr_syscall *ktp;
size_t buflen;
Change namei and syscall ktrace events to malloc work buffers before obtaining a ktr_request structure from the free pool so we can avoid starving other threads of ktr_request structures.
2002-09-11 20:46:50 +00:00
char *buf = NULL;
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
Change namei and syscall ktrace events to malloc work buffers before obtaining a ktr_request structure from the free pool so we can avoid starving other threads of ktr_request structures.
2002-09-11 20:46:50 +00:00
buflen = sizeof(register_t) * narg;
if (buflen > 0) {
Back out M_* changes, per decision of the TRB. Approved by: trb
2003-02-19 05:47:46 +00:00
buf = malloc(buflen, M_KTRACE, M_WAITOK);
Change namei and syscall ktrace events to malloc work buffers before obtaining a ktr_request structure from the free pool so we can avoid starving other threads of ktr_request structures.
2002-09-11 20:46:50 +00:00
bcopy(args, buf, buflen);
}
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
req = ktr_getrequest(KTR_SYSCALL);
Plug memory leaks. Detected by: FlexeLint Approved by: jhb
2002-09-30 19:19:47 +00:00
if (req == NULL) {
if (buf != NULL)
free(buf, M_KTRACE);
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
return;
Plug memory leaks. Detected by: FlexeLint Approved by: jhb
2002-09-30 19:19:47 +00:00
}
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
ktp = &req->ktr_data.ktr_syscall;
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
ktp->ktr_code = code;
ktp->ktr_narg = narg;
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
if (buflen > 0) {
req->ktr_header.ktr_len = buflen;
Merge kern_ktrace.c:1.102, ktrace.h:1.30 from HEAD to RELENG_6: Replace ktr_buffer pointer in struct ktr_header with a ktr_unused intptr_t. The buffer length needs to be written to disk as part of the trace log, but the kernel pointer for the buffer does not. Add a new ktr_buffer pointer to the kernel-only ktrace request structure to hold that pointer. This frees up an integer in the ktrace record format that can be used to hold the threadid, although older ktrace files will have a garbage ktr_buffer field (or more accurately, a kernel pointer value). Space requested by: davidxu
2005-11-16 08:11:06 +00:00
req->ktr_buffer = buf;
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
}
ktr_submitrequest(req);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
}
Remove the MPSAFE keyword from the parser for syscalls.master. Instead introduce the [M] prefix to existing keywords. e.g. MSTD is the MP SAFE version of STD. This is prepatory for a massive Giant lock pushdown. The old MPSAFE keyword made syscalls.master too messy. Begin comments MP-Safe procedures with the comment: /* * MPSAFE */ This comments means that the procedure may be called without Giant held (The procedure itself may still need to obtain Giant temporarily to do its thing). sv_prepsyscall() is now MP SAFE and assumed to be MP SAFE sv_transtrap() is now MP SAFE and assumed to be MP SAFE ktrsyscall() and ktrsysret() are now MP SAFE (Giant Pushdown) trapsignal() is now MP SAFE (Giant Pushdown) Places which used to do the if (mtx_owned(&Giant)) mtx_unlock(&Giant) test in syscall[2]() in */*/trap.c now do not. Instead they explicitly unlock Giant if they previously obtained it, and then assert that it is no longer held to catch broken system calls. Rebuild syscall tables.
2001-08-30 18:50:57 +00:00
/*
* MPSAFE
*/
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
void
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
ktrsysret(code, error, retval)
Make sure syscall arguments properly aligned in ktrace records. Make syscall return value a register_t. Based on a patch from Hidetoshi Shimokawa. Mostly reviewed by: Hidetoshi Shimokawa and Bruce Evans.
1999-06-16 18:37:01 +00:00
int code, error;
register_t retval;
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
{
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
struct ktr_request *req;
struct ktr_sysret *ktp;
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
req = ktr_getrequest(KTR_SYSRET);
if (req == NULL)
return;
ktp = &req->ktr_data.ktr_sysret;
ktp->ktr_code = code;
ktp->ktr_error = error;
ktp->ktr_retval = retval; /* what about val2 ? */
ktr_submitrequest(req);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
}
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
void
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
ktrnamei(path)
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
char *path;
{
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
struct ktr_request *req;
int namelen;
Change namei and syscall ktrace events to malloc work buffers before obtaining a ktr_request structure from the free pool so we can avoid starving other threads of ktr_request structures.
2002-09-11 20:46:50 +00:00
char *buf = NULL;
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
Change namei and syscall ktrace events to malloc work buffers before obtaining a ktr_request structure from the free pool so we can avoid starving other threads of ktr_request structures.
2002-09-11 20:46:50 +00:00
namelen = strlen(path);
if (namelen > 0) {
Back out M_* changes, per decision of the TRB. Approved by: trb
2003-02-19 05:47:46 +00:00
buf = malloc(namelen, M_KTRACE, M_WAITOK);
Change namei and syscall ktrace events to malloc work buffers before obtaining a ktr_request structure from the free pool so we can avoid starving other threads of ktr_request structures.
2002-09-11 20:46:50 +00:00
bcopy(path, buf, namelen);
}
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
req = ktr_getrequest(KTR_NAMEI);
Plug memory leaks. Detected by: FlexeLint Approved by: jhb
2002-09-30 19:19:47 +00:00
if (req == NULL) {
if (buf != NULL)
free(buf, M_KTRACE);
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
return;
Plug memory leaks. Detected by: FlexeLint Approved by: jhb
2002-09-30 19:19:47 +00:00
}
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
if (namelen > 0) {
req->ktr_header.ktr_len = namelen;
Merge kern_ktrace.c:1.102, ktrace.h:1.30 from HEAD to RELENG_6: Replace ktr_buffer pointer in struct ktr_header with a ktr_unused intptr_t. The buffer length needs to be written to disk as part of the trace log, but the kernel pointer for the buffer does not. Add a new ktr_buffer pointer to the kernel-only ktrace request structure to hold that pointer. This frees up an integer in the ktrace record format that can be used to hold the threadid, although older ktrace files will have a garbage ktr_buffer field (or more accurately, a kernel pointer value). Space requested by: davidxu
2005-11-16 08:11:06 +00:00
req->ktr_buffer = buf;
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
}
ktr_submitrequest(req);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
}
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
/*
* Since the uio may not stay valid, we can not hand off this request to
* the thread and need to process it synchronously. However, we wish to
* keep the relative order of records in a trace file correct, so we
* do put this request on the queue (if it isn't empty) and then block.
* The ktrace thread waks us back up when it is time for this event to
* be posted and blocks until we have completed writing out the event
* and woken it back up.
*/
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
void
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
ktrgenio(fd, rw, uio, error)
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
int fd;
enum uio_rw rw;
Modify ktrace's general I/O tracing, ktrgenio(), to use a struct uio * instead of a struct iovec * array and int len. Get rid of stupidly trying to allocate all of the memory and copyin()ing the entire iovec[], and instead just do the proper VOP_WRITE() in ktrwrite() using a copy of the struct uio that the syscall originally used. This solves the DoS which could easily be performed; to work around the DoS, one could also remove "options KTRACE" from the kernel. This is a very strong MFC candidate for 4.1. Found by: art@OpenBSD.org
2000-07-02 08:08:09 +00:00
struct uio *uio;
int error;
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
{
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
struct ktr_request *req;
struct ktr_genio *ktg;
- Change ktrace genio events to only copy up to ktr_geniosize bytes of a transfer to a malloc'd buffer and use that bufer for the ktrace event. This means that genio ktrace events no longer need to be synchronous. - Now that ktr_buffer isn't overloaded to sometimes point to a cached uio pointer for genio requests and always points to a malloc'd buffer if not NULL, free the buffer in ktr_freerequest() instead of in ktr_writerequest(). This closes a memory leak for ktrace events that used a malloc'd buffer that had their vnode ripped out from under them while they were on the todo list. Suggested by: bde (1, in principle)
2002-09-11 20:56:05 +00:00
int datalen;
char *buf;
Remove trailing whitespace.
1995-05-30 08:16:23 +00:00
Clean up and wash struct iovec and struct uio handling. Add copyiniov() which copies a struct iovec array in from userland into a malloc'ed struct iovec. Caller frees. Change uiofromiov() to malloc the uio (caller frees) and name it copyinuio() which is more appropriate. Add cloneuio() which returns a malloc'ed copy. Caller frees. Use them throughout.
2004-07-10 15:42:16 +00:00
if (error) {
free(uio, M_IOV);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
return;
Clean up and wash struct iovec and struct uio handling. Add copyiniov() which copies a struct iovec array in from userland into a malloc'ed struct iovec. Caller frees. Change uiofromiov() to malloc the uio (caller frees) and name it copyinuio() which is more appropriate. Add cloneuio() which returns a malloc'ed copy. Caller frees. Use them throughout.
2004-07-10 15:42:16 +00:00
}
- Change ktrace genio events to only copy up to ktr_geniosize bytes of a transfer to a malloc'd buffer and use that bufer for the ktrace event. This means that genio ktrace events no longer need to be synchronous. - Now that ktr_buffer isn't overloaded to sometimes point to a cached uio pointer for genio requests and always points to a malloc'd buffer if not NULL, free the buffer in ktr_freerequest() instead of in ktr_writerequest(). This closes a memory leak for ktrace events that used a malloc'd buffer that had their vnode ripped out from under them while they were on the todo list. Suggested by: bde (1, in principle)
2002-09-11 20:56:05 +00:00
uio->uio_offset = 0;
uio->uio_rw = UIO_WRITE;
datalen = imin(uio->uio_resid, ktr_geniosize);
Back out M_* changes, per decision of the TRB. Approved by: trb
2003-02-19 05:47:46 +00:00
buf = malloc(datalen, M_KTRACE, M_WAITOK);
Clean up and wash struct iovec and struct uio handling. Add copyiniov() which copies a struct iovec array in from userland into a malloc'ed struct iovec. Caller frees. Change uiofromiov() to malloc the uio (caller frees) and name it copyinuio() which is more appropriate. Add cloneuio() which returns a malloc'ed copy. Caller frees. Use them throughout.
2004-07-10 15:42:16 +00:00
error = uiomove(buf, datalen, uio);
free(uio, M_IOV);
if (error) {
- Change ktrace genio events to only copy up to ktr_geniosize bytes of a transfer to a malloc'd buffer and use that bufer for the ktrace event. This means that genio ktrace events no longer need to be synchronous. - Now that ktr_buffer isn't overloaded to sometimes point to a cached uio pointer for genio requests and always points to a malloc'd buffer if not NULL, free the buffer in ktr_freerequest() instead of in ktr_writerequest(). This closes a memory leak for ktrace events that used a malloc'd buffer that had their vnode ripped out from under them while they were on the todo list. Suggested by: bde (1, in principle)
2002-09-11 20:56:05 +00:00
free(buf, M_KTRACE);
return;
}
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
req = ktr_getrequest(KTR_GENIO);
- Change ktrace genio events to only copy up to ktr_geniosize bytes of a transfer to a malloc'd buffer and use that bufer for the ktrace event. This means that genio ktrace events no longer need to be synchronous. - Now that ktr_buffer isn't overloaded to sometimes point to a cached uio pointer for genio requests and always points to a malloc'd buffer if not NULL, free the buffer in ktr_freerequest() instead of in ktr_writerequest(). This closes a memory leak for ktrace events that used a malloc'd buffer that had their vnode ripped out from under them while they were on the todo list. Suggested by: bde (1, in principle)
2002-09-11 20:56:05 +00:00
if (req == NULL) {
free(buf, M_KTRACE);
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
return;
- Change ktrace genio events to only copy up to ktr_geniosize bytes of a transfer to a malloc'd buffer and use that bufer for the ktrace event. This means that genio ktrace events no longer need to be synchronous. - Now that ktr_buffer isn't overloaded to sometimes point to a cached uio pointer for genio requests and always points to a malloc'd buffer if not NULL, free the buffer in ktr_freerequest() instead of in ktr_writerequest(). This closes a memory leak for ktrace events that used a malloc'd buffer that had their vnode ripped out from under them while they were on the todo list. Suggested by: bde (1, in principle)
2002-09-11 20:56:05 +00:00
}
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
ktg = &req->ktr_data.ktr_genio;
ktg->ktr_fd = fd;
ktg->ktr_rw = rw;
- Change ktrace genio events to only copy up to ktr_geniosize bytes of a transfer to a malloc'd buffer and use that bufer for the ktrace event. This means that genio ktrace events no longer need to be synchronous. - Now that ktr_buffer isn't overloaded to sometimes point to a cached uio pointer for genio requests and always points to a malloc'd buffer if not NULL, free the buffer in ktr_freerequest() instead of in ktr_writerequest(). This closes a memory leak for ktrace events that used a malloc'd buffer that had their vnode ripped out from under them while they were on the todo list. Suggested by: bde (1, in principle)
2002-09-11 20:56:05 +00:00
req->ktr_header.ktr_len = datalen;
Merge kern_ktrace.c:1.102, ktrace.h:1.30 from HEAD to RELENG_6: Replace ktr_buffer pointer in struct ktr_header with a ktr_unused intptr_t. The buffer length needs to be written to disk as part of the trace log, but the kernel pointer for the buffer does not. Add a new ktr_buffer pointer to the kernel-only ktrace request structure to hold that pointer. This frees up an integer in the ktrace record format that can be used to hold the threadid, although older ktrace files will have a garbage ktr_buffer field (or more accurately, a kernel pointer value). Space requested by: davidxu
2005-11-16 08:11:06 +00:00
req->ktr_buffer = buf;
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
ktr_submitrequest(req);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
}
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
void
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
ktrpsig(sig, action, mask, code)
Fix style bug. Submitted by: bde
1999-10-04 18:29:51 +00:00
int sig;
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
sig_t action;
sigset_t change (part 2 of 5) ----------------------------- The core of the signalling code has been rewritten to operate on the new sigset_t. No methodological changes have been made. Most references to a sigset_t object are through macros (see signalvar.h) to create a level of abstraction and to provide a basis for further improvements. The NSIG constant has not been changed to reflect the maximum number of signals possible. The reason is that it breaks programs (especially shells) which assume that all signals have a non-null name in sys_signame. See src/bin/sh/trap.c for an example. Instead _SIG_MAXSIG has been introduced to hold the maximum signal possible with the new sigset_t. struct sigprop has been moved from signalvar.h to kern_sig.c because a) it is only used there, and b) access must be done though function sigprop(). The latter because the table doesn't holds properties for all signals, but only for the first NSIG signals. signal.h has been reorganized to make reading easier and to add the new and/or modified structures. The "old" structures are moved to signalvar.h to prevent namespace polution. Especially the coda filesystem suffers from the change, because it contained lines like (p->p_sigmask == SIGIO), which is easy to do for integral types, but not for compound types. NOTE: kdump (and port linux_kdump) must be recompiled. Thanks to Garrett Wollman and Daniel Eischen for pressing the importance of changing sigreturn as well.
1999-09-29 15:03:48 +00:00
sigset_t *mask;
Fix style bug. Submitted by: bde
1999-10-04 18:29:51 +00:00
int code;
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
{
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
struct ktr_request *req;
struct ktr_psig *kp;
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
req = ktr_getrequest(KTR_PSIG);
if (req == NULL)
return;
kp = &req->ktr_data.ktr_psig;
kp->signo = (char)sig;
kp->action = action;
kp->mask = *mask;
kp->code = code;
ktr_submitrequest(req);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
}
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
void
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
ktrcsw(out, user)
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
int out, user;
{
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
struct ktr_request *req;
struct ktr_csw *kc;
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
req = ktr_getrequest(KTR_CSW);
if (req == NULL)
return;
kc = &req->ktr_data.ktr_csw;
kc->out = out;
kc->user = user;
ktr_submitrequest(req);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
}
- Push down Giant around vnode operations in ktrace(). - Mark the ktrace() and utrace() syscalls as being MP safe. - Validate the facs argument to ktrace() prior to doing any vnode operations or acquiring any locks. - Share lock the proctree lock over the entire section that calls ktrsetchildren() and ktrops(). We already did this for process groups. Doing it for the process case closes a small race where a process might go away after we look it up. As a result of this, ktrstchildren() now just asserts that the proctree lock is locked rather than acquiring the lock itself. - Add some missing comments to #else and #endif.
2003-04-25 19:59:35 +00:00
#endif /* KTRACE */
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
/* Interface and common routines */
/*
* ktrace system call
- Push down Giant around vnode operations in ktrace(). - Mark the ktrace() and utrace() syscalls as being MP safe. - Validate the facs argument to ktrace() prior to doing any vnode operations or acquiring any locks. - Share lock the proctree lock over the entire section that calls ktrsetchildren() and ktrops(). We already did this for process groups. Doing it for the process case closes a small race where a process might go away after we look it up. As a result of this, ktrstchildren() now just asserts that the proctree lock is locked rather than acquiring the lock itself. - Add some missing comments to #else and #endif.
2003-04-25 19:59:35 +00:00
*
* MPSAFE
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
*/
Included <sys/sysproto.h> to get central declarations for syscall args structs and prototypes for syscalls. Ifdefed duplicated decentralized declarations of args structs. It's convenient to have this visible but they are hard to maintain. Some are already different from the central declarations. 4.4lite2 puts them in comments in the function headers but I wanted to avoid the large changes for that.
1995-11-12 06:43:28 +00:00
#ifndef _SYS_SYSPROTO_H_
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
struct ktrace_args {
char *fname;
int ops;
int facs;
int pid;
};
Included <sys/sysproto.h> to get central declarations for syscall args structs and prototypes for syscalls. Ifdefed duplicated decentralized declarations of args structs. It's convenient to have this visible but they are hard to maintain. Some are already different from the central declarations. 4.4lite2 puts them in comments in the function headers but I wanted to avoid the large changes for that.
1995-11-12 06:43:28 +00:00
#endif
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
/* ARGSUSED */
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
int
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
ktrace(td, uap)
struct thread *td;
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
register struct ktrace_args *uap;
{
Converted two options over to the new scheme: USER_LDT and KTRACE.
1996-01-03 21:42:35 +00:00
#ifdef KTRACE
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
register struct vnode *vp = NULL;
register struct proc *p;
struct pgrp *pg;
int facs = uap->facs & ~KTRFAC_ROOT;
int ops = KTROP(uap->ops);
int descend = uap->ops & KTRFLAG_DESCEND;
Close another information leak in ktrace(2): one was able to find active process groups outside a jail, etc. by using ktrace(2). OK'ed by: rwatson Approved by: re (scottl) MFC after: 1 week
2005-06-24 12:05:24 +00:00
int nfound, ret = 0;
Move the truncation code out of vn_open and into the open system call after the acquisition of any advisory locks. This fix corrects a case in which a process tries to open a file with a non-blocking exclusive lock. Even if it fails to get the lock it would still truncate the file even though its open failed. With this change, the truncation is done only after the lock is successfully acquired. Obtained from: BSD/OS
2000-07-04 03:34:11 +00:00
int flags, error = 0;
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
struct nameidata nd;
- Cache a reference to the credential of the thread that starts a ktrace in struct proc as p_tracecred alongside the current cache of the vnode in p_tracep. This credential is then used for all later ktrace operations on this file rather than using the credential of the current thread at the time of each ktrace event. - Now that we have multiple ktrace-related items in struct proc that are pointers, rename p_tracep to p_tracevp to make it less ambiguous. Requested by: rwatson (1)
2003-03-13 18:24:22 +00:00
struct ucred *cred;
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
- Push down Giant around vnode operations in ktrace(). - Mark the ktrace() and utrace() syscalls as being MP safe. - Validate the facs argument to ktrace() prior to doing any vnode operations or acquiring any locks. - Share lock the proctree lock over the entire section that calls ktrsetchildren() and ktrops(). We already did this for process groups. Doing it for the process case closes a small race where a process might go away after we look it up. As a result of this, ktrstchildren() now just asserts that the proctree lock is locked rather than acquiring the lock itself. - Add some missing comments to #else and #endif.
2003-04-25 19:59:35 +00:00
/*
* Need something to (un)trace.
*/
if (ops != KTROP_CLEARFILE && facs == 0)
return (EINVAL);
- Add a td_pflags field to struct thread for private flags accessed only by curthread. Unlike td_flags, this field does not need any locking. - Replace the td_inktr and td_inktrace variables with equivalent private thread flags. - Move TDF_OLDMASK over to the private flags field so it no longer requires sched_lock.
2003-06-09 17:38:32 +00:00
td->td_pflags |= TDP_INKTRACE;
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
if (ops != KTROP_CLEAR) {
/*
* an operation which requires a file argument.
*/
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_USERSPACE, uap->fname, td);
Move the truncation code out of vn_open and into the open system call after the acquisition of any advisory locks. This fix corrects a case in which a process tries to open a file with a non-blocking exclusive lock. Even if it fails to get the lock it would still truncate the file even though its open failed. With this change, the truncation is done only after the lock is successfully acquired. Obtained from: BSD/OS
2000-07-04 03:34:11 +00:00
flags = FREAD | FWRITE | O_NOFOLLOW;
- Push down Giant around vnode operations in ktrace(). - Mark the ktrace() and utrace() syscalls as being MP safe. - Validate the facs argument to ktrace() prior to doing any vnode operations or acquiring any locks. - Share lock the proctree lock over the entire section that calls ktrsetchildren() and ktrops(). We already did this for process groups. Doing it for the process case closes a small race where a process might go away after we look it up. As a result of this, ktrstchildren() now just asserts that the proctree lock is locked rather than acquiring the lock itself. - Add some missing comments to #else and #endif.
2003-04-25 19:59:35 +00:00
mtx_lock(&Giant);
Add fdidx argument to vn_open() and vn_open_cred() and pass -1 throughout.
2003-07-27 17:04:56 +00:00
error = vn_open(&nd, &flags, 0, -1);
All of this is cosmetic. prototypes, #includes, printfs and so on. Makes GCC a lot more silent.
1994-10-02 17:35:40 +00:00
if (error) {
- Push down Giant around vnode operations in ktrace(). - Mark the ktrace() and utrace() syscalls as being MP safe. - Validate the facs argument to ktrace() prior to doing any vnode operations or acquiring any locks. - Share lock the proctree lock over the entire section that calls ktrsetchildren() and ktrops(). We already did this for process groups. Doing it for the process case closes a small race where a process might go away after we look it up. As a result of this, ktrstchildren() now just asserts that the proctree lock is locked rather than acquiring the lock itself. - Add some missing comments to #else and #endif.
2003-04-25 19:59:35 +00:00
mtx_unlock(&Giant);
- Add a td_pflags field to struct thread for private flags accessed only by curthread. Unlike td_flags, this field does not need any locking. - Replace the td_inktr and td_inktrace variables with equivalent private thread flags. - Move TDF_OLDMASK over to the private flags field so it no longer requires sched_lock.
2003-06-09 17:38:32 +00:00
td->td_pflags &= ~TDP_INKTRACE;
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
return (error);
}
Introduce NDFREE (and remove VOP_ABORTOP)
1999-12-15 23:02:35 +00:00
NDFREE(&nd, NDF_ONLY_PNBUF);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
vp = nd.ni_vp;
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
VOP_UNLOCK(vp, 0, td);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
if (vp->v_type != VREG) {
Simple p_ucred -> td_ucred changes to start using the per-thread ucred reference.
2002-02-27 18:32:23 +00:00
(void) vn_close(vp, FREAD|FWRITE, td->td_ucred, td);
- Push down Giant around vnode operations in ktrace(). - Mark the ktrace() and utrace() syscalls as being MP safe. - Validate the facs argument to ktrace() prior to doing any vnode operations or acquiring any locks. - Share lock the proctree lock over the entire section that calls ktrsetchildren() and ktrops(). We already did this for process groups. Doing it for the process case closes a small race where a process might go away after we look it up. As a result of this, ktrstchildren() now just asserts that the proctree lock is locked rather than acquiring the lock itself. - Add some missing comments to #else and #endif.
2003-04-25 19:59:35 +00:00
mtx_unlock(&Giant);
- Add a td_pflags field to struct thread for private flags accessed only by curthread. Unlike td_flags, this field does not need any locking. - Replace the td_inktr and td_inktrace variables with equivalent private thread flags. - Move TDF_OLDMASK over to the private flags field so it no longer requires sched_lock.
2003-06-09 17:38:32 +00:00
td->td_pflags &= ~TDP_INKTRACE;
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
return (EACCES);
}
- Push down Giant around vnode operations in ktrace(). - Mark the ktrace() and utrace() syscalls as being MP safe. - Validate the facs argument to ktrace() prior to doing any vnode operations or acquiring any locks. - Share lock the proctree lock over the entire section that calls ktrsetchildren() and ktrops(). We already did this for process groups. Doing it for the process case closes a small race where a process might go away after we look it up. As a result of this, ktrstchildren() now just asserts that the proctree lock is locked rather than acquiring the lock itself. - Add some missing comments to #else and #endif.
2003-04-25 19:59:35 +00:00
mtx_unlock(&Giant);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
}
/*
Fix ktrace enablement/disablement races that can result in a vnode ref count panic. Bug noticed by: ps Reviewed by: ps MFC after: 1 day
2001-10-24 01:05:39 +00:00
* Clear all uses of the tracefile.
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
*/
if (ops == KTROP_CLEARFILE) {
Convert the allproc and proctree locks from lockmgr locks to sx locks.
2001-03-28 11:52:56 +00:00
sx_slock(&allproc_lock);
This is a partial commit of the patch from PR 14914: Alot of the code in sys/kern directly accesses the *Q_HEAD and *Q_ENTRY structures for list operations. This patch makes all list operations in sys/kern use the queue(3) macros, rather than directly accessing the *Q_{HEAD,ENTRY} structures. This batch of changes compile to the same object files. Reviewed by: phk Submitted by: Jake Burkholder <jake@checker.org> PR: 14914
1999-11-16 10:56:05 +00:00
LIST_FOREACH(p, &allproc, p_list) {
- Change the first argument of ktrcanset(), ktrsetchildren(), and ktrops() to a thread pointer so that ktrcanset() can use td_ucred. - Add some proc locking to partially protect p_tracep and p_traceflag.
2002-04-13 22:54:18 +00:00
PROC_LOCK(p);
- Cache a reference to the credential of the thread that starts a ktrace in struct proc as p_tracecred alongside the current cache of the vnode in p_tracep. This credential is then used for all later ktrace operations on this file rather than using the credential of the current thread at the time of each ktrace event. - Now that we have multiple ktrace-related items in struct proc that are pointers, rename p_tracep to p_tracevp to make it less ambiguous. Requested by: rwatson (1)
2003-03-13 18:24:22 +00:00
if (p->p_tracevp == vp) {
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
if (ktrcanset(td, p)) {
mtx_lock(&ktrace_mtx);
- Cache a reference to the credential of the thread that starts a ktrace in struct proc as p_tracecred alongside the current cache of the vnode in p_tracep. This credential is then used for all later ktrace operations on this file rather than using the credential of the current thread at the time of each ktrace event. - Now that we have multiple ktrace-related items in struct proc that are pointers, rename p_tracep to p_tracevp to make it less ambiguous. Requested by: rwatson (1)
2003-03-13 18:24:22 +00:00
cred = p->p_tracecred;
p->p_tracecred = NULL;
p->p_tracevp = NULL;
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
p->p_traceflag = 0;
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
mtx_unlock(&ktrace_mtx);
- Change the first argument of ktrcanset(), ktrsetchildren(), and ktrops() to a thread pointer so that ktrcanset() can use td_ucred. - Add some proc locking to partially protect p_tracep and p_traceflag.
2002-04-13 22:54:18 +00:00
PROC_UNLOCK(p);
- Push down Giant around vnode operations in ktrace(). - Mark the ktrace() and utrace() syscalls as being MP safe. - Validate the facs argument to ktrace() prior to doing any vnode operations or acquiring any locks. - Share lock the proctree lock over the entire section that calls ktrsetchildren() and ktrops(). We already did this for process groups. Doing it for the process case closes a small race where a process might go away after we look it up. As a result of this, ktrstchildren() now just asserts that the proctree lock is locked rather than acquiring the lock itself. - Add some missing comments to #else and #endif.
2003-04-25 19:59:35 +00:00
mtx_lock(&Giant);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
(void) vn_close(vp, FREAD|FWRITE,
- Cache a reference to the credential of the thread that starts a ktrace in struct proc as p_tracecred alongside the current cache of the vnode in p_tracep. This credential is then used for all later ktrace operations on this file rather than using the credential of the current thread at the time of each ktrace event. - Now that we have multiple ktrace-related items in struct proc that are pointers, rename p_tracep to p_tracevp to make it less ambiguous. Requested by: rwatson (1)
2003-03-13 18:24:22 +00:00
cred, td);
- Push down Giant around vnode operations in ktrace(). - Mark the ktrace() and utrace() syscalls as being MP safe. - Validate the facs argument to ktrace() prior to doing any vnode operations or acquiring any locks. - Share lock the proctree lock over the entire section that calls ktrsetchildren() and ktrops(). We already did this for process groups. Doing it for the process case closes a small race where a process might go away after we look it up. As a result of this, ktrstchildren() now just asserts that the proctree lock is locked rather than acquiring the lock itself. - Add some missing comments to #else and #endif.
2003-04-25 19:59:35 +00:00
mtx_unlock(&Giant);
- Cache a reference to the credential of the thread that starts a ktrace in struct proc as p_tracecred alongside the current cache of the vnode in p_tracep. This credential is then used for all later ktrace operations on this file rather than using the credential of the current thread at the time of each ktrace event. - Now that we have multiple ktrace-related items in struct proc that are pointers, rename p_tracep to p_tracevp to make it less ambiguous. Requested by: rwatson (1)
2003-03-13 18:24:22 +00:00
crfree(cred);
Fix ktrace enablement/disablement races that can result in a vnode ref count panic. Bug noticed by: ps Reviewed by: ps MFC after: 1 day
2001-10-24 01:05:39 +00:00
} else {
- Change the first argument of ktrcanset(), ktrsetchildren(), and ktrops() to a thread pointer so that ktrcanset() can use td_ucred. - Add some proc locking to partially protect p_tracep and p_traceflag.
2002-04-13 22:54:18 +00:00
PROC_UNLOCK(p);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
error = EPERM;
Fix ktrace enablement/disablement races that can result in a vnode ref count panic. Bug noticed by: ps Reviewed by: ps MFC after: 1 day
2001-10-24 01:05:39 +00:00
}
- Change the first argument of ktrcanset(), ktrsetchildren(), and ktrops() to a thread pointer so that ktrcanset() can use td_ucred. - Add some proc locking to partially protect p_tracep and p_traceflag.
2002-04-13 22:54:18 +00:00
} else
PROC_UNLOCK(p);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
}
Convert the allproc and proctree locks from lockmgr locks to sx locks.
2001-03-28 11:52:56 +00:00
sx_sunlock(&allproc_lock);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
goto done;
}
Remove trailing whitespace.
1995-05-30 08:16:23 +00:00
/*
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
* do it
*/
- Push down Giant around vnode operations in ktrace(). - Mark the ktrace() and utrace() syscalls as being MP safe. - Validate the facs argument to ktrace() prior to doing any vnode operations or acquiring any locks. - Share lock the proctree lock over the entire section that calls ktrsetchildren() and ktrops(). We already did this for process groups. Doing it for the process case closes a small race where a process might go away after we look it up. As a result of this, ktrstchildren() now just asserts that the proctree lock is locked rather than acquiring the lock itself. - Add some missing comments to #else and #endif.
2003-04-25 19:59:35 +00:00
sx_slock(&proctree_lock);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
if (uap->pid < 0) {
/*
* by process group
*/
pg = pgfind(-uap->pid);
if (pg == NULL) {
Lock proctree_lock instead of pgrpsess_lock.
2002-04-16 17:11:34 +00:00
sx_sunlock(&proctree_lock);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
error = ESRCH;
goto done;
}
Lock struct pgrp, session and sigio. New locks are: - pgrpsess_lock which locks the whole pgrps and sessions, - pg_mtx which protects the pgrp members, and - s_mtx which protects the session members. Please refer to sys/proc.h for the coverage of these locks. Changes on the pgrp/session interface: - pgfind() needs the pgrpsess_lock held. - The caller of enterpgrp() is responsible to allocate a new pgrp and session. - Call enterthispgrp() in order to enter an existing pgrp. - pgsignal() requires a pgrp lock held. Reviewed by: jhb, alfred Tested on: cvsup.jp.FreeBSD.org (which is a quad-CPU machine running -current)
2002-02-23 11:12:57 +00:00
/*
* ktrops() may call vrele(). Lock pg_members
Lock proctree_lock instead of pgrpsess_lock.
2002-04-16 17:11:34 +00:00
* by the proctree_lock rather than pg_mtx.
Lock struct pgrp, session and sigio. New locks are: - pgrpsess_lock which locks the whole pgrps and sessions, - pg_mtx which protects the pgrp members, and - s_mtx which protects the session members. Please refer to sys/proc.h for the coverage of these locks. Changes on the pgrp/session interface: - pgfind() needs the pgrpsess_lock held. - The caller of enterpgrp() is responsible to allocate a new pgrp and session. - Call enterthispgrp() in order to enter an existing pgrp. - pgsignal() requires a pgrp lock held. Reviewed by: jhb, alfred Tested on: cvsup.jp.FreeBSD.org (which is a quad-CPU machine running -current)
2002-02-23 11:12:57 +00:00
*/
PGRP_UNLOCK(pg);
Close another information leak in ktrace(2): one was able to find active process groups outside a jail, etc. by using ktrace(2). OK'ed by: rwatson Approved by: re (scottl) MFC after: 1 week
2005-06-24 12:05:24 +00:00
nfound = 0;
LIST_FOREACH(p, &pg->pg_members, p_pglist) {
PROC_LOCK(p);
if (p_cansee(td, p) != 0) {
PROC_UNLOCK(p);
continue;
}
PROC_UNLOCK(p);
nfound++;
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
if (descend)
- Change the first argument of ktrcanset(), ktrsetchildren(), and ktrops() to a thread pointer so that ktrcanset() can use td_ucred. - Add some proc locking to partially protect p_tracep and p_traceflag.
2002-04-13 22:54:18 +00:00
ret |= ktrsetchildren(td, p, ops, facs, vp);
Remove trailing whitespace.
1995-05-30 08:16:23 +00:00
else
- Change the first argument of ktrcanset(), ktrsetchildren(), and ktrops() to a thread pointer so that ktrcanset() can use td_ucred. - Add some proc locking to partially protect p_tracep and p_traceflag.
2002-04-13 22:54:18 +00:00
ret |= ktrops(td, p, ops, facs, vp);
Close another information leak in ktrace(2): one was able to find active process groups outside a jail, etc. by using ktrace(2). OK'ed by: rwatson Approved by: re (scottl) MFC after: 1 week
2005-06-24 12:05:24 +00:00
}
if (nfound == 0) {
sx_sunlock(&proctree_lock);
error = ESRCH;
goto done;
}
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
} else {
/*
* by pid
*/
p = pfind(uap->pid);
if (p == NULL) {
- Push down Giant around vnode operations in ktrace(). - Mark the ktrace() and utrace() syscalls as being MP safe. - Validate the facs argument to ktrace() prior to doing any vnode operations or acquiring any locks. - Share lock the proctree lock over the entire section that calls ktrsetchildren() and ktrops(). We already did this for process groups. Doing it for the process case closes a small race where a process might go away after we look it up. As a result of this, ktrstchildren() now just asserts that the proctree lock is locked rather than acquiring the lock itself. - Add some missing comments to #else and #endif.
2003-04-25 19:59:35 +00:00
sx_sunlock(&proctree_lock);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
error = ESRCH;
goto done;
}
Remove process information leak from inside a jail, when security.bsd.see_other_uids is set to 0, etc. One can check if invisible process is active, by doing: # ktrace -p <pid> If ktrace returns 'Operation not permitted' the process is alive and if returns 'No such process' there is no such process. MFC after: 1 week
2005-06-09 18:33:21 +00:00
error = p_cansee(td, p);
- Push down Giant around vnode operations in ktrace(). - Mark the ktrace() and utrace() syscalls as being MP safe. - Validate the facs argument to ktrace() prior to doing any vnode operations or acquiring any locks. - Share lock the proctree lock over the entire section that calls ktrsetchildren() and ktrops(). We already did this for process groups. Doing it for the process case closes a small race where a process might go away after we look it up. As a result of this, ktrstchildren() now just asserts that the proctree lock is locked rather than acquiring the lock itself. - Add some missing comments to #else and #endif.
2003-04-25 19:59:35 +00:00
/*
* The slock of the proctree lock will keep this process
* from going away, so unlocking the proc here is ok.
*/
Change the pfind() and zpfind() functions to lock the process that they find before releasing the allproc lock and returning. Reviewed by: -smp, dfr, jake
2001-04-24 00:51:53 +00:00
PROC_UNLOCK(p);
Add missing unlock. Pointy hat to: pjd Approved by: re (dwhite)
2005-06-21 21:17:02 +00:00
if (error) {
sx_sunlock(&proctree_lock);
Remove process information leak from inside a jail, when security.bsd.see_other_uids is set to 0, etc. One can check if invisible process is active, by doing: # ktrace -p <pid> If ktrace returns 'Operation not permitted' the process is alive and if returns 'No such process' there is no such process. MFC after: 1 week
2005-06-09 18:33:21 +00:00
goto done;
Add missing unlock. Pointy hat to: pjd Approved by: re (dwhite)
2005-06-21 21:17:02 +00:00
}
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
if (descend)
- Change the first argument of ktrcanset(), ktrsetchildren(), and ktrops() to a thread pointer so that ktrcanset() can use td_ucred. - Add some proc locking to partially protect p_tracep and p_traceflag.
2002-04-13 22:54:18 +00:00
ret |= ktrsetchildren(td, p, ops, facs, vp);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
else
- Change the first argument of ktrcanset(), ktrsetchildren(), and ktrops() to a thread pointer so that ktrcanset() can use td_ucred. - Add some proc locking to partially protect p_tracep and p_traceflag.
2002-04-13 22:54:18 +00:00
ret |= ktrops(td, p, ops, facs, vp);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
}
- Push down Giant around vnode operations in ktrace(). - Mark the ktrace() and utrace() syscalls as being MP safe. - Validate the facs argument to ktrace() prior to doing any vnode operations or acquiring any locks. - Share lock the proctree lock over the entire section that calls ktrsetchildren() and ktrops(). We already did this for process groups. Doing it for the process case closes a small race where a process might go away after we look it up. As a result of this, ktrstchildren() now just asserts that the proctree lock is locked rather than acquiring the lock itself. - Add some missing comments to #else and #endif.
2003-04-25 19:59:35 +00:00
sx_sunlock(&proctree_lock);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
if (!ret)
error = EPERM;
done:
- Push down Giant around vnode operations in ktrace(). - Mark the ktrace() and utrace() syscalls as being MP safe. - Validate the facs argument to ktrace() prior to doing any vnode operations or acquiring any locks. - Share lock the proctree lock over the entire section that calls ktrsetchildren() and ktrops(). We already did this for process groups. Doing it for the process case closes a small race where a process might go away after we look it up. As a result of this, ktrstchildren() now just asserts that the proctree lock is locked rather than acquiring the lock itself. - Add some missing comments to #else and #endif.
2003-04-25 19:59:35 +00:00
if (vp != NULL) {
mtx_lock(&Giant);
Simple p_ucred -> td_ucred changes to start using the per-thread ucred reference.
2002-02-27 18:32:23 +00:00
(void) vn_close(vp, FWRITE, td->td_ucred, td);
- Push down Giant around vnode operations in ktrace(). - Mark the ktrace() and utrace() syscalls as being MP safe. - Validate the facs argument to ktrace() prior to doing any vnode operations or acquiring any locks. - Share lock the proctree lock over the entire section that calls ktrsetchildren() and ktrops(). We already did this for process groups. Doing it for the process case closes a small race where a process might go away after we look it up. As a result of this, ktrstchildren() now just asserts that the proctree lock is locked rather than acquiring the lock itself. - Add some missing comments to #else and #endif.
2003-04-25 19:59:35 +00:00
mtx_unlock(&Giant);
}
- Add a td_pflags field to struct thread for private flags accessed only by curthread. Unlike td_flags, this field does not need any locking. - Replace the td_inktr and td_inktrace variables with equivalent private thread flags. - Move TDF_OLDMASK over to the private flags field so it no longer requires sched_lock.
2003-06-09 17:38:32 +00:00
td->td_pflags &= ~TDP_INKTRACE;
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
return (error);
- Push down Giant around vnode operations in ktrace(). - Mark the ktrace() and utrace() syscalls as being MP safe. - Validate the facs argument to ktrace() prior to doing any vnode operations or acquiring any locks. - Share lock the proctree lock over the entire section that calls ktrsetchildren() and ktrops(). We already did this for process groups. Doing it for the process case closes a small race where a process might go away after we look it up. As a result of this, ktrstchildren() now just asserts that the proctree lock is locked rather than acquiring the lock itself. - Add some missing comments to #else and #endif.
2003-04-25 19:59:35 +00:00
#else /* !KTRACE */
return (ENOSYS);
#endif /* KTRACE */
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
}
Add the utrace(caddr_t addr,size_t len) syscall, that will store the data pointed at in a ktrace file, if this process is being ktrace'ed. I'm using this to profile malloc usage. The advantage is that there is no context around this call, ie, no open file or socket, so it will work in any process, and you can decide if you want it to collect data or not.
1996-09-19 19:49:13 +00:00
/*
* utrace system call
- Push down Giant around vnode operations in ktrace(). - Mark the ktrace() and utrace() syscalls as being MP safe. - Validate the facs argument to ktrace() prior to doing any vnode operations or acquiring any locks. - Share lock the proctree lock over the entire section that calls ktrsetchildren() and ktrops(). We already did this for process groups. Doing it for the process case closes a small race where a process might go away after we look it up. As a result of this, ktrstchildren() now just asserts that the proctree lock is locked rather than acquiring the lock itself. - Add some missing comments to #else and #endif.
2003-04-25 19:59:35 +00:00
*
* MPSAFE
Add the utrace(caddr_t addr,size_t len) syscall, that will store the data pointed at in a ktrace file, if this process is being ktrace'ed. I'm using this to profile malloc usage. The advantage is that there is no context around this call, ie, no open file or socket, so it will work in any process, and you can decide if you want it to collect data or not.
1996-09-19 19:49:13 +00:00
*/
/* ARGSUSED */
int
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
utrace(td, uap)
struct thread *td;
Add the utrace(caddr_t addr,size_t len) syscall, that will store the data pointed at in a ktrace file, if this process is being ktrace'ed. I'm using this to profile malloc usage. The advantage is that there is no context around this call, ie, no open file or socket, so it will work in any process, and you can decide if you want it to collect data or not.
1996-09-19 19:49:13 +00:00
register struct utrace_args *uap;
{
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
Add the utrace(caddr_t addr,size_t len) syscall, that will store the data pointed at in a ktrace file, if this process is being ktrace'ed. I'm using this to profile malloc usage. The advantage is that there is no context around this call, ie, no open file or socket, so it will work in any process, and you can decide if you want it to collect data or not.
1996-09-19 19:49:13 +00:00
#ifdef KTRACE
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
struct ktr_request *req;
More caddr_t removal, make fo_ioctl take a void * instead of a caddr_t.
2002-06-29 01:50:25 +00:00
void *cp;
- Change utrace ktrace events to malloc the work buffer before getting a request structure. - Re-optimize the case of utrace being disabled by doing an explicit KTRPOINT check instead of relying on the one in ktr_getrequest() so that we don't waste time on a malloc in the non-tracing case. - Change utrace() to return an error if the copyin() fails. Before it would just ignore the request but still return success. This last is a change in behavior and can be backed out if necessary.
2002-09-11 21:00:56 +00:00
int error;
Add the utrace(caddr_t addr,size_t len) syscall, that will store the data pointed at in a ktrace file, if this process is being ktrace'ed. I'm using this to profile malloc usage. The advantage is that there is no context around this call, ie, no open file or socket, so it will work in any process, and you can decide if you want it to collect data or not.
1996-09-19 19:49:13 +00:00
- Change utrace ktrace events to malloc the work buffer before getting a request structure. - Re-optimize the case of utrace being disabled by doing an explicit KTRPOINT check instead of relying on the one in ktr_getrequest() so that we don't waste time on a malloc in the non-tracing case. - Change utrace() to return an error if the copyin() fails. Before it would just ignore the request but still return success. This last is a change in behavior and can be backed out if necessary.
2002-09-11 21:00:56 +00:00
if (!KTRPOINT(td, KTR_USER))
return (0);
Don't use SCARG. Pointed out by: bde
2001-01-08 07:22:06 +00:00
if (uap->len > KTR_USER_MAXLEN)
Limit size of passed in data for utrace function. Requested by: rwatson Obtained from: NetBSD
2001-01-06 09:34:20 +00:00
return (EINVAL);
Back out M_* changes, per decision of the TRB. Approved by: trb
2003-02-19 05:47:46 +00:00
cp = malloc(uap->len, M_KTRACE, M_WAITOK);
- Change utrace ktrace events to malloc the work buffer before getting a request structure. - Re-optimize the case of utrace being disabled by doing an explicit KTRPOINT check instead of relying on the one in ktr_getrequest() so that we don't waste time on a malloc in the non-tracing case. - Change utrace() to return an error if the copyin() fails. Before it would just ignore the request but still return success. This last is a change in behavior and can be backed out if necessary.
2002-09-11 21:00:56 +00:00
error = copyin(uap->addr, cp, uap->len);
Plug memory leaks. Detected by: FlexeLint Approved by: jhb
2002-09-30 19:19:47 +00:00
if (error) {
free(cp, M_KTRACE);
- Change utrace ktrace events to malloc the work buffer before getting a request structure. - Re-optimize the case of utrace being disabled by doing an explicit KTRPOINT check instead of relying on the one in ktr_getrequest() so that we don't waste time on a malloc in the non-tracing case. - Change utrace() to return an error if the copyin() fails. Before it would just ignore the request but still return success. This last is a change in behavior and can be backed out if necessary.
2002-09-11 21:00:56 +00:00
return (error);
Plug memory leaks. Detected by: FlexeLint Approved by: jhb
2002-09-30 19:19:47 +00:00
}
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
req = ktr_getrequest(KTR_USER);
Plug memory leaks. Detected by: FlexeLint Approved by: jhb
2002-09-30 19:19:47 +00:00
if (req == NULL) {
free(cp, M_KTRACE);
Have utrace(2) return ENOMEM if malloc() fails. Document this error return in its manual page. Reviewed by: jhb
2003-11-11 04:54:11 +00:00
return (ENOMEM);
Plug memory leaks. Detected by: FlexeLint Approved by: jhb
2002-09-30 19:19:47 +00:00
}
Merge kern_ktrace.c:1.102, ktrace.h:1.30 from HEAD to RELENG_6: Replace ktr_buffer pointer in struct ktr_header with a ktr_unused intptr_t. The buffer length needs to be written to disk as part of the trace log, but the kernel pointer for the buffer does not. Add a new ktr_buffer pointer to the kernel-only ktrace request structure to hold that pointer. This frees up an integer in the ktrace record format that can be used to hold the threadid, although older ktrace files will have a garbage ktr_buffer field (or more accurately, a kernel pointer value). Space requested by: davidxu
2005-11-16 08:11:06 +00:00
req->ktr_buffer = cp;
- Change utrace ktrace events to malloc the work buffer before getting a request structure. - Re-optimize the case of utrace being disabled by doing an explicit KTRPOINT check instead of relying on the one in ktr_getrequest() so that we don't waste time on a malloc in the non-tracing case. - Change utrace() to return an error if the copyin() fails. Before it would just ignore the request but still return success. This last is a change in behavior and can be backed out if necessary.
2002-09-11 21:00:56 +00:00
req->ktr_header.ktr_len = uap->len;
ktr_submitrequest(req);
Add the utrace(caddr_t addr,size_t len) syscall, that will store the data pointed at in a ktrace file, if this process is being ktrace'ed. I'm using this to profile malloc usage. The advantage is that there is no context around this call, ie, no open file or socket, so it will work in any process, and you can decide if you want it to collect data or not.
1996-09-19 19:49:13 +00:00
return (0);
- Push down Giant around vnode operations in ktrace(). - Mark the ktrace() and utrace() syscalls as being MP safe. - Validate the facs argument to ktrace() prior to doing any vnode operations or acquiring any locks. - Share lock the proctree lock over the entire section that calls ktrsetchildren() and ktrops(). We already did this for process groups. Doing it for the process case closes a small race where a process might go away after we look it up. As a result of this, ktrstchildren() now just asserts that the proctree lock is locked rather than acquiring the lock itself. - Add some missing comments to #else and #endif.
2003-04-25 19:59:35 +00:00
#else /* !KTRACE */
Add the utrace(caddr_t addr,size_t len) syscall, that will store the data pointed at in a ktrace file, if this process is being ktrace'ed. I'm using this to profile malloc usage. The advantage is that there is no context around this call, ie, no open file or socket, so it will work in any process, and you can decide if you want it to collect data or not.
1996-09-19 19:49:13 +00:00
return (ENOSYS);
- Push down Giant around vnode operations in ktrace(). - Mark the ktrace() and utrace() syscalls as being MP safe. - Validate the facs argument to ktrace() prior to doing any vnode operations or acquiring any locks. - Share lock the proctree lock over the entire section that calls ktrsetchildren() and ktrops(). We already did this for process groups. Doing it for the process case closes a small race where a process might go away after we look it up. As a result of this, ktrstchildren() now just asserts that the proctree lock is locked rather than acquiring the lock itself. - Add some missing comments to #else and #endif.
2003-04-25 19:59:35 +00:00
#endif /* KTRACE */
Add the utrace(caddr_t addr,size_t len) syscall, that will store the data pointed at in a ktrace file, if this process is being ktrace'ed. I'm using this to profile malloc usage. The advantage is that there is no context around this call, ie, no open file or socket, so it will work in any process, and you can decide if you want it to collect data or not.
1996-09-19 19:49:13 +00:00
}
Converted two options over to the new scheme: USER_LDT and KTRACE.
1996-01-03 21:42:35 +00:00
#ifdef KTRACE
A Major staticize sweep. Generates a couple of warnings that I'll deal with later. A number of unused vars removed. A number of unused procs removed or #ifdefed.
1995-12-14 08:32:45 +00:00
static int
- Change the first argument of ktrcanset(), ktrsetchildren(), and ktrops() to a thread pointer so that ktrcanset() can use td_ucred. - Add some proc locking to partially protect p_tracep and p_traceflag.
2002-04-13 22:54:18 +00:00
ktrops(td, p, ops, facs, vp)
struct thread *td;
struct proc *p;
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
int ops, facs;
struct vnode *vp;
{
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
struct vnode *tracevp = NULL;
- Cache a reference to the credential of the thread that starts a ktrace in struct proc as p_tracecred alongside the current cache of the vnode in p_tracep. This credential is then used for all later ktrace operations on this file rather than using the credential of the current thread at the time of each ktrace event. - Now that we have multiple ktrace-related items in struct proc that are pointers, rename p_tracep to p_tracevp to make it less ambiguous. Requested by: rwatson (1)
2003-03-13 18:24:22 +00:00
struct ucred *tracecred = NULL;
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
- Change the first argument of ktrcanset(), ktrsetchildren(), and ktrops() to a thread pointer so that ktrcanset() can use td_ucred. - Add some proc locking to partially protect p_tracep and p_traceflag.
2002-04-13 22:54:18 +00:00
PROC_LOCK(p);
if (!ktrcanset(td, p)) {
PROC_UNLOCK(p);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
return (0);
- Change the first argument of ktrcanset(), ktrsetchildren(), and ktrops() to a thread pointer so that ktrcanset() can use td_ucred. - Add some proc locking to partially protect p_tracep and p_traceflag.
2002-04-13 22:54:18 +00:00
}
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
mtx_lock(&ktrace_mtx);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
if (ops == KTROP_SET) {
- Cache a reference to the credential of the thread that starts a ktrace in struct proc as p_tracecred alongside the current cache of the vnode in p_tracep. This credential is then used for all later ktrace operations on this file rather than using the credential of the current thread at the time of each ktrace event. - Now that we have multiple ktrace-related items in struct proc that are pointers, rename p_tracep to p_tracevp to make it less ambiguous. Requested by: rwatson (1)
2003-03-13 18:24:22 +00:00
if (p->p_tracevp != vp) {
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
/*
- Change the first argument of ktrcanset(), ktrsetchildren(), and ktrops() to a thread pointer so that ktrcanset() can use td_ucred. - Add some proc locking to partially protect p_tracep and p_traceflag.
2002-04-13 22:54:18 +00:00
* if trace file already in use, relinquish below
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
*/
- Cache a reference to the credential of the thread that starts a ktrace in struct proc as p_tracecred alongside the current cache of the vnode in p_tracep. This credential is then used for all later ktrace operations on this file rather than using the credential of the current thread at the time of each ktrace event. - Now that we have multiple ktrace-related items in struct proc that are pointers, rename p_tracep to p_tracevp to make it less ambiguous. Requested by: rwatson (1)
2003-03-13 18:24:22 +00:00
tracevp = p->p_tracevp;
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
VREF(vp);
- Cache a reference to the credential of the thread that starts a ktrace in struct proc as p_tracecred alongside the current cache of the vnode in p_tracep. This credential is then used for all later ktrace operations on this file rather than using the credential of the current thread at the time of each ktrace event. - Now that we have multiple ktrace-related items in struct proc that are pointers, rename p_tracep to p_tracevp to make it less ambiguous. Requested by: rwatson (1)
2003-03-13 18:24:22 +00:00
p->p_tracevp = vp;
}
if (p->p_tracecred != td->td_ucred) {
tracecred = p->p_tracecred;
p->p_tracecred = crhold(td->td_ucred);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
}
p->p_traceflag |= facs;
- Change the first argument of ktrcanset(), ktrsetchildren(), and ktrops() to a thread pointer so that ktrcanset() can use td_ucred. - Add some proc locking to partially protect p_tracep and p_traceflag.
2002-04-13 22:54:18 +00:00
if (td->td_ucred->cr_uid == 0)
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
p->p_traceflag |= KTRFAC_ROOT;
Remove trailing whitespace.
1995-05-30 08:16:23 +00:00
} else {
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
/* KTROP_CLEAR */
if (((p->p_traceflag &= ~facs) & KTRFAC_MASK) == 0) {
/* no more tracing */
p->p_traceflag = 0;
- Cache a reference to the credential of the thread that starts a ktrace in struct proc as p_tracecred alongside the current cache of the vnode in p_tracep. This credential is then used for all later ktrace operations on this file rather than using the credential of the current thread at the time of each ktrace event. - Now that we have multiple ktrace-related items in struct proc that are pointers, rename p_tracep to p_tracevp to make it less ambiguous. Requested by: rwatson (1)
2003-03-13 18:24:22 +00:00
tracevp = p->p_tracevp;
p->p_tracevp = NULL;
tracecred = p->p_tracecred;
p->p_tracecred = NULL;
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
}
}
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
mtx_unlock(&ktrace_mtx);
- Change the first argument of ktrcanset(), ktrsetchildren(), and ktrops() to a thread pointer so that ktrcanset() can use td_ucred. - Add some proc locking to partially protect p_tracep and p_traceflag.
2002-04-13 22:54:18 +00:00
PROC_UNLOCK(p);
- Push down Giant around vnode operations in ktrace(). - Mark the ktrace() and utrace() syscalls as being MP safe. - Validate the facs argument to ktrace() prior to doing any vnode operations or acquiring any locks. - Share lock the proctree lock over the entire section that calls ktrsetchildren() and ktrops(). We already did this for process groups. Doing it for the process case closes a small race where a process might go away after we look it up. As a result of this, ktrstchildren() now just asserts that the proctree lock is locked rather than acquiring the lock itself. - Add some missing comments to #else and #endif.
2003-04-25 19:59:35 +00:00
if (tracevp != NULL) {
mtx_lock(&Giant);
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
vrele(tracevp);
- Push down Giant around vnode operations in ktrace(). - Mark the ktrace() and utrace() syscalls as being MP safe. - Validate the facs argument to ktrace() prior to doing any vnode operations or acquiring any locks. - Share lock the proctree lock over the entire section that calls ktrsetchildren() and ktrops(). We already did this for process groups. Doing it for the process case closes a small race where a process might go away after we look it up. As a result of this, ktrstchildren() now just asserts that the proctree lock is locked rather than acquiring the lock itself. - Add some missing comments to #else and #endif.
2003-04-25 19:59:35 +00:00
mtx_unlock(&Giant);
}
- Cache a reference to the credential of the thread that starts a ktrace in struct proc as p_tracecred alongside the current cache of the vnode in p_tracep. This credential is then used for all later ktrace operations on this file rather than using the credential of the current thread at the time of each ktrace event. - Now that we have multiple ktrace-related items in struct proc that are pointers, rename p_tracep to p_tracevp to make it less ambiguous. Requested by: rwatson (1)
2003-03-13 18:24:22 +00:00
if (tracecred != NULL)
crfree(tracecred);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
return (1);
}
A Major staticize sweep. Generates a couple of warnings that I'll deal with later. A number of unused vars removed. A number of unused procs removed or #ifdefed.
1995-12-14 08:32:45 +00:00
static int
- Change the first argument of ktrcanset(), ktrsetchildren(), and ktrops() to a thread pointer so that ktrcanset() can use td_ucred. - Add some proc locking to partially protect p_tracep and p_traceflag.
2002-04-13 22:54:18 +00:00
ktrsetchildren(td, top, ops, facs, vp)
struct thread *td;
struct proc *top;
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
int ops, facs;
struct vnode *vp;
{
register struct proc *p;
register int ret = 0;
p = top;
- Push down Giant around vnode operations in ktrace(). - Mark the ktrace() and utrace() syscalls as being MP safe. - Validate the facs argument to ktrace() prior to doing any vnode operations or acquiring any locks. - Share lock the proctree lock over the entire section that calls ktrsetchildren() and ktrops(). We already did this for process groups. Doing it for the process case closes a small race where a process might go away after we look it up. As a result of this, ktrstchildren() now just asserts that the proctree lock is locked rather than acquiring the lock itself. - Add some missing comments to #else and #endif.
2003-04-25 19:59:35 +00:00
sx_assert(&proctree_lock, SX_LOCKED);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
for (;;) {
- Change the first argument of ktrcanset(), ktrsetchildren(), and ktrops() to a thread pointer so that ktrcanset() can use td_ucred. - Add some proc locking to partially protect p_tracep and p_traceflag.
2002-04-13 22:54:18 +00:00
ret |= ktrops(td, p, ops, facs, vp);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
/*
* If this process has children, descend to them next,
* otherwise do any siblings, and if done with this level,
* follow back up the tree (but not past top).
*/
This is a partial commit of the patch from PR 14914: Alot of the code in sys/kern directly accesses the *Q_HEAD and *Q_ENTRY structures for list operations. This patch makes all list operations in sys/kern use the queue(3) macros, rather than directly accessing the *Q_{HEAD,ENTRY} structures. This batch of changes compile to the same object files. Reviewed by: phk Submitted by: Jake Burkholder <jake@checker.org> PR: 14914
1999-11-16 10:56:05 +00:00
if (!LIST_EMPTY(&p->p_children))
p = LIST_FIRST(&p->p_children);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
else for (;;) {
- Push down Giant around vnode operations in ktrace(). - Mark the ktrace() and utrace() syscalls as being MP safe. - Validate the facs argument to ktrace() prior to doing any vnode operations or acquiring any locks. - Share lock the proctree lock over the entire section that calls ktrsetchildren() and ktrops(). We already did this for process groups. Doing it for the process case closes a small race where a process might go away after we look it up. As a result of this, ktrstchildren() now just asserts that the proctree lock is locked rather than acquiring the lock itself. - Add some missing comments to #else and #endif.
2003-04-25 19:59:35 +00:00
if (p == top)
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
return (ret);
This is a partial commit of the patch from PR 14914: Alot of the code in sys/kern directly accesses the *Q_HEAD and *Q_ENTRY structures for list operations. This patch makes all list operations in sys/kern use the queue(3) macros, rather than directly accessing the *Q_{HEAD,ENTRY} structures. This batch of changes compile to the same object files. Reviewed by: phk Submitted by: Jake Burkholder <jake@checker.org> PR: 14914
1999-11-16 10:56:05 +00:00
if (LIST_NEXT(p, p_sibling)) {
p = LIST_NEXT(p, p_sibling);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
break;
}
From Lite2: proc LIST changes. Reviewed by: david & bde
1996-03-11 06:05:03 +00:00
p = p->p_pptr;
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
}
}
/*NOTREACHED*/
}
A Major staticize sweep. Generates a couple of warnings that I'll deal with later. A number of unused vars removed. A number of unused procs removed or #ifdefed.
1995-12-14 08:32:45 +00:00
static void
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
ktr_writerequest(struct ktr_request *req)
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
{
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
struct ktr_header *kth;
struct vnode *vp;
struct proc *p;
struct thread *td;
struct ucred *cred;
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
struct uio auio;
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
struct iovec aiov[3];
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
struct mount *mp;
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
int datalen, buflen, vrele_count;
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
int error;
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
vp = req->ktr_vp;
/*
* If vp is NULL, the vp has been cleared out from under this
* request, so just drop it.
*/
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
if (vp == NULL)
return;
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
kth = &req->ktr_header;
Consistently use the BSD u_int and u_short instead of the SYSV uint and ushort. In most of these files, there was a mixture of both styles and this change just makes them self-consistent. Requested by: bde (kern_ktrace.c)
2003-08-07 15:04:27 +00:00
datalen = data_lengths[(u_short)kth->ktr_type & ~KTR_DROP];
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
buflen = kth->ktr_len;
cred = req->ktr_cred;
td = curthread;
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
auio.uio_iov = &aiov[0];
auio.uio_offset = 0;
auio.uio_segflg = UIO_SYSSPACE;
auio.uio_rw = UIO_WRITE;
aiov[0].iov_base = (caddr_t)kth;
aiov[0].iov_len = sizeof(struct ktr_header);
auio.uio_resid = sizeof(struct ktr_header);
auio.uio_iovcnt = 1;
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
auio.uio_td = td;
if (datalen != 0) {
aiov[1].iov_base = (caddr_t)&req->ktr_data;
aiov[1].iov_len = datalen;
auio.uio_resid += datalen;
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
auio.uio_iovcnt++;
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
kth->ktr_len += datalen;
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
}
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
if (buflen != 0) {
Merge kern_ktrace.c:1.102, ktrace.h:1.30 from HEAD to RELENG_6: Replace ktr_buffer pointer in struct ktr_header with a ktr_unused intptr_t. The buffer length needs to be written to disk as part of the trace log, but the kernel pointer for the buffer does not. Add a new ktr_buffer pointer to the kernel-only ktrace request structure to hold that pointer. This frees up an integer in the ktrace record format that can be used to hold the threadid, although older ktrace files will have a garbage ktr_buffer field (or more accurately, a kernel pointer value). Space requested by: davidxu
2005-11-16 08:11:06 +00:00
KASSERT(req->ktr_buffer != NULL, ("ktrace: nothing to write"));
aiov[auio.uio_iovcnt].iov_base = req->ktr_buffer;
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
aiov[auio.uio_iovcnt].iov_len = buflen;
auio.uio_resid += buflen;
auio.uio_iovcnt++;
- Change ktrace genio events to only copy up to ktr_geniosize bytes of a transfer to a malloc'd buffer and use that bufer for the ktrace event. This means that genio ktrace events no longer need to be synchronous. - Now that ktr_buffer isn't overloaded to sometimes point to a cached uio pointer for genio requests and always points to a malloc'd buffer if not NULL, free the buffer in ktr_freerequest() instead of in ktr_writerequest(). This closes a memory leak for ktrace events that used a malloc'd buffer that had their vnode ripped out from under them while they were on the todo list. Suggested by: bde (1, in principle)
2002-09-11 20:56:05 +00:00
}
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
mtx_lock(&Giant);
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
vn_start_write(vp, &mp, V_WAIT);
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
(void)VOP_LEASE(vp, td, cred, LEASE_WRITE);
Introduce support for Mandatory Access Control and extensible kernel access control. Instrument the ktrace write operation so that it invokes the MAC framework's vnode write authorization check. Obtained from: TrustedBSD Project Sponsored by: DARPA, NAI Labs
2002-08-01 01:07:03 +00:00
#ifdef MAC
Pass active_cred and file_cred into the MAC framework explicitly for mac_check_vnode_{poll,read,stat,write}(). Pass in fp->f_cred when calling these checks with a struct file available. Otherwise, pass NOCRED. All currently MAC policies use active_cred, but could now offer the cached credential semantic used for the base system security model. Obtained from: TrustedBSD Project Sponsored by: DARPA, NAI Labs
2002-08-19 19:04:53 +00:00
error = mac_check_vnode_write(cred, NOCRED, vp);
Introduce support for Mandatory Access Control and extensible kernel access control. Instrument the ktrace write operation so that it invokes the MAC framework's vnode write authorization check. Obtained from: TrustedBSD Project Sponsored by: DARPA, NAI Labs
2002-08-01 01:07:03 +00:00
if (error == 0)
#endif
error = VOP_WRITE(vp, &auio, IO_UNIT | IO_APPEND, cred);
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
VOP_UNLOCK(vp, 0, td);
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
vn_finished_write(mp);
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
mtx_unlock(&Giant);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
if (!error)
return;
/*
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
* If error encountered, give up tracing on this vnode. We defer
* all the vrele()'s on the vnode until after we are finished walking
* the various lists to avoid needlessly holding locks.
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
*/
log(LOG_NOTICE, "ktrace write failed, errno %d, tracing stopped\n",
error);
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
vrele_count = 0;
/*
* First, clear this vnode from being used by any processes in the
* system.
* XXX - If one process gets an EPERM writing to the vnode, should
* we really do this? Other processes might have suitable
* credentials for the operation.
*/
- Cache a reference to the credential of the thread that starts a ktrace in struct proc as p_tracecred alongside the current cache of the vnode in p_tracep. This credential is then used for all later ktrace operations on this file rather than using the credential of the current thread at the time of each ktrace event. - Now that we have multiple ktrace-related items in struct proc that are pointers, rename p_tracep to p_tracevp to make it less ambiguous. Requested by: rwatson (1)
2003-03-13 18:24:22 +00:00
cred = NULL;
Convert the allproc and proctree locks from lockmgr locks to sx locks.
2001-03-28 11:52:56 +00:00
sx_slock(&allproc_lock);
This is a partial commit of the patch from PR 14914: Alot of the code in sys/kern directly accesses the *Q_HEAD and *Q_ENTRY structures for list operations. This patch makes all list operations in sys/kern use the queue(3) macros, rather than directly accessing the *Q_{HEAD,ENTRY} structures. This batch of changes compile to the same object files. Reviewed by: phk Submitted by: Jake Burkholder <jake@checker.org> PR: 14914
1999-11-16 10:56:05 +00:00
LIST_FOREACH(p, &allproc, p_list) {
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
PROC_LOCK(p);
- Cache a reference to the credential of the thread that starts a ktrace in struct proc as p_tracecred alongside the current cache of the vnode in p_tracep. This credential is then used for all later ktrace operations on this file rather than using the credential of the current thread at the time of each ktrace event. - Now that we have multiple ktrace-related items in struct proc that are pointers, rename p_tracep to p_tracevp to make it less ambiguous. Requested by: rwatson (1)
2003-03-13 18:24:22 +00:00
if (p->p_tracevp == vp) {
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
mtx_lock(&ktrace_mtx);
- Cache a reference to the credential of the thread that starts a ktrace in struct proc as p_tracecred alongside the current cache of the vnode in p_tracep. This credential is then used for all later ktrace operations on this file rather than using the credential of the current thread at the time of each ktrace event. - Now that we have multiple ktrace-related items in struct proc that are pointers, rename p_tracep to p_tracevp to make it less ambiguous. Requested by: rwatson (1)
2003-03-13 18:24:22 +00:00
p->p_tracevp = NULL;
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
p->p_traceflag = 0;
- Cache a reference to the credential of the thread that starts a ktrace in struct proc as p_tracecred alongside the current cache of the vnode in p_tracep. This credential is then used for all later ktrace operations on this file rather than using the credential of the current thread at the time of each ktrace event. - Now that we have multiple ktrace-related items in struct proc that are pointers, rename p_tracep to p_tracevp to make it less ambiguous. Requested by: rwatson (1)
2003-03-13 18:24:22 +00:00
cred = p->p_tracecred;
p->p_tracecred = NULL;
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
mtx_unlock(&ktrace_mtx);
vrele_count++;
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
}
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
PROC_UNLOCK(p);
- Cache a reference to the credential of the thread that starts a ktrace in struct proc as p_tracecred alongside the current cache of the vnode in p_tracep. This credential is then used for all later ktrace operations on this file rather than using the credential of the current thread at the time of each ktrace event. - Now that we have multiple ktrace-related items in struct proc that are pointers, rename p_tracep to p_tracevp to make it less ambiguous. Requested by: rwatson (1)
2003-03-13 18:24:22 +00:00
if (cred != NULL) {
crfree(cred);
cred = NULL;
}
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
}
Convert the allproc and proctree locks from lockmgr locks to sx locks.
2001-03-28 11:52:56 +00:00
sx_sunlock(&allproc_lock);
Overhaul the ktrace subsystem a bit. For the most part, the actual vnode operations to dump a ktrace event out to an output file are now handled asychronously by a ktrace worker thread. This enables most ktrace events to not need Giant once p_tracep and p_traceflag are suitably protected by the new ktrace_lock. There is a single todo list of pending ktrace requests. The various ktrace tracepoints allocate a ktrace request object and tack it onto the end of the queue. The ktrace kernel thread grabs requests off the head of the queue and processes them using the trace vnode and credentials of the thread triggering the event. Since we cannot assume that the user memory referenced when doing a ktrgenio() will be valid and since we can't access it from the ktrace worker thread without a bit of hassle anyways, ktrgenio() requests are still handled synchronously. However, in order to ensure that the requests from a given thread still maintain relative order to one another, when a synchronous ktrace event (such as a genio event) is triggered, we still put the request object on the todo list to synchronize with the worker thread. The original thread blocks atomically with putting the item on the queue. When the worker thread comes across an asynchronous request, it wakes up the original thread and then blocks to ensure it doesn't manage to write a later event before the original thread has a chance to write out the synchronous event. When the original thread wakes up, it writes out the synchronous using its own context and then finally wakes the worker thread back up. Yuck. The sychronous events aren't pretty but they do work. Since ktrace events can be triggered in fairly low-level areas (msleep() and cv_wait() for example) the ktrace code is designed to use very few locks when posting an event (currently just the ktrace_mtx lock and the vnode interlock to bump the refcoun on the trace vnode). This also means that we can't allocate a ktrace request object when an event is triggered. Instead, ktrace request objects are allocated from a pre-allocated pool and returned to the pool after a request is serviced. The size of this pool defaults to 100 objects, which is about 13k on an i386 kernel. The size of the pool can be adjusted at compile time via the KTRACE_REQUEST_POOL kernel option, at boot time via the kern.ktrace_request_pool loader tunable, or at runtime via the kern.ktrace_request_pool sysctl. If the pool of request objects is exhausted, then a warning message is printed to the console. The message is rate-limited in that it is only printed once until the size of the pool is adjusted via the sysctl. I have tested all kernel traces but have not tested user traces submitted by utrace(2), though they should work fine in theory. Since a ktrace request has several properties (content of event, trace vnode, details of originating process, credentials for I/O, etc.), I chose to drop the first argument to the various ktrfoo() functions. Currently the functions just assume the event is posted from curthread. If there is a great desire to do so, I suppose I could instead put back the first argument but this time make it a thread pointer instead of a vnode pointer. Also, KTRPOINT() now takes a thread as its first argument instead of a process. This is because the check for a recursive ktrace event is now per-thread instead of process-wide. Tested on: i386 Compiles on: sparc64, alpha
2002-06-07 05:32:59 +00:00
/*
* Second, clear this vnode from any pending requests.
*/
mtx_lock(&ktrace_mtx);
STAILQ_FOREACH(req, &ktr_todo, ktr_list) {
if (req->ktr_vp == vp) {
req->ktr_vp = NULL;
vrele_count++;
}
}
mtx_unlock(&ktrace_mtx);
mtx_lock(&Giant);
while (vrele_count-- > 0)
vrele(vp);
mtx_unlock(&Giant);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
}
/*
* Return true if caller has permission to set the ktracing state
* of target. Essentially, the target can't possess any
* more permissions than the caller. KTRFAC_ROOT signifies that
Remove trailing whitespace.
1995-05-30 08:16:23 +00:00
* root previously set the tracing status on the target process, and
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
* so, only root may further change it.
*/
A Major staticize sweep. Generates a couple of warnings that I'll deal with later. A number of unused vars removed. A number of unused procs removed or #ifdefed.
1995-12-14 08:32:45 +00:00
static int
- Change the first argument of ktrcanset(), ktrsetchildren(), and ktrops() to a thread pointer so that ktrcanset() can use td_ucred. - Add some proc locking to partially protect p_tracep and p_traceflag.
2002-04-13 22:54:18 +00:00
ktrcanset(td, targetp)
struct thread *td;
struct proc *targetp;
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
{
- Change the first argument of ktrcanset(), ktrsetchildren(), and ktrops() to a thread pointer so that ktrcanset() can use td_ucred. - Add some proc locking to partially protect p_tracep and p_traceflag.
2002-04-13 22:54:18 +00:00
PROC_LOCK_ASSERT(targetp, MA_OWNED);
o Replace calls to p_can(..., P_CAN_xxx) with calls to p_canxxx(). The p_can(...) construct was a premature (and, it turns out, awkward) abstraction. The individual calls to p_canxxx() better reflect differences between the inter-process authorization checks, such as differing checks based on the type of signal. This has a side effect of improving code readability. o Replace direct credential authorization checks in ktrace() with invocation of p_candebug(), while maintaining the special case check of KTR_ROOT. This allows ktrace() to "play more nicely" with new mandatory access control schemes, as well as making its authorization checks consistent with other "debugging class" checks. o Eliminate "privused" construct for p_can*() calls which allowed the caller to determine if privilege was required for successful evaluation of the access control check. This primitive is currently unused, and as such, serves only to complicate the API. Approved by: ({procfs,linprocfs} changes) des Obtained from: TrustedBSD Project
2001-07-05 17:10:46 +00:00
if (targetp->p_traceflag & KTRFAC_ROOT &&
Rename suser_cred()'s PRISON_ROOT flag to SUSER_ALLOWJAIL. This is somewhat clearer, but more importantly allows for a consistent naming scheme for suser_cred flags. The old name is still defined, but will be removed in a few days (unless I hear any complaints...) Discussed with: rwatson, scottl Requested by: jhb
2004-07-26 07:24:04 +00:00
suser_cred(td->td_ucred, SUSER_ALLOWJAIL))
This Implements the mumbled about "Jail" feature. This is a seriously beefed up chroot kind of thing. The process is jailed along the same lines as a chroot does it, but with additional tough restrictions imposed on what the superuser can do. For all I know, it is safe to hand over the root bit inside a prison to the customer living in that prison, this is what it was developed for in fact: "real virtual servers". Each prison has an ip number associated with it, which all IP communications will be coerced to use and each prison has its own hostname. Needless to say, you need more RAM this way, but the advantage is that each customer can run their own particular version of apache and not stomp on the toes of their neighbors. It generally does what one would expect, but setting up a jail still takes a little knowledge. A few notes: I have no scripts for setting up a jail, don't ask me for them. The IP number should be an alias on one of the interfaces. mount a /proc in each jail, it will make ps more useable. /proc/<pid>/status tells the hostname of the prison for jailed processes. Quotas are only sensible if you have a mountpoint per prison. There are no privisions for stopping resource-hogging. Some "#ifdef INET" and similar may be missing (send patches!) If somebody wants to take it from here and develop it into more of a "virtual machine" they should be most welcome! Tools, comments, patches & documentation most welcome. Have fun... Sponsored by: http://www.rndassociates.com/ Run for almost a year by: http://www.servetheweb.com/
1999-04-28 11:38:52 +00:00
return (0);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
Change p_can{debug,see,sched,signal}()'s first argument to be a thread pointer instead of a proc pointer and require the process pointed to by the second argument to be locked. We now use the thread ucred reference for the credential checks in p_can*() as a result. p_canfoo() should now no longer need Giant.
2002-05-19 00:14:50 +00:00
if (p_candebug(td, targetp) != 0)
o Replace calls to p_can(..., P_CAN_xxx) with calls to p_canxxx(). The p_can(...) construct was a premature (and, it turns out, awkward) abstraction. The individual calls to p_canxxx() better reflect differences between the inter-process authorization checks, such as differing checks based on the type of signal. This has a side effect of improving code readability. o Replace direct credential authorization checks in ktrace() with invocation of p_candebug(), while maintaining the special case check of KTR_ROOT. This allows ktrace() to "play more nicely" with new mandatory access control schemes, as well as making its authorization checks consistent with other "debugging class" checks. o Eliminate "privused" construct for p_can*() calls which allowed the caller to determine if privilege was required for successful evaluation of the access control check. This primitive is currently unused, and as such, serves only to complicate the API. Approved by: ({procfs,linprocfs} changes) des Obtained from: TrustedBSD Project
2001-07-05 17:10:46 +00:00
return (0);
return (1);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
}
Converted two options over to the new scheme: USER_LDT and KTRACE.
1996-01-03 21:42:35 +00:00
#endif /* KTRACE */
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