The intention was to just limit leading zeroes on numeric names. That
check is now improved to also catch the leading spaces and '+' that
strtoul can pass through.
PR: 204897
MFC after: 3 days
A panicking thread always executes with a critical section held, so any
attempt to allocate or free memory while dumping will otherwise cause a
second panic. This can occur, for example, if xpt_polled_action() completes
non-dump I/O that was pending at the time of the panic. The fact that this
can occur is itself a bug, but asserting in this case does little but
reduce the reliability of kernel dumps.
Suggested by: kib
Reported by: pho
These helper functions can be used to read in or write a buffer from or to
an arbitrary process' address space. Without them, this can only be done
using proc_rwmem(), which requires the caller to fill out a uio. This is
onerous and results in code duplication; the new functions provide a simpler
interface which is sufficient for most existing callers of proc_rwmem().
This change also adds a manual page for proc_rwmem() and the new functions.
Reviewed by: jhb, kib
Differential Revision: https://reviews.freebsd.org/D4245
clock_gettime(2) on ARMv7 and ARMv8 systems which have architectural
generic timer hardware. It is similar how the RDTSC timer is used in
userspace on x86.
Fix a permission problem where generic timer access from EL0 (or
userspace on v7) was not properly initialized on APs.
For ARMv7, mark the stack non-executable. The shared page is added for
all arms (including ARMv8 64bit), and the signal trampoline code is
moved to the page.
Reviewed by: andrew
Discussed with: emaste, mmel
Sponsored by: The FreeBSD Foundation
Differential revision: https://reviews.freebsd.org/D4209
For completeness add a VNASSERT that there are no threads waiting on a
range lock (this was previously checked on every vnode free).
Reported by; Rick Macklem
Fix from: Mateusz Guzik
PR: 204949
camdd(8) utility.
CCBs may be queued to the driver via the new CAMIOQUEUE ioctl, and
completed CCBs may be retrieved via the CAMIOGET ioctl. User
processes can use poll(2) or kevent(2) to get notification when
I/O has completed.
While the existing CAMIOCOMMAND blocking ioctl interface only
supports user virtual data pointers in a CCB (generally only
one per CCB), the new CAMIOQUEUE ioctl supports user virtual and
physical address pointers, as well as user virtual and physical
scatter/gather lists. This allows user applications to have more
flexibility in their data handling operations.
Kernel memory for data transferred via the queued interface is
allocated from the zone allocator in MAXPHYS sized chunks, and user
data is copied in and out. This is likely faster than the
vmapbuf()/vunmapbuf() method used by the CAMIOCOMMAND ioctl in
configurations with many processors (there are more TLB shootdowns
caused by the mapping/unmapping operation) but may not be as fast
as running with unmapped I/O.
The new memory handling model for user requests also allows
applications to send CCBs with request sizes that are larger than
MAXPHYS. The pass(4) driver now limits queued requests to the I/O
size listed by the SIM driver in the maxio field in the Path
Inquiry (XPT_PATH_INQ) CCB.
There are some things things would be good to add:
1. Come up with a way to do unmapped I/O on multiple buffers.
Currently the unmapped I/O interface operates on a struct bio,
which includes only one address and length. It would be nice
to be able to send an unmapped scatter/gather list down to
busdma. This would allow eliminating the copy we currently do
for data.
2. Add an ioctl to list currently outstanding CCBs in the various
queues.
3. Add an ioctl to cancel a request, or use the XPT_ABORT CCB to do
that.
4. Test physical address support. Virtual pointers and scatter
gather lists have been tested, but I have not yet tested
physical addresses or scatter/gather lists.
5. Investigate multiple queue support. At the moment there is one
queue of commands per pass(4) device. If multiple processes
open the device, they will submit I/O into the same queue and
get events for the same completions. This is probably the right
model for most applications, but it is something that could be
changed later on.
Also, add a new utility, camdd(8) that uses the asynchronous pass(4)
driver interface.
This utility is intended to be a basic data transfer/copy utility,
a simple benchmark utility, and an example of how to use the
asynchronous pass(4) interface.
It can copy data to and from pass(4) devices using any target queue
depth, starting offset and blocksize for the input and ouptut devices.
It currently only supports SCSI devices, but could be easily extended
to support ATA devices.
It can also copy data to and from regular files, block devices, tape
devices, pipes, stdin, and stdout. It does not support queueing
multiple commands to any of those targets, since it uses the standard
read(2)/write(2)/writev(2)/readv(2) system calls.
The I/O is done by two threads, one for the reader and one for the
writer. The reader thread sends completed read requests to the
writer thread in strictly sequential order, even if they complete
out of order. That could be modified later on for random I/O patterns
or slightly out of order I/O.
camdd(8) uses kqueue(2)/kevent(2) to get I/O completion events from
the pass(4) driver and also to send request notifications internally.
For pass(4) devcies, camdd(8) uses a single buffer (CAM_DATA_VADDR)
per CAM CCB on the reading side, and a scatter/gather list
(CAM_DATA_SG) on the writing side. In addition to testing both
interfaces, this makes any potential reblocking of I/O easier. No
data is copied between the reader and the writer, but rather the
reader's buffers are split into multiple I/O requests or combined
into a single I/O request depending on the input and output blocksize.
For the file I/O path, camdd(8) also uses a single buffer (read(2),
write(2), pread(2) or pwrite(2)) on reads, and a scatter/gather list
(readv(2), writev(2), preadv(2), pwritev(2)) on writes.
Things that would be nice to do for camdd(8) eventually:
1. Add support for I/O pattern generation. Patterns like all
zeros, all ones, LBA-based patterns, random patterns, etc. Right
Now you can always use /dev/zero, /dev/random, etc.
2. Add support for a "sink" mode, so we do only reads with no
writes. Right now, you can use /dev/null.
3. Add support for automatic queue depth probing, so that we can
figure out the right queue depth on the input and output side
for maximum throughput. At the moment it defaults to 6.
4. Add support for SATA device passthrough I/O.
5. Add support for random LBAs and/or lengths on the input and
output sides.
6. Track average per-I/O latency and busy time. The busy time
and latency could also feed in to the automatic queue depth
determination.
sys/cam/scsi/scsi_pass.h:
Define two new ioctls, CAMIOQUEUE and CAMIOGET, that queue
and fetch asynchronous CAM CCBs respectively.
Although these ioctls do not have a declared argument, they
both take a union ccb pointer. If we declare a size here,
the ioctl code in sys/kern/sys_generic.c will malloc and free
a buffer for either the CCB or the CCB pointer (depending on
how it is declared). Since we have to keep a copy of the
CCB (which is fairly large) anyway, having the ioctl malloc
and free a CCB for each call is wasteful.
sys/cam/scsi/scsi_pass.c:
Add asynchronous CCB support.
Add two new ioctls, CAMIOQUEUE and CAMIOGET.
CAMIOQUEUE adds a CCB to the incoming queue. The CCB is
executed immediately (and moved to the active queue) if it
is an immediate CCB, but otherwise it will be executed
in passstart() when a CCB is available from the transport layer.
When CCBs are completed (because they are immediate or
passdone() if they are queued), they are put on the done
queue.
If we get the final close on the device before all pending
I/O is complete, all active I/O is moved to the abandoned
queue and we increment the peripheral reference count so
that the peripheral driver instance doesn't go away before
all pending I/O is done.
The new passcreatezone() function is called on the first
call to the CAMIOQUEUE ioctl on a given device to allocate
the UMA zones for I/O requests and S/G list buffers. This
may be good to move off to a taskqueue at some point.
The new passmemsetup() function allocates memory and
scatter/gather lists to hold the user's data, and copies
in any data that needs to be written. For virtual pointers
(CAM_DATA_VADDR), the kernel buffer is malloced from the
new pass(4) driver malloc bucket. For virtual
scatter/gather lists (CAM_DATA_SG), buffers are allocated
from a new per-pass(9) UMA zone in MAXPHYS-sized chunks.
Physical pointers are passed in unchanged. We have support
for up to 16 scatter/gather segments (for the user and
kernel S/G lists) in the default struct pass_io_req, so
requests with longer S/G lists require an extra kernel malloc.
The new passcopysglist() function copies a user scatter/gather
list to a kernel scatter/gather list. The number of elements
in each list may be different, but (obviously) the amount of data
stored has to be identical.
The new passmemdone() function copies data out for the
CAM_DATA_VADDR and CAM_DATA_SG cases.
The new passiocleanup() function restores data pointers in
user CCBs and frees memory.
Add new functions to support kqueue(2)/kevent(2):
passreadfilt() tells kevent whether or not the done
queue is empty.
passkqfilter() adds a knote to our list.
passreadfiltdetach() removes a knote from our list.
Add a new function, passpoll(), for poll(2)/select(2)
to use.
Add devstat(9) support for the queued CCB path.
sys/cam/ata/ata_da.c:
Add support for the BIO_VLIST bio type.
sys/cam/cam_ccb.h:
Add a new enumeration for the xflags field in the CCB header.
(This doesn't change the CCB header, just adds an enumeration to
use.)
sys/cam/cam_xpt.c:
Add a new function, xpt_setup_ccb_flags(), that allows specifying
CCB flags.
sys/cam/cam_xpt.h:
Add a prototype for xpt_setup_ccb_flags().
sys/cam/scsi/scsi_da.c:
Add support for BIO_VLIST.
sys/dev/md/md.c:
Add BIO_VLIST support to md(4).
sys/geom/geom_disk.c:
Add BIO_VLIST support to the GEOM disk class. Re-factor the I/O size
limiting code in g_disk_start() a bit.
sys/kern/subr_bus_dma.c:
Change _bus_dmamap_load_vlist() to take a starting offset and
length.
Add a new function, _bus_dmamap_load_pages(), that will load a list
of physical pages starting at an offset.
Update _bus_dmamap_load_bio() to allow loading BIO_VLIST bios.
Allow unmapped I/O to start at an offset.
sys/kern/subr_uio.c:
Add two new functions, physcopyin_vlist() and physcopyout_vlist().
sys/pc98/include/bus.h:
Guard kernel-only parts of the pc98 machine/bus.h header with
#ifdef _KERNEL.
This allows userland programs to include <machine/bus.h> to get the
definition of bus_addr_t and bus_size_t.
sys/sys/bio.h:
Add a new bio flag, BIO_VLIST.
sys/sys/uio.h:
Add prototypes for physcopyin_vlist() and physcopyout_vlist().
share/man/man4/pass.4:
Document the CAMIOQUEUE and CAMIOGET ioctls.
usr.sbin/Makefile:
Add camdd.
usr.sbin/camdd/Makefile:
Add a makefile for camdd(8).
usr.sbin/camdd/camdd.8:
Man page for camdd(8).
usr.sbin/camdd/camdd.c:
The new camdd(8) utility.
Sponsored by: Spectra Logic
MFC after: 1 week
on every allocation and fully releases them on every free. These
are not trivial costs: it starts by zeroing a large structure then
initializes a mutex, a lock manager lock, an rw lock, four lists,
and six pointers. And looking at vfs.vnodes_created, these operations
are being done millions of times an hour on a busy machine.
As a performance optimization, this code update uses the uma_init
and uma_fini routines to do these initializations and cleanups only
as the vnodes enter and leave the vnode_zone. With this change the
initializations are only done kern.maxvnodes times at system startup
and then only rarely again. The frees are done only if the vnode_zone
shrinks which never happens in practice. For those curious about the
avoided work, look at the vnode_init() and vnode_fini() functions in
kern/vfs_subr.c to see the code that has been removed from the main
vnode allocation/free path.
Reviewed by: kib
Tested by: Peter Holm
sysent.
sv_prepsyscall is unused.
sv_sigsize and sv_sigtbl translate signal number from the FreeBSD
namespace into the ABI domain. It is only utilized on i386 for iBCS2
binaries. The issue with this approach is that signals for iBCS2 were
delivered with the FreeBSD signal frame layout, which does not follow
iBCS2. The same note is true for any other potential user if
sv_sigtbl. In other words, if ABI needs signal number translation, it
really needs custom sv_sendsig method instead.
Sponsored by: The FreeBSD Foundation
active list, into the header comment for vdrop(), which is the
function that decides whether to leave the vnode on the list. Note
that dirty page write-out in vinactive() is asynchronous.
Discussed with: alc
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
targets. See the comment above wantfreevnodes variable for the
description of the algorithm.
The vfs.vlru_alloc_cache_src sysctl is removed. New code frees
namecache sources as the last chance to satisfy the highest watermark,
instead of selecting the source vnodes randomly. This provides good
enough behaviour to keep vn_fullpath() working in most situations.
The filesystem layout with deep trees, where the removed knob was
required, is thus handled automatically.
Submitted by: bde
Discussed with: mckusick
Tested by: pho
MFC after: 1 month
sysentvec. This allows the timekeep data to be shared between similar
ABIs which cannot share sysentvec.
Make the timekeep_push_vdso() tick callback to the timekeep structures
instead of sysentvecs. If several sysentvec share the vdso_sv_tk
structure, we would update the userspace data several times on each
tick, without the change.
Only allocate vdso_sv_tk in the exec_sysvec_init() sysinit when
sysentvec is marked with the new SV_TIMEKEEP flag. This saves
allocation and update of unneeded vdso_sv_tk for ABIs which do not
provide userspace gettimeofday yet, which are PowerPCs arches right
now.
Make vdso_sv_tk allocator public, namely split out and export
alloc_sv_tk() and alloc_sv_tk_compat32(). ABIs which share timekeep
data now can allocate it manually and share as appropriate.
Requested by: nwhitehorn
Tested by: nwhitehorn, pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
All versions of getfsstat(3) are supposed to return the number of [o]statfs
structs in the array that was copied out.
Also fix missing bounds checking and signed comparison of unsigned types.
Submitted by: bde@
MFC after: 1 month
Sponsored by: The FreeBSD Foundation
critical section.
uma_zalloc_arg()/uma_zalloc_free() may acquire a sleepable lock on the
zone. The malloc() family of functions may call uma_zalloc_arg() or
uma_zalloc_free().
The malloc(9) man page currently claims that free() will never sleep.
It also implies that the malloc() family of functions will not sleep
when called with M_NOWAIT. However, it is more correct to say that
these functions will not sleep indefinitely. Indeed, they may acquire
a sleepable lock. However, a developer may overlook this restriction
because the WITNESS check that catches attempts to call the malloc()
family of functions within a critical section is inconsistenly
applied.
This change clarifies the language of the malloc(9) man page to clarify
the restriction against calling the malloc() family of functions
while in a critical section or holding a spin lock. It also adds
KASSERTs at appropriate points to make the enforcement of this
restriction more consistent.
PR: 204633
Differential Revision: https://reviews.freebsd.org/D4197
Reviewed by: markj
Approved by: gnn (mentor)
Sponsored by: Juniper Networks
This is useful in environments where system configuration is performed by
automated interaction with the system console, since unexpected witness
output makes such automation difficult. With this change, the new
debug.witness.output_channel sysctl allows one to specify that witness
output is to be printed to the kernel log (using log(9)) rather than the
console.
Reviewed by: cem, jhb
MFC after: 2 weeks
Relnotes: yes
Sponsored by: EMC / Isilon Storage Division
Differential Revision: https://reviews.freebsd.org/D4183
branded as well as unbranded binaries. This will be required to add
support for the new ELFv2 ABI on powerpc64, which is distinguished from
ELFv1 by the contents of the ELF header's flags field.
Reviewed by: imp
MFC after: 2 weeks
- While at it, arrange #ifndefs in kern_dump.c more intelligently; it's
rather confusing to have multiple competing and/or unused functions in
the kernel.
during iteration instead of relocking it for each traversed rule.
Reviewed by: mjg@
MFC after: 1 month
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D4110
new return codes of -1 were mistakenly being considered "true". Callout_stop
now returns -1 to indicate the callout had either already completed or
was not running and 0 to indicate it could not be stopped. Also update
the manual page to make it more consistent no non-zero in the callout_stop
or callout_reset descriptions.
MFC after: 1 Month with associated callout change.
certain kernel structures for use by debuggers. This mostly aids
in examining cores from a kernel without debug symbols as a debugger
can infer these values if debug symbols are available.
One set of variables describes the layout of 'struct linker_file' to
walk the list of loaded kernel modules.
A second set of variables describes the layout of 'struct proc' and
'struct thread' to walk the list of processes in the kernel and the
threads in each process.
The 'pcb_size' variable is used to index into the stoppcbs[] array.
The 'vm_maxuser_address' is used to distinguish kernel virtual addresses
from user addresses. This doesn't have to be perfect, and
'vm_maxuser_address' is a cheap and simple way to differentiate kernel
pointers from simple values like TIDs and PIDs.
While here, annotate the fields in struct pcb used by kgdb on amd64
and i386 to note that their ABI should be preserved. Annotations for
other platforms will be added in the future.
Reviewed by: kib
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D3773
should be used by TCP for sure in its cleanup of the IN-PCB (will be coming shortly).
Sponsored by: Netflix Inc.
Differential Revision: https://reviews.freebsd.org/D4076
If you attempt to set a pcpu limit that is higher than
110% using rctl (for instance, you want a jail to be
able to use 2 cores on your system so you set pcpu to
200%) the thing you are trying to limit becomes unthrottled.
PR: 189870
Submitted by: dustinwenz@ebureau.com
Reviewed by: trasz
MFC after: 1 week
as otherwise most of the time is spent resolving UIDs to names.
Reviewed by: mjg@
MFC after: 1 month
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D4059
variable during mp_start() which is too late. Move this to mp_setmaxid()
where other architectures set it and move x86 assertions to MI code.
Reviewed by: kib (x86 part)
is non-zero.
- Include the process address in the PROC_ASSERT_HELD() and
PROC_ASSERT_NOT_HELD() assertion messages so that the corresponding
process can be found easily when debugging.
MFC after: 1 week
Use the right intmax_t type instead of intptr_t in a few remaining
places.
Add support for CTLFLAG_TUN for the new fixed with types. Bruce will be
upset that the new handlers silently truncate tuned quad-sized inputs,
but so do all of the existing handlers.
Add the new types to debug_dump_node, for whatever use that is.
Bump FreeBSD_version again, for good measure. We are changing
SYSCTL_HANDLER_ARGS and a member of struct sysctl_oid to intmax_t.
Correct the sysctl typed NULL values for the fixed-width types. (Hat
tip: hps@.)
Suggested by: hps (partial)
Sponsored by: EMC / Isilon Storage Division
Things seem to get stuck in low memory conditions where no bufs are available,
the reclamation path is called to wakeup the daemon, but no sleeping is done.
Because of this, we are stuck in a tight loop in the current process and
never run said reclamation path.
This was introduced in r289279 . This is only a temporary workaround
to restore system usefulness until the more permanent solutions can be
found.
Tested:
* Carambola2, 64MB (and 32MB by manual config.)
Add S8, S16, S32, and U32 types; add SYSCTL*() macros for them, as well
as for the existing 64-bit types. (While SYSCTL*QUAD and UQUAD macros
already exist, they do not take the same sort of 'val' parameter that
the other macros do.)
Clean up the documented "types" in the sysctl.9 document. (These are
macros and thus not real types, but the manual page documents intent.)
The sysctl_add_oid(9) arg2 has been bumped from intptr_t to intmax_t to
accommodate 64-bit types on 32-bit pointer architectures.
This is just the kernel support piece; the userspace sysctl(1) support
will follow in a later patch.
Submitted by: Ravi Pokala <rpokala@panasas.com>
Reviewed by: cem
Relnotes: no
Sponsored by: Panasas
Differential Revision: https://reviews.freebsd.org/D4091
not be found. Otherwise, relocations against such symbols will be silently
ignored instead of causing an error to be raised.
Reviewed by: kib
MFC after: 1 week
whether an error is recoverable. Always re-dirty the buffer on errors
from write requests. The invalidation we used to do for errors not EIO
doesn't need to be done for a device that's really gone, since that's
done in a different path.
Reviewed by: mckusick@, kib@
self-documented, and eases addition of new ops.
For the similar reasons, eliminate UMTX_OP_MAX. nitems() handles the
only use of the symbol.
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
if they are not required for mounting rootfs. However, it's possible
that some setups try to mount them in mountcritlocal (ie from fstab).
Export the list of current root mount holds using a new sysctl,
vfs.root_mount_hold, and make mountcritlocal retry if "mount -a" fails
and the list is not empty.
MFC after: 1 month
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D3709
When destroying a character device the si_devsw field is set to NULL
before all references are gone, to indicate the character device is
going away. This can cause a NULL-dereference fault inside physio().
The callers of physio() should own a thread reference on the cdev and
if si_devsw is seen as non-NULL, it is usable during the execution of
the function. Else an ENXIO error code is returned.
Reviewed by: kib
MFC after: 2 weeks
is 0. Without this change it was sleeping for one tick. Maybe not a big
deal, but it makes share/dtrace/blocking script to report that.
Reviewed by: jhb
Differential Revision: https://reviews.freebsd.org/D3814
Sponsored by: Wheel Systems, http://wheelsystems.com
linux_syscallnames[] from linux_* to linux32_* to avoid conflicts with
linux64.ko. While here, add support for linux64 binaries to systrace.
- Update NOPROTO entries in amd64/linux/syscalls.master to match the
main table to fix systrace build.
- Add a special case for union l_semun arguments to the systrace
generation.
- The systrace_linux32 module now only builds the systrace_linux32.ko.
module on amd64.
- Add a new systrace_linux module that builds on both i386 and amd64.
For i386 it builds the existing systrace_linux.ko. For amd64 it
builds a systrace_linux.ko for 64-bit binaries.
Reviewed by: markj
Differential Revision: https://reviews.freebsd.org/D3954
For CloudABI we need to initialize the registers of new threads
differently based on whether the thread got created through a fork or
through simple thread creation.
Add a flag, TDP_FORKING, that is set by do_fork() and cleared by
fork_exit(). This can be tested against in schedtail.
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D3973
r289660:
Do not allow to execute ptrace(PT_TRACE_ME) when the process is
already traced.
Do not allow to execute ptrace(PT_TRACE_ME) when there is no parent
which can trace the process, i.e. when the parent is already init.
Note that after the PT_TRACE_ME request the process is unkillable and
non-continuable until a debugger is attached, or parent is killed, the
later clears P_TRACED state. Since init clearly would not debug the
caller, and cannot be killed, disallow creation of unkillable
processes.
Reviewed by: jhb, pho
Reported and tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D3908
When establishing the locking state for several lock types (including
blockable mutexes and sx) failed, locking primitives try to spin while
the owner thread is running. The spinning loop performs the test for
running condition by dereferencing the owner->td_state field of the
owner thread. If the owner thread exited while spinner was put off
the processor, it is harmless to access reused struct thread owner,
since in some near future the current processor would notice the owner
change and make appropriate progress. But it could be that the page
which carried the freed struct thread was unmapped, then we fault
(this cannot happen on amd64).
For now, disallowing free of the struct thread seems to be good
enough, and tests which create a lot of threads once, did not
demonstrated regressions.
Reviewed by: jhb, pho
Reported and tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D3908
atapicd(4) has been removed since r249083, and if a system has more than one
optical drive, it will likely be /dev/cd1
Update mount.conf(8) to reflect the change in behavior
MFC after: never
Sponsored by: EMC / Isilon Storage Division
executable image. Keep one page (arbitrary) limit on the max allowed
size of the PT_NOTES.
The ELF image activators still require that program headers of the
executable are fully contained in the first page of the image file.
Reviewed by: emaste, jhb
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D3871
8x performance improvement in a micro benchmark on a 4 socket machine.
- Get buffer headers from a per-cpu uma cache that sits in from of the
free queue.
- Use a per-cpu quantum cache in vmem to eliminate contention for kva.
- Use multiple clean queues according to buffer cache size to eliminate
clean queue lock contention.
- Introduce a bufspace daemon that attempts to prevent getnewbuf() callers
from blocking or doing direct recycling.
- Close some bufspace allocation races that could lead to endless
recycling.
- Further the transition to a more modern style of small functions grouped
by prefix in order to improve growing complexity.
Sponsored by: EMC / Isilon
Reviewed by: kib
Tested by: pho
packets and/or state transitions from each TCP socket. That would help with
narrowing down certain problems we see in the field that are hard to reproduce
without understanding the history of how we got into a certain state. This
change provides just that.
It saves copies of the last N packets in a list in the tcpcb. When the tcpcb is
destroyed, the list is freed. I thought this was likely to be more
performance-friendly than saving copies of the tcpcb. Plus, with the packets,
you should be able to reverse-engineer what happened to the tcpcb.
To enable the feature, you will need to compile a kernel with the TCPPCAP
option. Even then, the feature defaults to being deactivated. You can activate
it by setting a positive value for the number of captured packets. You can do
that on either a global basis or on a per-socket basis (via a setsockopt call).
There is no way to get the packets out of the kernel other than using kmem or
getting a coredump. I thought that would help some of the legal/privacy concerns
regarding such a feature. However, it should be possible to add a future effort
to export them in PCAP format.
I tested this at low scale, and found that there were no mbuf leaks and the peak
mbuf usage appeared to be unchanged with and without the feature.
The main performance concern I can envision is the number of mbufs that would be
used on systems with a large number of sockets. If you save five packets per
direction per socket and have 3,000 sockets, that will consume at least 30,000
mbufs just to keep these packets. I tried to reduce the concerns associated with
this by limiting the number of clusters (not mbufs) that could be used for this
feature. Again, in my testing, that appears to work correctly.
Differential Revision: D3100
Submitted by: Jonathan Looney <jlooney at juniper dot net>
Reviewed by: gnn, hiren
This removes the need for manually changing this flag for Google Chrome
users. It also improves compatibility with Linux applications running under
Linuxulator compatibility layer, and possibly also helps in porting software
from Linux.
Generally speaking, the flag allows applications to create the shared memory
segment, attach it, remove it, and then continue to use it and to reattach it
later. This means that the kernel will automatically "clean up" after the
application exits.
It could be argued that it's against POSIX. However, SUSv3 says this
about IPC_RMID: "Remove the shared memory identifier specified by shmid from
the system and destroy the shared memory segment and shmid_ds data structure
associated with it." From my reading, we break it in any case by deferring
removal of the segment until it's detached; we won't break it any more
by also deferring removal of the identifier.
This is the behaviour exhibited by Linux since... probably always, and
also by OpenBSD since the following commit:
revision 1.54
date: 2011/10/27 07:56:28; author: robert; state: Exp; lines: +3 -8;
Allow segments to be used even after they were marked for deletion with
the IPC_RMID flag.
This is permitted as an extension beyond the standards and this is similar
to what other operating systems like linux do.
MFC after: 1 month
Relnotes: yes
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D3603
struct thread and kernel stack for the thread. Otherwise, a load
similar to a fork bomb would exhaust KVA and possibly kmem, mostly due
to the struct proc being type-stable.
The nprocs counter is changed from being protected by allproc_lock sx
to be an atomic variable. Note that ddb/db_ps.c:db_ps() use of nprocs
was unsafe before, and is still unsafe, but it seems that the only
possible undesired consequence is the harmless warning printed when
allproc linked list length does not match nprocs.
Diagnosed by: Svatopluk Kraus <onwahe@gmail.com>
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
mbuf. Unlike in the pre-r248371 code, assert that M_PKTHDR is set
only on a first mbuf.
Reported & tested by: Andriy Voskoboinyk <s3erios gmail.com>
Sponsored by: Nginx, Inc.
- Always set td_dbg_sc_* when P_TRACED is set on system call entry
even if the debugger is not tracing system call entries. This
ensures the fields are valid when reporting other stops that
occur at system call boundaries such as for PT_FOLLOW_FORKS or
when only tracing system call exits.
- Set TDB_SCX when reporting the stop for a new child process in
fork_return(). This causes the event to be reported as a system
call exit.
- Report a system call exit event in fork_return() for new threads in
a traced process.
- Copy td_dbg_sc_* to new threads instead of zeroing. This ensures
that td_dbg_sc_code in particular will report the system call that
created the new thread or process when it reports a system call
exit event in fork_return().
- Add new ptrace tests to verify that new child processes and threads
report system call exit events with a valid pl_syscall_code via
PT_LWPINFO.
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D3822
This fix is spiritually similar to r287442 and was discovered thanks to
the KASSERT added in that revision.
NT_PROCSTAT_VMMAP output length, when packing kinfo structs, is tied to
the length of filenames corresponding to vnodes in the process' vm map
via vn_fullpath. As vnodes may move during coredump, this is racy.
We do not remove the race, only prevent it from causing coredump
corruption.
- Add a sysctl, kern.coredump_pack_vmmapinfo, to allow users to disable
kinfo packing for PROCSTAT_VMMAP notes. This avoids VMMAP corruption
and truncation, even if names change, at the cost of up to PATH_MAX
bytes per mapped object. The new sysctl is documented in core.5.
- Fix note_procstat_vmmap to self-limit in the second pass. This
addresses corruption, at the cost of sometimes producing a truncated
result.
- Fix PROCSTAT_VMMAP consumers libutil (and libprocstat, via copy-paste)
to grok the new zero padding.
Reported by: pho (https://people.freebsd.org/~pho/stress/log/datamove4-2.txt)
Relnotes: yes
Sponsored by: EMC / Isilon Storage Division
Differential Revision: https://reviews.freebsd.org/D3824
- The new PC value and signal passed to PT_CONTINUE, PT_DETACH, PT_SYSCALL,
and PT_TO_SC[EX].
- The system call code returned via PT_LWPINFO.
MFC after: 1 week
to shut down; close laptop lid" scenario which otherwise tended to end
with a laptop overheating or the battery dying.
The implementation uses a new sysctl, kern.suspend_blocked; init(8) sets
this while rc.suspend runs, and the ACPI sleep code ignores requests while
the sysctl is set.
Discussed on: freebsd-acpi (35 emails)
MFC after: 1 week
of POSIX_FADV_DONTNEED so that it causes the backing pages to be moved to
the head of the inactive queue instead of being cached.
This affects the implementation of POSIX_FADV_NOREUSE as well, since it
works by applying POSIX_FADV_DONTNEED to file ranges after they have been
read or written. At that point the corresponding buffers may still be
dirty, so the previous implementation would coalesce successive ranges and
apply POSIX_FADV_DONTNEED to the result, ensuring that pages backing the
dirty buffers would eventually be cached. To preserve this behaviour in an
efficient manner, this change adds a new buf flag, B_NOREUSE, which causes
the pages backing a VMIO buf to be placed at the head of the inactive queue
when the buf is released. POSIX_FADV_NOREUSE then works by setting this
flag in bufs that underlie the specified range.
Reviewed by: alc, kib
Sponsored by: EMC / Isilon Storage Division
Differential Revision: https://reviews.freebsd.org/D3726
SDT_PROBE requires 5 parameters whereas SDT_PROBE<n> requires n parameters
where n is typically smaller than 5.
Perhaps SDT_PROBE should be made a private implementation detail.
MFC after: 20 days
- Allow vfs_vmio_invalidate() to free the pages, leaving us with a
single loop and bufobj lock when B_NOCACHE/B_INVAL is used.
- Eliminate the special B_ASYNC handling on free that has not been
relevant for some time.
- Remove the extraneous page busy from vfs_vmio_truncate().
Reviewed by: kib
Tested by: pho
Sponsored by: EMC / Isilon storage division
Revamp sbuf_put_byte() to sbuf_put_bytes() in the obvious fashion and
fixup callers.
Add a thin shim around sbuf_put_bytes() with the old ABI to avoid ugly
changes to some callers.
Reviewed by: jhb, markj
Obtained from: Dan Sledz
Sponsored by: EMC / Isilon Storage Division
Differential Revision: https://reviews.freebsd.org/D3717
are updated lockess, different CPUs write its own view of timecounter
state. The critical section is done for safety, callers of
tc_cpu_ticks() are supposed to already enter critical section, or to
own a spinlock.
The change fixes sporadical reports of too high values reported for
the (W)CPU on platforms that do not provide cpu ticker and use
tc_cpu_ticks(), in particular, arm*.
Diagnosed and reviewed by: jhb
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
- Eliminate bogus page replacement that is inconsistently applied in the
invalidation loop in brelse. This has been a no-op in modern times as
biodone() is responsible for cleaning up after bogus pages. This
would've spammed the console with printfs at a minimum.
- Allow the compiler and human readers alike to reason about allocbuf()
by splitting it into constituent parts.
- Separate the VM manipulating and buf manipulating code in brelse() and
bufdone() so that the intentions are clear. This makes it evident that
there are several duplicated buf pages loops that will be consolidated
at a later time.
Reviewed by: kib
Tested by: pho
Sponsored by: EMC / Isilon Storage Division
queue and (2) returns a Boolean indicating whether the page's wire count
transitioned to zero.
Exploit this change in vfs_vmio_release() to avoid pointlessly enqueueing
a page that is about to be freed.
(An earlier version of this change was developed by attilio@ and kmacy@.
Any errors in this version are my own.)
Reviewed by: kib
Sponsored by: EMC / Isilon Storage Division
Changes to kern.pid_max mib after the boot can break this relation.
The maxfiles value was calculated by the MAXFILES formula based on
maxproc value, but this change decouples them, and MAXFILES now
references maxusers. Without manual tuning, the maxfiles default
value remains as it was prior to this commit. But for systems which
have tuned maxproc and rely on maxfiles to adjust, additional
reconfiguration is needed.
Reported by: rwatson
Reviewed by: emaste
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
linkers no longer raise an error when undefined weak symbols are
found, but relocate as if the symbol value was 0. Note that we do not
repeat the mistake of userspace dynamic linker of making the symbol
lookup prefer non-weak symbol definition over the weak one, if both
are available. In fact, kernel linker uses the first definition
found, and ignores duplicates.
Signature of the elf_lookup() and elf_obj_lookup() functions changed
to split result/error code and the symbol address returned.
Otherwise, it is impossible to return zero address as the symbol
value, to MD relocation code. This explains the mechanical changes in
elf_machdep.c sources.
The powerpc64 R_PPC_JMP_SLOT handler did not checked error from the
lookup() call, the patch leaves the code as is (untested).
Reported by: glebius
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Note that the mountlist manipulations are somewhat fragile, and not very
pretty. The reason for this is to avoid changing vfs_mountroot(), which
is (obviously) rather mission-critical, but not very well documented,
and thus hard to test properly. It might be possible to rework it to use
its own simple root mount mechanism instead of vfs_mountroot().
Reviewed by: kib@
MFC after: 1 month
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D2698
TDB_USERWR flag may still be set after a debugger detaches from a
process via PT_DETACH. Previously the flag would never be cleared
forcing a double fetch of the system call arguments for each system
call. Note that the flag cannot be cleared at PT_DETACH time in case
one of the threads in the process is currently stopped in
syscallenter() and the debugger has modified the arguments for that
pending system call before detaching.
Reviewed by: kib
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D3678
sent SIGHUP and SIGCONT if any of the processes are stopped. Currently this
behavior is triggered for any type of process stop including ptrace() stops
and transient stops for single threading during exit() and execve().
Thus, if a debugger is attached to a process in a group when the leader
exits, the entire group can be HUPed. Instead, only send the signals if a
process in the group is stopped due to SIGSTOP.
PR: 201149
Reviewed by: kib
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D3681
to sleep. The rmlock implementation enforces this by disabling
sleeping when a read lock is acquired. To simplify the implementation,
sleeping is disabled for most of the duration of rm_rlock. However,
it doesn't need to be disabled until the lock is acquired. If a
sleepable rm lock is contested, then rm_rlock may need to acquire the
backing sx lock. This tripped the overly-broad assertion. Fix by
relaxing the assertion around the call to sx_xlock().
Reported by: mjg
Reviewed by: kib, mjg
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D3324
In poll mode, check for and wake VBAD vnodes. (Vnodes that are VBAD at
registration will never be woken by the RECLAIM trigger.)
Add post-VOP_RECLAIM hook to trigger notes on vnode reclamation. (Vnodes that
were fine at registration but are vgoned while being monitored should signal
waiters.)
Reviewed by: kib
Approved by: markj (mentor)
Sponsored by: EMC / Isilon Storage Division
Differential Revision: https://reviews.freebsd.org/D3675
branch.
This function is used to drain a callout via a callback instead of
blocking the caller until the drain is complete. Refer to the
callout_drain_async() manual page for a detailed description.
Limitation: If a lock is used with the callout, the callout can only
be drained asynchronously one time unless the callout_init_mtx()
function is called again. This limitation is not present in
projects/hps_head and will require more invasive changes to the
timeout code, which was not in the scope of this patch.
Differential Revision: https://reviews.freebsd.org/D3521
Reviewed by: wblock
MFC after: 1 month
running thread.
It is currently implemented only on amd64 and i386; on these
architectures, it is implemented by raising an NMI on the CPU on which
the target thread is currently running. Unlike stack_save_td(), it may
fail, for example if the thread is running in user mode.
This change also modifies the kern.proc.kstack sysctl to use this function,
so that stacks of running threads are shown in the output of "procstat -kk".
This is handy for debugging threads that are stuck in a busy loop.
Reviewed by: bdrewery, jhb, kib
Sponsored by: EMC / Isilon Storage Division
Differential Revision: https://reviews.freebsd.org/D3256
Auto-tuning threshold discussions aside, it turns out that if you want
to lower this on say, rather memory-packed machines, you either set maxusers
or kern.maxfiles, or you set it in sysctl. The former is a non-exact
way to tune this; the latter doesn't actually affect anything in the
startup scripts.
This first occured because I wondered why the hell screen would take upwards
of 10 seconds to spawn a new screen. I then found python doing the same
thing during fork/exec of child processes - it calls close() on each FD
up to the current openfiles limit. On a 1TB machine this is like, 26 million
FDs per process. Ugh.
So:
* This allows it to be set early in /boot/loader.conf;
* It can be used to work around the ridiculous situation of
screen, python, etc doing a close() on potentially millions of FDs
even though you only have four open.
Tested:
* 4GB, 32GB, 64GB, 128GB, 384GB, 1TB systems with autotune, ensuring
screen and python forking doesn't result in some pretty hilariously
bad behaviour.
TODO:
* Note that the default login.conf sets openfiles-cur to unlimited,
effectively obeying kern.maxfilesperproc. Perhaps we should fix
this.
* .. and even if we do, we need to also ensure that daemons get
a soft limit of something reasonable and capped - they can request
more FDs themselves.
MFC after: 1 week
Sponsored by: Norse Corp, Inc.
named node, open(2) cannot create directories. But do allow the flag
combination to succeed if the directory already exists.
Declare the open("name", O_DIRECTORY | O_CREAT | O_EXCL) always
invalid for the same reason, since open(2) cannot create directory.
Note that there is an argument that O_DIRECTORY | O_CREAT should be
invalid always, regardless of the target directory existence or
O_EXCL. The current fix is conservative and allows the call to
succeed in the situation where it succeeded before the patch.
Reported by: Tom Ridge <freebsd@tom-ridge.com>
Reviewed by: rwatson
PR: 202892
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
The filedesc lock is only needed if ioctls caps are present, which is a
rare situation. This is a step towards reducing the scope of the filedesc
lock.
the size of the name cache hash table (mapping file names to vnodes)
and the vnode hash table (mapping mount point and inode number to vnode).
An appropriate locking strategy is the key to changing hash table sizes
while they are in active use.
Reviewed by: kib
Tested by: Peter Holm
Differential Revision: https://reviews.freebsd.org/D2265
MFC after: 2 weeks
Coredump notes depend on being able to invoke dump routines twice; once
in a dry-run mode to get the size of the note, and another to actually
emit the note to the corefile.
When a note helper emits a different length section the second time
around than the length it requested the first time, the kernel produces
a corrupt coredump.
NT_PROCSTAT_FILES output length, when packing kinfo structs, is tied to
the length of filenames corresponding to vnodes in the process' fd table
via vn_fullpath. As vnodes may move around during dump, this is racy.
So:
- Detect badly behaved notes in putnote() and pad underfilled notes.
- Add a fail point, debug.fail_point.fill_kinfo_vnode__random_path to
exercise the NT_PROCSTAT_FILES corruption. It simply picks random
lengths to expand or truncate paths to in fo_fill_kinfo_vnode().
- Add a sysctl, kern.coredump_pack_fileinfo, to allow users to
disable kinfo packing for PROCSTAT_FILES notes. This should avoid
both FILES note corruption and truncation, even if filenames change,
at the cost of about 1 kiB in padding bloat per open fd. Document
the new sysctl in core.5.
- Fix note_procstat_files to self-limit in the 2nd pass. Since
sometimes this will result in a short write, pad up to our advertised
size. This addresses note corruption, at the risk of sometimes
truncating the last several fd info entries.
- Fix NT_PROCSTAT_FILES consumers libutil and libprocstat to grok the
zero padding.
With suggestions from: bjk, jhb, kib, wblock
Approved by: markj (mentor)
Relnotes: yes
Sponsored by: EMC / Isilon Storage Division
Differential Revision: https://reviews.freebsd.org/D3548
Originally it was added in order to prevent trashing of objects with
INVARIANTS enabled. The same effect is now provided with mere UMA_ZONE_NOFREE.
This reverts r286921.
Discussed with: kib
and exit events. procfs stop events for system call tracing report these
values (argument count for system call entry and code for system call exit),
but ptrace() does not provide this information. (Note that while the system
call code can be determined in an ABI-specific manner during system call
entry, it is not generally available during system call exit.)
The values are exported via new fields at the end of struct ptrace_lwpinfo
available via PT_LWPINFO.
Reviewed by: kib
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D3536
particular, this invalidates the knote kn_link linkage, making the
SLIST_FOREACH() loop accessing undefined values (e.g. trashed by
QUEUE_MACRO_DEBUG). If the knote is freed by other thread when kq
lock is released or when influx is cleared, e.g. by knote_scan() for
kqueue owning the knote, the iteration step would access freed memory.
Use SLIST_FOREACH_SAFE() to fix iteration.
Diagnosed by: avg
Tested by: avg, lstewart, pawel
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Explain why it is fine to not check for M_NOWAIT failures in
kqueue_register(). Remove unneeded check for NULL result from
waitable allocation in kqueue_scan(). uma_free(9) handles NULL
argument correctly, remove checks for NULL. Remove useless cast and
adjust style in knote_alloc().
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
The typo was introduced in r278469 / 344ecf88af.
As a result of the bug there was a timing window where callout_reset()
would fail to cancel a concurrent execution of a callout that is about
to start and would schedule the callout again.
The callout would fire more times than it is scheduled.
That would happen even if the callout is initialized with a lock.
For example, the bug triggered the "Stray timeout" assertion in
taskqueue_timeout_func().
MFC after: 5 days
scheduler types. It was intended to be used there, compare with the
min value, and with the test for correctness in ksched_setscheduler().
Note that P1B_PRIO_MAX and RTP_PRIO_MAX do have the same numerical
values, the change is cosmetical.
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
it helps only the TCP timers callout(9) usage. As the benefit for
others callout(9) usages did not reach a consensus the historical
usage should prevail.
Differential Revision: https://reviews.freebsd.org/D3078
To make it easier to understand how Capsicum interacts with linkat() and
renameat(), rename the rights to CAP_{LINK,RENAME}AT_{SOURCE,TARGET}.
This also addresses a shortcoming in Capsicum, where it isn't possible
to disable linking to files stored in a directory. Creating hardlinks
essentially makes it possible to access files with additional rights.
Reviewed by: rwatson, wblock
Differential Revision: https://reviews.freebsd.org/D3411
being serviced return 0 (fail) but it is applicable only
mpsafe callouts. Thanks to hselasky for finding this.
Differential Revision: https://reviews.freebsd.org/D3078 (Updated)
Submitted by: hselasky
Reviewed by: jch
was invalid. Don't trigger a mount failure (which by default means
a panic), but instead just move on to the next directive in the
configuration. This typically has us ask for the root mount.
PR: 163245
reason this didn't result in an unclean shutdown is that devfs ignores
MNT_FORCE flag.
Reviewed by: kib@
MFC after: 1 month
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D3467
Add a check to preload_search_info to make sure mod is set. Most of the
callers of preload_search_info don't check that the mod parameter is
set, which can cause page faults. While at it, remove some now unnecessary
checks before calling preload_search_info.
Sponsored by: Citrix Systems R&D
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D3440
having some children, the children' reaper is not reset to the parent.
This allows for the situation where reaper has children but not
descendands and the too strict asserts in the reap_status() fire.
Remove the wrong asserts, add some clarification for the situation to
the procctl(2) REAP_STATUS.
Reported and tested by: feld
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
zero. The file_zone if no-free, but r284861 added trashing of the
freed memory. Most visible manifestation of the issue were 'memory
modified after free' panics for the file zone, triggered from
falloc_noinstall().
Add UMA_ZONE_ZINIT flag to turn off trashing. Mjg noted that it makes
sense to not trash freed memory for any non-free zone, which will be
done later.
Reported and tested by: pho
Discussed with: mjg
Sponsored by: The FreeBSD Foundation
being serviced and indeed unstoppable.
A scenario to reproduce this case is:
- the callout is being serviced and at same time,
- callout_reset() is called on this callout that sets
the CALLOUT_PENDING flag and at same time,
- callout_stop() is called on this callout and returns 1 (success)
even if the callout is indeed currently running and unstoppable.
This issue was caught up while making r284245 (D2763) workaround, and
was discussed at BSDCan 2015. Once applied the r284245 workaround
is not needed anymore and will be reverted.
Differential Revision: https://reviews.freebsd.org/D3078
Reviewed by: jhb
Sponsored by: Verisign, Inc.
with higher quality registers (presumably in a module that has just been
loaded), do not undo the user's choice by switching to the new timecounter.
Document that behavior, and also the fact that there is no way to unregister
a timecounter (and thus no way to unload a module containing one).
