Commit Graph

327 Commits

Author SHA1 Message Date
John Baldwin
88bf5036fc Include the associated wait channel message for context switch ktrace
records.  kdump supports both the old and new messages.

Submitted by:	Andrey Zonov  andrey zonov org
MFC after:	1 week
2012-04-20 15:32:36 +00:00
Fabien Thomas
f5f9340b98 Add software PMC support.
New kernel events can be added at various location for sampling or counting.
This will for example allow easy system profiling whatever the processor is
with known tools like pmcstat(8).

Simultaneous usage of software PMC and hardware PMC is possible, for example
looking at the lock acquire failure, page fault while sampling on
instructions.

Sponsored by: NETASQ
MFC after:	1 month
2012-03-28 20:58:30 +00:00
Konstantin Belousov
24f3dcfe50 Assert that exiting process does not return to usermode.
Reviewed by:	avg, jhb
MFC after:	1 week
2011-10-03 16:58:58 +00:00
Kip Macy
8451d0dd78 In order to maximize the re-usability of kernel code in user space this
patch modifies makesyscalls.sh to prefix all of the non-compatibility
calls (e.g. not linux_, freebsd32_) with sys_ and updates the kernel
entry points and all places in the code that use them. It also
fixes an additional name space collision between the kernel function
psignal and the libc function of the same name by renaming the kernel
psignal kern_psignal(). By introducing this change now we will ease future
MFCs that change syscalls.

Reviewed by:	rwatson
Approved by:	re (bz)
2011-09-16 13:58:51 +00:00
Konstantin Belousov
26ccf4f10f Inline the syscallenter() and syscallret(). This reduces the time measured
by the syscall entry speed microbenchmarks by ~10% on amd64.

Submitted by:	jhb
Approved by:	re (bz)
MFC after:	2 weeks
2011-09-11 16:05:09 +00:00
Jonathan Anderson
24c1c3bf71 We may split today's CAPABILITIES into CAPABILITY_MODE (which has
to do with global namespaces) and CAPABILITIES (which has to do with
constraining file descriptors). Just in case, and because it's a better
name anyway, let's move CAPABILITIES out of the way.

Also, change opt_capabilities.h to opt_capsicum.h; for now, this will
only hold CAPABILITY_MODE, but it will probably also hold the new
CAPABILITIES (implying constrained file descriptors) in the future.

Approved by: rwatson
Sponsored by: Google UK Ltd
2011-06-29 13:03:05 +00:00
Robert Watson
fc94e4476b Continue introducing Capsicum capability mode support:
If a system call wasn't listed in capabilities.conf, return ECAPMODE at
syscall entry.

Reviewed by:	anderson
Discussed with:	benl, kris, pjd
Sponsored by:	Google, Inc.
Obtained from:	Capsicum Project
MFC after:	3 months
2011-03-01 13:32:07 +00:00
Bjoern A. Zeeb
bf9ce95bd2 Mfp4 CH=177256:
Catch a set vnet upon return to user space. This usually
  means return paths with CURVNET_RESTORE() missing.

  If VNET_DEBUG is turned on we can even tell the function
  that did the CURVNET_SET() which is really helpful; else
  we print "N/A".

  Sponsored by: The FreeBSD Foundation
  Sponsored by: CK Software GmbH
  Reviewed by:  jhb

MFC after:	11 days
2011-02-14 20:49:37 +00:00
Konstantin Belousov
6fa39a7327 Allow debugger to specify that children of the traced process should be
automatically traced. Extend the ptrace(PL_LWPINFO) to report that child
just forked.

Reviewed by:	davidxu, jhb
MFC after:	2 weeks
2011-01-25 10:59:21 +00:00
Ed Maste
25e45560da Remove extra braces for style(9) (found while cleaning up an old work tree). 2010-09-28 01:36:01 +00:00
Rui Paulo
b3d354c9ce Call the systrace_probe_func() when the error value.
Sponsored by:	The FreeBSD Foundation
2010-08-22 11:30:49 +00:00
John Baldwin
f2a664ac97 Retire td_syscalls now that it is no longer needed. 2010-07-15 20:24:37 +00:00
Konstantin Belousov
34a39b7b1f Obey sv_syscallnames bounds in syscallname().
Reported and tested by:	pho
2010-07-04 18:16:17 +00:00
John Baldwin
fc0de8f0b6 Move prototypes for kern_sigtimedwait() and kern_sigprocmask() to
<sys/syscallsubr.h> where all other kern_<syscall> prototypes live.
2010-06-30 18:03:42 +00:00
Konstantin Belousov
153ac44cf6 Count number of threads that enter and leave dynamically registered
syscalls. On the dynamic syscall deregistration, wait until all
threads leave the syscall code. This somewhat increases the safety
of the loadable modules unloading.

Reviewed by:	jhb
Tested by:	pho
MFC after:	1 month
2010-06-28 18:06:46 +00:00
Konstantin Belousov
699d648aab Remove the support for int13 FPU exception reporting on i386. It is
believed that all 486-class CPUs FreeBSD is capable to run on, either
have no FPU and cannot use external coprocessor, or have FPU on the
package and can use #MF.

Reviewed by:	bde
Tested by:	pho (previous version)
2010-06-23 11:12:58 +00:00
Rui Paulo
f05a947676 Make DTrace syscall provider work again by including opt_kdtrace.h here. 2010-06-17 17:34:45 +00:00
Konstantin Belousov
b2318c2860 Allow to use syscallname(9) outside subr_trap.c.
MFC after:	1 month
2010-05-26 15:39:43 +00:00
Konstantin Belousov
afe1a68827 Reorganize syscall entry and leave handling.
Extend struct sysvec with three new elements:
sv_fetch_syscall_args - the method to fetch syscall arguments from
  usermode into struct syscall_args. The structure is machine-depended
  (this might be reconsidered after all architectures are converted).
sv_set_syscall_retval - the method to set a return value for usermode
  from the syscall. It is a generalization of
  cpu_set_syscall_retval(9) to allow ABIs to override the way to set a
  return value.
sv_syscallnames - the table of syscall names.

Use sv_set_syscall_retval in kern_sigsuspend() instead of hardcoding
the call to cpu_set_syscall_retval().

The new functions syscallenter(9) and syscallret(9) are provided that
use sv_*syscall* pointers and contain the common repeated code from
the syscall() implementations for the architecture-specific syscall
trap handlers.

Syscallenter() fetches arguments, calls syscall implementation from
ABI sysent table, and set up return frame. The end of syscall
bookkeeping is done by syscallret().

Take advantage of single place for MI syscall handling code and
implement ptrace_lwpinfo pl_flags PL_FLAG_SCE, PL_FLAG_SCX and
PL_FLAG_EXEC. The SCE and SCX flags notify the debugger that the
thread is stopped at syscall entry or return point respectively.  The
EXEC flag augments SCX and notifies debugger that the process address
space was changed by one of exec(2)-family syscalls.

The i386, amd64, sparc64, sun4v, powerpc and ia64 syscall()s are
changed to use syscallenter()/syscallret(). MIPS and arm are not
converted and use the mostly unchanged syscall() implementation.

Reviewed by:	jhb, marcel, marius, nwhitehorn, stas
Tested by:	marcel (ia64), marius (sparc64), nwhitehorn (powerpc),
	stas (mips)
MFC after:	1 month
2010-05-23 18:32:02 +00:00
Konstantin Belousov
066d836b02 Current pselect(3) is implemented in usermode and thus vulnerable to
well-known race condition, which elimination was the reason for the
function appearance in first place. If sigmask supplied as argument to
pselect() enables a signal, the signal might be delivered before thread
called select(2), causing lost wakeup. Reimplement pselect() in kernel,
making change of sigmask and sleep atomic.

Since signal shall be delivered to the usermode, but sigmask restored,
set TDP_OLDMASK and save old mask in td_oldsigmask. The TDP_OLDMASK
should be cleared by ast() in case signal was not gelivered during
syscall execution.

Reviewed by:	davidxu
Tested by:	pho
MFC after:	1 month
2009-10-27 10:55:34 +00:00
Konstantin Belousov
6b286ee8b5 Currently, when signal is delivered to the process and there is a thread
not blocking the signal, signal is placed on the thread sigqueue. If
the selected thread is in kernel executing thr_exit() or sigprocmask()
syscalls, then signal might be not delivered to usermode for arbitrary
amount of time, and for exiting thread it is lost.

Put process-directed signals to the process queue unconditionally,
selecting the thread to deliver the signal only by the thread returning
to usermode, since only then the thread can handle delivery of signal
reliably. For exiting thread or thread that has blocked some signals,
check whether the newly blocked signal is queued for the process, and
try to find a thread to wakeup for delivery, in reschedule_signal(). For
exiting thread, assume that all signals are blocked.

Change cursig() and postsig() to look both into the thread and process
signal queues. When there is a signal that thread returning to usermode
could consume, TDF_NEEDSIGCHK flag is not neccessary set now. Do
unlocked read of p_siglist and p_pendingcnt to check for queued signals.

Note that thread that has a signal unblocked might get spurious wakeup
and EINTR from the interruptible system call now, due to the possibility
of being selected by reschedule_signals(), while other thread returned
to usermode earlier and removed the signal from process queue. This
should not cause compliance issues, since the thread has not blocked a
signal and thus should be ready to receive it anyway.

Reported by:	Justin Teller <justin.teller gmail com>
Reviewed by:	davidxu, jilles
MFC after:	1 month
2009-10-11 16:49:30 +00:00
Konstantin Belousov
f33a947b56 Add new msleep(9) flag PBDY that shall be specified together with
PCATCH, to indicate that thread shall not be stopped upon receipt of
SIGSTOP until it reaches the kernel->usermode boundary.

Also change thread_single(SINGLE_NO_EXIT) to only stop threads at
the user boundary unconditionally.

Tested by:	pho
Reviewed by:	jhb
Approved by:	re (kensmith)
2009-07-14 22:52:46 +00:00
Robert Watson
bcf11e8d00 Move "options MAC" from opt_mac.h to opt_global.h, as it's now in GENERIC
and used in a large number of files, but also because an increasing number
of incorrect uses of MAC calls were sneaking in due to copy-and-paste of
MAC-aware code without the associated opt_mac.h include.

Discussed with:	pjd
2009-06-05 14:55:22 +00:00
Joseph Koshy
6fe00c7876 - Bug fix: prevent a thread from migrating between CPUs between the
time it is marked for user space callchain capture in the NMI
  handler and the time the callchain capture callback runs.

- Improve code and control flow clarity by invoking hwpmc(4)'s user
  space callchain capture callback directly from low-level code.

Reviewed by:	jhb (kern/subr_trap.c)
Testing (various patch revisions): gnn,
		Fabien Thomas <fabien dot thomas at netasq dot com>,
		Artem Belevich <artemb at gmail dot com>
2008-12-13 13:07:12 +00:00
Kip Macy
50d6e42434 - Forward port flush of page table updates on context switch or userret
- Forward port vfork XEN hack
2008-10-19 01:35:27 +00:00
Jeff Roberson
8df78c41d6 - Make SCHED_STATS more generic by adding a wrapper to create the
variables and sysctl nodes.
 - In reset walk the children of kern_sched_stats and reset the counters
   via the oid_arg1 pointer.  This allows us to add arbitrary counters to
   the tree and still reset them properly.
 - Define a set of switch types to be passed with flags to mi_switch().
   These types are named SWT_*.  These types correspond to SCHED_STATS
   counters and are automatically handled in this way.
 - Make the new SWT_ types more specific than the older switch stats.
   There are now stats for idle switches, remote idle wakeups, remote
   preemption ithreads idling, etc.
 - Add switch statistics for ULE's pickcpu algorithm.  These stats include
   how much migration there is, how often affinity was successful, how
   often threads were migrated to the local cpu on wakeup, etc.

Sponsored by:	Nokia
2008-04-17 04:20:10 +00:00
Jeff Roberson
b7edba7704 - Add a new td flag TDF_NEEDSUSPCHK that is set whenever a thread needs
to enter thread_suspend_check().
 - Set TDF_ASTPENDING along with TDF_NEEDSUSPCHK so we can move the
   thread_suspend_check() to ast() rather than userret().
 - Check TDF_NEEDSUSPCHK in the sleepq_catch_signals() optimization so
   that we don't miss a suspend request.  If this is set use the
   expensive signal path.
 - Set NEEDSUSPCHK when creating a new thread in thr in case the
   creating thread is due to be suspended as well but has not yet.

Reviewed by:	davidxu (Authored original patch)
2008-03-21 08:23:25 +00:00
Jeff Roberson
6617724c5f Remove kernel support for M:N threading.
While the KSE project was quite successful in bringing threading to
FreeBSD, the M:N approach taken by the kse library was never developed
to its full potential.  Backwards compatibility will be provided via
libmap.conf for dynamically linked binaries and static binaries will
be broken.
2008-03-12 10:12:01 +00:00
Joseph Koshy
d07f36b075 Kernel and hwpmc(4) support for callchain capture.
Sponsored by:	FreeBSD Foundation and Google Inc.
2007-12-07 08:20:17 +00:00
Julian Elischer
e01eafef2a A bunch more files that should probably print out a thread name
instead of a process name.
2007-11-14 06:51:33 +00:00
Jeff Roberson
b61ce5b0e6 - Move all of the PS_ flags into either p_flag or td_flags.
- p_sflag was mostly protected by PROC_LOCK rather than the PROC_SLOCK or
   previously the sched_lock.  These bugs have existed for some time.
 - Allow swapout to try each thread in a process individually and then
   swapin the whole process if any of these fail.  This allows us to move
   most scheduler related swap flags into td_flags.
 - Keep ki_sflag for backwards compat but change all in source tools to
   use the new and more correct location of P_INMEM.

Reported by:	pho
Reviewed by:	attilio, kib
Approved by:	re (kensmith)
2007-09-17 05:31:39 +00:00
Jeff Roberson
3036ab79e3 - Include opt_sched.h for SCHED_STATS. 2007-06-12 23:27:31 +00:00
Jeff Roberson
982d11f836 Commit 14/14 of sched_lock decomposition.
- Use thread_lock() rather than sched_lock for per-thread scheduling
   sychronization.
 - Use the per-process spinlock rather than the sched_lock for per-process
   scheduling synchronization.

Tested by:      kris, current@
Tested on:      i386, amd64, ULE, 4BSD, libthr, libkse, PREEMPTION, etc.
Discussed with: kris, attilio, kmacy, jhb, julian, bde (small parts each)
2007-06-05 00:00:57 +00:00
Attilio Rao
b4b7081961 Do proper "locking" for missing vmmeters part.
Now, we assume no more sched_lock protection for some of them and use the
distribuited loads method for vmmeter (distribuited through CPUs).

Reviewed by: alc, bde
Approved by: jeff (mentor)
2007-06-04 21:45:18 +00:00
Jeff Roberson
1c4bcd050a - Move rusage from being per-process in struct pstats to per-thread in
td_ru.  This removes the requirement for per-process synchronization in
   statclock() and mi_switch().  This was previously supported by
   sched_lock which is going away.  All modifications to rusage are now
   done in the context of the owning thread.  reads proceed without locks.
 - Aggregate exiting threads rusage in thread_exit() such that the exiting
   thread's rusage is not lost.
 - Provide a new routine, rufetch() to fetch an aggregate of all rusage
   structures from all threads in a process.  This routine must be used
   in any place requiring a rusage from a process prior to it's exit.  The
   exited process's rusage is still available via p_ru.
 - Aggregate tick statistics only on demand via rufetch() or when a thread
   exits.  Tick statistics are kept in the thread and protected by sched_lock
   until it exits.

Initial patch by:	attilio
Reviewed by:		attilio, bde (some objections), arch (mostly silent)
2007-06-01 01:12:45 +00:00
Attilio Rao
2feb50bf7d Revert VMCNT_* operations introduction.
Probabilly, a general approach is not the better solution here, so we should
solve the sched_lock protection problems separately.

Requested by: alc
Approved by: jeff (mentor)
2007-05-31 22:52:15 +00:00
Jeff Roberson
222d01951f - define and use VMCNT_{GET,SET,ADD,SUB,PTR} macros for manipulating
vmcnts.  This can be used to abstract away pcpu details but also changes
   to use atomics for all counters now.  This means sched lock is no longer
   responsible for protecting counts in the switch routines.

Contributed by:		Attilio Rao <attilio@FreeBSD.org>
2007-05-18 07:10:50 +00:00
Robert Watson
0c14ff0eb5 Remove 'MPSAFE' annotations from the comments above most system calls: all
system calls now enter without Giant held, and then in some cases, acquire
Giant explicitly.

Remove a number of other MPSAFE annotations in the credential code and
tweak one or two other adjacent comments.
2007-03-04 22:36:48 +00:00
Julian Elischer
ad1e7d285a Threading cleanup.. part 2 of several.
Make part of John Birrell's KSE patch permanent..
Specifically, remove:
Any reference of the ksegrp structure. This feature was
never fully utilised and made things overly complicated.
All code in the scheduler that tried to make threaded programs
fair to unthreaded programs.  Libpthread processes will already
do this to some extent and libthr processes already disable it.

Also:
Since this makes such a big change to the scheduler(s), take the opportunity
to rename some structures and elements that had to be moved anyhow.
This makes the code a lot more readable.

The ULE scheduler compiles again but I have no idea if it works.

The 4bsd scheduler still reqires a little cleaning and some functions that now do
ALMOST nothing will go away, but I thought I'd do that as a separate commit.

Tested by David Xu, and Dan Eischen using libthr and libpthread.
2006-12-06 06:34:57 +00:00
John Birrell
8460a577a4 Make KSE a kernel option, turned on by default in all GENERIC
kernel configs except sun4v (which doesn't process signals properly
with KSE).

Reviewed by:	davidxu@
2006-10-26 21:42:22 +00:00
Robert Watson
aed5570872 Complete break-out of sys/sys/mac.h into sys/security/mac/mac_framework.h
begun with a repo-copy of mac.h to mac_framework.h.  sys/mac.h now
contains the userspace and user<->kernel API and definitions, with all
in-kernel interfaces moved to mac_framework.h, which is now included
across most of the kernel instead.

This change is the first step in a larger cleanup and sweep of MAC
Framework interfaces in the kernel, and will not be MFC'd.

Obtained from:	TrustedBSD Project
Sponsored by:	SPARTA
2006-10-22 11:52:19 +00:00
Bruce Evans
1ca2c0183f kern_intr.c:
- Count (scheduling of) software interrupts (SWIs) as SWIs, not as
  hardware interrupts.
- Don't count (scheduling of) delayed SWIs as interrupts at all, since
  in the delayed case it is expected that there are many more scheduling
  calls than handling calls.  Perhaps all interrupts should be counted
  only when they are handled, but it is only counts of delayed SWIs that
  shouldn never be combined with the other counts.

subr_trap.c:
- Count (handling of) Asynchronous System Traps (ASTs) as traps, not as
  software interrupts.

Before these changes, the counter for SWIs only counted ASTs, and SWIs
weren't counted separately, but a subcounter for ASTs alone is less
needed than for most other exception sources.

4.4BSD-Lite uses the counters for similar things (actually matching
their names) on its main arches (hp300, ..., !i386) where more of the
exceptions are in hardware.
2006-10-18 04:48:09 +00:00
David Xu
42925630b6 Test before modifying p_sflag to avoid unconditionally cache line
ping-pong on SMP.
2006-02-10 14:59:16 +00:00
Poul-Henning Kamp
eb2da9a51f Simplify system time accounting for profiling.
Rename struct thread's td_sticks to td_pticks, we will need the
other name for more appropriately named use shortly.  Reduce it
from uint64_t to u_int.

Clear td_pticks whenever we enter the kernel instead of recording
its value as reference for userret().  Use the absolute value of
td->pticks in userret() and eliminate third argument.
2006-02-08 08:09:17 +00:00
Poul-Henning Kamp
5b1a8eb397 Modify the way we account for CPU time spent (step 1)
Keep track of time spent by the cpu in various contexts in units of
"cputicks" and scale to real-world microsec^H^H^H^H^H^H^H^Hclock_t
only when somebody wants to inspect the numbers.

For now "cputicks" are still derived from the current timecounter
and therefore things should by definition remain sensible also on
SMP machines.  (The main reason for this first milestone commit is
to verify that hypothesis.)

On slower machines, the avoided multiplications to normalize timestams
at every context switch, comes out as a 5-7% better score on the
unixbench/context1 microbenchmark.  On more modern hardware no change
in performance is seen.
2006-02-07 21:22:02 +00:00
Robert Watson
2c255e9df6 Moderate rewrite of kernel ktrace code to attempt to generally improve
reliability when tracing fast-moving processes or writing traces to
slow file systems by avoiding unbounded queueuing and dropped records.
Record loss was previously possible when the global pool of records
become depleted as a result of record generation outstripping record
commit, which occurred quickly in many common situations.

These changes partially restore the 4.x model of committing ktrace
records at the point of trace generation (synchronous), but maintain
the 5.x deferred record commit behavior (asynchronous) for situations
where entering VFS and sleeping is not possible (i.e., in the
scheduler).  Records are now queued per-process as opposed to
globally, with processes responsible for committing records from their
own context as required.

- Eliminate the ktrace worker thread and global record queue, as they
  are no longer used.  Keep the global free record list, as records
  are still used.

- Add a per-process record queue, which will hold any asynchronously
  generated records, such as from context switches.  This replaces the
  global queue as the place to submit asynchronous records to.

- When a record is committed asynchronously, simply queue it to the
  process.

- When a record is committed synchronously, first drain any pending
  per-process records in order to maintain ordering as best we can.
  Currently ordering between competing threads is provided via a global
  ktrace_sx, but a per-process flag or lock may be desirable in the
  future.

- When a process returns to user space following a system call, trap,
  signal delivery, etc, flush any pending records.

- When a process exits, flush any pending records.

- Assert on process tear-down that there are no pending records.

- Slightly abstract the notion of being "in ktrace", which is used to
  prevent the recursive generation of records, as well as generating
  traces for ktrace events.

Future work here might look at changing the set of events marked for
synchronous and asynchronous record generation, re-balancing queue
depth, timeliness of commit to disk, and so on.  I.e., performing a
drain every (n) records.

MFC after:	1 month
Discussed with:	jhb
Requested by:	Marc Olzheim <marcolz at stack dot nl>
2005-11-13 13:27:44 +00:00
David Xu
9104847f21 1. Change prototype of trapsignal and sendsig to use ksiginfo_t *, most
changes in MD code are trivial, before this change, trapsignal and
   sendsig use discrete parameters, now they uses member fields of
   ksiginfo_t structure. For sendsig, this change allows us to pass
   POSIX realtime signal value to user code.

2. Remove cpu_thread_siginfo, it is no longer needed because we now always
   generate ksiginfo_t data and feed it to libpthread.

3. Add p_sigqueue to proc structure to hold shared signals which were
   blocked by all threads in the proc.

4. Add td_sigqueue to thread structure to hold all signals delivered to
   thread.

5. i386 and amd64 now return POSIX standard si_code, other arches will
   be fixed.

6. In this sigqueue implementation, pending signal set is kept as before,
   an extra siginfo list holds additional siginfo_t data for signals.
   kernel code uses psignal() still behavior as before, it won't be failed
   even under memory pressure, only exception is when deleting a signal,
   we should call sigqueue_delete to remove signal from sigqueue but
   not SIGDELSET. Current there is no kernel code will deliver a signal
   with additional data, so kernel should be as stable as before,
   a ksiginfo can carry more information, for example, allow signal to
   be delivered but throw away siginfo data if memory is not enough.
   SIGKILL and SIGSTOP have fast path in sigqueue_add, because they can
   not be caught or masked.
   The sigqueue() syscall allows user code to queue a signal to target
   process, if resource is unavailable, EAGAIN will be returned as
   specification said.
   Just before thread exits, signal queue memory will be freed by
   sigqueue_flush.
   Current, all signals are allowed to be queued, not only realtime signals.

Earlier patch reviewed by: jhb, deischen
Tested on: i386, amd64
2005-10-14 12:43:47 +00:00
Jeff Roberson
9d65cdf6ff - Rev 1.83 of kern_lock.c fixes the td_locks assert, reenable it here.
Sponsored by:	Isilon Systems, Inc.
2005-03-28 12:52:46 +00:00
Jeff Roberson
eb8d0e01c0 - The td_locks check is currently broken with snapshots and possibly
some case in unmount.  Disable the KASSERT until these problems can
   be diagnosed.

Sponsored by:	Isilon Systems, Inc.
2005-03-25 09:56:56 +00:00
Jeff Roberson
61ef09d118 - Fail an assert if we attempt to return with any lockmgr locks held in
userret().

Sponsored by:	Isilon Systems, Inc.
2005-03-24 09:35:38 +00:00