Commit Graph

17 Commits

Author SHA1 Message Date
mjg
67f2eebb44 Generalised support for copy-on-write structures shared by threads.
Thread credentials are maintained as follows: each thread has a pointer to
creds and a reference on them. The pointer is compared with proc's creds on
userspace<->kernel boundary and updated if needed.

This patch introduces a counter which can be compared instead, so that more
structures can use this scheme without adding more comparisons on the boundary.
2015-06-10 10:43:59 +00:00
kib
042604e2ce Thread waiting for the vfork(2)-ed child to exec or exit, must allow
for the suspension.

Currently, the loop performs uninterruptible cv_wait(9) call, which
prevents suspension until child allows further execution of parent.
If child is stopped, suspension or single-threading is delayed
indefinitely.

Create a helper thread_suspend_check_needed() to identify the need for
a call to thread_suspend_check().  It is required since call to the
thread_suspend_check() cannot be safely done while owning the child
(p2) process lock.  Only when suspension is needed, drop p2 lock and
call thread_suspend_check().  Perform wait for cv with timeout, in
case suspend is requested after wait started; I do not see a better
way to interrupt the wait.

Reported and tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2014-12-08 16:18:05 +00:00
rwatson
33fdc14c0c Update kernel inclusions of capability.h to use capsicum.h instead; some
further refinement is required as some device drivers intended to be
portable over FreeBSD versions rely on __FreeBSD_version to decide whether
to include capability.h.

MFC after:	3 weeks
2014-03-16 10:55:57 +00:00
attilio
7ee4e910ce - For kernel compiled only with KDTRACE_HOOKS and not any lock debugging
option, unbreak the lock tracing release semantic by embedding
  calls to LOCKSTAT_PROFILE_RELEASE_LOCK() direclty in the inlined
  version of the releasing functions for mutex, rwlock and sxlock.
  Failing to do so skips the lockstat_probe_func invokation for
  unlocking.
- As part of the LOCKSTAT support is inlined in mutex operation, for
  kernel compiled without lock debugging options, potentially every
  consumer must be compiled including opt_kdtrace.h.
  Fix this by moving KDTRACE_HOOKS into opt_global.h and remove the
  dependency by opt_kdtrace.h for all files, as now only KDTRACE_FRAMES
  is linked there and it is only used as a compile-time stub [0].

[0] immediately shows some new bug as DTRACE-derived support for debug
in sfxge is broken and it was never really tested.  As it was not
including correctly opt_kdtrace.h before it was never enabled so it
was kept broken for a while.  Fix this by using a protection stub,
leaving sfxge driver authors the responsibility for fixing it
appropriately [1].

Sponsored by:	EMC / Isilon storage division
Discussed with:	rstone
[0] Reported by:	rstone
[1] Discussed with:	philip
2013-11-25 07:38:45 +00:00
gonzo
0875ed61b8 Fix build on ARM (and probably other platforms) 2012-12-28 06:52:53 +00:00
jeff
0a985cfcde - Add new machine parsable KTR macros for timing events.
- Use this new format to automatically handle syscalls and VOPs.  This
   changes the earlier format but is still human readable.

Sponsored by:	EMC / Isilon Storage Division
2012-12-19 20:10:00 +00:00
attilio
7f498fac4a Move the checks for td_pinned, td_critnest, TDP_NOFAULTING and
TDP_NOSLEEPING leaking from syscallret() to userret() so that also
trap handling is covered. Also, the check on td_locks is not duplicated
between the two functions.

Reported by:	avg
Reviewed by:	kib
MFC after:	1 week
2012-09-08 18:35:15 +00:00
jhb
9e9c95ef1d Assert that system calls do not leak a pinned thread (via sched_pin()) to
userland.
2012-08-22 20:02:42 +00:00
kib
7638868334 Assert that TDP_NOFAULTING and TDP_NOSPEEPING thread flags do not leak
when thread returns from a syscall to usermode.

Tested by:	pho
MFC after:	1 week
2012-05-30 13:44:42 +00:00
kib
319ab382ef Add thread-private flag to indicate that error value is already placed
in td_errno. Flag is supposed to be used by syscalls returning
EJUSTRETURN because errno was already placed into the usermode frame
by a call to set_syscall_retval(9). Both ktrace and dtrace get errno
value from td_errno if the flag is set.

Use the flag to fix sigsuspend(2) error return ktrace records.

Requested by:	bde
MFC after:	1 week
2012-04-12 10:48:43 +00:00
kib
0c3998cc9e Currently, the debugger attached to the process executing vfork() does
not get syscall exit notification until the child performed exec of
exit.  Swap the order of doing ptracestop() and waiting for P_PPWAIT
clearing, by postponing the wait into syscallret after ptracestop()
notification is done.

Reported, tested and reviewed by:	Dmitry Mikulin <dmitrym juniper net>
MFC after:	 2 weeks
2012-02-27 21:10:10 +00:00
kib
4658c8a871 The PTRACESTOP() macro is used only once. Inline the only use and remove
the macro.

MFC after:	1 week
2012-02-11 14:49:25 +00:00
kib
e1d70baef7 A debugger which requested PT_FOLLOW_FORK should get the notification
about new child not only when doing PT_TO_SCX, but also for PT_CONTINUE.
If TDB_FORK flag is set, always issue a stop, the same as is done for
TDB_EXEC.

Reported by:	Dmitry Mikulin <dmitrym juniper net>
MFC after:	1 week
2012-01-30 20:00:29 +00:00
marcel
11d8234b97 Revert rev. 226893: subr_syscall.c is being included from C files and
on amd64 with FREEBSD32 enabled, this means that systrace_probe_func
gets defined twice.
2011-10-30 02:19:39 +00:00
marcel
ac13f9cbdb Define systrace_probe_func in subr_syscall.c where it's used, instead
of defining it in MD code. This eliminates porting to other architectures.
2011-10-29 01:26:36 +00:00
kib
f15c4ba986 Do not deliver SIGTRAP on exec as the normal signal, use ptracestop() on
syscall exit path. Otherwise, if SIGTRAP is ignored, that tdsendsignal()
do not want to deliver the signal, and debugger never get a notification
of exec.

Found and tested by:	Anton Yuzhaninov <citrin citrin ru>
Discussed with:	jhb
MFC after:	2 weeks
2011-09-27 13:17:02 +00:00
kib
55d0a85118 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