Commit Graph

402 Commits

Author SHA1 Message Date
Konstantin Belousov
a7ca2c6ad0 Ensure that cached struct thread does not keep spurious td_su
reference on an UFS mount point.

Reported and tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2017-06-03 14:12:17 +00:00
Konstantin Belousov
6992112349 Commit the 64-bit inode project.
Extend the ino_t, dev_t, nlink_t types to 64-bit ints.  Modify
struct dirent layout to add d_off, increase the size of d_fileno
to 64-bits, increase the size of d_namlen to 16-bits, and change
the required alignment.  Increase struct statfs f_mntfromname[] and
f_mntonname[] array length MNAMELEN to 1024.

ABI breakage is mitigated by providing compatibility using versioned
symbols, ingenious use of the existing padding in structures, and
by employing other tricks.  Unfortunately, not everything can be
fixed, especially outside the base system.  For instance, third-party
APIs which pass struct stat around are broken in backward and
forward incompatible ways.

Kinfo sysctl MIBs ABI is changed in backward-compatible way, but
there is no general mechanism to handle other sysctl MIBS which
return structures where the layout has changed. It was considered
that the breakage is either in the management interfaces, where we
usually allow ABI slip, or is not important.

Struct xvnode changed layout, no compat shims are provided.

For struct xtty, dev_t tty device member was reduced to uint32_t.
It was decided that keeping ABI compat in this case is more useful
than reporting 64-bit dev_t, for the sake of pstat.

Update note: strictly follow the instructions in UPDATING.  Build
and install the new kernel with COMPAT_FREEBSD11 option enabled,
then reboot, and only then install new world.

Credits: The 64-bit inode project, also known as ino64, started life
many years ago as a project by Gleb Kurtsou (gleb).  Kirk McKusick
(mckusick) then picked up and updated the patch, and acted as a
flag-waver.  Feedback, suggestions, and discussions were carried
by Ed Maste (emaste), John Baldwin (jhb), Jilles Tjoelker (jilles),
and Rick Macklem (rmacklem).  Kris Moore (kris) performed an initial
ports investigation followed by an exp-run by Antoine Brodin (antoine).
Essential and all-embracing testing was done by Peter Holm (pho).
The heavy lifting of coordinating all these efforts and bringing the
project to completion were done by Konstantin Belousov (kib).

Sponsored by:	The FreeBSD Foundation (emaste, kib)
Differential revision:	https://reviews.freebsd.org/D10439
2017-05-23 09:29:05 +00:00
Konstantin Belousov
d1780e8dac Use atop() instead of OFF_TO_IDX() for convertion of addresses or
addresses offsets, as intended.

Suggested and reviewed by:	alc
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
2017-03-14 19:39:17 +00:00
Hans Petter Selasky
316e092a77 Make sure the thread constructor and destructor eventhandlers are
called for all threads belonging to a procedure. Currently the first
thread in a procedure is kept around as an optimisation step and is
never freed. Because the first thread in a procedure is never freed
nor allocated, its destructor and constructor callbacks are never
called which means per thread structures allocated by dtrace and the
Linux emulation layers for example, might be present for threads which
don't need these structures.

This patch adds a thread construction and destruction call for the
first thread in a procedure.

Tested:			dtrace, linux emulation
Reviewed by:		kib @
MFC after:		1 week
Sponsored by:		Mellanox Technologies
2017-02-19 13:15:33 +00:00
Eric van Gyzen
3d32d4a7c9 Export the whole thread name in kinfo_proc
kinfo_proc::ki_tdname is three characters shorter than
thread::td_name.  Add a ki_moretdname field for these three
extra characters.  Add the new field to kinfo_proc32, as well.
Update all in-tree consumers to read the new field and assemble
the full name, except for lldb's HostThreadFreeBSD.cpp, which
I will handle separately.  Bump __FreeBSD_version.

Reviewed by:	kib
MFC after:	1 week
Relnotes:	yes
Sponsored by:	Dell EMC
Differential Revision:	https://reviews.freebsd.org/D8722
2016-12-07 15:04:22 +00:00
Ed Maste
69a2875821 Renumber license clauses in sys/kern to avoid skipping #3 2016-09-15 13:16:20 +00:00
Ed Maste
18c23dffac ANSIfy kern_proc.c and delete register keyword
Reviewed by:	kib
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D6478
2016-07-27 14:27:08 +00:00
Konstantin Belousov
584b675ed6 Hide the boottime and bootimebin globals, provide the getboottime(9)
and getboottimebin(9) KPI. Change consumers of boottime to use the
KPI.  The variables were renamed to avoid shadowing issues with local
variables of the same name.

Issue is that boottime* should be adjusted from tc_windup(), which
requires them to be members of the timehands structure.  As a
preparation, this commit only introduces the interface.

Some uses of boottime were found doubtful, e.g. NLM uses boottime to
identify the system boot instance.  Arguably the identity should not
change on the leap second adjustment, but the commit is about the
timekeeping code and the consumers were kept bug-to-bug compatible.

Tested by:	pho (as part of the bigger patch)
Reviewed by:	jhb (same)
Discussed with:	bde
Sponsored by:	The FreeBSD Foundation
MFC after:	1 month
X-Differential revision:	https://reviews.freebsd.org/D7302
2016-07-27 11:08:59 +00:00
Konstantin Belousov
93ccd6bf87 Get rid of struct proc p_sched and struct thread td_sched pointers.
p_sched is unused.

The struct td_sched is always co-allocated with the struct thread,
except for the thread0.  Avoid useless indirection, instead calculate
td_sched location using simple pointer arithmetic in td_get_sched(9).
For thread0, which is statically allocated, create a structure to
emulate layout of the dynamic allocation.

Reviewed by:	jhb (previous version)
Sponsored by:	The FreeBSD Foundation
Differential revision:	https://reviews.freebsd.org/D6711
2016-06-05 17:04:03 +00:00
Konstantin Belousov
314381b529 Use ANSI function definition.
Sponsored by:	The FreeBSD Foundation
2016-06-05 16:55:55 +00:00
Mark Johnston
11748dae80 Use a loop instead of a goto in sysctl_kern_proc_kstack().
MFC after:	3 days
2016-04-17 23:22:32 +00:00
Konstantin Belousov
ccd0ec4066 The struct thread td_estcpu member is only used by the 4BSD scheduler.
Move it to the struct td_sched for 4BSD, removing always present
field, otherwise unused for ULE.

New scheduler method sched_estcpu() returns the estimation for
kinfo_proc consumption.  As before, it always returns 0 for ULE.

Remove sched_tick() scheduler method, unused both by 4BSD and ULE.

Update locking comment for the 4BSD struct td_sched, copying it from
the same comment for ULE.

Spell MAXPRI as PRI_MAX_TIMESHARE in the 4BSD comment.

Based on some notes from, and reviewed by:	bde
Sponsored by:	The FreeBSD Foundation
2016-04-17 11:04:27 +00:00
Pedro F. Giffuni
b85f65af68 kern: for pointers replace 0 with NULL.
These are mostly cosmetical, no functional change.

Found with devel/coccinelle.
2016-04-15 16:10:11 +00:00
Konstantin Belousov
db57c70a5b Rename P_KTHREAD struct proc p_flag to P_KPROC.
I left as is an apparent bug in ntoskrnl_var.h:AT_PASSIVE_LEVEL()
definition.

Suggested by:	jhb
Sponsored by:	The FreeBSD Foundation
2016-02-09 16:30:16 +00:00
Konstantin Belousov
2dab579bfc Remove the assert which outlived its usefulness, and, by default,
disable compilation of the code which made it possible to call
stop_all_proc() from usermode at all.

Move the comment to the preamble of stop_all_proc() and reword it to
give overview of the function intent.

proc0 has P_HADTHREADS flag set due to kthread_add(), but no
P_KTHREAD, which triggered the assert, which does not serve a purpose
now.

Reported by:	Oliver Pinter
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
2016-02-08 10:54:27 +00:00
Mateusz Guzik
17182b1351 session: avoid proctree lock on proc exit when possible
We can get away with the common case with only proc lock held.

Reviewed by:	kib
2016-01-20 23:33:58 +00:00
Mateusz Guzik
6760182c5d session: tidy up fixjobc
This stops abusing the 'p' pointer for iteration over children processes
and gets rid of useless locking around PRS_ZOMBIE check.

Suggested by:	kib
2016-01-20 23:22:36 +00:00
Mateusz Guzik
aa0241d623 proc: fix a race which could result in dereference of bad p_pgrp pointer on fork
During fork p_starcopy - p_endcopy area of a process is populated with bcopy
with only proc lock held. Another forking thread can find such a process and
proceed to access p_pgrp included in said area.

Fix the problem by moving the field outside. It is being properly assigned
later.

Reviewed by:	kib
Diagnosed by:	kib
Tested by:	Fabian Keil <freebsd-listen fabiankeil.de>
MFC after:	10 days
2015-12-18 16:33:15 +00:00
Mark Johnston
3616095801 Fix style issues around existing SDT probes.
- Use SDT_PROBE<N>() instead of SDT_PROBE(). This has no functional effect
  at the moment, but will be needed for some future changes.
- Don't hardcode the module component of the probe identifier. This is
  set automatically by the SDT framework.

MFC after:	1 week
2015-12-16 23:39:27 +00:00
Mark Johnston
711fbd17ec Add helper functions proc_readmem() and proc_writemem().
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
2015-12-07 21:33:15 +00:00
John Baldwin
645743ea99 Export various helper variables describing the layout and size of
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
2015-11-12 22:00:59 +00:00
Conrad Meyer
e6b95927f3 Fix core corruption caused by race in note_procstat_vmmap
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
2015-10-06 18:07:00 +00:00
Andriy Gapon
2f2f522b5d save some bytes by using more concise SDT_PROBE<n> instead of SDT_PROBE
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
2015-09-28 12:14:16 +00:00
John Baldwin
4295bec16a When a process group leader exits, all of the processes in the group are
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
2015-09-16 16:40:07 +00:00
Mark Johnston
610141cebb Add stack_save_td_running(), a function to trace the kernel stack of a
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
2015-09-11 03:54:37 +00:00
Konstantin Belousov
b4490c6e93 The si_status field of the siginfo_t, provided by the waitid(2) and
SIGCHLD signal, should keep full 32 bits of the status passed to the
_exit(2).

Split the combined p_xstat of the struct proc into the separate exit
status p_xexit for normal process exit, and signalled termination
information p_xsig.  Kernel-visible macro KW_EXITCODE() reconstructs
old p_xstat from p_xexit and p_xsig.  p_xexit contains complete status
and copied out into si_status.

Requested by:	Joerg Schilling
Reviewed by:	jilles (previous version), pho
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
2015-07-18 09:02:50 +00:00
Mateusz Guzik
f6f6d24062 Implement lockless resource limits.
Use the same scheme implemented to manage credentials.

Code needing to look at process's credentials (as opposed to thred's) is
provided with *_proc variants of relevant functions.

Places which possibly had to take the proc lock anyway still use the proc
pointer to access limits.
2015-06-10 10:48:12 +00:00
Eric van Gyzen
63e4c6cdf9 Provide vnode in memory map info for files on tmpfs
When providing memory map information to userland, populate the vnode pointer
for tmpfs files.  Set the memory mapping to appear as a vnode type, to match
FreeBSD 9 behavior.

This fixes the use of tmpfs files with the dtrace pid provider,
procstat -v, procfs, linprocfs, pmc (pmcstat), and ptrace (PT_VM_ENTRY).

Submitted by:   Eric Badger <eric@badgerio.us> (initial revision)
Obtained from:  Dell Inc.
PR:             198431
MFC after:      2 weeks
Reviewed by:    jhb
Approved by:    kib (mentor)
2015-06-02 18:37:04 +00:00
Edward Tomasz Napierala
aa32b5e076 Make setproctitle(3) work in Capsicum capability mode. This makes
ctld(8) child processes to indicate initiator address and name in
their titles, similar to what iscsid(8) child processes do.

PR:		181352
Differential Revision:	https://reviews.freebsd.org/D2363
Reviewed by:	rwatson@, mjg@
MFC after:	1 month
Sponsored by:	The FreeBSD Foundation
2015-04-27 11:18:16 +00:00
Ian Lepore
296f235de0 The sysctls that return process argv and envv return binary data, so clear
the SBUF_INCLUDENUL flag.

Pointed out by:	    tijl@
2015-03-22 21:18:44 +00:00
Mateusz Guzik
f97af9706b proc: use MTX_NEW flag in proc_init
This allows us to get rid of bzero which was added specifically to make
mtx_init on p_mtx reliable.

This also fixes a potential problem where mtx_init on other mutexes
could trip over on unitialized memory and fire an assertion.

Reviewed by:	kib
2015-03-21 20:25:34 +00:00
Ian Lepore
1eafc07856 Set the SBUF_INCLUDENUL flag in sbuf_new_for_sysctl() so that sysctl
strings returned to userland include the nulterm byte.

Some uses of sbuf_new_for_sysctl() write binary data rather than strings;
clear the SBUF_INCLUDENUL flag after calling sbuf_new_for_sysctl() in
those cases.  (Note that the sbuf code still automatically adds a nulterm
byte in sbuf_finish(), but since it's not included in the length it won't
get copied to userland along with the binary data.)

Remove explicit adding of a nulterm byte in a couple places now that it
gets done automatically by the sbuf drain code.

PR:		195668
2015-03-14 17:08:28 +00:00
Konstantin Belousov
83d7eb544c Fix gcc build.
Sponsored by:	The FreeBSD Foundation
MFC after:	13 days
2014-12-14 08:43:13 +00:00
Konstantin Belousov
6ddcc23386 Add facility to stop all userspace processes. The supposed use of the
feature is to quisce the system before suspend.

Stop is implemented by reusing the thread_single(9) with the special
mode SINGLE_ALLPROC.  SINGLE_ALLPROC differs from the existing
single-threading modes by allowing (requiring) caller to operate on
other process.  Interruptible sleeps for !TDF_SBDRY threads are
suspended like SIGSTOP does it, instead of aborting the sleep, like
SINGLE_NO_EXIT, to avoid spurious EINTRs on resume.

Provide debugging sysctl debug.stop_all_proc, which causes total stop
and suspends syncer, while waiting for variable reset for resume.  It
is used for debugging; should be removed after the real use of the
interface is added.

In collaboration with:	pho
Discussed with:	avg
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
2014-12-13 16:18:29 +00:00
Konstantin Belousov
6afb32fc67 Disable recursion for the process spinlock.
Tested by:	pho
Discussed with:	jhb
Sponsored by:	The FreeBSD Foundation
MFC after:	1 month
2014-12-01 17:36:10 +00:00
Konstantin Belousov
5c7bebf961 The process spin lock currently has the following distinct uses:
- Threads lifetime cycle, in particular, counting of the threads in
  the process, and interlocking with process mutex and thread lock.
  The main reason of this is that turnstile locks are after thread
  locks, so you e.g. cannot unlock blockable mutex (think process
  mutex) while owning thread lock.

- Virtual and profiling itimers, since the timers activation is done
  from the clock interrupt context.  Replace the p_slock by p_itimmtx
  and PROC_ITIMLOCK().

- Profiling code (profil(2)), for similar reason.  Replace the p_slock
  by p_profmtx and PROC_PROFLOCK().

- Resource usage accounting.  Need for the spinlock there is subtle,
  my understanding is that spinlock blocks context switching for the
  current thread, which prevents td_runtime and similar fields from
  changing (updates are done at the mi_switch()).  Replace the p_slock
  by p_statmtx and PROC_STATLOCK().

The split is done mostly for code clarity, and should not affect
scalability.

Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2014-11-26 14:10:00 +00:00
Adrian Chadd
e77f9fed15 Update the ULE scheduler + thread and kinfo structs to use int for cpuid
rather than u_char.

To try and play nice with the ABI, the u_char CPU ID values are clamped
at 254.  The new fields now contain the full CPU ID, or -1 for no cpu.

Differential Revision:	D955
Reviewed by:	jhb, kib
Sponsored by:	Norse Corp, Inc.
2014-10-18 19:36:11 +00:00
Konstantin Belousov
57c2505e65 On error, sbuf_bcat() returns -1. Some callers returned this -1 to
the upper layers, which interpret it as errno value, which happens to
be ERESTART.  The result was spurious restarts of the sysctls in loop,
e.g. kern.proc.proc, instead of returning ENOMEM to caller.

Convert -1 from sbuf_bcat() to ENOMEM, when returning to the callers
expecting errno.

In collaboration with:	pho
Sponsored by:	The FreeBSD Foundation (kib)
MFC after:	1 week
2014-10-05 17:35:59 +00:00
Mateusz Guzik
2570cdd605 Plug a hypothetical use after free in sysctl kern.proc.groups.
MFC after:	1 week
2014-09-04 01:21:33 +00:00
Gleb Smirnoff
5b5477d762 Fix dereference after NULL check.
CID:		1234607
Sponsored by:	Nginx, Inc.
2014-09-03 08:14:07 +00:00
Mateusz Guzik
8b04bbef31 Return real parent pid in kinfo (used by e.g. ps)
Add a separate field which exports tracer pid and add a new keyword
("tracer") for ps to display it.

This is a follow up to r270444.

Reviewed by:	kib
MFC after:	1 week
Relnotes:	yes
2014-08-28 08:41:11 +00:00
Konstantin Belousov
d735998057 Correct the problems with the ptrace(2) making the debuggee an orphan.
One problem is inferior(9) looping due to the process tree becoming a
graph instead of tree if the parent is traced by child. Another issue
is due to the use of p_oppid to restore the original parent/child
relationship, because real parent could already exited and its pid
reused (noted by mjg).

Add the function proc_realparent(9), which calculates the parent for
given process. It uses the flag P_TREE_FIRST_ORPHAN to detect the head
element of the p_orphan list and than stepping back to its container
to find the parent process. If the parent has already exited, the
init(8) is returned.

Move the P_ORPHAN and the new helper flag from the p_flag* to new
p_treeflag field of struct proc, which is protected by proctree lock
instead of proc lock, since the orphans relationship is managed under
the proctree_lock already.

The remaining uses of p_oppid in ptrace(PT_DETACH) and process
reapping are replaced by proc_realparent(9).

Phabric:	D417
Reviewed by:	jhb
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
2014-08-07 05:47:53 +00:00
Konstantin Belousov
d3a3b8b038 Simplify the expression, by removing redundand calculation.
Noted by:	"O'Connor, Daniel" <Daniel.O'Connor@emc.com>
MFC after:	3 days
2014-07-29 01:46:31 +00:00
Konstantin Belousov
a62eb1398a Followup to r268466.
- Move the code to calculate resident count into separate function.
  It reduces the indent level and makes the operation of
  vmmap_skip_res_cnt tunable more clear.
- Optimize the calculation of the resident page count for map entry.
  Skip directly to the next lowest available index and page among the
  whole shadow chain.
- Restore the use of pmap_incore(9), only to verify that current
  mapping is indeed superpage.
- Note the issue with the invalid pages.

Suggested and reviewed by:	alc
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2014-07-15 19:57:03 +00:00
Konstantin Belousov
3760e341ca Change the calculation of the kinfo_vmentry field kve_private_resident
to reflect its name.

Noted and reviewed by:	alc
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2014-07-15 19:49:00 +00:00
Konstantin Belousov
479fcb4e32 Unconditionally initialize addr to handle the case of changed map
timestamp while the map is unlocked.

Reported by:	bz
Sponsored by:	The FreeBSD Foundation
MFC after:	6 days
2014-07-10 11:20:24 +00:00
Konstantin Belousov
a91831a261 Current code in sysctl proc.vmmap, which intent is to calculate the
amount of resident pages, in fact calculates the amount of installed
pte entries in the region.  Resident pages which were not soft-faulted
yet are not counted.

Calculate the amount of resident pages by looking in the objects chain
backing the region.

Add a knob to disable the residency calculation at all.  For large
sparce regions, either previous or updated algorithm runs for too long
time, while several introspection tools do not need the (advisory) RSS
value at all.

PR:	kern/188911
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2014-07-09 19:11:57 +00:00
John Baldwin
2db08c03f0 Expose OBJT_MGTDEVICE VM objects used for GEM/TTM with drm2 as an
explicit object type.

Reviewed by:	kib
MFC after:	1 week
2014-02-11 21:57:37 +00:00
Konstantin Belousov
80c3af4e80 Add an kinfo sysctl to retrieve signal trampoline location for the
given process.

Note that the correctness of the trampoline length returned for ABIs
which do not use shared page depends on the correctness of the struct
sysvec sv_szsigcodebase member, which will be fixed on as-need basis.

Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2013-11-26 19:47:09 +00:00
Andriy Gapon
d9fae5ab88 dtrace sdt: remove the ugly sname parameter of SDT_PROBE_DEFINE
In its stead use the Solaris / illumos approach of emulating '-' (dash)
in probe names with '__' (two consecutive underscores).

Reviewed by:	markj
MFC after:	3 weeks
2013-11-26 08:46:27 +00:00