Commit Graph

53 Commits

Author SHA1 Message Date
Konstantin Belousov
08bfbd4359 rtld: workaround for broken ABI
Right now, libthr does not initialize RtldLockInfo.rtli_version when calling
_rtld_thread_init(), which makes versioning the interface troublesome.

Add a workaround: if the calling object of _rtld_thread_init() exports
the "_pli_rtli_version" symbol, then consider rtli_version initialized.
Otherwise, forcibly set it to RTLI_VERSION_ONE, currently defined as
RTLI_VERSION.

Export "_pli_rtli_version" from libthr and properly initialize rtli_version.

Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D29633
2021-04-10 17:33:33 +03:00
Konstantin Belousov
2ef84b7da9 Add pthread_getname_np() and pthread_setname_np() aliases for
pthread_get_name_np() and pthread_set_name_np().

This re-applies r361770 after compatibility fixes.

Reviewed by:	antoine, jkim, markj
Tested by:	antoine (exp-run)
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D25117
2020-06-10 22:13:24 +00:00
Konstantin Belousov
064c283d65 Revert r361770 "Add pthread_getname_np() and pthread_setname_np() aliases" for now.
It is not compatible enough with Linux.

Requested by:	antoine, jkim
Sponsored by:	The FreeBSD Foundation
2020-06-04 09:06:03 +00:00
Konstantin Belousov
9bed49fea4 Add pthread_getname_np() and pthread_setname_np() aliases
for pthread_get_name_np() and pthread_set_name_np(), to be
compatible with Linux.

PR:	238404
Proposed and reviewed by:	markj
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D25117
2020-06-03 20:54:36 +00:00
Konstantin Belousov
132fb3dc99 Add pthread_peekjoin_np(3).
The function allows to peek at the thread exit status and even see
return value, without joining (and thus finally destroying) the target
thread.

Reviewed by:	markj
Sponsored by:	The FreeBSD Foundation (kib)
MFC after:	2 weeks
Differential revision:	https://reviews.freebsd.org/D23676
2020-02-15 23:25:39 +00:00
Konstantin Belousov
5d00c5a657 Fix initial exec TLS mode for dynamically loaded shared objects.
If dso uses initial exec TLS mode, rtld tries to allocate TLS in
static space. If there is no space left, the dlopen(3) fails. If space
if allocated, initial content from PT_TLS segment is distributed to
all threads' pcbs, which was missed and caused un-initialized TLS
segment for such dso after dlopen(3).

The mode is auto-detected either due to the relocation used, or if the
DF_STATIC_TLS dynamic flag is set.  In the later case, the TLS segment
is tried to allocate earlier, which increases chance of the dlopen(3)
to succeed.  LLD was recently fixed to properly emit the flag, ld.bdf
did it always.

Initial test by:	dumbbell
Tested by:	emaste (amd64), ian (arm)
Tested by:	Gerald Aryeetey <aryeeteygerald_rogers.com> (arm64)
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
Differential revision:	https://reviews.freebsd.org/D19072
2019-03-29 17:52:57 +00:00
Konstantin Belousov
4627d47bc8 Add pthread_get_name_np(3).
The function retrieves the thread name previously set by
pthread_set_name_np(3). The name is cached in the process memory.

Requested by:	Willem Jan Withagen <wjw@digiware.nl>
Man page update:	Yuri Pankov <yuripv@yuripv.net>
Reviewed by:	ian (previous version)
Discussed with:	arichardson, bjk (man page)
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
Differential revision:	https://reviews.freebsd.org/D16702
2018-08-17 18:34:07 +00:00
Konstantin Belousov
2a339d9e3d Add implementation of robust mutexes, hopefully close enough to the
intention of the POSIX IEEE Std 1003.1TM-2008/Cor 1-2013.

A robust mutex is guaranteed to be cleared by the system upon either
thread or process owner termination while the mutex is held.  The next
mutex locker is then notified about inconsistent mutex state and can
execute (or abandon) corrective actions.

The patch mostly consists of small changes here and there, adding
neccessary checks for the inconsistent and abandoned conditions into
existing paths.  Additionally, the thread exit handler was extended to
iterate over the userspace-maintained list of owned robust mutexes,
unlocking and marking as terminated each of them.

The list of owned robust mutexes cannot be maintained atomically
synchronous with the mutex lock state (it is possible in kernel, but
is too expensive).  Instead, for the duration of lock or unlock
operation, the current mutex is remembered in a special slot that is
also checked by the kernel at thread termination.

Kernel must be aware about the per-thread location of the heads of
robust mutex lists and the current active mutex slot.  When a thread
touches a robust mutex for the first time, a new umtx op syscall is
issued which informs about location of lists heads.

The umtx sleep queues for PP and PI mutexes are split between
non-robust and robust.

Somewhat unrelated changes in the patch:
1. Style.
2. The fix for proper tdfind() call use in umtxq_sleep_pi() for shared
   pi mutexes.
3. Removal of the userspace struct pthread_mutex m_owner field.
4. The sysctl kern.ipc.umtx_vnode_persistent is added, which controls
   the lifetime of the shared mutex associated with a vnode' page.

Reviewed by:	jilles (previous version, supposedly the objection was fixed)
Discussed with:	brooks, Martin Simmons <martin@lispworks.com> (some aspects)
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
2016-05-17 09:56:22 +00:00
Konstantin Belousov
bd43f0691c If libthr.so is dlopened without RTLD_GLOBAL flag, the libthr symbols
do not participate in the global symbols namespace, but rtld locks are
still replaced and functions are interposed.  In particular,
__pthread_map_stacks_exec is resolved to the libc version.  If a
library is loaded later, which requires adjustment of the stack
protection mode, rtld calls into libc __pthread_map_stacks_exec due to
the symbols scope.  The libc version might recurse into binder and
recursively acquire rtld bind lock, causing the hang.

Make libc __pthread_map_stacks_exec() interposed, which synchronizes
rtld locks and version of the stack exec hook when libthr loaded,
regardless of the symbol scope control or symbol resolution order.

The __pthread_map_stacks_exec() symbol is removed from the private
version in libthr since libc symbol now operates correctly in presence
of libthr.

Reported and tested by:	markj
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
2016-02-08 19:24:13 +00:00
Konstantin Belousov
8495e8b1e9 Fix known issues which blow up the process after dlopen("libthr.so")
(or loading a dso linked to libthr.so into process which was not
linked against threading library).

- Remove libthr interposers of the libc functions, including
  __error(). Instead, functions calls are indirected through the
  interposing table, similar to how pthread stubs in libc are already
  done.  Libc by default points either to syscall trampolines or to
  existing libc implementations.  On libthr load, libthr rewrites the
  pointers to the cancellable implementations already in libthr.  The
  interposition table is separate from pthreads stubs indirection
  table to not pull pthreads stubs into static binaries.

- Postpone the malloc(3) internal mutexes initialization until libthr
  is loaded.  This avoids recursion between calloc(3) and static
  pthread_mutex_t initialization.

- Reinstall signal handlers with wrapper on libthr load.  The
  _rtld_is_dlopened(3) is used to avoid useless calls to sigaction(2)
  when libthr is statically referenced from the main binary.

In the process, fix openat(2), swapcontext(2) and setcontext(2)
interposing.  The libc symbols were exported at different versions
than libthr interposers.  Export both libc and libthr versions from
libc now, with default set to the higher version from libthr.

Remove unused and disconnected swapcontext(3) userspace implementation
from libc/gen.

No objections from:	deischen
Tested by:	pho, antoine (exp-run) (previous versions)
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2015-01-03 18:38:46 +00:00
Jilles Tjoelker
da7d2afb6d Add accept4() system call.
The accept4() function, compared to accept(), allows setting the new file
descriptor atomically close-on-exec and explicitly controlling the
non-blocking status on the new socket. (Note that the latter point means
that accept() is not equivalent to any form of accept4().)

The linuxulator's accept4 implementation leaves a race window where the new
file descriptor is not close-on-exec because it calls sys_accept(). This
implementation leaves no such race window (by using falloc() flags). The
linuxulator could be fixed and simplified by using the new code.

Like accept(), accept4() is async-signal-safe, a cancellation point and
permitted in capability mode.
2013-05-01 20:10:21 +00:00
Jung-uk Kim
678b238c85 Introduce a non-portable function pthread_getthreadid_np(3) to retrieve
calling thread's unique integral ID, which is similar to AIX function of
the same name.  Bump __FreeBSD_version to note its introduction.

Reviewed by:	kib
2011-02-07 21:26:46 +00:00
Konstantin Belousov
da2fcff746 Implement the __pthread_map_stacks_exec() for libthr.
Stack creation code is changed to call _rtld_get_stack_prot() to get
the stack protection right. There is a race where thread is created
during dlopen() of dso that requires executable stacks. Then,
_rtld_get_stack_prot() may return PROT_READ | PROT_WRITE, but thread
is still not linked into the thread list. In this case, the callback
misses the thread stack, and rechecks the required protection
afterward.

Reviewed by:	davidxu
2011-01-09 12:38:40 +00:00
David Xu
de1e74c6a5 Revert revision 214007, I realized that MySQL wants to resolve
a silly rwlock deadlock problem, the deadlock is caused by writer
waiters, if a thread has already locked a reader lock, and wants to
acquire another reader lock, it will be blocked by writer waiters,
but we had already fixed it years ago.
2010-10-20 02:34:02 +00:00
David Xu
bc15e58058 sort function name. 2010-10-18 05:16:44 +00:00
David Xu
a6b9b59e04 Add pthread_rwlockattr_setkind_np and pthread_rwlockattr_getkind_np, the
functions set or get pthread_rwlock type, current supported types are:
   PTHREAD_RWLOCK_PREFER_READER_NP,
   PTHREAD_RWLOCK_PREFER_WRITER_NONRECURSIVE_NP,
   PTHREAD_RWLOCK_PREFER_WRITER_NP,
default is PTHREAD_RWLOCK_PREFER_WRITER_NONCECURSIVE_NP, this maintains
binary compatible with old code.
2010-10-18 05:09:22 +00:00
David Xu
f4213b9006 To support stack unwinding for cancellation points, add -fexceptions flag
for them, two functions _pthread_cancel_enter and _pthread_cancel_leave
are added to let thread enter and leave a cancellation point, it also
makes it possible that other functions can be cancellation points in
libraries without having to be rewritten in libthr.
2010-09-25 01:57:47 +00:00
David Xu
fa1efe5efd Update symbol. 2010-09-13 09:23:38 +00:00
David Xu
5cf2219535 Add wrapper for setcontext() and swapcontext(), the wrappers
unblock SIGCANCEL which is needed by thread cancellation.
2010-08-24 09:57:06 +00:00
Konstantin Belousov
ea246b6369 On shared object unload, in __cxa_finalize, call and clear all installed
atexit and __cxa_atexit handlers that are either installed by unloaded
dso, or points to the functions provided by the dso.

Use _rtld_addr_phdr to locate segment information from the address of
private variable belonging to the dso, supplied by crtstuff.c. Provide
utility function __elf_phdr_match_addr to do the match of address against
dso executable segment.

Call back into libthr from __cxa_finalize using weak
__pthread_cxa_finalize symbol to remove any atfork handler which
function points into unloaded object.

The rtld needs private __pthread_cxa_finalize symbol to not require
resolution of the weak undefined symbol at initialization time. This
cannot work, since rtld is relocated before sym_zero is set up.

Idea by:	kan
Reviewed by:	kan (previous version)
MFC after:	3 weeks
2010-08-23 15:38:02 +00:00
David Xu
791f7a99e2 Remove extra new semaphore stubs, because libc already has them, and
ld can find the newest version which is default.

Poked by: kan@
2010-01-05 06:21:29 +00:00
David Xu
9b0f1823b5 Use umtx to implement process sharable semaphore, to make this work,
now type sema_t is a structure which can be put in a shared memory area,
and multiple processes can operate it concurrently.
User can either use mmap(MAP_SHARED) + sem_init(pshared=1) or use sem_open()
to initialize a shared semaphore.
Named semaphore uses file system and is located in /tmp directory, and its
file name is prefixed with 'SEMD', so now it is chroot or jail friendly.
In simplist cases, both for named and un-named semaphore, userland code
does not have to enter kernel to reduce/increase semaphore's count.
The semaphore is designed to be crash-safe, it means even if an application
is crashed in the middle of operating semaphore, the semaphore state is
still safely recovered by later use, there is no waiter counter maintained
by userland code.
The main semaphore code is in libc and libthr only has some necessary stubs,
this makes it possible that a non-threaded application can use semaphore
without linking to thread library.
Old semaphore implementation is kept libc to maintain binary compatibility.
The kernel ksem API is no longer used in the new implemenation.

Discussed on: threads@
2010-01-05 02:37:59 +00:00
Jilles Tjoelker
29670497af Make openat(2) a cancellation point.
This is required by POSIX and matches open(2).

Reviewed by:	kib, jhb
MFC after:	1 month
2009-10-11 20:19:45 +00:00
David Xu
83a0758789 Make pthread_cleanup_push() and pthread_cleanup_pop() as a pair of macros,
use stack space to keep cleanup information, this eliminates overhead of
calling malloc() and free() in thread library.

Discussed on: thread@
2008-06-09 01:14:10 +00:00
David Xu
9939a13667 Add POSIX pthread API pthread_getcpuclockid() to get a thread's cpu
time clock id.
2008-03-22 09:59:20 +00:00
David Xu
07bbb16640 Add more cpu affinity function's symbols. 2008-03-05 06:56:35 +00:00
David Xu
57030e1071 Implement functions pthread_getaffinity_np and pthread_setaffinity_np to
get and set thread's cpu affinity mask.
2008-03-03 09:16:29 +00:00
Dag-Erling Smørgrav
47252f4e65 Yet another pointy hat: when I zapped FBSDprivate_1.1, I forgot to move
its contents to FBSDprivate_1.0.
2008-02-06 20:45:46 +00:00
Dag-Erling Smørgrav
a9b9744ff8 Convert pthread.map to the format expected by version_gen.awk, and modify
the Makefile accordingly; libthr now explicitly uses libc's Versions.def.

MFC after:	2 weeks
2008-02-06 20:25:00 +00:00
Dag-Erling Smørgrav
facfc98226 Remove incorrectly added FBSDprivate_1.1 namespace, and move symbols which
are new in FreeBSD 8 to the appropriate namespace.
2008-02-06 20:20:29 +00:00
Dag-Erling Smørgrav
1cbdac2668 Per discussion on -threads, rename _islocked_np() to _isowned_np(). 2008-02-06 19:34:31 +00:00
Dag-Erling Smørgrav
5fd410a787 Add pthread_mutex_islocked_np(), a cheap way to verify that a mutex is
locked.  This is intended primarily to support the userland equivalent
of the various *_ASSERT_LOCKED() macros we have in the kernel.

MFC after:	2 weeks
2008-02-03 22:38:10 +00:00
David Xu
06c8eb55ce Remove vfork() overloading, it is no longer needed. 2007-12-20 04:32:28 +00:00
David Xu
093fcf1694 1. Add function pthread_mutex_setspinloops_np to turn a mutex's spin
loop count.
2. Add function pthread_mutex_setyieldloops_np to turn a mutex's yield
   loop count.
3. Make environment variables PTHREAD_SPINLOOPS and PTHREAD_YIELDLOOPS
   to be only used for turnning PTHREAD_MUTEX_ADAPTIVE_NP mutex.
2007-12-14 06:25:57 +00:00
Jason Evans
e1636e1f97 Add _pthread_mutex_init_calloc_cb() to libthr and libkse, so that malloc(3)
(part of libc) can use pthreads mutexes without causing infinite recursion
during initialization.
2007-11-27 03:16:44 +00:00
Daniel Eischen
00fb440c1a Enable symbol versioning by default. Use WITHOUT_SYMVER to disable it.
Warning, after symbol versioning is enabled, going back is not easy
(use WITHOUT_SYMVER at your own risk).

Change the default thread library to libthr.

There most likely still needs to be a version bump for at least the
thread libraries.  If necessary, this will happen later.
2007-05-13 14:12:40 +00:00
Daniel Eischen
5f864214bb Use C comments since we now preprocess these files with CPP. 2007-04-29 14:05:22 +00:00
David Xu
05c3a5eab4 1. Don't override underscore version of aio_suspend(), system(),
wait(), waitpid() and usleep(), they are internal versions and
   should not be cancellation points.
2. Make wait3() as a cancellation point.
3. Move raise() and pause() into file thr_sig.c.
4. Add functions _sigsuspend, _sigwait, _sigtimedwait and _sigwaitinfo,
   remove SIGCANCEL bit in wait-set for those functions, the signal is
   used internally to implement thread cancellation.
2006-07-25 12:50:05 +00:00
David Xu
e92b415c5a Add symbol versions: FBSD_1.0 and FBSDprivate. 2006-05-11 07:02:52 +00:00
David Xu
37a6356bbe WARNS level 4 cleanup. 2006-04-04 02:57:49 +00:00
David Xu
d3de1dcae7 Remove mqueue and timer, now they are in librt. 2006-03-08 23:47:04 +00:00
David Xu
5131df80a5 1. Add SIGEV_THREAD notification for mq_notify.
2. Reuse current timer code and abstract some common code to
   to support both timer and mqueue.
2006-01-04 11:48:02 +00:00
David Xu
7a65760923 Follow the mistake in libpthread, the first version name in libpthread
is LIBTHREAD_1_0, but really it should be LIBPTHREAD_1_0.
Fix it so libmap.conf works again (it was broken by recent versioning
code in rtld_elf).
2005-12-21 02:34:20 +00:00
David Xu
53bbdf8646 Add code to handle timer_delete(). The timer wrapper code is completely
rewritten, now timers created with same sigev_notify_attributes will
run in same thread, this allows user to organize which timers can
run in same thread to save some thread resource.
2005-11-01 06:53:22 +00:00
David Xu
4a050d016e Add timer_create wrapper. 2005-10-30 03:16:30 +00:00
David Xu
9fc171584d Put pthread_condattr_init sorted order. 2005-10-25 00:09:58 +00:00
David Xu
7dcb6ea4f6 Export following functions:
_pthread_mutexattr_getpshared
	_pthread_mutexattr_setpshared
	pthread_condattr_getpshared
	pthread_condattr_setpshared
	pthread_mutexattr_getpshared
	pthread_mutexattr_setpshared
2005-10-24 05:20:04 +00:00
David Xu
d1f3c70b6e Sort function names. 2005-10-04 08:28:46 +00:00
David Xu
9e49a2370c Add function pthread_timedjoin_np, the function is similar with pthread_join
except the function will return ETIMEDOUT if target thread does not exit
before specified absolute time passes.
2005-10-04 06:15:25 +00:00
Daniel Eischen
2ce2892eaf Add usleep to the map files.
Noticed by:	davidxu
2005-08-03 01:54:52 +00:00