Commit graph

597 commits

Author SHA1 Message Date
Konstantin Belousov 412ef5da8a libc: Add pthread_attr_get_np(3) stub, reporting ESRCH.
This seems to be required by recent clang asan.
I do not see other way than put the symbol under FBSD_1.0 version.

PR:	251112
Reported by:	Andrew Stitcher <astitcher@apache.org>
Reviewed by:	emaste
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D27389
2020-11-28 12:19:20 +00:00
Konstantin Belousov 20b8e1a25c Style.
Sponsored by:	The FreeBSD Foundation
MFC after: 3 days
2020-11-26 20:23:17 +00:00
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 751fae1eff Return success, instead of ESRCH, from pthread_cancel(3) applied to the
exited but not yet joined thread.

Before, if the thread exited but was not yet joined, we returned
ESRCH.

According to IEEE Std 1003.1™-2017 recommendation in the
description of pthread_cancel(3):
  If an implementation detects use of a thread ID after the end of its
  lifetime, it is recommended that the function should fail and report
  an [ESRCH] error.
So it seems desirable to not return ESRCH until the lifetime of the
thread ID ends.  According to the section 2.9.2 Thread IDs,
  The lifetime of a thread ID ends after the thread terminates if it
  was created with the detachstate attribute set to
  PTHREAD_CREATE_DETACHED or if pthread_detach() or pthread_join()
  has been called for that thread.
In other words, lifetime for thread ID of exited but not yet joined thread
did not ended yet.

Prompted by:	cperciva
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2020-02-13 23:22:12 +00:00
Konstantin Belousov fc908e5001 Use sigfastblock(2) for masking signals in libthr.
Ensure proper handshake to transfer sigfastblock(2) blocking word
ownership from rtld to libthr.

Unfortunately sigfastblock(2) is not enough to stop intercepting
signals in libthr, because critical sections must ensure more than
just signal blocking.

Tested by:	pho
Disscussed with:	cem, emaste, jilles
Sponsored by:	The FreeBSD Foundation
Differential revision:	https://reviews.freebsd.org/D12773
2020-02-09 12:27:22 +00:00
Konstantin Belousov f9bf9282c9 Fix destruction of the robust mutexes.
If robust mutex' owner terminated, causing kernel-assisted state
recovery, and then pthread_mutex_destroy() is executed as the next
action, assert is triggered about mutex still being on the list.
Ignore the mutex linkage in pthread_mutex_destroy() for shared robust
mutexes with dead owner, same as for enqueue_mutex().

Reported by:	avg
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2019-09-23 13:24:31 +00:00
Konstantin Belousov 65174f684c Fix _pthread_cancel_enter() and _pthread_cancel_leave() jmptable entries.
PR:	240022
Reported by:	Andrew Gierth <andrew@tao11.riddles.org.uk>
Sponsored by:	The FreeBSD Foundation
MFC after:	3 days
2019-08-21 19:53:50 +00:00
Konstantin Belousov 3638455c92 Avoid conflicts with libc symbols in libthr jump table.
In some corner cases of static linking and unexpected libraries order
on the linker command line, libc symbol might preempt the same libthr
symbol, in which case libthr jump table points back to libc causing
either infinite recursion or loop.  Handle all of such symbols by
using private libthr names for them, ensuring that the right pointers
are installed into the table.

In collaboration with: arichardson
PR:	239475
Tested by:	pho
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
Differential revision:	https://reviews.freebsd.org/D21088
2019-07-31 20:04:39 +00:00
Konstantin Belousov 0ab1bfc7b2 Avoid conflicts with libc symbols in libthr jump table.
In some corner cases of static linking and unexpected libraries order
on the linker command line, libc symbol might preempt the same libthr
symbol, in which case libthr jump table points back to libc causing
either infinite recursion or loop.  Handle all of such symbols by
using private libthr names for them, ensuring that the right pointers
are installed into the table.

In collaboration with: arichardson
PR:	239475
Tested by:	pho
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
Differential revision:	https://reviews.freebsd.org/D21088
2019-07-31 19:27:20 +00:00
Konstantin Belousov 3212ada519 Restore ability to pass NULL name argument to pthread_set_name_np(3)
to clear the thread name.

PR:	239142
Submitted by:	Lewis Donzis <lew@perftech.com>
MFC after:	3 days
2019-07-11 16:19:33 +00:00
Konstantin Belousov 2d8c3eeb12 Add libc stub for pthread_getthreadid_np(3).
Requested by:	jbeich
PR:	238650
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2019-06-23 10:50:26 +00:00
Konstantin Belousov b8f75b175c Do not access mutex memory after unlock.
PR:	237195
Reported by:	freebsd@hurrikhan.eu
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2019-04-12 17:27:19 +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
Mark Johnston b16150ea90 Have pthread_cond_destroy() return EBUSY if the condvar has waiters.
This is not required of a compliant implementation, but it's easy to
check for and helps improve compatibility with other common
implementations.  Moreover, it's consistent with our
pthread_mutex_destroy().

PR:		234805
Reviewed by:	jhb, kib, ngie
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D19496
2019-03-08 21:07:08 +00:00
Konstantin Belousov e4314da2e4 Fixes for very early use of the pthread_mutex_* and libthr malloc.
When libthr is statically linked into the binary, order of the
constructors execution is not deterministic.  It is possible for the
application constructor to use pthread_mutex_* functions before the
libthr initialization was done.

Handle it by:
- making thr_malloc.c locking functions operational when curthread is not
  yet set;
- making __thr_malloc_init() idempotent, allowing more than one call to it;
- unconditionally calling __thr_malloc_init() before initializing
  a process-private mutex.

Reported and tested by:	mmel
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2019-02-04 21:16:15 +00:00
Konstantin Belousov 381c2d2e9a Untangle jemalloc and mutexes initialization.
The need to use libc malloc(3) from some places in libthr always
caused issues.  For instance, per-thread key allocation was switched to
use plain mmap(2) to get storage, because some third party mallocs
used keys for implementation of calloc(3).

Even more important, libthr calls calloc(3) during initialization of
pthread mutexes, and jemalloc uses pthread mutexes.  Jemalloc provides
some way to both postpone the initialization, and to make
initialization to use specialized allocator, but this is very fragile
and often breaks.  See the referenced PR for another example.

Add the small malloc implementation used by rtld, to libthr. Use it in
thr_spec.c and for mutexes initialization. This avoids the issues with
mutual dependencies between malloc and libthr in principle.  The
drawback is that some more allocations are not interceptable for
alternate malloc implementations.  There should be not too much memory
use from this allocator, and the alternative, direct use of mmap(2) is
obviously worse.

PR:	235211
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
Differential revision:	https://reviews.freebsd.org/D18988
2019-01-29 22:46:44 +00:00
Brooks Davis 52af996782 Remove declarations of syscalls not used in libthr.
Reviewed by:	kib
Sponsored by:	DARPA, AFRL
2018-12-03 22:09:23 +00:00
Eric van Gyzen dbb1c64e82 Use _thr_isthreaded() and _thr_setthreaded() wrappers
...instead of directly using the global variable.

MFC after:	2 weeks
Sponsored by:	Dell EMC Isilon
2018-11-30 03:02:49 +00:00
Eric van Gyzen ad8c236b28 _thr_setthreaded() cannot fail; change return type to void
Also remove logic to avoid unnecessary stores to the global variable.
Thread creation and destruction are heavy enough that any supposed savings
is in the noise.

MFC after:	2 weeks
Sponsored by:	Dell EMC Isilon
2018-11-30 03:01:32 +00:00
Edward Tomasz Napierala a4f02d5d6d Make libthr(3) use sysconf(_SC_NPROCESSORS_CONF); this shaves off
two calls to sysctl(2) from the binary startup.

Reviewed by:	kib
MFC after:	2 weeks
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D18046
2018-11-19 18:24:08 +00:00
Pedro F. Giffuni ab82c6bdad libthr: minor spacing cleanup.
No functional change.

X-MFC with:	r337992
2018-08-21 01:33:25 +00:00
Pedro F. Giffuni b6413b6db8 POSIX compliance improvements in the pthread(3) functions.
This basically adds makes use of the C99 restrict keyword, and also
adds some 'const's to four threading functions: pthread_mutexattr_gettype(),
pthread_mutexattr_getprioceiling(), pthread_mutexattr_getprotocol(), and
pthread_mutex_getprioceiling. The changes are in accordance to POSIX/SUSv4-2018.

Hinted by:	DragonFlyBSD

Relnotes:	yes
MFC after:	1 month
Differential Revision:	D16722
2018-08-18 01:05:38 +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
John Baldwin dc3566067a Ensure thread library is initialized in pthread_testcancel().
Call _thr_check_init() before reading curthread in pthread_testcancel().

If a constructor in a library creates a semaphore via sem_init() and
then waits for it via sem_wait(), the program can core dump in
_pthread_testcancel() called from sem_wait().  This is because the
semaphore implementation lives in libc, so the library's constructors
can be run before libthr's constructors.

Reported by:	arichardson
Reviewed by:	kib
Obtained from:	CheriBSD
MFC after:	1 week
Sponsored by:	DARPA / AFRL
Differential Revision:	https://reviews.freebsd.org/D14786
2018-03-21 21:13:26 +00:00
Pedro F. Giffuni b9b20abf2b libthr: Fix missing break in switch.
This is also a warning in recent GCC with -Wimplicit-fallthrough.

CID:	1356262
Obtained from:	DragonFly (git 0f037c78 - partial)
2018-01-27 22:27:55 +00:00
Pedro F. Giffuni 5e53a4f90f lib: further adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using mis-identified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
2017-11-26 02:00:33 +00:00
Pedro F. Giffuni 8a16b7a18f General further adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 3-Clause license.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.
2017-11-20 19:49:47 +00:00
Pedro F. Giffuni df57947f08 spdx: initial adoption of licensing ID tags.
The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.

Initially, only tag files that use BSD 4-Clause "Original" license.

RelNotes:	yes
Differential Revision:	https://reviews.freebsd.org/D13133
2017-11-18 14:26:50 +00:00
Michael Zhilin 37a6f46190 [libthr] revert change of visibility of _thread_keytable to unbreak debugger
Fix regression by r318539. The sysutils/pstack uses library libthread_db to
read information about threads state. The function pt_ta_new makes lookup of
several key symbols including _thread_keytable. But r318539 mades this field
static. It causes silent ignore of libthr library by pstack and as result
sysutils/pstack doesn't output any thread information.

This fix changes this field back to non-static.

MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D11738
2017-10-02 20:33:16 +00:00
Pedro F. Giffuni 1c9158aabe libthr: check for possible overflow in the pthread_barrier_init() count.
Following up on r320900, where the check for negative count values was
removed, add a check to prevent integer overflow. This is to account that
b_count, b_waiters but most importantly the total number of threads in
the system are signed values.

Discussed with:	kib
MFC after:	2 weeks
2017-07-15 15:00:13 +00:00
Pedro F. Giffuni 97c3a994e4 libthr: 'count' is unsigned so don't check for negative values.
Obtained from:	DragonFlyBSD (git e7db8139)
2017-07-14 16:05:54 +00:00
Eric van Gyzen 718fb5ba5b libthr: fix warnings at WARNS=6
Fix more warnings about redundant declarations.

Reviewed by:	kib emaste
MFC after:	3 days
Sponsored by:	Dell EMC
Differential Revision:	https://reviews.freebsd.org/D10932
2017-05-26 15:56:28 +00:00
Eric van Gyzen 01618b339f libthr: fix style in previous commit
I intended to add this to the previous commit.

Reviewed by:	kib
MFC after:	3 days
Sponsored by:	Dell EMC
2017-05-26 15:53:27 +00:00
Eric van Gyzen d25183e0a7 libthr: prevent setcontext() from masking SIGTHR
__thr_setcontext() mistakenly tested for the presence of SIGCANCEL
in its local ucontext_t instead of the parameter. Therefore,
if a thread calls setcontext() with a context whose signal mask
contains SIGTHR (a.k.a. SIGCANCEL), that signal will be blocked,
preventing the thread from being cancelled or suspended.

Reported by:	gcc 6.1 via RISC-V tinderbox
Reviewed by:	kib
MFC after:	3 days
Sponsored by:	Dell EMC
Differential Revision:	https://reviews.freebsd.org/D10933
2017-05-26 15:51:51 +00:00
Eric van Gyzen 5a6d7b723f libthr: fix warnings from GCC when WARNS=6
Fix warnings about:
- redundant declarations
- a local variable shadowing a global function (dlinfo)
- an old-style function definition (with an empty parameter list)
- a variable that is possibly used uninitialized

"make tinderbox" passes this time, except for a few unrelated
kernel failures.

Reviewed by:	kib
MFC after:	3 days
Sponsored by:	Dell EMC
Differential Revision:	https://reviews.freebsd.org/D10870
2017-05-23 16:12:50 +00:00
Eric van Gyzen 0b2f3f2058 libthr: Use CLI flags instead of pragmas to disable warnings
People tweaking the build system or compilers tend to look into
the Makefile and not into the source.  Having some warning controls
in the Makefile and some in the source code is surprising.

Pragmas have the advantage that they leave the warnings enabled
for more code, but that advantage isn't very relevant in these cases.

Requested by:	kib
Reviewed by:	kib
MFC after:	3 days
Sponsored by:	Dell EMC
Differential Revision:	https://reviews.freebsd.org/D10832
2017-05-20 17:33:47 +00:00
Eric van Gyzen 07f29d9f76 Remove old spinlock_debug code from libc
This no longer seems useful.  Remove it.

This was prompted by a "cast discards volatile qualifier" warning
in libthr when WARNS=6.

Reviewed by:	kib
MFC after:	3 days
Sponsored by:	Dell EMC
Differential Revision:	https://reviews.freebsd.org/D10832
2017-05-20 17:32:01 +00:00
Eric van Gyzen 048ad6aedc libthr: change CHECK_AND_INIT_RWLOCK to an inline function
This was prompted by a compiler warning about 'ret' shadowing
a local variable in the callers of the macro.

Reviewed by:	kib
MFC after:	3 days
Sponsored by:	Dell EMC
Differential Revision:	https://reviews.freebsd.org/D10832
2017-05-20 17:30:48 +00:00
Eric van Gyzen d2335a57f4 libthr: fix warnings at WARNS=6
Fix warnings about the following when WARNS=6 (which I will commit soon):

- casting away const
- no previous 'extern' declaration for non-static variable
- others as explained by #pragmas and comments
- unused parameters

The last is the only functional change.

Reviewed by:	kib
MFC after:	3 days
Sponsored by:	Dell EMC
Differential Revision:	https://reviews.freebsd.org/D10808
2017-05-19 13:04:05 +00:00
Jason Evans c45e7190ab Fix __pthread_mutex_trylock() to call THR_CRITICAL_LEAVE() on failure rather
than on success.  This regression was introduced by r300043 (Add implementation
of robust mutexes...).

MFC after:	1 day
2017-05-13 17:49:53 +00:00
Eric van Gyzen 3f8455b090 Add clock_nanosleep()
Add a clock_nanosleep() syscall, as specified by POSIX.
Make nanosleep() a wrapper around it.

Attach the clock_nanosleep test from NetBSD. Adjust it for the
FreeBSD behavior of updating rmtp only when interrupted by a signal.
I believe this to be POSIX-compliant, since POSIX mentions the rmtp
parameter only in the paragraph about EINTR. This is also what
Linux does. (NetBSD updates rmtp unconditionally.)

Copy the whole nanosleep.2 man page from NetBSD because it is complete
and closely resembles the POSIX description. Edit, polish, and reword it
a bit, being sure to keep any relevant text from the FreeBSD page.

Reviewed by:	kib, ngie, jilles
MFC after:	3 weeks
Relnotes:	yes
Sponsored by:	Dell EMC
Differential Revision:	https://reviews.freebsd.org/D10020
2017-03-19 00:51:12 +00:00
Pedro F. Giffuni 649702c5a3 Make use of clang nullability attributes.
Replace uses of the GCC __nonnull__ attribute with the clang nullability
qualifiers. The replacement should be transparent for clang developers as
the new qualifiers will produce the same warnings and will be useful for
static checkers but will not cause aggressive optimizations.

GCC will not produce such warnings and developers will have to use
upgraded GCC ports built with the system headers from r312538.

Hinted by:	Apple's Libc-1158.20.4, Bionic libc
MFC after:	11.1 Release

Differential Revision:	https://reviews.freebsd.org/D9004
2017-01-28 20:54:43 +00:00
Ed Maste 2d0e733b3a libthr: coalesce repeated #if blocks 2017-01-25 20:19:48 +00:00
Konstantin Belousov 4dafad49c6 Do not leak curthread->inact_mtx when cancelling in pthread_cond_wait(3).
Leave robust-protected region before checking for cancellation by
calling _thr_testcancel().  Otherwise, if cancelling request was
pending, the cancel handler is called with the dandling inact_mtx,
which triggers an assert if any mutex operation is performed by the
handler.

Reported and tested by:	Dimitri Staessens <dimitri.staessens@intec.ugent.be>
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2016-12-06 17:13:17 +00:00
Konstantin Belousov 1c1cc89580 The fdatasync(2) call must be cancellation point.
Sponsored by:	The FreeBSD Foundation
MFC after:	13 days
2016-08-16 08:27:03 +00:00
Konstantin Belousov b585cd3e2c Add __cxa_thread_atexit(3) API implementation.
This is the backing feature to implement C++11 thread storage duration
specified by the thread_local keyword.  A destructor for given
thread-local object is registered to be executed at the thread
termination time using __cxa_thread_atexit().  Libc calls the
__cxa_thread_calls_dtors() during exit(3), before finalizers and
atexit functions, and libthr calls the function at the thread
termination time, after the stack unwinding and thread-specific key
destruction.

There are several uncertainties in the API which lacks a formal
specification.  Among them:
- is it allowed to register destructors during destructing;
	we allow, but limiting the nesting level.  If too many iterations
	detected, a diagnostic is issued to stderr and thread forcibly
	terminates for now.
- how to handle destructors which belong to an unloading dso;
	for now, we ignore destructor calls for such entries, and
	issue a diagnostic.  Linux does prevent dso unload until all
	threads with destructors from the dso terminated.
It is supposed that the diagnostics allow to detect real-world
applications relying on the above details and possibly adjust
our implementation.  Right now the choices were to provide the slim
API (but that rarely stands the practice test).

Tests are added to check generic functionality and to specify some of
the above implementation choices.

Submitted by:	Mahdi Mokhtari <mokhi64_gmail.com>
Reviewed by:	theraven
Discussed with:	dim (detection of -std=c++11 supoort for tests)
Sponsored by:	The FreeBSD Foundation (my involvement)
MFC after:	2 weeks
Differential revisions:	https://reviews.freebsd.org/D7224,
    https://reviews.freebsd.org/D7427
2016-08-06 13:32:40 +00:00
Konstantin Belousov bf890e4877 Remove empty initializer for the once facility. It was not needed
since r179417.

Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2016-07-27 15:14:11 +00:00
Konstantin Belousov 4edfc1e3bf Revert r302194, there are issues with some applications after changing
the return value, in particular console-kit-daemon.

Reported by:	Ivan Klymenko <fidaj@ukr.net>
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
Approved by:	re (gjb)
2016-06-25 20:20:24 +00:00
Konstantin Belousov a068480247 For pthread_mutex_trylock() call on owned error-check or non-portable
adaptive mutex, return EDEADLK as required by POSIX.  The
pthread_mutex_lock() is already compliant.

Tested by:	Guy Yur <guyyur@gmail.com>
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
Approved by:	re (gjb)
2016-06-25 11:30:40 +00:00
Conrad Meyer c72ef5eab3 libthr: Use formatted PANIC()
No functional change, although _thread_printf() may be slightly less functional
or render some values differently from libc snprintf(3).  No ABI change.

Reviewed by:	kib
Sponsored by:	EMC / Isilon Storage Division
Differential Revision:	https://reviews.freebsd.org/D6672
2016-06-01 16:12:26 +00:00
Conrad Meyer a3c0056121 libthr: _thread_vprintf: Enhance support for %p, %#x
No functional change.  No ABI change.

Reviewed by:	kib
Sponsored by:	EMC / Isilon Storage Division
Differential Revision:	https://reviews.freebsd.org/D6672
2016-06-01 16:11:09 +00:00
Conrad Meyer 3a7d122f96 libthr: Add vprintf variant of _thread_printf, formatted PANIC()
No ABI change.

Reviewed by:	kib
Sponsored by:	EMC / Isilon Storage Division
Differential Revision:	https://reviews.freebsd.org/D6672
2016-06-01 16:09:56 +00:00
Konstantin Belousov 6180f50bbb Stop inlining the struct ucond definition into struct pthread_cond.
This avoids unneccessary casts and make the calls to _thr_ucond_*()
functions less questionable.

The c_spare field was not included into struct pthread_cond, so the
change modifies libthr ABI for shared condvars.  But since an off-page
does not legitimately contains any other data past the struct
pthread_cond, the change keeps shared condvars from pre- and post-
changed libthr compatible.  Also note that the whole struct ucond was
never copied in or out by kernel.

For private condvars, the privately allocated memory was never exposed
outside libthr.

Sponsored by:	The FreeBSD Foundation
2016-05-29 19:35:55 +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 321e2a0090 Do not leak THR_FLAGS_SUSPENDED from the previous suspend/resume
cycle.  The flag currently is cleared by the resumed thread.  If next
suspend request comes before the thread was able to clean the flag, in
which case suspender skip the thread.

Instead, clear the THR_FLAGS_SUSPEND flag in resume_common(), we do
not care how much code was executed in the resumed thread when the
pthread_resume_*np(s) functions returned.

PR:	209233
Reported by:	Lawrence Esswood <le277@cam.ac.uk>
MFC after:	1 week
2016-05-05 10:20:22 +00:00
Konstantin Belousov fe60c14631 If off-page lookup failed, there is no memory to perform
shared_mutex_init() upon.

Sponsored by:	The FreeBSD Foundation
2016-04-12 10:25:44 +00:00
Konstantin Belousov 3279301186 Use __FBSDID() for .c files from lib/libthr/thread.
Sponsored by:	The FreeBSD Foundation
2016-04-08 11:15:26 +00:00
Konstantin Belousov 5c43c9a105 Use ANSI C function definitions, fix spelling in a comment.
Sponsored by:	The FreeBSD Foundation
2016-04-08 10:59:06 +00:00
Konstantin Belousov 9e821f2796 Assert that the lock objects put into the off-page, fit into the page.
Sponsored by:	The FreeBSD Foundation
2016-04-08 10:21:43 +00:00
Konstantin Belousov 841ecd471a Remove unused variable. It was write-only before r297139.
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2016-04-04 06:58:59 +00:00
Konstantin Belousov 6044c03a37 Apparently there are some popular programs around which assume that it
is safe to call pthread_mutex_init() on the same shared mutex several
times.  POSIX claims that the behaviour in this case is undefined.

Make this working by only allowing one caller to initialize the mutex.
Other callers either see already completed initialization and do
nothing, or busy-loop yielding while designated initializer finishes.
Also make the API requirements loose by initializing mutexes on other
pthread_mutex*() calls if they see uninitialized shared mutex.

Only mutexes provide the hack for now, but it could be also
implemented for other process shared primitives from libthr.

Reported and tested by:	"Oleg V. Nauman" <oleg@opentransfer.com>
Sponsored by:	The FreeBSD Foundation
2016-03-22 10:51:42 +00:00
Konstantin Belousov 53fd961f05 Lock pshared_lock shared around fork, to ensure that the COW snapshot
of the pshared hash in child is consistent and can be safely used.

Reported and tested by:	"Oleg V. Nauman" <oleg@opentransfer.com>
Sponsored by:	The FreeBSD Foundation
2016-03-21 06:52:35 +00:00
Konstantin Belousov 07f22a288d Provide more information on failing checks in mutex_assert_is_owned()
and mutex_assert_not_owned().  snprintf() use in this context should
be safe.

Sponsored by:	The FreeBSD Foundation
2016-03-21 06:48:11 +00:00
Konstantin Belousov b6751c3f87 From libthr, remove special and strange code to set up session and
control terminal, activated when running with pid 1.  It is
application duty to handle this, and unsuspecting init replacements
which are linked with libthr would be broken by this.

The pre-resolving of getpid() is restored, just in case.

Reviewed by:	jilles
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
2016-03-21 06:46:16 +00:00
Konstantin Belousov 6eced731e8 Implement process-shared spinlocks.
Sponsored by:	The FreeBSD Foundation
2016-03-21 06:40:54 +00:00
Konstantin Belousov 064094126c Add two comments explaining the fine points of the hash
implementation.

Reviewed by:	emaste
Sponsored by:	The FreeBSD Foundation
Differential revision:	https://reviews.freebsd.org/D5490
2016-03-01 15:21:01 +00:00
Konstantin Belousov 1bdbd70599 Implement process-shared locks support for libthr.so.3, without
breaking the ABI.  Special value is stored in the lock pointer to
indicate shared lock, and offline page in the shared memory is
allocated to store the actual lock.

Reviewed by:	vangyzen (previous version)
Discussed with:	deischen, emaste, jhb, rwatson,
	Martin Simmons <martin@lispworks.com>
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
2016-02-28 17:52:33 +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
Eric van Gyzen 8e402f34b9 libthr: const-ify two variables
Make the default umutex and urwlock initializers const,
because they can be, and as a microoptimization.

MFC after:	5 days
Sponsored by:	Dell Inc.
2016-01-13 22:34:55 +00:00
Konstantin Belousov d6717e1b51 Typo. 2015-12-27 01:14:42 +00:00
Jilles Tjoelker 17981398bd libthr: Don't use both __sys_open() and __sys_openat(). 2015-12-20 16:33:56 +00:00
Konstantin Belousov b684727b07 Style. Use ANSI definition, wrap long lines, no initialization in
declaration for locals.

Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2015-09-08 08:48:53 +00:00
Konstantin Belousov 3e7e67c08d In the pthread_once(), if the initializer has already run, then the
calling thread is supposed to see accesses issued by the initializer.
This means that the read of the once_control->state variable should
have an acquire semantic.  Use atomic_thread_fence_acq() when the
value read is ONCE_DONE, instead of straightforward atomic_load_acq(),
to only put a barrier when needed (*).

On the other hand, the updates of the once_control->state with the
intermediate progress state do not need to synchronize with other
state accesses, remove _acq suffix.

Reviewed by:	alc (previous version)
Suggested by:	alc (*)
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2015-09-08 08:41:07 +00:00
Konstantin Belousov 3d40192d3d Pre-resolve symbols required for the deferred signal processing. This
avoids recursion into rtld when leaving libthr critical section for
the deferred signal delivery.

For the same reason, use syscall(2) instead of referencing
__sys_sigreturn(2).  Syscall() is already pre-resolved for fork()
interceptor.

Tested by:	Andre Meiser <ortadur@web.de>
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2015-08-10 17:02:42 +00:00
Pedro F. Giffuni 850c6f5fd2 cosmetic: whitespaces-tab before EOL
Obtained from:	cpi-llvm project
2015-07-08 16:35:24 +00:00
Konstantin Belousov c5e7289c10 Fix typo in comment.
MFC after:	3 days
2015-06-14 19:19:46 +00:00
Konstantin Belousov 9be6046a47 Some third-party malloc(3) implementations use pthread_setspecific(3)
to handle per-thread information.  Since our pthread_setspecific()
implementation calls calloc(3) to allocate per-thread specific data
storage, things get complicated.

Switch the allocator to use bare mmap(2).  There is some loss of the
allocated page, since e.g. on amd64, PTHREAD_KEYS_MAX * sizeof(struct
pthread_specific_elem) is 3K (it actually spans whole page due to
padding), but I believe it is more acceptable than additional code for
specialized allocator().

The alternatives would either to make the specific data array be part of
the struct thread, or use internal bindings to call the libc malloc,
avoiding interposing.

Also do the style pass over the thr_spec.c, esp. simplify the
conditionals nesting by returning early when an error detected.
Remove trivial comments.

Found by:	yuri@rawbw.com
PR:	200138
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
2015-05-15 08:40:17 +00:00
Pedro F. Giffuni 9acf5917d3 _pthread_cleanup_push: fix allocator sizeof operand mismatch
Same fix appears to be in DragonFly's libthread_xu.

Found by:	Clang Static Analyzer
MFC after:	1 week
2015-04-22 16:51:21 +00:00
Konstantin Belousov 0538aafc41 The lseek(2), mmap(2), truncate(2), ftruncate(2), pread(2), and
pwrite(2) syscalls are wrapped to provide compatibility with pre-7.x
kernels which required padding before the off_t parameter.  The
fcntl(2) contains compatibility code to handle kernels before the
struct flock was changed during the 8.x CURRENT development.  The
shims were reasonable to allow easier revert to the older kernel at
that time.

Now, two or three major releases later, shims do not serve any
purpose.  Such old kernels cannot handle current libc, so revert the
compatibility code.

Make padded syscalls support conditional under the COMPAT6 config
option.  For COMPAT32, the syscalls were under COMPAT6 already.

Remove WITHOUT_SYSCALL_COMPAT build option, which only purpose was to
(partially) disable the removed shims.

Reviewed by:	jhb, imp (previous versions)
Discussed with:	peter
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2015-04-18 21:50:13 +00:00
Konstantin Belousov 3d0045bb2b Make wait6(2), waitid(3) and ppoll(2) cancellation points. The
waitid() function is required to be cancellable by the standard.  The
wait6() and ppoll() follow the other syscalls in their groups.

Reviewed by:	jhb, jilles (previous versions)
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2015-04-18 21:35:41 +00:00
Konstantin Belousov b072e86d09 Make kevent(2) a cancellation point.
Note that to cancel blocked kevent(2) call, changelist must be empty,
since we cannot cancel a call which already made changes to the
process state.  And in reverse, call which only makes changes to the
kqueue state, without waiting for an event, is not cancellable.  This
makes a natural usage model to migrate kqueue loop to support
cancellation, where existing single kevent(2) call must be split into
two: first uncancellable update of kqueue, then cancellable wait for
events.

Note that this is ABI-incompatible change, but it is believed that
there is no cancel-safe code that relies on kevent(2) not being a
cancellation point.  Option to preserve the ABI would be to keep
kevent(2) as is, but add new call with flags to specify cancellation
behaviour, which only value seems to add complications.

Suggested and reviewed by:	jilles
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
2015-03-29 19:14:41 +00:00
Jung-uk Kim be070eb896 Fix a typo in comment and explain the reason. 2015-03-09 20:26:42 +00:00
Konstantin Belousov 3e6d2e9b4e Propagate errors from _thr_umutex_unlock2 through mutex_unlock_common.
Errors from _thr_umutex_unlock2 should "never happen" in normal
circumstances.  If they do, however, return them to the application
so it can fail early and loudly.  Hiding the errors will only delay
the inevitable failure, making it harder to find and diagnose.

Submitted by:	Eric van Gyzen <eric_van_gyzen@dell.com>
Obtained from:	Dell Inc.
PR:	198914
MFC after:	1 week
2015-02-25 16:18:26 +00:00
Konstantin Belousov 45468c5356 Properly interpose libc spinlocks, was missed in r276630. In
particular, stdio locking was affected.

Reported and tested by:	"Matthew D. Fuller" <fullermd@over-yonder.net>
Sponsored by:	The FreeBSD Foundation
MFC after:	3 days
2015-02-14 11:47:40 +00:00
Konstantin Belousov 83d74204c8 Fully initialize allocated memory for the new barrier. The
b_destroying member was left uninitialized, which caused spurious
EBUSY.

PR:	197365
Noted by:	Florent Guiliani <fguiliani@verisign.com>
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2015-02-06 12:18:38 +00:00
Andrew Turner 20fe2c9465 Merge all the copies of _tcb_ctor and _tcb_dtor.
The amd64, i386, and sparc64 versions were identical, with the one
difference where the former two used inline asm instead of _tcb_get. I
have compared the function before and after replacing the asm with _tcb_get
and found the object files to be identical.

The arm, mips, and powerpc versions were almost identical. The only
difference was the powerpc version used an alignment of 1 where arm and
mips used 16. As this is an increase in alignment is will be safe.

Along with this arm, mips, and powerpc all passed, when initial was true,
the value returned from _tcb_get as the first argument to
_rtld_allocate_tls. This would then return this pointer back to the caller.
We can remove these extra calls by checking if initial is set and setting
the thread control block directly. As this is what the sparc64 code does
we can use it directly.

As after these observations all the architectures can now have identical
code we can merge them into a common file.

Differential Revision:	https://reviews.freebsd.org/D1556
Reviewed by:	kib
Sponsored by:	The FreeBSD Foundation
2015-01-21 16:41:05 +00:00
Konstantin Belousov 9e8bff64cb Fix bug in r276630. Do not allow pthread_sigmask() to block SIGCANCEL.
Reported and tested by:	royger
Sponsored by:	The FreeBSD Foundation
MFC after:	3 days
2015-01-21 16:13:37 +00:00
Konstantin Belousov 397d851d66 Reduce the size of the interposing table and amount of
cancellation-handling code in the libthr.  Translate some syscalls
into their more generic counterpart, and remove translated syscalls
from the table.

List of the affected syscalls:
creat, open -> openat
raise -> thr_kill
sleep, usleep -> nanosleep
pause -> sigsuspend
wait, wait3, waitpid -> wait4

Suggested and reviewed by:	jilles (previous version)
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2015-01-11 22:16:31 +00:00
Konstantin Belousov 1a744fefc2 Avoid calling internal libc function through PLT or accessing data
though GOT, by staticizing and hiding.  Add setter for
__error_selector to hide it as well.

Suggested and reviewed by:	jilles
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2015-01-05 01:06:54 +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
Ed Maste 294246bb7d Revert r274772: it is not valid on MIPS
Reported by:	sbruno
2014-11-25 03:50:31 +00:00
Ed Maste 688fd61ae8 Use canonical __PIC__ flag
It is automatically set when -fPIC is passed to the compiler.

Reviewed by:	dim, kib
Sponsored by:	The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D1179
2014-11-21 02:05:48 +00:00
Konstantin Belousov 36bcb07ab5 Switch the defaults to not split the RLIMIT_STACK-sized initial thread
stack into the stacks of the created threads.  Add knob
LIBPTHREAD_SPLITSTACK_MAIN to restore the older behaviour.

Sponsored by:	The FreeBSD Foundation
MFC after:	3 weeks
2014-09-24 12:39:12 +00:00
Rui Paulo 585bf8ae67 Fix typo in a comment. 2014-09-02 18:21:19 +00:00
Konstantin Belousov 6c8ce3bfce Add a knob LIBPTHREAD_BIGSTACK_MAIN, which instructs libthr to leave
the whole RLIMIT_STACK-sized region of the kernel-allocated stack as
the stack of main thread.

By default, the main thread stack is clamped at 2MB (4MB on 64bit
ABIs) and the rest is used for other threads stack allocation.  Since
there is no programmatic way to adjust the size of the main thread
stack, pthread_attr_setstacksize() is too late, the knob allows user
to manage the main stack size both for single-threaded and
multi-threaded processes with the rlimit.

Reported by:	"Ivan A. Kosarev" <ivan@ivan-labs.com>
Tested by:	dim
Sponsored by:	The FreeBSD Foundation
MFC after:	3 days
2014-08-13 05:53:41 +00:00
Konstantin Belousov f6abec6c64 Style.
Sponsored by:	The FreeBSD Foundation
MFC after:	3 days
2014-08-13 05:47:49 +00:00
Konstantin Belousov 1c70d00733 Right now, the rtld prefork hook locks the rtld bind lock in the read
mode.  This allows the binder to be functional in the child after the
fork (assuming no lazy loading of a filter is needed), but other rtld
services which require write lock on rtld_bind_lock cause deadlock, if
called by child.

Change the _rtld_atfork() to lock the bind lock in write mode, making
the rtld fully functional after the fork.

Pre-resolve the symbols which are called by the libthr' fork()
interposer, since dynamic resolution causes deadlock due to the
rtld_bind_lock already owned in the write mode.

Reported and tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
2014-05-24 10:23:06 +00:00