Commit Graph

520 Commits

Author SHA1 Message Date
pfg
c8ef5bee29 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
pfg
260ba0bff1 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
pfg
872b698bd4 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
pfg
9da7bdde06 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
mizhka
cc1f74e813 [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
pfg
2030aa27d2 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
pfg
c3bb00fcff libthr: 'count' is unsigned so don't check for negative values.
Obtained from:	DragonFlyBSD (git e7db8139)
2017-07-14 16:05:54 +00:00
vangyzen
2eebf6371b 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
vangyzen
e5af1a7c3b 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
vangyzen
a32b7a2ad2 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
vangyzen
99a8da4537 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
vangyzen
0dd2185001 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
vangyzen
df2338fa68 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
vangyzen
9712b7c0c0 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
vangyzen
2a25f0f3be 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
jasone
e820802837 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
vangyzen
d6de25428d 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
pfg
74d3e29a11 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
emaste
113c297465 libthr: coalesce repeated #if blocks 2017-01-25 20:19:48 +00:00
kib
d6cb692fee 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
kib
e04600d300 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
kib
117ade20e9 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
kib
9a6f37a73a 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
kib
89e7e12759 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
kib
75248c1348 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
cem
6a53a3dd42 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
cem
51037ae517 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
cem
d29b361251 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
kib
1bed4ff78e 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
kib
8da898f26c 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
kib
070c6cd670 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
kib
e472ae2aec 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
kib
fe92c9d1a4 Use __FBSDID() for .c files from lib/libthr/thread.
Sponsored by:	The FreeBSD Foundation
2016-04-08 11:15:26 +00:00
kib
7dbfd5ad02 Use ANSI C function definitions, fix spelling in a comment.
Sponsored by:	The FreeBSD Foundation
2016-04-08 10:59:06 +00:00
kib
21446f2890 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
kib
725da9cdbc 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
kib
2a4182c291 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
kib
bdf946f966 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
kib
7c5b09c965 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
kib
1e240521d2 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
kib
9e847808a6 Implement process-shared spinlocks.
Sponsored by:	The FreeBSD Foundation
2016-03-21 06:40:54 +00:00
kib
ac7a1d6753 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
kib
e76eb4255b 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
kib
42e09be9c2 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
vangyzen
e39bbe5207 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
kib
27f78ada40 Typo. 2015-12-27 01:14:42 +00:00
jilles
507e66a915 libthr: Don't use both __sys_open() and __sys_openat(). 2015-12-20 16:33:56 +00:00
kib
b522c482ce 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
kib
36ed4c2481 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
kib
def7a72957 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