libc: Give __thr_jtable protected visibility

This function pointer table is overwritten by libthr when it's loaded.
libc's pthread stubs are implemented by looking up an entry in this
table and invo

libc: Give __thr_jtable protected visibility

This function pointer table is overwritten by libthr when it's loaded.
libc's pthread stubs are implemented by looking up an entry in this
table and invoking the function pointer contained in the entry.

pthread calls are fairly expensive even when libthr is not loaded: each
call involves indirection through the PLT, then through the GOT to look
up __thr_jtable, then the function pointer itself. We can however
eliminate one level of indirection by disallowing preemption of the
__thr_jtable symbol, and since the existence table is an internal
implementation detail, disabling preemption is unlikely to break
anything. This gives a modest improvement in some microbenchmarks which
call libc's pthread stubs.

Reviewed by: kib
MFC after: 1 month
Sponsored by: Innovate UK
Differential Revision: https://reviews.freebsd.org/D50354

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libc: fix the stubs for pthread_{suspend,resume}_all_np

Noticed just a little too late, stub_null returns a `void *` but these
prototypes have no return value. As far as I know, all of our archs
wi

libc: fix the stubs for pthread_{suspend,resume}_all_np

Noticed just a little too late, stub_null returns a `void *` but these
prototypes have no return value. As far as I know, all of our archs
will throw the return value in a caller-saved register and it'll simply
be ignored, but it's probably worth being more accurate.

Fixes: 83aafcdc8892 ("libc, libthr: coordinate stubs for [...]")

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libc, libthr: coordinate stubs for pthread_{suspend,resume}_all_np

If libthr isn't linked into the process, then we don't have any pthreads
to worry about and our stubs can just return success -- th

libc, libthr: coordinate stubs for pthread_{suspend,resume}_all_np

If libthr isn't linked into the process, then we don't have any pthreads
to worry about and our stubs can just return success -- there are none
to suspend/resume.

Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D47350

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libc: Purge unneeded cdefs.h

These sys/cdefs.h are not needed. Purge them. They are mostly left-over
from the $FreeBSD$ removal. A few in libc are still required for macros
that cdefs.h defines. Kee

libc: Purge unneeded cdefs.h

These sys/cdefs.h are not needed. Purge them. They are mostly left-over
from the $FreeBSD$ removal. A few in libc are still required for macros
that cdefs.h defines. Keep those.

Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D42385

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libc/gen/_pthread_stubs.c: Remove stray whitespaces

Sponsored by: The FreeBSD Foundation
MFC after: 1 week

libc: export pthread_getname_np stub

pthread_getname_np needs to be provided by libc in order to import
jemalloc 5.3.0.

A stub implementation for libc pthread_getname_np() is added for
_pthread_stu

libc: export pthread_getname_np stub

pthread_getname_np needs to be provided by libc in order to import
jemalloc 5.3.0.

A stub implementation for libc pthread_getname_np() is added for
_pthread_stubs.c, which always reports empty name for the main thread.

Internal _pthread_getname_np() is not exported, but provided for libc
own use.

Reviewed by: kib
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D41461

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Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD

The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD

The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.

Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix

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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: An

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

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Remove stray column.

Sponsored by: The FreeBSD Foundation
MFC after: 3 days

Use designated initializers for libc pthread stubs' jump table.

Sponsored by: The FreeBSD Foundation
MFC after: 1 week

MFHead @349476

Sponsored by: The FreeBSD Foundation

Add libc stub for pthread_getthreadid_np(3).

Requested by: jbeich
PR: 238650
Sponsored by: The FreeBSD Foundation
MFC after: 1 week

libc: 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
p

libc: 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.

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MFhead@r320180

Merge ^/head r319973 through 321382.

Merge ^/head r320398 through r320572.

Correct signatures of several pthreads stubs.

Most important, use a correct signature for the
__pthread_cleanup_push_imp() stub, which was incorrectly generated
with two-args variant. The pthread_c

Correct signatures of several pthreads stubs.

Most important, use a correct signature for the
__pthread_cleanup_push_imp() stub, which was incorrectly generated
with two-args variant. The pthread_cleanup_info pointer was corrupted
in the forwarded call to the real libthr implementation, visible on
PowerPC and possibly ARM. [1]

Found and tested by: Mark Millard <markmi@dsl-only.net> [1]
Sponsored by: The FreeBSD Foundation
MFC after: 1 week

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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
thr

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

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IFC @230489 (pending review).

IFC to head to catch up the bhyve branch

Approved by: grehan@

style(9) fix.

Approved by: dim (mentor)

Return not-implemented from pthread_once and pthread_key_create, rather
than silently failing and returning success.

Without this, code calls pthread_once(), receives a return value of
success, and

Return not-implemented from pthread_once and pthread_key_create, rather
than silently failing and returning success.

Without this, code calls pthread_once(), receives a return value of
success, and thinks that the passed function has been called.

Approved by: dim (mentor)

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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 cancellatio

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.

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IFH@204581