Commit Graph

274 Commits

Author SHA1 Message Date
Adhemerval Zanella
e070501d12 Replace __libc_multiple_threads with __libc_single_threaded
And also fixes the SINGLE_THREAD_P macro for SINGLE_THREAD_BY_GLOBAL,
since header inclusion single-thread.h is in the wrong order, the define
needs to come before including sysdeps/unix/sysdep.h.  The macro
is now moved to a per-arch single-threade.h header.

The SINGLE_THREAD_P is used on some more places.

Checked on aarch64-linux-gnu and x86_64-linux-gnu.
2022-07-05 10:14:47 -03:00
Adhemerval Zanella
baf2a265c7 misc: Optimize internal usage of __libc_single_threaded
By adding an internal alias to avoid the GOT indirection.
On some architecture, __libc_single_thread may be accessed through
copy relocations and thus it requires to update also the copies
default copy.

This is done by adding a new internal macro,
libc_hidden_data_{proto,def}, which has an addition argument that
specifies the alias name (instead of default __GI_ one).

Checked on x86_64-linux-gnu and i686-linux-gnu.

Reviewed-by: Fangrui Song <maskray@google.com>
2022-06-24 17:45:58 -03:00
Wangyang Guo
8162147872 nptl: Add backoff mechanism to spinlock loop
When mutiple threads waiting for lock at the same time, once lock owner
releases the lock, waiters will see lock available and all try to lock,
which may cause an expensive CAS storm.

Binary exponential backoff with random jitter is introduced. As try-lock
attempt increases, there is more likely that a larger number threads
compete for adaptive mutex lock, so increase wait time in exponential.
A random jitter is also added to avoid synchronous try-lock from other
threads.

v2: Remove read-check before try-lock for performance.

v3:
1. Restore read-check since it works well in some platform.
2. Make backoff arch dependent, and enable it for x86_64.
3. Limit max backoff to reduce latency in large critical section.

v4: Fix strict-prototypes error in sysdeps/nptl/pthread_mutex_backoff.h

v5: Commit log updated for regression in large critical section.

Result of pthread-mutex-locks bench

Test Platform: Xeon 8280L (2 socket, 112 CPUs in total)
First Row: thread number
First Col: critical section length
Values: backoff vs upstream, time based, low is better

non-critical-length: 1
	1	2	4	8	16	32	64	112	140
0	0.99	0.58	0.52	0.49	0.43	0.44	0.46	0.52	0.54
1	0.98	0.43	0.56	0.50	0.44	0.45	0.50	0.56	0.57
2	0.99	0.41	0.57	0.51	0.45	0.47	0.48	0.60	0.61
4	0.99	0.45	0.59	0.53	0.48	0.49	0.52	0.64	0.65
8	1.00	0.66	0.71	0.63	0.56	0.59	0.66	0.72	0.71
16	0.97	0.78	0.91	0.73	0.67	0.70	0.79	0.80	0.80
32	0.95	1.17	0.98	0.87	0.82	0.86	0.89	0.90	0.90
64	0.96	0.95	1.01	1.01	0.98	1.00	1.03	0.99	0.99
128	0.99	1.01	1.01	1.17	1.08	1.12	1.02	0.97	1.02

non-critical-length: 32
	1	2	4	8	16	32	64	112	140
0	1.03	0.97	0.75	0.65	0.58	0.58	0.56	0.70	0.70
1	0.94	0.95	0.76	0.65	0.58	0.58	0.61	0.71	0.72
2	0.97	0.96	0.77	0.66	0.58	0.59	0.62	0.74	0.74
4	0.99	0.96	0.78	0.66	0.60	0.61	0.66	0.76	0.77
8	0.99	0.99	0.84	0.70	0.64	0.66	0.71	0.80	0.80
16	0.98	0.97	0.95	0.76	0.70	0.73	0.81	0.85	0.84
32	1.04	1.12	1.04	0.89	0.82	0.86	0.93	0.91	0.91
64	0.99	1.15	1.07	1.00	0.99	1.01	1.05	0.99	0.99
128	1.00	1.21	1.20	1.22	1.25	1.31	1.12	1.10	0.99

non-critical-length: 128
	1	2	4	8	16	32	64	112	140
0	1.02	1.00	0.99	0.67	0.61	0.61	0.61	0.74	0.73
1	0.95	0.99	1.00	0.68	0.61	0.60	0.60	0.74	0.74
2	1.00	1.04	1.00	0.68	0.59	0.61	0.65	0.76	0.76
4	1.00	0.96	0.98	0.70	0.63	0.63	0.67	0.78	0.77
8	1.01	1.02	0.89	0.73	0.65	0.67	0.71	0.81	0.80
16	0.99	0.96	0.96	0.79	0.71	0.73	0.80	0.84	0.84
32	0.99	0.95	1.05	0.89	0.84	0.85	0.94	0.92	0.91
64	1.00	0.99	1.16	1.04	1.00	1.02	1.06	0.99	0.99
128	1.00	1.06	0.98	1.14	1.39	1.26	1.08	1.02	0.98

There is regression in large critical section. But adaptive mutex is
aimed for "quick" locks. Small critical section is more common when
users choose to use adaptive pthread_mutex.

Signed-off-by: Wangyang Guo <wangyang.guo@intel.com>
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
2022-05-09 14:38:40 -07:00
Adhemerval Zanella
4f7b7d00e0 posix: Remove unused definition on _Fork
Checked on x86_64-linux-gnu.
2022-04-26 14:21:08 -03:00
Adhemerval Zanella
404656009b nptl: Handle spurious EINTR when thread cancellation is disabled (BZ#29029)
Some Linux interfaces never restart after being interrupted by a signal
handler, regardless of the use of SA_RESTART [1].  It means that for
pthread cancellation, if the target thread disables cancellation with
pthread_setcancelstate and calls such interfaces (like poll or select),
it should not see spurious EINTR failures due the internal SIGCANCEL.

However recent changes made pthread_cancel to always sent the internal
signal, regardless of the target thread cancellation status or type.
To fix it, the previous semantic is restored, where the cancel signal
is only sent if the target thread has cancelation enabled in
asynchronous mode.

The cancel state and cancel type is moved back to cancelhandling
and atomic operation are used to synchronize between threads.  The
patch essentially revert the following commits:

  8c1c0aae20 nptl: Move cancel type out of cancelhandling
  2b51742531 nptl: Move cancel state out of cancelhandling
  26cfbb7162 nptl: Remove CANCELING_BITMASK

However I changed the atomic operation to follow the internal C11
semantic and removed the MACRO usage, it simplifies a bit the
resulting code (and removes another usage of the old atomic macros).

Checked on x86_64-linux-gnu, i686-linux-gnu, aarch64-linux-gnu,
and powerpc64-linux-gnu.

[1] https://man7.org/linux/man-pages/man7/signal.7.html

Reviewed-by: Florian Weimer <fweimer@redhat.com>
Tested-by: Aurelien Jarno <aurelien@aurel32.net>
2022-04-14 12:48:31 -03:00
Florian Weimer
6c33b01843 Linux: Use ptrdiff_t for __rseq_offset
This matches the data size initial-exec relocations use on most
targets.

Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2022-02-02 22:37:20 +01:00
Paul Eggert
581c785bf3 Update copyright dates with scripts/update-copyrights
I used these shell commands:

../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")

and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 7061 files FOO.

I then removed trailing white space from math/tgmath.h,
support/tst-support-open-dev-null-range.c, and
sysdeps/x86_64/multiarch/strlen-vec.S, to work around the following
obscure pre-commit check failure diagnostics from Savannah.  I don't
know why I run into these diagnostics whereas others evidently do not.

remote: *** 912-#endif
remote: *** 913:
remote: *** 914-
remote: *** error: lines with trailing whitespace found
...
remote: *** error: sysdeps/unix/sysv/linux/statx_cp.c: trailing lines
2022-01-01 11:40:24 -08:00
Florian Weimer
c901c3e764 nptl: Add public rseq symbols and <sys/rseq.h>
The relationship between the thread pointer and the rseq area
is made explicit.  The constant offset can be used by JIT compilers
to optimize rseq access (e.g., for really fast sched_getcpu).

Extensibility is provided through __rseq_size and __rseq_flags.
(In the future, the kernel could request a different rseq size
via the auxiliary vector.)

Co-Authored-By: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
2021-12-09 09:49:32 +01:00
Florian Weimer
e3e589829d nptl: Add glibc.pthread.rseq tunable to control rseq registration
This tunable allows applications to register the rseq area instead
of glibc.

Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2021-12-09 09:49:32 +01:00
Florian Weimer
95e114a091 nptl: Add rseq registration
The rseq area is placed directly into struct pthread.  rseq
registration failure is not treated as an error, so it is possible
that threads run with inconsistent registration status.

<sys/rseq.h> is not yet installed as a public header.

Co-Authored-By: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2021-12-09 09:49:32 +01:00
Florian Weimer
8d1927d8dc nptl: Introduce THREAD_GETMEM_VOLATILE
This will be needed for rseq TCB access.

Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
2021-12-09 09:49:32 +01:00
Florian Weimer
ce2248ab91 nptl: Introduce <tcb-access.h> for THREAD_* accessors
These are common between most architectures.  Only the x86 targets
are outliers.

Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
2021-12-09 09:49:32 +01:00
Florian Weimer
8dbeb0561e nptl: Add <thread_pointer.h> for defining __thread_pointer
<tls.h> already contains a definition that is quite similar,
but it is not consistent across architectures.

Only architectures for which rseq support is added are covered.

Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
2021-12-09 09:49:32 +01:00
Florian Weimer
8bd336a00a nptl: Extract <bits/atomic_wide_counter.h> from pthread_cond_common.c
And make it an installed header.  This addresses a few aliasing
violations (which do not seem to result in miscompilation due to
the use of atomics), and also enables use of wide counters in other
parts of the library.

The debug output in nptl/tst-cond22 has been adjusted to print
the 32-bit values instead because it avoids a big-endian/little-endian
difference.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-11-17 12:20:13 +01:00
Adhemerval Zanella
8352b6df37 nptl: Use FUTEX_LOCK_PI2 when available
This patch uses the new futex PI operation provided by Linux v5.14
when it is required.

The futex_lock_pi64() is moved to futex-internal.c (since it used on
two different places and its code size might be large depending of the
kernel configuration) and clockid is added as an argument.

Co-authored-by: Kurt Kanzenbach <kurt@linutronix.de>
2021-10-01 08:09:13 -03:00
Florian Weimer
f3e6645633 nptl: Fix type of pthread_mutexattr_getrobust_np, pthread_mutexattr_setrobust_np (bug 28036)
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2021-09-21 07:13:05 +02:00
Siddhesh Poyarekar
30891f35fa Remove "Contributed by" lines
We stopped adding "Contributed by" or similar lines in sources in 2012
in favour of git logs and keeping the Contributors section of the
glibc manual up to date.  Removing these lines makes the license
header a bit more consistent across files and also removes the
possibility of error in attribution when license blocks or files are
copied across since the contributed-by lines don't actually reflect
reality in those cases.

Move all "Contributed by" and similar lines (Written by, Test by,
etc.) into a new file CONTRIBUTED-BY to retain record of these
contributions.  These contributors are also mentioned in
manual/contrib.texi, so we just maintain this additional record as a
courtesy to the earlier developers.

The following scripts were used to filter a list of files to edit in
place and to clean up the CONTRIBUTED-BY file respectively.  These
were not added to the glibc sources because they're not expected to be
of any use in future given that this is a one time task:

https://gist.github.com/siddhesh/b5ecac94eabfd72ed2916d6d8157e7dc
https://gist.github.com/siddhesh/15ea1f5e435ace9774f485030695ee02

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2021-09-03 22:06:44 +05:30
Florian Weimer
aaacde11f2 Reduce <limits.h> pollution due to dynamic PTHREAD_STACK_MIN
<limits.h> used to be a header file with no declarations.
GCC's libgomp includes it in a #pragma GCC visibility hidden block.
Including <unistd.h> from <limits.h> (indirectly) declares everything
in <unistd.h> with hidden visibility, resulting in linker failures.

This commit avoids C declarations in assembler mode and only declares
__sysconf in <limits.h> (and not the entire contents of <unistd.h>).
The __sysconf symbol is already part of the ABI.  PTHREAD_STACK_MIN
is no longer defined for __USE_DYNAMIC_STACK_SIZE && __ASSEMBLER__
because there is no possible definition.

Additionally, PTHREAD_STACK_MIN is now defined by <pthread.h> for
__USE_MISC because this is what developers expect based on the macro
name.  It also helps to avoid libgomp linker failures in GCC because
libgomp includes <pthread.h> before its visibility hacks.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2021-07-12 18:43:32 +02:00
Florian Weimer
7c241325d6 Force building with -fno-common
As a result, is not necessary to specify __attribute__ ((nocommon))
on individual definitions.

GCC 10 defaults to -fno-common on all architectures except ARC,
but this change is compatible with older GCC versions and ARC, too.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2021-07-09 20:09:14 +02:00
Florian Weimer
508ee037a3 nptl: Use out-of-line wake function in __libc_lock_unlock slow path
This slightly reduces code size, as can be seen below.
__libc_lock_unlock is usually used along with __libc_lock_lock in
the same function.  __libc_lock_lock already has an out-of-line
slow path, so this change should not introduce many additional
non-leaf functions.

This change also fixes a link failure in 32-bit Arm thumb mode
because commit 1f9c804fbd
("nptl: Use internal low-level lock type for !IS_IN (libc)")
introduced __libc_do_syscall calls outside of libc.

Before x86-64:

   text	   data	    bss	    dec	    hex	filename
1937748	  20456	  54896	2013100	 1eb7ac	libc.so.6
  25601	    856	  12768	  39225	   9939	nss/libnss_db.so.2
  40310	    952	  25144	  66406	  10366	nss/libnss_files.so.2

After x86-64:
   text	   data	    bss	    dec	    hex	filename
1935312	  20456	  54896	2010664	 1eae28	libc.so.6
  25559	    864	  12768	  39191	   9917	nss/libnss_db.so.2
  39764	    960	  25144	  65868	  1014c	nss/libnss_files.so.2

Before i686:

2110961	  11272	  39144	2161377	 20fae1	libc.so.6
  27243	    428	  12652	  40323	   9d83	nss/libnss_db.so.2
  43062	    476	  25028	  68566	  10bd6	nss/libnss_files.so.2

After i686:

2107347	  11272	  39144	2157763	 20ecc3	libc.so.6
  26929	    432	  12652	  40013	   9c4d	nss/libnss_db.so.2
  43132	    480	  25028	  68640	  10c20	nss/libnss_files.so.2

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-07-09 10:59:22 +02:00
Florian Weimer
1f9c804fbd nptl: Use internal low-level lock type for !IS_IN (libc)
This avoids an ABI hazard (types changing between different modules
of glibc) without introducing linknamespace issues. In particular,
NSS modules now call __lll_lock_wait_private@@GLIBC_PRIVATE to wait
on internal locks (the unlock path is inlined and performs a direct
system call).

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-07-07 08:41:14 +02:00
Florian Weimer
dbb949f53d resolv: Move libanl into libc (if libpthread is in libc)
The symbols gai_cancel, gai_error, gai_suspend, getaddrinfo_a,
__gai_suspend_time64 were moved using scripts/move-symbol-to-libc.py.

For Hurd (which remains !PTHREAD_IN_LIBC), a few #define redirects
had to be added because several pthread functions are not available
under __.  (Linux uses __ prefixes for most hidden aliases, and has
to in some cases to avoid linknamespace issues.)
2021-07-02 11:45:00 +02:00
Florian Weimer
dd45734e32 nptl: Add glibc.pthread.stack_cache_size tunable
The valgrind/helgrind test suite needs a way to make stack dealloction
more prompt, and this feature seems to be generally useful.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2021-06-28 16:41:58 +02:00
Florian Weimer
30639e79d3 Linux: Cleanups after librt move
librt.so is no longer installed for PTHREAD_IN_LIBC, and tests
are not linked against it.  $(librt) is introduced globally for
shared tests that need to be linked for both PTHREAD_IN_LIBC
and !PTHREAD_IN_LIBC.

GLIBC_PRIVATE symbols that were needed during the transition are
removed again.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2021-06-28 09:51:01 +02:00
Florian Weimer
2c16cb88a6 Linux: Move timer helper routines from librt to libc
This adds several temporary GLIBC_PRIVATE exports.  The symbol names
are changed so that they all start with __timer_.

It is now possible to invoke the fork handler directly, so
pthread_atfork is no longer necessary.  The associated error cannot
happen anymore, and cancellation handling can be removed from
the helper thread routine.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-06-25 12:21:12 +02:00
Florian Weimer
2da5f22fff Linux: Move mq_notify from librt to libc
The symbol was moved using scripts/move-symbol-to-libc.py.

An explicit call from fork into the mq_notify implementation replaces
the previous use of pthread_atfork.

Reviewed-by: Adhemerva Zanella  <adhemerval.zanella@linaro.org>
2021-06-25 12:20:47 +02:00
Florian Weimer
d12506b2db Linux: Move aio_init from librt into libc
This commit also moves the aio_misc and aio_sigquue helper,
so GLIBC_PRIVATE exports need to be added.

The symbol was moved using scripts/move-symbol-to-libc.py.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-06-25 11:48:25 +02:00
Adhemerval Zanella
9f70985569 Consolidate pthread_atfork
The pthread_atfork is similar between Linux and Hurd, only the compat
version bits differs.  The generic version is place at sysdeps/pthread
with a common name.

It also fixes an issue with Hurd license, where the static-only object
did not use LGPL + exception.

Checked on x86_64-linux-gnu, i686-linux-gnu, and with a build for
i686-gnu.
2021-06-24 10:04:41 -03:00
Adhemerval Zanella
9a75654037 posix: Consolidate fork implementation
The Linux nptl implementation is used as base for generic fork
implementation to handle the internal locks and mutexes.  The
system specific bits are moved a new internal _Fork symbol.

(This new implementation will be used to provide a async-signal-safe
_Fork now that POSIX has clarified that fork might not be
async-signal-safe [1]).

For Hurd it means that the __nss_database_fork_prepare_parent and
__nss_database_fork_subprocess will be run in a slight different
order.

[1] https://austingroupbugs.net/view.php?id=62
2021-06-24 10:02:06 -03:00
Adhemerval Zanella
b769b0a2cb linux: Only use 64-bit syscall if required for internal futex
For !__ASSUME_TIME64_SYSCALLS there is no need to issue a 64-bit syscall
if the provided timeout fits in a 32-bit one.  The 64-bit usage should
be rare since the timeout is a relative one.

Checked on i686-linux-gnu on a 4.15 kernel and on a 5.11 kernel
(with and without --enable-kernel=5.1) and on x86_64-linux-gnu.

Reviewed-by: Lukasz Majewski <lukma@denx.de>
2021-06-22 12:09:52 -03:00
Florian Weimer
3c79234c7a nptl: Move pthreadP.h into sysdeps directory
This mirrors the situation on Hurd.  These directories are on
the include search part, so #include <pthreadP.h> works after this
change on both Hurd and nptl.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-06-22 09:51:10 +02:00
Adhemerval Zanella
47f24c21ee y2038: Add support for 64-bit time on legacy ABIs
A new build flag, _TIME_BITS, enables the usage of the newer 64-bit
time symbols for legacy ABI (where 32-bit time_t is default).  The 64
bit time support is only enabled if LFS (_FILE_OFFSET_BITS=64) is
also used.

Different than LFS support, the y2038 symbols are added only for the
required ABIs (armhf, csky, hppa, i386, m68k, microblaze, mips32,
mips64-n32, nios2, powerpc32, sparc32, s390-32, and sh).  The ABIs with
64-bit time support are unchanged, both for symbol and types
redirection.

On Linux the full 64-bit time support requires a minimum of kernel
version v5.1.  Otherwise, the 32-bit fallbacks are used and might
results in error with overflow return code (EOVERFLOW).

The i686-gnu does not yet support 64-bit time.

This patch exports following rediretions to support 64-bit time:

  * libc:
    adjtime
    adjtimex
    clock_adjtime
    clock_getres
    clock_gettime
    clock_nanosleep
    clock_settime
    cnd_timedwait
    ctime
    ctime_r
    difftime
    fstat
    fstatat
    futimens
    futimes
    futimesat
    getitimer
    getrusage
    gettimeofday
    gmtime
    gmtime_r
    localtime
    localtime_r
    lstat_time
    lutimes
    mktime
    msgctl
    mtx_timedlock
    nanosleep
    nanosleep
    ntp_gettime
    ntp_gettimex
    ppoll
    pselec
    pselect
    pthread_clockjoin_np
    pthread_cond_clockwait
    pthread_cond_timedwait
    pthread_mutex_clocklock
    pthread_mutex_timedlock
    pthread_rwlock_clockrdlock
    pthread_rwlock_clockwrlock
    pthread_rwlock_timedrdlock
    pthread_rwlock_timedwrlock
    pthread_timedjoin_np
    recvmmsg
    sched_rr_get_interval
    select
    sem_clockwait
    semctl
    semtimedop
    sem_timedwait
    setitimer
    settimeofday
    shmctl
    sigtimedwait
    stat
    thrd_sleep
    time
    timegm
    timerfd_gettime
    timerfd_settime
    timespec_get
    utime
    utimensat
    utimes
    utimes
    wait3
    wait4

  * librt:
    aio_suspend
    mq_timedreceive
    mq_timedsend
    timer_gettime
    timer_settime

  * libanl:
    gai_suspend

Reviewed-by: Lukasz Majewski <lukma@denx.de>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2021-06-15 10:42:11 -03:00
Adhemerval Zanella
8c1c0aae20 nptl: Move cancel type out of cancelhandling
Now that the thread cancellation type is not accessed concurrently
anymore, it is possible to move it out the cancelhandling.

By removing the cancel state out of the internal thread cancel handling
state there is no need to check if cancelled bit was set in CAS
operation.

It allows simplifing the cancellation wrappers and the
CANCEL_CANCELED_AND_ASYNCHRONOUS is removed.

Checked on x86_64-linux-gnu and aarch64-linux-gnu.
2021-06-09 15:16:45 -03:00
Adhemerval Zanella
2b51742531 nptl: Move cancel state out of cancelhandling
Now that thread cancellation state is not accessed concurrently anymore,
it is possible to move it out the 'cancelhandling'.

The code is also simplified: CANCELLATION_P is replaced with a
internal pthread_testcancel call and the CANCELSTATE_BIT{MASK} is
removed.

With this behavior pthread_setcancelstate does not require to act on
cancellation if cancel type is asynchronous (is already handled either
by pthread_setcanceltype or by the signal handler).

Checked on x86_64-linux-gnu and aarch64-linux-gnu.
2021-06-09 15:16:45 -03:00
Adhemerval Zanella
57094e576a libio: Assume _IO_lock_inexpensive
It is already set by both Linux and Hurd.
2021-06-04 09:54:52 -03:00
Adhemerval Zanella
eaa53d0f77 nptl: Remove exit-thread.h
No function change.  The code is used only for Linux, besides
being included in generic code.
2021-06-04 09:52:28 -03:00
Florian Weimer
3b638095a5 nptl: Do not install libpthread.so and do not link tests with it
Keep installing libpthread.a, so that -lpthread works.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-05-25 11:30:23 +02:00
Florian Weimer
49e182c737 nptl: Remove remaining code from libpthread
Only the placeholder compatibility symbols are left now.

The __errno_location symbol was removed (moved) using
scripts/move-symbol-to-libc.py.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-05-21 22:35:01 +02:00
Florian Weimer
f47f1d91af nptl: Move pthread_create, thrd_create into libc
The symbols were moved using scripts/move-symbol-to-libc.py.

The libpthread placeholder symbols need some changes because some
symbol versions have gone away completely.  But
__errno_location@@GLIBC_2.0 still exists, so the GLIBC_2.0 version
is still there.

The internal __pthread_create symbol now points to the correct
function, so the sysdeps/nptl/thrd_create.c override is no longer
necessary.

There was an issue how the hidden alias of pthread_getattr_default_np
was defined, so this commit cleans up that aspects and removes the
GLIBC_PRIVATE export altogether.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-05-21 22:35:00 +02:00
Florian Weimer
d03511f48f nptl: Eliminate the __static_tls_size, __static_tls_align_m1 variables
Use the  __nptl_tls_static_size_for_stack inline function instead,
and the GLRO (dl_tls_static_align) value directly.

The computation of GLRO (dl_tls_static_align)  in
_dl_determine_tlsoffset ensures that the alignment is at least
TLS_TCB_ALIGN, which at least STACK_ALIGN (see allocate_stack).
Therefore, the additional rounding-up step is removed.

ALso move the initialization of the default stack size from
__pthread_initialize_minimal_internal to __pthread_early_init.
This introduces an extra system call during single-threaded startup,
but this simplifies the initialization sequence.  No locking is
needed around the writes to __default_pthread_attr because the
process is single-threaded at this point.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-05-21 22:35:00 +02:00
Florian Weimer
a78e5979a9 nptl: Move __nptl_initial_report_events into ld.so/startup code
The initialization of the report_events TCB field is now performed
in __tls_init_tp instead of __pthread_initialize_minimal_internal
(in libpthread).

The events interface is difficult to test because GDB stopped using it
in 2015.  The td_thr_get_info change to ignore lookup issues is enough
to support GDB with this change.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-05-17 10:04:06 +02:00
Florian Weimer
732139dabe Linux: Move __reclaim_stacks into the fork implementation in libc
As a result, __libc_pthread_init is no longer needed.

Tested-by: Carlos O'Donell <carlos@redhat.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2021-05-10 10:31:42 +02:00
Florian Weimer
9d124d81f0 nptl: Move more stack management variables into _rtld_global
Permissions of the cached stacks may have to be updated if an object
is loaded that requires executable stacks, so the dynamic loader
needs to know about these cached stacks.

The move of in_flight_stack and stack_cache_actsize is a requirement for
merging __reclaim_stacks into the fork implementation in libc.

Tested-by: Carlos O'Donell <carlos@redhat.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2021-05-10 10:31:41 +02:00
Florian Weimer
d017b0ab5a elf: Introduce __tls_pre_init_tp
This is an early variant of __tls_init_tp, primarily for initializing
thread-related elements of _rtld_global/GL.

Some existing initialization code not needed for NPTL is moved into
the generic version of this function.

Tested-by: Carlos O'Donell <carlos@redhat.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2021-05-10 10:31:41 +02:00
Florian Weimer
d6163dfd38 elf, nptl: Resolve recursive lock implementation early
If libpthread is included in libc, it is not necessary to delay
initialization of the lock/unlock function pointers until libpthread
is loaded.  This eliminates two unprotected function pointers
from _rtld_global and removes some initialization code from
libpthread.

Tested-by: Carlos O'Donell <carlos@redhat.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2021-05-10 10:31:41 +02:00
Florian Weimer
ce0b7961ae nptl: Consolidate async cancel enable/disable implementation in libc
Previously, the source file nptl/cancellation.c was compiled multiple
times, for libc, libpthread, librt.  This commit switches to a single
implementation, with new __pthread_enable_asynccancel@@GLIBC_PRIVATE,
__pthread_disable_asynccancel@@GLIBC_PRIVATE exports.

The almost-unused CANCEL_ASYNC and CANCEL_RESET macros are replaced
by LIBC_CANCEL_ASYNC and LIBC_CANCEL_ASYNC macros.  They call the
__pthread_* functions unconditionally now.  The macros are still
needed because shared code uses them; Hurd has different definitions.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-05-05 17:19:32 +02:00
Florian Weimer
c2fd60a586 nptl: Move pthread_yield into libc, as a compatibility symbol
And deprecate it in <pthread.h>, redirecting it to sched_yield
for the time being.

The symbol was moved using scripts/move-symbol-to-libc.py.

No GLIBC_2.34 symbol version is added because of the compatibility
symbol status.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2021-05-03 09:23:44 +02:00
Florian Weimer
e8a9597159 nptl: Move pthread_rwlock_trywrlock into libc
And __pthread_rwlock_trywrlock as a compatibility symbol.

Remove the unused __libc_rwlock_trywrlock macro.

The symbols were moved using scripts/move-symbol-to-libc.py.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2021-05-03 09:18:20 +02:00
Florian Weimer
c96dddd731 nptl: Move pthread_rwlock_tryrdlock into libc
And __pthread_rwlock_tryrdlock as a compatibility symbol.

Remove the unused __libc_rwlock_tryrdlock macro.

The symbols were moved using scripts/move-symbol-to-libc.py.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2021-05-03 09:18:16 +02:00
Florian Weimer
63627246f3 nptl: Move pthread_rwlock_init into libc
And __pthread_rwlock_init as a compatibility symbol.

__libc_rwlock_init is changed to call __pthread_rwlock_init directly.

The symbols were moved using scripts/move-symbol-to-libc.py.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2021-05-03 09:17:59 +02:00