From: Stefan Liebler <stli@linux.ibm.com>
To: libc-alpha@sourceware.org
Subject: Re: [PATCH] Fix race in pthread_mutex_lock while promoting to PTHREAD_MUTEX_ELISION_NP [BZ #23275]
Date: Tue, 19 Jun 2018 07:45:00 -0000 [thread overview]
Message-ID: <4614fea8-43b9-0125-1346-603ad8ad66e4@linux.ibm.com> (raw)
In-Reply-To: <f3fc33e5-aa98-f772-a1bf-c02ddf9352c7@linux.ibm.com>
PING
On 06/12/2018 04:24 PM, Stefan Liebler wrote:
> Hi,
>
> The race leads either to pthread_mutex_destroy returning EBUSY or
> triggering an assertion (See description in bugzilla).
>
> This patch is fixing the race by ensuring that the elision path is used
> in all cases if elision is enabled by the GLIBC_TUNABLES framework.
>
> The __kind variable in struct __pthread_mutex_s is accessed
> concurrently. Therefore we are now using the atomic macros.
>
> The new testcase tst-mutex10 is triggering the race on s390x and intel.
> Presumably also on power, but I don't have access to a power machine
> with lock-elision. At least the code for power is the same as on the
> other two architectures. Can somebody test it on power?
>
> Bye
> Stefan
>
> ChangeLog:
>
> Â Â Â Â [BZ #23275]
> Â Â Â Â * nptl/tst-mutex10.c: New File.
> Â Â Â Â * nptl/Makefile (tests): Add tst-mutex10.
> Â Â Â Â (tst-mutex-ENV): New variable.
> Â Â Â Â * sysdeps/unix/sysv/linux/s390/force-elision.h: (FORCE_ELISION):
> Â Â Â Â Ensure that elision path is used if elision is available.
> Â Â Â Â * sysdeps/unix/sysv/linux/powerpc/force-elision.h
> Â Â Â Â (FORCE_ELISION): Likewise.
> Â Â Â Â * sysdeps/unix/sysv/linux/x86/force-elision.h: (FORCE_ELISION):
> Â Â Â Â Likewise.
> Â Â Â Â * nptl/pthreadP.h (PTHREAD_MUTEX_TYPE,
> Â Â Â Â PTHREAD_MUTEX_TYPE_ELISION, PTHREAD_MUTEX_PSHARED):
> Â Â Â Â Use atomic_load_relaxed.
> Â Â Â Â * nptl/pthread_mutex_consistent.c (pthread_mutex_consistent):
> Â Â Â Â Likewise.
> Â Â Â Â * nptl/pthread_mutex_getprioceiling.c
> Â Â Â Â (pthread_mutex_getprioceiling): Likewise.
> Â Â Â Â * nptl/pthread_mutex_lock.c (__pthread_mutex_lock_full,
> Â Â Â Â __pthread_mutex_cond_lock_adjust): Likewise.
> Â Â Â Â * nptl/pthread_mutex_setprioceiling.c
> Â Â Â Â (pthread_mutex_setprioceiling): Likewise.
> Â Â Â Â * nptl/pthread_mutex_timedlock.c (__pthread_mutex_timedlock):
> Â Â Â Â Likewise.
> Â Â Â Â * nptl/pthread_mutex_trylock.c (__pthread_mutex_trylock):
> Â Â Â Â Likewise.
> Â Â Â Â * nptl/pthread_mutex_unlock.c (__pthread_mutex_unlock_full):
> Â Â Â Â Likewise.
> Â Â Â Â * sysdeps/nptl/bits/thread-shared-types.h
> Â Â Â Â (struct __pthread_mutex_s): Add comments.
> Â Â Â Â * nptl/pthread_mutex_destroy.c (__pthread_mutex_destroy):
> Â Â Â Â Use atomic_load_relaxed and atomic_store_relaxed.
> Â Â Â Â * nptl/pthread_mutex_init.c (__pthread_mutex_init):
> Â Â Â Â Use atomic_store_relaxed.
next prev parent reply other threads:[~2018-06-19 7:45 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-12 14:25 Stefan Liebler
2018-06-13 8:43 ` Florian Weimer
2018-06-13 9:18 ` Stefan Liebler
2018-06-13 9:36 ` Florian Weimer
2018-06-13 15:25 ` Stefan Liebler
2018-06-14 8:04 ` Stefan Liebler
2018-06-13 21:45 ` Tulio Magno Quites Machado Filho
2018-06-19 7:45 ` Stefan Liebler [this message]
2018-06-26 6:45 ` [PING][PATCH] " Stefan Liebler
2018-07-03 6:28 ` Stefan Liebler
2018-07-10 6:34 ` Stefan Liebler
2018-07-16 11:57 ` Stefan Liebler
2018-07-23 6:42 ` Stefan Liebler
2018-07-30 7:22 ` Stefan Liebler
2018-08-27 9:12 ` Stefan Liebler
2018-09-03 7:10 ` Stefan Liebler
2018-09-10 12:01 ` Stefan Liebler
2018-09-17 13:38 ` [PATCH] " Florian Weimer
2018-10-04 16:08 ` Stefan Liebler
2018-10-16 14:23 ` Florian Weimer
2018-10-17 10:36 ` Stefan Liebler
2018-10-18 13:24 ` [COMMITTED 2.27 / 2.28] " Stefan Liebler
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