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From: Stefan Liebler <stli@linux.ibm.com>
To: libc-alpha@sourceware.org
Subject: Re: [PING][PATCH] Fix race in pthread_mutex_lock while promoting to PTHREAD_MUTEX_ELISION_NP [BZ #23275]
Date: Mon, 16 Jul 2018 11:57:00 -0000	[thread overview]
Message-ID: <fe70ace4-4f60-d169-9157-63197b0f8950@linux.ibm.com> (raw)
In-Reply-To: <8e0d0ec6-5071-1d15-1f40-20a4928871a0@linux.ibm.com>

PING

On 07/10/2018 08:33 AM, Stefan Liebler wrote:
> PING
> 
> On 07/03/2018 08:28 AM, Stefan Liebler wrote:
>> PING
>>
>> On 06/26/2018 08:45 AM, Stefan Liebler wrote:
>>> PING
>>>
>>> On 06/19/2018 09:45 AM, Stefan Liebler wrote:
>>>> 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:
>>>>>
>>>>>      [BZ #23275]
>>>>>      * nptl/tst-mutex10.c: New File.
>>>>>      * nptl/Makefile (tests): Add tst-mutex10.
>>>>>      (tst-mutex-ENV): New variable.
>>>>>      * sysdeps/unix/sysv/linux/s390/force-elision.h: (FORCE_ELISION):
>>>>>      Ensure that elision path is used if elision is available.
>>>>>      * sysdeps/unix/sysv/linux/powerpc/force-elision.h
>>>>>      (FORCE_ELISION): Likewise.
>>>>>      * sysdeps/unix/sysv/linux/x86/force-elision.h: (FORCE_ELISION):
>>>>>      Likewise.
>>>>>      * nptl/pthreadP.h (PTHREAD_MUTEX_TYPE,
>>>>>      PTHREAD_MUTEX_TYPE_ELISION, PTHREAD_MUTEX_PSHARED):
>>>>>      Use atomic_load_relaxed.
>>>>>      * nptl/pthread_mutex_consistent.c (pthread_mutex_consistent):
>>>>>      Likewise.
>>>>>      * nptl/pthread_mutex_getprioceiling.c
>>>>>      (pthread_mutex_getprioceiling): Likewise.
>>>>>      * nptl/pthread_mutex_lock.c (__pthread_mutex_lock_full,
>>>>>      __pthread_mutex_cond_lock_adjust): Likewise.
>>>>>      * nptl/pthread_mutex_setprioceiling.c
>>>>>      (pthread_mutex_setprioceiling): Likewise.
>>>>>      * nptl/pthread_mutex_timedlock.c (__pthread_mutex_timedlock):
>>>>>      Likewise.
>>>>>      * nptl/pthread_mutex_trylock.c (__pthread_mutex_trylock):
>>>>>      Likewise.
>>>>>      * nptl/pthread_mutex_unlock.c (__pthread_mutex_unlock_full):
>>>>>      Likewise.
>>>>>      * sysdeps/nptl/bits/thread-shared-types.h
>>>>>      (struct __pthread_mutex_s): Add comments.
>>>>>      * nptl/pthread_mutex_destroy.c (__pthread_mutex_destroy):
>>>>>      Use atomic_load_relaxed and atomic_store_relaxed.
>>>>>      * nptl/pthread_mutex_init.c (__pthread_mutex_init):
>>>>>      Use atomic_store_relaxed.
>>>>
>>>
>>
> 

  reply	other threads:[~2018-07-16 11:57 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-06-12 14:25 [PATCH] " 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
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 [this message]
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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