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author | Stefan Liebler <stli@linux.ibm.com> | 2019-02-07 15:18:36 +0100 |
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committer | Stefan Liebler <stli@linux.ibm.com> | 2019-02-07 15:18:36 +0100 |
commit | 823624bdc47f1f80109c9c52dee7939b9386d708 (patch) | |
tree | 3fb27f0046891cd5894df1f99362547730e412cd /sysdeps/unix/sysv/linux/arm/libc.abilist | |
parent | 8311c83f91a3127ccd2fe684e25bc60c5178d23b (diff) | |
download | glibc-823624bdc47f1f80109c9c52dee7939b9386d708.tar.gz glibc-823624bdc47f1f80109c9c52dee7939b9386d708.tar.xz glibc-823624bdc47f1f80109c9c52dee7939b9386d708.zip |
Add compiler barriers around modifications of the robust mutex list for pthread_mutex_trylock. [BZ #24180]
While debugging a kernel warning, Thomas Gleixner, Sebastian Sewior and Heiko Carstens found a bug in pthread_mutex_trylock due to misordered instructions: 140: a5 1b 00 01 oill %r1,1 144: e5 48 a0 f0 00 00 mvghi 240(%r10),0 <--- THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL); 14a: e3 10 a0 e0 00 24 stg %r1,224(%r10) <--- last THREAD_SETMEM of ENQUEUE_MUTEX_PI vs (with compiler barriers): 140: a5 1b 00 01 oill %r1,1 144: e3 10 a0 e0 00 24 stg %r1,224(%r10) 14a: e5 48 a0 f0 00 00 mvghi 240(%r10),0 Please have a look at the discussion: "Re: WARN_ON_ONCE(!new_owner) within wake_futex_pi() triggerede" (https://lore.kernel.org/lkml/20190202112006.GB3381@osiris/) This patch is introducing the same compiler barriers and comments for pthread_mutex_trylock as introduced for pthread_mutex_lock and pthread_mutex_timedlock by commit 8f9450a0b7a9e78267e8ae1ab1000ebca08e473e "Add compiler barriers around modifications of the robust mutex list." ChangeLog: [BZ #24180] * nptl/pthread_mutex_trylock.c (__pthread_mutex_trylock):
Diffstat (limited to 'sysdeps/unix/sysv/linux/arm/libc.abilist')
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