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| author | Bernard Ogden <bernie.ogden@linaro.org> | 2014-08-11 15:26:48 +0100 |
|---|---|---|
| committer | Will Newton <will.newton@linaro.org> | 2014-08-12 12:57:27 +0100 |
| commit | 4e75751cbbd47242946f817111066f511dbba739 (patch) | |
| tree | 5d9b2b351ff0621f8090b7b4116ca17ce9d3a52c | |
| parent | bb2ce416563a61bb065f92e022dfd231097d90b6 (diff) | |
| download | glibc-4e75751cbbd47242946f817111066f511dbba739.tar.gz glibc-4e75751cbbd47242946f817111066f511dbba739.tar.xz glibc-4e75751cbbd47242946f817111066f511dbba739.zip | |
Check value of futex before updating in __lll_timedlock
2014-08-12 Bernard Ogden <bernie.ogden@linaro.org> [BZ #16892] * sysdeps/nptl/lowlevellock.h (__lll_timedlock): Use atomic_compare_and_exchange_bool_acq rather than atomic_exchange_acq.
| -rw-r--r-- | ChangeLog | 6 | ||||
| -rw-r--r-- | sysdeps/nptl/lowlevellock.h | 5 |
2 files changed, 10 insertions, 1 deletions
diff --git a/ChangeLog b/ChangeLog index c73d092a20..a1285a8087 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,9 @@ +2014-08-12 Bernard Ogden <bernie.ogden@linaro.org> + + [BZ #16892] + * sysdeps/nptl/lowlevellock.h (__lll_timedlock): Use + atomic_compare_and_exchange_bool_acq rather than atomic_exchange_acq. + 2014-08-12 Sean Anderson <seanga2@gmail.com> * malloc/malloc.c: Fix typo in comment. diff --git a/sysdeps/nptl/lowlevellock.h b/sysdeps/nptl/lowlevellock.h index 548a9c842b..28f4ba3978 100644 --- a/sysdeps/nptl/lowlevellock.h +++ b/sysdeps/nptl/lowlevellock.h @@ -88,12 +88,15 @@ extern int __lll_timedlock_wait (int *futex, const struct timespec *, extern int __lll_robust_timedlock_wait (int *futex, const struct timespec *, int private) attribute_hidden; +/* Take futex if it is untaken. + Otherwise block until either we get the futex or abstime runs out. */ #define __lll_timedlock(futex, abstime, private) \ ({ \ int *__futex = (futex); \ int __val = 0; \ \ - if (__glibc_unlikely (atomic_exchange_acq (__futex, 1))) \ + if (__glibc_unlikely \ + (atomic_compare_and_exchange_bool_acq (__futex, 1, 0))) \ __val = __lll_timedlock_wait (__futex, abstime, private); \ __val; \ }) |