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author | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-12-24 09:43:21 -0800 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-12-24 09:43:21 -0800 |
commit | 5bd2010fbe027b224db2e74a4fdfec9a7b7918d2 (patch) | |
tree | 59106aae3930a3608409c101ec32d68742c8d168 /drivers/tty/tty_ldsem.c | |
parent | 41f107266b19d100c1bcef9e1e1aef00692c1209 (diff) | |
parent | 413541dd66d51f791a0b169d9b9014e4f56be13c (diff) | |
download | kernel_replicant_linux-5bd2010fbe027b224db2e74a4fdfec9a7b7918d2.tar.gz kernel_replicant_linux-5bd2010fbe027b224db2e74a4fdfec9a7b7918d2.tar.bz2 kernel_replicant_linux-5bd2010fbe027b224db2e74a4fdfec9a7b7918d2.zip |
Merge 3.13-rc5 into staging-next
We want these fixes here to handle some merge issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/tty_ldsem.c')
-rw-r--r-- | drivers/tty/tty_ldsem.c | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/drivers/tty/tty_ldsem.c b/drivers/tty/tty_ldsem.c index 22fad8ad5ac2..d8a55e87877f 100644 --- a/drivers/tty/tty_ldsem.c +++ b/drivers/tty/tty_ldsem.c @@ -86,11 +86,21 @@ static inline long ldsem_atomic_update(long delta, struct ld_semaphore *sem) return atomic_long_add_return(delta, (atomic_long_t *)&sem->count); } +/* + * ldsem_cmpxchg() updates @*old with the last-known sem->count value. + * Returns 1 if count was successfully changed; @*old will have @new value. + * Returns 0 if count was not changed; @*old will have most recent sem->count + */ static inline int ldsem_cmpxchg(long *old, long new, struct ld_semaphore *sem) { - long tmp = *old; - *old = atomic_long_cmpxchg(&sem->count, *old, new); - return *old == tmp; + long tmp = atomic_long_cmpxchg(&sem->count, *old, new); + if (tmp == *old) { + *old = new; + return 1; + } else { + *old = tmp; + return 0; + } } /* |