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authorGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-12-24 09:43:21 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-12-24 09:43:21 -0800
commit5bd2010fbe027b224db2e74a4fdfec9a7b7918d2 (patch)
tree59106aae3930a3608409c101ec32d68742c8d168 /drivers/tty/tty_ldsem.c
parent41f107266b19d100c1bcef9e1e1aef00692c1209 (diff)
parent413541dd66d51f791a0b169d9b9014e4f56be13c (diff)
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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.c16
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;
+ }
}
/*