Messages in this thread Patch in this message | | | From | Xiaoming Ni <> | Subject | [PATCH] semaphore: Add might_sleep() to down_*() family | Date | Mon, 9 Aug 2021 10:12:15 +0800 |
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Semaphore is sleeping lock. Add might_sleep() to down*() family (with exception of down_trylock()) to detect atomic context sleep.
Previously discussed with Peter Zijlstra, see link: https://lore.kernel.org/lkml/20210806082320.GD22037@worktop.programming.kicks-ass.net
Signed-off-by: Xiaoming Ni <nixiaoming@huawei.com> --- kernel/locking/semaphore.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/kernel/locking/semaphore.c b/kernel/locking/semaphore.c index 9aa855a96c4a..9ee381e4d2a4 100644 --- a/kernel/locking/semaphore.c +++ b/kernel/locking/semaphore.c @@ -54,6 +54,7 @@ void down(struct semaphore *sem) { unsigned long flags; + might_sleep(); raw_spin_lock_irqsave(&sem->lock, flags); if (likely(sem->count > 0)) sem->count--; @@ -77,6 +78,7 @@ int down_interruptible(struct semaphore *sem) unsigned long flags; int result = 0; + might_sleep(); raw_spin_lock_irqsave(&sem->lock, flags); if (likely(sem->count > 0)) sem->count--; @@ -103,6 +105,7 @@ int down_killable(struct semaphore *sem) unsigned long flags; int result = 0; + might_sleep(); raw_spin_lock_irqsave(&sem->lock, flags); if (likely(sem->count > 0)) sem->count--; @@ -157,6 +160,7 @@ int down_timeout(struct semaphore *sem, long timeout) unsigned long flags; int result = 0; + might_sleep(); raw_spin_lock_irqsave(&sem->lock, flags); if (likely(sem->count > 0)) sem->count--; -- 2.27.0
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