[tip: locking/core] locking/semaphore: Add might_sleep() to down_*() family

["tip-bot2 for Xiaoming Ni" <tip-bot2@linutronix.de>]

The following commit has been merged into the locking/core branch of tip:

Commit-ID:     99409b935c9ac5ea36ab5218954115c52449234d
Gitweb:        https://git.kernel.org/tip/99409b935c9ac5ea36ab5218954115c52449234d
Author:        Xiaoming Ni <nixiaoming@huawei.com>
AuthorDate:    Mon, 09 Aug 2021 10:12:15 +08:00
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Fri, 20 Aug 2021 12:33:17 +02:00

locking/semaphore: Add might_sleep() to down_*() family

Semaphore is sleeping lock. Add might_sleep() to down*() family
(with exception of down_trylock()) to detect atomic context sleep.

Signed-off-by: Xiaoming Ni <nixiaoming@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210809021215.19991-1-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 9aa855a..9ee381e 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--;