[PATCH v2 06/14] locking/rwsem: Annotate rwsem internal functions with __must_hold()

[Bart Van Assche <bvanassche@acm.org>]

Annotate rwsem_del_waiter(), rwsem_mark_wake(), and
rwsem_cond_wake_waiter() with __must_hold(&sem->wait_lock).

rwsem_del_waiter(), rwsem_mark_wake(), and rwsem_cond_wake_waiter()
access members guarded by sem->wait_lock and call functions requiring
sem->wait_lock. Currently, lockdep_assert_held(&sem->wait_lock)
implicitly assumes lock ownership for Clang context analysis. Prepare
for removing the context assumption from lockdep_assert_held() by
explicitly annotating these functions with __must_hold(&sem->wait_lock).

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 kernel/locking/rwsem.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c
index b9c180ac1eee..c76a3a712c31 100644
--- a/kernel/locking/rwsem.c
+++ b/kernel/locking/rwsem.c
@@ -392,6 +392,7 @@ bool __rwsem_del_waiter(struct rw_semaphore *sem, struct rwsem_waiter *waiter)
  */
 static inline bool
 rwsem_del_waiter(struct rw_semaphore *sem, struct rwsem_waiter *waiter)
+	__must_hold(&sem->wait_lock)
 {
 	lockdep_assert_held(&sem->wait_lock);
 	if (__rwsem_del_waiter(sem, waiter))
@@ -429,6 +430,7 @@ struct rwsem_waiter *next_waiter(const struct rw_semaphore *sem,
 static void rwsem_mark_wake(struct rw_semaphore *sem,
 			    enum rwsem_wake_type wake_type,
 			    struct wake_q_head *wake_q)
+	__must_hold(&sem->wait_lock)
 {
 	struct rwsem_waiter *waiter, *next;
 	long oldcount, woken = 0, adjustment = 0;
@@ -995,6 +997,7 @@ rwsem_spin_on_owner(struct rw_semaphore *sem)
  */
 static inline void rwsem_cond_wake_waiter(struct rw_semaphore *sem, long count,
 					  struct wake_q_head *wake_q)
+	__must_hold(&sem->wait_lock)
 {
 	enum rwsem_wake_type wake_type;