diff options
| -rw-r--r-- | kernel/futex.c | 31 |
1 files changed, 23 insertions, 8 deletions
diff --git a/kernel/futex.c b/kernel/futex.c index b766d28accd6..6feeea4f8f15 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -775,6 +775,24 @@ retry: return ret; } +/** + * __unqueue_futex() - Remove the futex_q from its futex_hash_bucket + * @q: The futex_q to unqueue + * + * The q->lock_ptr must not be NULL and must be held by the caller. + */ +static void __unqueue_futex(struct futex_q *q) +{ + struct futex_hash_bucket *hb; + + if (WARN_ON(!q->lock_ptr || !spin_is_locked(q->lock_ptr) + || plist_node_empty(&q->list))) + return; + + hb = container_of(q->lock_ptr, struct futex_hash_bucket, lock); + plist_del(&q->list, &hb->chain); +} + /* * The hash bucket lock must be held when this is called. * Afterwards, the futex_q must not be accessed. @@ -792,7 +810,7 @@ static void wake_futex(struct futex_q *q) */ get_task_struct(p); - plist_del(&q->list, &q->list.plist); + __unqueue_futex(q); /* * The waiting task can free the futex_q as soon as * q->lock_ptr = NULL is written, without taking any locks. A @@ -1100,8 +1118,7 @@ void requeue_pi_wake_futex(struct futex_q *q, union futex_key *key, get_futex_key_refs(key); q->key = *key; - WARN_ON(plist_node_empty(&q->list)); - plist_del(&q->list, &q->list.plist); + __unqueue_futex(q); WARN_ON(!q->rt_waiter); q->rt_waiter = NULL; @@ -1504,8 +1521,7 @@ retry: spin_unlock(lock_ptr); goto retry; } - WARN_ON(plist_node_empty(&q->list)); - plist_del(&q->list, &q->list.plist); + __unqueue_futex(q); BUG_ON(q->pi_state); @@ -1525,8 +1541,7 @@ retry: static void unqueue_me_pi(struct futex_q *q) __releases(q->lock_ptr) { - WARN_ON(plist_node_empty(&q->list)); - plist_del(&q->list, &q->list.plist); + __unqueue_futex(q); BUG_ON(!q->pi_state); free_pi_state(q->pi_state); @@ -2167,7 +2182,7 @@ int handle_early_requeue_pi_wakeup(struct futex_hash_bucket *hb, * We were woken prior to requeue by a timeout or a signal. * Unqueue the futex_q and determine which it was. */ - plist_del(&q->list, &q->list.plist); + plist_del(&q->list, &hb->chain); /* Handle spurious wakeups gracefully */ ret = -EWOULDBLOCK; |