diff options
Diffstat (limited to 'kernel/futex.c')
| -rw-r--r-- | kernel/futex.c | 31 |
1 files changed, 16 insertions, 15 deletions
diff --git a/kernel/futex.c b/kernel/futex.c index 9b9fda73ba2e..a118bf160e0b 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -1367,7 +1367,6 @@ static inline struct futex_hash_bucket *queue_lock(struct futex_q *q) { struct futex_hash_bucket *hb; - get_futex_key_refs(&q->key); hb = hash_futex(&q->key); q->lock_ptr = &hb->lock; @@ -1380,7 +1379,6 @@ queue_unlock(struct futex_q *q, struct futex_hash_bucket *hb) __releases(&hb->lock) { spin_unlock(&hb->lock); - drop_futex_key_refs(&q->key); } /** @@ -1487,8 +1485,6 @@ static void unqueue_me_pi(struct futex_q *q) q->pi_state = NULL; spin_unlock(q->lock_ptr); - - drop_futex_key_refs(&q->key); } /* @@ -1819,7 +1815,10 @@ static int futex_wait(u32 __user *uaddr, int fshared, } retry: - /* Prepare to wait on uaddr. */ + /* + * Prepare to wait on uaddr. On success, holds hb lock and increments + * q.key refs. + */ ret = futex_wait_setup(uaddr, val, fshared, &q, &hb); if (ret) goto out; @@ -1829,24 +1828,23 @@ retry: /* If we were woken (and unqueued), we succeeded, whatever. */ ret = 0; + /* unqueue_me() drops q.key ref */ if (!unqueue_me(&q)) - goto out_put_key; + goto out; ret = -ETIMEDOUT; if (to && !to->task) - goto out_put_key; + goto out; /* * We expect signal_pending(current), but we might be the * victim of a spurious wakeup as well. */ - if (!signal_pending(current)) { - put_futex_key(fshared, &q.key); + if (!signal_pending(current)) goto retry; - } ret = -ERESTARTSYS; if (!abs_time) - goto out_put_key; + goto out; restart = ¤t_thread_info()->restart_block; restart->fn = futex_wait_restart; @@ -1863,8 +1861,6 @@ retry: ret = -ERESTART_RESTARTBLOCK; -out_put_key: - put_futex_key(fshared, &q.key); out: if (to) { hrtimer_cancel(&to->timer); @@ -2243,7 +2239,10 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, int fshared, q.rt_waiter = &rt_waiter; q.requeue_pi_key = &key2; - /* Prepare to wait on uaddr. */ + /* + * Prepare to wait on uaddr. On success, increments q.key (key1) ref + * count. + */ ret = futex_wait_setup(uaddr, val, fshared, &q, &hb); if (ret) goto out_key2; @@ -2261,7 +2260,9 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, int fshared, * In order for us to be here, we know our q.key == key2, and since * we took the hb->lock above, we also know that futex_requeue() has * completed and we no longer have to concern ourselves with a wakeup - * race with the atomic proxy lock acquition by the requeue code. + * race with the atomic proxy lock acquisition by the requeue code. The + * futex_requeue dropped our key1 reference and incremented our key2 + * reference count. */ /* Check if the requeue code acquired the second futex for us. */ |