diff options
Diffstat (limited to 'kernel/futex.c')
| -rw-r--r-- | kernel/futex.c | 36 |
1 files changed, 23 insertions, 13 deletions
diff --git a/kernel/futex.c b/kernel/futex.c index 6c91f938005d..1dc98e4dd287 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -607,6 +607,22 @@ static int unlock_futex_pi(u32 __user *uaddr, u32 uval) } /* + * Express the locking dependencies for lockdep: + */ +static inline void +double_lock_hb(struct futex_hash_bucket *hb1, struct futex_hash_bucket *hb2) +{ + if (hb1 <= hb2) { + spin_lock(&hb1->lock); + if (hb1 < hb2) + spin_lock_nested(&hb2->lock, SINGLE_DEPTH_NESTING); + } else { /* hb1 > hb2 */ + spin_lock(&hb2->lock); + spin_lock_nested(&hb1->lock, SINGLE_DEPTH_NESTING); + } +} + +/* * Wake up all waiters hashed on the physical page that is mapped * to this virtual address: */ @@ -630,8 +646,10 @@ static int futex_wake(u32 __user *uaddr, int nr_wake) list_for_each_entry_safe(this, next, head, list) { if (match_futex (&this->key, &key)) { - if (this->pi_state) - return -EINVAL; + if (this->pi_state) { + ret = -EINVAL; + break; + } wake_futex(this); if (++ret >= nr_wake) break; @@ -672,11 +690,7 @@ retryfull: hb2 = hash_futex(&key2); retry: - if (hb1 < hb2) - spin_lock(&hb1->lock); - spin_lock(&hb2->lock); - if (hb1 > hb2) - spin_lock(&hb1->lock); + double_lock_hb(hb1, hb2); op_ret = futex_atomic_op_inuser(op, uaddr2); if (unlikely(op_ret < 0)) { @@ -785,11 +799,7 @@ static int futex_requeue(u32 __user *uaddr1, u32 __user *uaddr2, hb1 = hash_futex(&key1); hb2 = hash_futex(&key2); - if (hb1 < hb2) - spin_lock(&hb1->lock); - spin_lock(&hb2->lock); - if (hb1 > hb2) - spin_lock(&hb1->lock); + double_lock_hb(hb1, hb2); if (likely(cmpval != NULL)) { u32 curval; @@ -1208,7 +1218,7 @@ static int do_futex_lock_pi(u32 __user *uaddr, int detect, int trylock, } down_read(&curr->mm->mmap_sem); - hb = queue_lock(&q, -1, NULL); + spin_lock(q.lock_ptr); /* * Got the lock. We might not be the anticipated owner if we |