futex: make futex_(get|put)_key() calls symmetric
Impact: cleanup This patch makes the calls to futex_get_key_refs() and futex_drop_key_refs() explicitly symmetric by only "putting" keys we successfully "got". Also cleanup a couple return points that didn't "put" after a successful "get". Build and boot tested on an x86_64 system. Signed-off-by: Darren Hart <dvhltc@us.ibm.com> Cc: <stable@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Darren Hart
Ingo Molnar
parent
b56863630d
commit
42d35d48ce
1 changed files with 36 additions and 31 deletions
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@ -723,8 +723,8 @@ static int futex_wake(u32 __user *uaddr, int fshared, int nr_wake, u32 bitset)
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}
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spin_unlock(&hb->lock);
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out:
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put_futex_key(fshared, &key);
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out:
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return ret;
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}
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@ -748,7 +748,7 @@ retryfull:
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goto out;
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ret = get_futex_key(uaddr2, fshared, &key2);
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if (unlikely(ret != 0))
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goto out;
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goto out_put_key1;
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hb1 = hash_futex(&key1);
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hb2 = hash_futex(&key2);
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@ -770,12 +770,12 @@ retry:
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* but we might get them from range checking
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*/
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ret = op_ret;
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goto out;
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goto out_put_keys;
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#endif
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if (unlikely(op_ret != -EFAULT)) {
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ret = op_ret;
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goto out;
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goto out_put_keys;
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}
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/*
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@ -789,7 +789,7 @@ retry:
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ret = futex_handle_fault((unsigned long)uaddr2,
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attempt);
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if (ret)
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goto out;
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goto out_put_keys;
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goto retry;
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}
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@ -827,10 +827,11 @@ retry:
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spin_unlock(&hb1->lock);
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if (hb1 != hb2)
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spin_unlock(&hb2->lock);
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out:
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out_put_keys:
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put_futex_key(fshared, &key2);
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out_put_key1:
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put_futex_key(fshared, &key1);
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out:
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return ret;
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}
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@ -847,13 +848,13 @@ static int futex_requeue(u32 __user *uaddr1, int fshared, u32 __user *uaddr2,
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struct futex_q *this, *next;
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int ret, drop_count = 0;
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retry:
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retry:
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ret = get_futex_key(uaddr1, fshared, &key1);
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if (unlikely(ret != 0))
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goto out;
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ret = get_futex_key(uaddr2, fshared, &key2);
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if (unlikely(ret != 0))
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goto out;
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goto out_put_key1;
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hb1 = hash_futex(&key1);
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hb2 = hash_futex(&key2);
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@ -875,7 +876,7 @@ static int futex_requeue(u32 __user *uaddr1, int fshared, u32 __user *uaddr2,
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if (!ret)
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goto retry;
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return ret;
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goto out_put_keys;
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}
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if (curval != *cmpval) {
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ret = -EAGAIN;
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@ -920,9 +921,11 @@ out_unlock:
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while (--drop_count >= 0)
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drop_futex_key_refs(&key1);
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out:
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out_put_keys:
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put_futex_key(fshared, &key2);
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out_put_key1:
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put_futex_key(fshared, &key1);
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out:
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return ret;
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}
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@ -983,7 +986,7 @@ static int unqueue_me(struct futex_q *q)
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int ret = 0;
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/* In the common case we don't take the spinlock, which is nice. */
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retry:
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retry:
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lock_ptr = q->lock_ptr;
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barrier();
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if (lock_ptr != NULL) {
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@ -1165,11 +1168,11 @@ static int futex_wait(u32 __user *uaddr, int fshared,
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q.pi_state = NULL;
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q.bitset = bitset;
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retry:
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retry:
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q.key = FUTEX_KEY_INIT;
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ret = get_futex_key(uaddr, fshared, &q.key);
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if (unlikely(ret != 0))
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goto out_release_sem;
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goto out;
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hb = queue_lock(&q);
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@ -1197,6 +1200,7 @@ static int futex_wait(u32 __user *uaddr, int fshared,
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if (unlikely(ret)) {
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queue_unlock(&q, hb);
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put_futex_key(fshared, &q.key);
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ret = get_user(uval, uaddr);
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@ -1206,7 +1210,7 @@ static int futex_wait(u32 __user *uaddr, int fshared,
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}
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ret = -EWOULDBLOCK;
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if (uval != val)
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goto out_unlock_release_sem;
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goto out_unlock_put_key;
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/* Only actually queue if *uaddr contained val. */
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queue_me(&q, hb);
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@ -1298,11 +1302,11 @@ static int futex_wait(u32 __user *uaddr, int fshared,
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return -ERESTART_RESTARTBLOCK;
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}
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out_unlock_release_sem:
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out_unlock_put_key:
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queue_unlock(&q, hb);
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out_release_sem:
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put_futex_key(fshared, &q.key);
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out:
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return ret;
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}
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@ -1351,16 +1355,16 @@ static int futex_lock_pi(u32 __user *uaddr, int fshared,
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}
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q.pi_state = NULL;
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retry:
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retry:
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q.key = FUTEX_KEY_INIT;
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ret = get_futex_key(uaddr, fshared, &q.key);
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if (unlikely(ret != 0))
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goto out_release_sem;
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goto out;
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retry_unlocked:
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retry_unlocked:
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hb = queue_lock(&q);
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retry_locked:
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retry_locked:
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ret = lock_taken = 0;
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/*
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@ -1381,14 +1385,14 @@ static int futex_lock_pi(u32 __user *uaddr, int fshared,
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*/
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if (unlikely((curval & FUTEX_TID_MASK) == task_pid_vnr(current))) {
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ret = -EDEADLK;
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goto out_unlock_release_sem;
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goto out_unlock_put_key;
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}
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/*
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* Surprise - we got the lock. Just return to userspace:
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*/
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if (unlikely(!curval))
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goto out_unlock_release_sem;
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goto out_unlock_put_key;
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uval = curval;
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@ -1424,7 +1428,7 @@ static int futex_lock_pi(u32 __user *uaddr, int fshared,
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* We took the lock due to owner died take over.
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*/
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if (unlikely(lock_taken))
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goto out_unlock_release_sem;
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goto out_unlock_put_key;
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/*
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* We dont have the lock. Look up the PI state (or create it if
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@ -1463,7 +1467,7 @@ static int futex_lock_pi(u32 __user *uaddr, int fshared,
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goto retry_locked;
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}
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default:
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goto out_unlock_release_sem;
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goto out_unlock_put_key;
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}
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}
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@ -1554,16 +1558,17 @@ static int futex_lock_pi(u32 __user *uaddr, int fshared,
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destroy_hrtimer_on_stack(&to->timer);
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return ret != -EINTR ? ret : -ERESTARTNOINTR;
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out_unlock_release_sem:
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out_unlock_put_key:
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queue_unlock(&q, hb);
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out_release_sem:
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out_put_key:
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put_futex_key(fshared, &q.key);
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out:
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if (to)
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destroy_hrtimer_on_stack(&to->timer);
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return ret;
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uaddr_faulted:
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uaddr_faulted:
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/*
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* We have to r/w *(int __user *)uaddr, and we have to modify it
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* atomically. Therefore, if we continue to fault after get_user()
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@ -1576,7 +1581,7 @@ static int futex_lock_pi(u32 __user *uaddr, int fshared,
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if (attempt++) {
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ret = futex_handle_fault((unsigned long)uaddr, attempt);
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if (ret)
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goto out_release_sem;
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goto out_put_key;
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goto retry_unlocked;
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}
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@ -1668,9 +1673,9 @@ retry_unlocked:
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out_unlock:
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spin_unlock(&hb->lock);
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out:
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put_futex_key(fshared, &key);
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out:
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return ret;
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pi_faulted:
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