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-rw-r--r--kernel/futex.c23
1 files changed, 16 insertions, 7 deletions
diff --git a/kernel/futex.c b/kernel/futex.c
index b911adc..fb65e82 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -150,7 +150,8 @@ static struct futex_hash_bucket *hash_futex(union futex_key *key)
*/
static inline int match_futex(union futex_key *key1, union futex_key *key2)
{
- return (key1->both.word == key2->both.word
+ return (key1 && key2
+ && key1->both.word == key2->both.word
&& key1->both.ptr == key2->both.ptr
&& key1->both.offset == key2->both.offset);
}
@@ -916,8 +917,8 @@ retry:
hb1 = hash_futex(&key1);
hb2 = hash_futex(&key2);
- double_lock_hb(hb1, hb2);
retry_private:
+ double_lock_hb(hb1, hb2);
op_ret = futex_atomic_op_inuser(op, uaddr2);
if (unlikely(op_ret < 0)) {
@@ -1028,7 +1029,6 @@ static inline
void requeue_pi_wake_futex(struct futex_q *q, union futex_key *key,
struct futex_hash_bucket *hb)
{
- drop_futex_key_refs(&q->key);
get_futex_key_refs(key);
q->key = *key;
@@ -1226,6 +1226,7 @@ retry_private:
*/
if (ret == 1) {
WARN_ON(pi_state);
+ drop_count++;
task_count++;
ret = get_futex_value_locked(&curval2, uaddr2);
if (!ret)
@@ -1304,6 +1305,7 @@ retry_private:
if (ret == 1) {
/* We got the lock. */
requeue_pi_wake_futex(this, &key2, hb2);
+ drop_count++;
continue;
} else if (ret) {
/* -EDEADLK */
@@ -1791,6 +1793,7 @@ static int futex_wait(u32 __user *uaddr, int fshared,
current->timer_slack_ns);
}
+retry:
/* Prepare to wait on uaddr. */
ret = futex_wait_setup(uaddr, val, fshared, &q, &hb);
if (ret)
@@ -1808,9 +1811,14 @@ static int futex_wait(u32 __user *uaddr, int fshared,
goto out_put_key;
/*
- * We expect signal_pending(current), but another thread may
- * have handled it for us already.
+ * 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);
+ goto retry;
+ }
+
ret = -ERESTARTSYS;
if (!abs_time)
goto out_put_key;
@@ -2117,11 +2125,12 @@ int handle_early_requeue_pi_wakeup(struct futex_hash_bucket *hb,
* Unqueue the futex_q and determine which it was.
*/
plist_del(&q->list, &q->list.plist);
- drop_futex_key_refs(&q->key);
+ /* Handle spurious wakeups gracefully */
+ ret = -EWOULDBLOCK;
if (timeout && !timeout->task)
ret = -ETIMEDOUT;
- else
+ else if (signal_pending(current))
ret = -ERESTARTNOINTR;
}
return ret;
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