[PATCH] pi-futex: futex_wake() lockup fix

Fix futex_wake() exit condition bug when handling the robust-list with PI
futexes on them.

(reported by Ulrich Drepper, debugged by the lock validator.)
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Cc: Ulrich Drepper <drepper@redhat.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

kernel/futex.c

@@ -630,8 +630,10 @@ 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;