4.5-stable review patch. If anyone has any objections, please let me know. ------------------ From: Davidlohr Bueso <dave@xxxxxxxxxxxx> commit fe1bce9e2107ba3a8faffe572483b6974201a0e6 upstream. Otherwise an incoming waker on the dest hash bucket can miss the waiter adding itself to the plist during the lockless check optimization (small window but still the correct way of doing this); similarly to the decrement counterpart. Suggested-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Signed-off-by: Davidlohr Bueso <dbueso@xxxxxxx> Cc: Davidlohr Bueso <dave@xxxxxxxxxxxx> Cc: bigeasy@xxxxxxxxxxxxx Cc: dvhart@xxxxxxxxxxxxx Link: http://lkml.kernel.org/r/1461208164-29150-1-git-send-email-dave@xxxxxxxxxxxx Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- kernel/futex.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/kernel/futex.c +++ b/kernel/futex.c @@ -1452,8 +1452,8 @@ void requeue_futex(struct futex_q *q, st if (likely(&hb1->chain != &hb2->chain)) { plist_del(&q->list, &hb1->chain); hb_waiters_dec(hb1); - plist_add(&q->list, &hb2->chain); hb_waiters_inc(hb2); + plist_add(&q->list, &hb2->chain); q->lock_ptr = &hb2->lock; } get_futex_key_refs(key2); -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html