From 38a3e1fc1dac480f3672ab22fc97e1f995c80ed7 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Tue, 6 Sep 2016 16:00:47 +0200 Subject: sched/wait: Fix abort_exclusive_wait(), it should pass TASK_NORMAL to wake_up() Otherwise this logic only works if mode is "compatible" with another exclusive waiter. If some wq has both TASK_INTERRUPTIBLE and TASK_UNINTERRUPTIBLE waiters, abort_exclusive_wait() won't wait an uninterruptible waiter. The main user is __wait_on_bit_lock() and currently it is fine but only because TASK_KILLABLE includes TASK_UNINTERRUPTIBLE and we do not have lock_page_interruptible() yet. Just use TASK_NORMAL and remove the "mode" arg from abort_exclusive_wait(). Yes, this means that (say) wake_up_interruptible() can wake up the non- interruptible waiter(s), but I think this is fine. And in fact I think that abort_exclusive_wait() must die, see the next change. Signed-off-by: Oleg Nesterov Signed-off-by: Peter Zijlstra (Intel) Cc: Al Viro Cc: Bart Van Assche Cc: Johannes Weiner Cc: Linus Torvalds Cc: Mike Galbraith Cc: Neil Brown Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20160906140047.GA6157@redhat.com Signed-off-by: Ingo Molnar --- include/linux/wait.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'include/linux/wait.h') diff --git a/include/linux/wait.h b/include/linux/wait.h index c3ff74d764fa..e4cfd1ed726e 100644 --- a/include/linux/wait.h +++ b/include/linux/wait.h @@ -281,8 +281,8 @@ wait_queue_head_t *bit_waitqueue(void *, int); if (___wait_is_interruptible(state) && __int) { \ __ret = __int; \ if (exclusive) { \ - abort_exclusive_wait(&wq, &__wait, \ - state, NULL); \ + abort_exclusive_wait(&wq, &__wait, \ + NULL); \ goto __out; \ } \ break; \ @@ -989,7 +989,7 @@ void prepare_to_wait(wait_queue_head_t *q, wait_queue_t *wait, int state); void prepare_to_wait_exclusive(wait_queue_head_t *q, wait_queue_t *wait, int state); long prepare_to_wait_event(wait_queue_head_t *q, wait_queue_t *wait, int state); void finish_wait(wait_queue_head_t *q, wait_queue_t *wait); -void abort_exclusive_wait(wait_queue_head_t *q, wait_queue_t *wait, unsigned int mode, void *key); +void abort_exclusive_wait(wait_queue_head_t *q, wait_queue_t *wait, void *key); long wait_woken(wait_queue_t *wait, unsigned mode, long timeout); int woken_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key); int autoremove_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key); -- cgit