io_uring: clear TIF_NOTIFY_SIGNAL if set and task_work not available

With how task_work is added and signaled, we can have TIF_NOTIFY_SIGNAL
set and no task_work pending as it got run in a previous loop. Treat
TIF_NOTIFY_SIGNAL like get_signal(), always clear it if set regardless
of whether or not task_work is pending to run.

Cc: stable@vger.kernel.org
Fixes: 46a525e199 ("io_uring: don't gate task_work run on TIF_NOTIFY_SIGNAL")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Jens Axboe 2022-11-25 09:36:29 -07:00
parent 12ad3d2d6c
commit 7cfe7a0948
1 changed files with 7 additions and 2 deletions

View File

@ -238,9 +238,14 @@ static inline unsigned int io_sqring_entries(struct io_ring_ctx *ctx)
static inline int io_run_task_work(void)
{
/*
* Always check-and-clear the task_work notification signal. With how
* signaling works for task_work, we can find it set with nothing to
* run. We need to clear it for that case, like get_signal() does.
*/
if (test_thread_flag(TIF_NOTIFY_SIGNAL))
clear_notify_signal();
if (task_work_pending(current)) {
if (test_thread_flag(TIF_NOTIFY_SIGNAL))
clear_notify_signal();
__set_current_state(TASK_RUNNING);
task_work_run();
return 1;