Commit 6200b0ae authored by Jens Axboe's avatar Jens Axboe
Browse files

io_uring: don't run task work on an exiting task 



This isn't safe, and isn't needed either. We are guaranteed that any
work we queue is on a live task (and will be run), or it goes to
our backup io-wq threads if the task is exiting.

Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 87ceb6a6

fs/io_uring.c

+11 −0
Original line number Diff line number Diff line
@@ -1753,6 +1753,9 @@ static int io_req_task_work_add(struct io_kiocb *req, struct callback_head *cb, 
	struct io_ring_ctx *ctx = req->ctx;

	int ret, notify;



	if (tsk->flags & PF_EXITING)

		return -ESRCH;



	/*

	 * SQPOLL kernel thread doesn't need notification, just a wakeup. For

	 * all other cases, use TWA_SIGNAL unconditionally to ensure we're
@@ -2012,6 +2015,12 @@ static inline unsigned int io_put_rw_kbuf(struct io_kiocb *req) 


static inline bool io_run_task_work(void)

{

	/*

	 * Not safe to run on exiting task, and the task_work handling will

	 * not add work to such a task.

	 */

	if (unlikely(current->flags & PF_EXITING))

		return false;

	if (current->task_works) {

		__set_current_state(TASK_RUNNING);

		task_work_run();
@@ -8184,6 +8193,8 @@ static void io_uring_cancel_files(struct io_ring_ctx *ctx, 
		/* cancel this request, or head link requests */

		io_attempt_cancel(ctx, cancel_req);

		io_put_req(cancel_req);

		/* cancellations _may_ trigger task work */

		io_run_task_work();

		schedule();

		finish_wait(&ctx->inflight_wait, &wait);

	}

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