[PATCH 4/4] io_uring: cancel requests enqueued as task_work's

Pavel Begunkov
2020-12-30T21:38:49Z

Currently request cancellations are happening before PF_EXITING is set,
so it's allowed to call task_work_run(). Even though it should work as
it's not it's safer to remove PF_EXITING checks.

Cc: stable@vger.kernel.org # 5.5+
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
fs/io_uring.c | 8 ++------
1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index ca46f314640b..8d4fa0031e0a 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -2361,12 +2361,8 @@ 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;
+ WARN_ON_ONCE(current->flags & PF_EXITING);
+
if (current->task_works) {
__set_current_state(TASK_RUNNING);
task_work_run();
--
2.24.0