From: Pavel Begunkov <asml.silence@gmail.com>
Date: Mon, 23 Jan 2023 14:37:13 +0000
Subject: [PATCH] io_uring: use user visible tail in io_uring_poll()
References: bsc#1012628
Patch-mainline: 6.2.3
Git-commit: c10bb64684813a326174c3eebcafb3ee5af52ca3
commit c10bb64684813a326174c3eebcafb3ee5af52ca3 upstream.
We return POLLIN from io_uring_poll() depending on whether there are
CQEs for the userspace, and so we should use the user visible tail
pointer instead of a transient cached value.
Cc: stable@vger.kernel.org
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/228ffcbf30ba98856f66ffdb9a6a60ead1dd96c0.1674484266.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
io_uring/io_uring.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index db623b31..fbeb9d21 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -2790,7 +2790,7 @@ static __poll_t io_uring_poll(struct file *file, poll_table *wait)
* pushes them to do the flush.
*/
- if (io_cqring_events(ctx) || io_has_work(ctx))
+ if (__io_cqring_events_user(ctx) || io_has_work(ctx))
mask |= EPOLLIN | EPOLLRDNORM;
return mask;
--
2.35.3