The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable@xxxxxxxxxxxxxxx>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x 2192bba03d80f829233bfa34506b428f71e531e7 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable@xxxxxxxxxxxxxxx>' --in-reply-to '2023061737-smartness-mummify-9865@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 2192bba03d80f829233bfa34506b428f71e531e7 Mon Sep 17 00:00:00 2001 From: Benjamin Segall <bsegall@xxxxxxxxxx> Date: Tue, 30 May 2023 11:32:28 -0700 Subject: [PATCH] epoll: ep_autoremove_wake_function should use list_del_init_careful autoremove_wake_function uses list_del_init_careful, so should epoll's more aggressive variant. It only doesn't because it was copied from an older wait.c rather than the most recent. [bsegall@xxxxxxxxxx: add comment] Link: https://lkml.kernel.org/r/xm26bki0ulsr.fsf_-_@xxxxxxxxxx Link: https://lkml.kernel.org/r/xm26pm6hvfer.fsf@xxxxxxxxxx Fixes: a16ceb139610 ("epoll: autoremove wakers even more aggressively") Signed-off-by: Ben Segall <bsegall@xxxxxxxxxx> Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: Christian Brauner <brauner@xxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> diff --git a/fs/eventpoll.c b/fs/eventpoll.c index 980483455cc0..266d45c7685b 100644 --- a/fs/eventpoll.c +++ b/fs/eventpoll.c @@ -1805,7 +1805,11 @@ static int ep_autoremove_wake_function(struct wait_queue_entry *wq_entry, { int ret = default_wake_function(wq_entry, mode, sync, key); - list_del_init(&wq_entry->entry); + /* + * Pairs with list_empty_careful in ep_poll, and ensures future loop + * iterations see the cause of this wakeup. + */ + list_del_init_careful(&wq_entry->entry); return ret; }
