Commit e14e9cc5 authored May 30, 2023 by Benjamin Segall Committed by Greg Kroah-Hartman Jun 28, 2023

epoll: ep_autoremove_wake_function should use list_del_init_careful

[ Upstream commit 2192bba03d80f829233bfa34506b428f71e531e7 ]

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@google.com: add comment]
  Link: https://lkml.kernel.org/r/xm26bki0ulsr.fsf_-_@google.com
Link: https://lkml.kernel.org/r/xm26pm6hvfer.fsf@google.com


Fixes: a16ceb139610 ("epoll: autoremove wakers even more aggressively")
Signed-off-by: Ben Segall <bsegall@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent e77e5481

fs/eventpoll.c

+5 −1

Original line number	Diff line number	Diff line
		@@ -1814,7 +1814,11 @@ 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;
		}