epoll: ep_autoremove_wake_function should use list_del_init_careful

commit 2192bba03d upstream.

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: a16ceb1396 ("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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Benjamin Segall 2023-05-30 11:32:28 -07:00 committed by Greg Kroah-Hartman
parent 4716c73b18
commit 370f5d98ff
1 changed files with 5 additions and 1 deletions

View File

@ -1817,7 +1817,11 @@ 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;
}