This is a note to let you know that I've just added the patch titled
watch_queue: Fix missing rcu annotation
to the 5.18-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
watch_queue-fix-missing-rcu-annotation.patch
and it can be found in the queue-5.18 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From e0339f036ef4beb9b20f0b6532a1e0ece7f594c6 Mon Sep 17 00:00:00 2001
From: David Howells <dhowells@xxxxxxxxxx>
Date: Thu, 28 Jul 2022 10:31:06 +0100
Subject: watch_queue: Fix missing rcu annotation
From: David Howells <dhowells@xxxxxxxxxx>
commit e0339f036ef4beb9b20f0b6532a1e0ece7f594c6 upstream.
Since __post_watch_notification() walks wlist->watchers with only the
RCU read lock held, we need to use RCU methods to add to the list (we
already use RCU methods to remove from the list).
Fix add_watch_to_object() to use hlist_add_head_rcu() instead of
hlist_add_head() for that list.
Fixes: c73be61cede5 ("pipe: Add general notification queue support")
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
kernel/watch_queue.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/kernel/watch_queue.c
+++ b/kernel/watch_queue.c
@@ -494,7 +494,7 @@ int add_watch_to_object(struct watch *wa
unlock_wqueue(wqueue);
}
- hlist_add_head(&watch->list_node, &wlist->watchers);
+ hlist_add_head_rcu(&watch->list_node, &wlist->watchers);
return 0;
}
EXPORT_SYMBOL(add_watch_to_object);
Patches currently in stable-queue which might be from dhowells@xxxxxxxxxx are
queue-5.18/watch_queue-fix-missing-rcu-annotation.patch
queue-5.18/watch_queue-fix-missing-locking-in-add_watch_to_object.patch
