tree 448a35c4c5f29e1b8884ffc7d18cbacbf38fa83d
parent 92aefc62f483be76e16f8bb106201c2e358984e1
author Juergen Gross <jgross@suse.com> 1615796558 +0100
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1615997038 +0100

xen/events: avoid handling the same event on two cpus at the same time

commit b6622798bc50b625a1e62f82c7190df40c1f5b21 upstream.

When changing the cpu affinity of an event it can happen today that
(with some unlucky timing) the same event will be handled on the old
and the new cpu at the same time.

Avoid that by adding an "event active" flag to the per-event data and
call the handler only if this flag isn't set.

Cc: stable@vger.kernel.org
Reported-by: Julien Grall <julien@xen.org>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Link: https://lore.kernel.org/r/20210306161833.4552-4-jgross@suse.com
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>