On Thu, 17 Dec 2020 15:50:34 +0100 "Jürgen Groß" jgross@suse.com wrote:
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On 17.12.20 09:17, SeongJae Park wrote:
From: SeongJae Park sjpark@amazon.de
This commit adds a counter of pending messages for each watch in the struct. It is used to skip unnecessary pending messages lookup in 'unregister_xenbus_watch()'. It could also be used in 'will_handle' callback.
This is part of XSA-349
This is upstream commit 3dc86ca6b4c8cfcba9da7996189d1b5a358a94fc
Cc: stable@vger.kernel.org Signed-off-by: SeongJae Park sjpark@amazon.de Reported-by: Michael Kurth mku@amazon.de Reported-by: Pawel Wieczorkiewicz wipawel@amazon.de Signed-off-by: Author Redacted security@xen.org Reviewed-by: Juergen Gross jgross@suse.com Signed-off-by: Juergen Gross jgross@suse.com
drivers/xen/xenbus/xenbus_xs.c | 30 ++++++++++++++++++------------ include/xen/xenbus.h | 2 ++ 2 files changed, 20 insertions(+), 12 deletions(-)
diff --git a/drivers/xen/xenbus/xenbus_xs.c b/drivers/xen/xenbus/xenbus_xs.c index 0ea1c259f2f1..420d478e1708 100644 --- a/drivers/xen/xenbus/xenbus_xs.c +++ b/drivers/xen/xenbus/xenbus_xs.c @@ -701,6 +701,8 @@ int register_xenbus_watch(struct xenbus_watch *watch) sprintf(token, "%lX", (long)watch);
- watch->nr_pending = 0;
I'm missing the incrementing of nr_pending, which was present in the upstream patch.
Oops, it should be in this patch, but I mistakenly put it in the fifth patch.
67 --- a/drivers/xen/xenbus/xenbus_xs.c 68 +++ b/drivers/xen/xenbus/xenbus_xs.c 69 @@ -917,6 +917,7 @@ static int process_msg(void) 70 msg->u.watch.vec_size))) { 71 spin_lock(&watch_events_lock); 72 list_add_tail(&msg->list, &watch_events); 73 + msg->u.watch.handle->nr_pending++; 74 wake_up(&watch_events_waitq); 75 spin_unlock(&watch_events_lock); 76 } else { 77 --
And I just realized I even didn't post the fifth patch.
I will fix this and post new version (v3) soon.
Thank you for catching this, Juergen.
Thanks, SeongJae Park