The function vhost_worker_queue() uses a function pointer in
vhost_worker, which is initialized based on the inherit_owner
value.

Signed-off-by: Cindy Lu <lulu@redhat.com>
---
 drivers/vhost/vhost.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 0175bbf4d8b3..d1aec41bcd56 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -237,13 +237,16 @@ EXPORT_SYMBOL_GPL(vhost_poll_stop);
 static void vhost_worker_queue(struct vhost_worker *worker,
 			       struct vhost_work *work)
 {
+	if (!worker)
+		return;
+
 	if (!test_and_set_bit(VHOST_WORK_QUEUED, &work->flags)) {
 		/* We can only add the work to the list after we're
 		 * sure it was not in the list.
 		 * test_and_set_bit() implies a memory barrier.
 		 */
 		llist_add(&work->node, &worker->work_list);
-		vhost_task_wake(worker->vtsk);
+		worker->task_wakeup(worker);
 	}
 }
 
-- 
2.45.0

On Wed, Dec 11, 2024 at 12:41:44AM +0800, Cindy Lu wrote:
>The function vhost_worker_queue() uses a function pointer in
>vhost_worker, which is initialized based on the inherit_owner
>value.
>
>Signed-off-by: Cindy Lu <lulu@redhat.com>
>---
> drivers/vhost/vhost.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
>diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
>index 0175bbf4d8b3..d1aec41bcd56 100644
>--- a/drivers/vhost/vhost.c
>+++ b/drivers/vhost/vhost.c
>@@ -237,13 +237,16 @@ EXPORT_SYMBOL_GPL(vhost_poll_stop);
> static void vhost_worker_queue(struct vhost_worker *worker,
> 			       struct vhost_work *work)
> {
>+	if (!worker)
>+		return;
>+

In which scenario can `worker` be NULL?

I would like to better understand why it couldn't happen before and now 
it can.

Thanks,
Stefano

> 	if (!test_and_set_bit(VHOST_WORK_QUEUED, &work->flags)) {
> 		/* We can only add the work to the list after we're
> 		 * sure it was not in the list.
> 		 * test_and_set_bit() implies a memory barrier.
> 		 */
> 		llist_add(&work->node, &worker->work_list);
>-		vhost_task_wake(worker->vtsk);
>+		worker->task_wakeup(worker);
> 	}
> }
>
>-- 
>2.45.0
>