On 01/18/2018 12:44 AM, Michael S. Tsirkin wrote:
On Wed, Jan 17, 2018 at 01:10:11PM +0800, Wei Wang wrote:
+static void virtballoon_changed(struct virtio_device *vdev)
+{
+ struct virtio_balloon *vb = vdev->priv;
+ unsigned long flags;
+ __u32 cmd_id;
+ s64 diff = towards_target(vb);
+
+ if (diff) {
+ spin_lock_irqsave(&vb->stop_update_lock, flags);
+ if (!vb->stop_update)
Why do you ignore stop_update for freeze?
This means new wq entries can be added during remove
causing use after free issues.
I think stop_update isn't needed, because the lock has already been
handled internally by the APIs. Similar examples like
mem_cgroup_css_free() in "mm/memcontrol.c", there is no such locks used
for cancel_work_sync(&memcg->high_work).
Best,
Wei
