[media] media-entity: clear media_gobj.mdev in _destroy()

media_gobj_destroy() may be called twice on one instance - once by media_device_unregister() and again by dvb_media_device_free(). The function media_remove_intf_links() establishes and documents the convention that mdev==NULL means that the object is not registered, but nobody ever NULLs this variable. So this patch really implements this behavior, and adds another mdev==NULL check to media_gobj_destroy() to protect against double removal. Signed-off-by: Max Kellermann <[email protected]> Signed-off-by: Mauro Carvalho Chehab <[email protected]>
kawasaki · Nov 18, 2016 · 6753743 · 6753743
1 parent 1f862a6
commit 6753743
Showing 1 changed file with 6 additions and 0 deletions.
diff --git a/drivers/media/media-entity.c b/drivers/media/media-entity.c
@@ -205,10 +205,16 @@ void media_gobj_destroy(struct media_gobj *gobj)
 {
 	dev_dbg_obj(__func__, gobj);
 
+	/* Do nothing if the object is not linked. */
+	if (gobj->mdev == NULL)
+		return;
+
 	gobj->mdev->topology_version++;
 
 	/* Remove the object from mdev list */
 	list_del(&gobj->list);
+
+	gobj->mdev = NULL;
 }
 
 int media_entity_pads_init(struct media_entity *entity, u16 num_pads,