@@ -179,6 +179,7 @@ struct vsp1_dl_cmd_pool {
* @has_chain: if true, indicates that there's a partition chain
* @chain: entry in the display list partition chain
* @flags: display list flags, a combination of VSP1_DL_FRAME_END_*
+ * @usage: usage counter to detect double list free
*/
struct vsp1_dl_list {
struct list_head list;
@@ -198,6 +199,7 @@ struct vsp1_dl_list {
struct list_head chain;
unsigned int flags;
+ int usage;
};
/**
@@ -617,6 +619,7 @@ struct vsp1_dl_list *vsp1_dl_list_get(struct vsp1_dl_manager *dlm)
* display list can assert list_empty() if it is not in a chain.
*/
INIT_LIST_HEAD(&dl->chain);
+ dl->usage++;
}
spin_unlock_irqrestore(&dlm->lock, flags);
@@ -657,6 +660,10 @@ static void __vsp1_dl_list_put(struct vsp1_dl_list *dl)
*/
dl->body0->num_entries = 0;
+ /* decrement usage count to detect invalid usage pattern. */
+ if (WARN_ON_ONCE(--dl->usage < 0))
+ dl->usage = 0;
+
list_add_tail(&dl->list, &dl->dlm->free);
}
In order to detect invalid usage pattern such as double list_put() calls, add a usage counter to each display list. Increment it whenever a list is get() and decrement it when the list is put(). Warn if the usage counter goes below 0. Signed-off-by: Jacopo Mondi <jacopo.mondi+renesas@ideasonboard.com> --- drivers/media/platform/renesas/vsp1/vsp1_dl.c | 7 +++++++ 1 file changed, 7 insertions(+)