media: v4l: subdev: Also return pads array information on stream functions

There are two sets of functions that return information from sub-device
state, one for stream-unaware users and another for stream-aware users.
Add support for stream-aware functions to return format, crop and compose
information from pad-based array that are functionally equivalent to the
old, stream-unaware ones.

Also check state is non-NULL, in order to guard against old drivers
potentially calling this with NULL state for active formats or selection
rectangles.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

2 files changed, 69 insertions, 3 deletions

diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
index cd3ff5b19d0c..554d0c128ee9 100644
--- a/drivers/media/v4l2-core/v4l2-subdev.c
+++ b/drivers/media/v4l2-core/v4l2-subdev.c
@@ -1691,6 +1691,27 @@ v4l2_subdev_state_get_stream_format(struct v4l2_subdev_state *state,
 	struct v4l2_subdev_stream_configs *stream_configs;
 	unsigned int i;
 
+	if (WARN_ON_ONCE(!state))
+		return NULL;
+
+	if (state->pads) {
+		if (stream)
+			return NULL;
+
+		/*
+		 * Set the pad to 0 on error as this is aligned with the
+		 * behaviour of the pad state information access functions. The
+		 * purpose of setting pad to 0 here is to avoid accessing memory
+		 * outside the pads array, but still issuing warning of the
+		 * invalid access while making the caller's error handling
+		 * easier.
+		 */
+		if (WARN_ON_ONCE(pad >= state->sd->entity.num_pads))
+			pad = 0;
+
+		return &state->pads[pad].format;
+	}
+
 	lockdep_assert_held(state->lock);
 
 	stream_configs = &state->stream_configs;
@@ -1712,6 +1733,27 @@ v4l2_subdev_state_get_stream_crop(struct v4l2_subdev_state *state,
 	struct v4l2_subdev_stream_configs *stream_configs;
 	unsigned int i;
 
+	if (WARN_ON_ONCE(!state))
+		return NULL;
+
+	if (state->pads) {
+		if (stream)
+			return NULL;
+
+		/*
+		 * Set the pad to 0 on error as this is aligned with the
+		 * behaviour of the pad state information access functions. The
+		 * purpose of setting pad to 0 here is to avoid accessing memory
+		 * outside the pads array, but still issuing warning of the
+		 * invalid access while making the caller's error handling
+		 * easier.
+		 */
+		if (WARN_ON_ONCE(pad >= state->sd->entity.num_pads))
+			pad = 0;
+
+		return &state->pads[pad].crop;
+	}
+
 	lockdep_assert_held(state->lock);
 
 	stream_configs = &state->stream_configs;
@@ -1733,6 +1775,27 @@ v4l2_subdev_state_get_stream_compose(struct v4l2_subdev_state *state,
 	struct v4l2_subdev_stream_configs *stream_configs;
 	unsigned int i;
 
+	if (WARN_ON_ONCE(!state))
+		return NULL;
+
+	if (state->pads) {
+		if (stream)
+			return NULL;
+
+		/*
+		 * Set the pad to 0 on error as this is aligned with the
+		 * behaviour of the pad state information access functions. The
+		 * purpose of setting pad to 0 here is to avoid accessing memory
+		 * outside the pads array, but still issuing warning of the
+		 * invalid access while making the caller's error handling
+		 * easier.
+		 */
+		if (WARN_ON_ONCE(pad >= state->sd->entity.num_pads))
+			pad = 0;
+
+		return &state->pads[pad].compose;
+	}
+
 	lockdep_assert_held(state->lock);
 
 	stream_configs = &state->stream_configs;
diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h
index 46296852cb5b..6b242ec58cb7 100644
--- a/include/media/v4l2-subdev.h
+++ b/include/media/v4l2-subdev.h
@@ -1543,7 +1543,8 @@ int v4l2_subdev_set_routing_with_fmt(struct v4l2_subdev *sd,
  * This returns a pointer to &struct v4l2_mbus_framefmt for the given pad +
  * stream in the subdev state.
  *
- * If the state does not contain the given pad + stream, NULL is returned.
+ * For stream-unaware drivers the format for the corresponding pad is returned.
+ * If the pad does not exist, NULL is returned.
  */
 struct v4l2_mbus_framefmt *
 v4l2_subdev_state_get_stream_format(struct v4l2_subdev_state *state,
@@ -1558,7 +1559,8 @@ v4l2_subdev_state_get_stream_format(struct v4l2_subdev_state *state,
  * This returns a pointer to crop rectangle for the given pad + stream in the
  * subdev state.
  *
- * If the state does not contain the given pad + stream, NULL is returned.
+ * For stream-unaware drivers the crop rectangle for the corresponding pad is
+ * returned. If the pad does not exist, NULL is returned.
  */
 struct v4l2_rect *
 v4l2_subdev_state_get_stream_crop(struct v4l2_subdev_state *state,
@@ -1574,7 +1576,8 @@ v4l2_subdev_state_get_stream_crop(struct v4l2_subdev_state *state,
  * This returns a pointer to compose rectangle for the given pad + stream in the
  * subdev state.
  *
- * If the state does not contain the given pad + stream, NULL is returned.
+ * For stream-unaware drivers the compose rectangle for the corresponding pad is
+ * returned. If the pad does not exist, NULL is returned.
  */
 struct v4l2_rect *
 v4l2_subdev_state_get_stream_compose(struct v4l2_subdev_state *state,