[media] v4l: vsp1: Protect against race conditions between get and set format

The subdev userspace API isn't serialized in the core, serialize access
to formats and selection rectangles in the driver.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/platform/vsp1/vsp1_bru.c

@@ -142,10 +142,15 @@ static int bru_set_format(struct v4l2_subdev *subdev,
 	struct vsp1_bru *bru = to_bru(subdev);
 	struct v4l2_subdev_pad_config *config;
 	struct v4l2_mbus_framefmt *format;
+	int ret = 0;
+
+	mutex_lock(&bru->entity.lock);
 
 	config = vsp1_entity_get_pad_config(&bru->entity, cfg, fmt->which);
-	if (!config)
-		return -EINVAL;
+	if (!config) {
+		ret = -EINVAL;
+		goto done;
+	}
 
 	bru_try_format(bru, config, fmt->pad, &fmt->format);
 
@@ -174,7 +179,9 @@ static int bru_set_format(struct v4l2_subdev *subdev,
 		}
 	}
 
-	return 0;
+done:
+	mutex_unlock(&bru->entity.lock);
+	return ret;
 }
 
 static int bru_get_selection(struct v4l2_subdev *subdev,
@@ -201,7 +208,9 @@ static int bru_get_selection(struct v4l2_subdev *subdev,
 		if (!config)
 			return -EINVAL;
 
+		mutex_lock(&bru->entity.lock);
 		sel->r = *bru_get_compose(bru, config, sel->pad);
+		mutex_unlock(&bru->entity.lock);
 		return 0;
 
 	default:
@@ -217,6 +226,7 @@ static int bru_set_selection(struct v4l2_subdev *subdev,
 	struct v4l2_subdev_pad_config *config;
 	struct v4l2_mbus_framefmt *format;
 	struct v4l2_rect *compose;
+	int ret = 0;
 
 	if (sel->pad == bru->entity.source_pad)
 		return -EINVAL;
@@ -224,9 +234,13 @@ static int bru_set_selection(struct v4l2_subdev *subdev,
 	if (sel->target != V4L2_SEL_TGT_COMPOSE)
 		return -EINVAL;
 
+	mutex_lock(&bru->entity.lock);
+
 	config = vsp1_entity_get_pad_config(&bru->entity, cfg, sel->which);
-	if (!config)
-		return -EINVAL;
+	if (!config) {
+		ret = -EINVAL;
+		goto done;
+	}
 
 	/* The compose rectangle top left corner must be inside the output
 	 * frame.
@@ -246,7 +260,9 @@ static int bru_set_selection(struct v4l2_subdev *subdev,
 	compose = bru_get_compose(bru, config, sel->pad);
 	*compose = sel->r;
 
-	return 0;
+done:
+	mutex_unlock(&bru->entity.lock);
+	return ret;
 }
 
 static const struct v4l2_subdev_pad_ops bru_pad_ops = {

drivers/media/platform/vsp1/vsp1_clu.c

@@ -148,10 +148,15 @@ static int clu_set_format(struct v4l2_subdev *subdev,
 	struct vsp1_clu *clu = to_clu(subdev);
 	struct v4l2_subdev_pad_config *config;
 	struct v4l2_mbus_framefmt *format;
+	int ret = 0;
+
+	mutex_lock(&clu->entity.lock);
 
 	config = vsp1_entity_get_pad_config(&clu->entity, cfg, fmt->which);
-	if (!config)
-		return -EINVAL;
+	if (!config) {
+		ret = -EINVAL;
+		goto done;
+	}
 
 	/* Default to YUV if the requested format is not supported. */
 	if (fmt->format.code != MEDIA_BUS_FMT_ARGB8888_1X32 &&
@@ -164,7 +169,7 @@ static int clu_set_format(struct v4l2_subdev *subdev,
 	if (fmt->pad == CLU_PAD_SOURCE) {
 		/* The CLU output format can't be modified. */
 		fmt->format = *format;
-		return 0;
+		goto done;
 	}
 
 	format->code = fmt->format.code;
@@ -182,7 +187,9 @@ static int clu_set_format(struct v4l2_subdev *subdev,
 					    CLU_PAD_SOURCE);
 	*format = fmt->format;
 
-	return 0;
+done:
+	mutex_unlock(&clu->entity.lock);
+	return ret;
 }
 
 /* -----------------------------------------------------------------------------

drivers/media/platform/vsp1/vsp1_entity.c

@@ -51,6 +51,9 @@ void vsp1_entity_route_setup(struct vsp1_entity *source,
  * @cfg: the TRY pad configuration
  * @which: configuration selector (ACTIVE or TRY)
  *
+ * When called with which set to V4L2_SUBDEV_FORMAT_ACTIVE the caller must hold
+ * the entity lock to access the returned configuration.
+ *
  * Return the pad configuration requested by the which argument. The TRY
  * configuration is passed explicitly to the function through the cfg argument
  * and simply returned when requested. The ACTIVE configuration comes from the
@@ -160,7 +163,9 @@ int vsp1_subdev_get_pad_format(struct v4l2_subdev *subdev,
 	if (!config)
 		return -EINVAL;
 
+	mutex_lock(&entity->lock);
 	fmt->format = *vsp1_entity_get_pad_format(entity, config, fmt->pad);
+	mutex_unlock(&entity->lock);
 
 	return 0;
 }
@@ -204,8 +209,10 @@ int vsp1_subdev_enum_mbus_code(struct v4l2_subdev *subdev,
 		if (!config)
 			return -EINVAL;
 
+		mutex_lock(&entity->lock);
 		format = vsp1_entity_get_pad_format(entity, config, 0);
 		code->code = format->code;
+		mutex_unlock(&entity->lock);
 	}
 
 	return 0;
@@ -235,6 +242,7 @@ int vsp1_subdev_enum_frame_size(struct v4l2_subdev *subdev,
 	struct vsp1_entity *entity = to_vsp1_entity(subdev);
 	struct v4l2_subdev_pad_config *config;
 	struct v4l2_mbus_framefmt *format;
+	int ret = 0;
 
 	config = vsp1_entity_get_pad_config(entity, cfg, fse->which);
 	if (!config)
@@ -242,8 +250,12 @@ int vsp1_subdev_enum_frame_size(struct v4l2_subdev *subdev,
 
 	format = vsp1_entity_get_pad_format(entity, config, fse->pad);
 
-	if (fse->index || fse->code != format->code)
-		return -EINVAL;
+	mutex_lock(&entity->lock);
+
+	if (fse->index || fse->code != format->code) {
+		ret = -EINVAL;
+		goto done;
+	}
 
 	if (fse->pad == 0) {
 		fse->min_width = min_width;
@@ -260,7 +272,9 @@ int vsp1_subdev_enum_frame_size(struct v4l2_subdev *subdev,
 		fse->max_height = format->height;
 	}
 
-	return 0;
+done:
+	mutex_unlock(&entity->lock);
+	return ret;
 }
 
 /* -----------------------------------------------------------------------------
@@ -358,6 +372,8 @@ int vsp1_entity_init(struct vsp1_device *vsp1, struct vsp1_entity *entity,
 	if (i == ARRAY_SIZE(vsp1_routes))
 		return -EINVAL;
 
+	mutex_init(&entity->lock);
+
 	entity->vsp1 = vsp1;
 	entity->source_pad = num_pads - 1;
 

drivers/media/platform/vsp1/vsp1_entity.h

@@ -14,7 +14,7 @@
 #define __VSP1_ENTITY_H__
 
 #include <linux/list.h>
-#include <linux/spinlock.h>
+#include <linux/mutex.h>
 
 #include <media/v4l2-subdev.h>
 
@@ -96,6 +96,8 @@ struct vsp1_entity {
 
 	struct v4l2_subdev subdev;
 	struct v4l2_subdev_pad_config *config;
+
+	struct mutex lock;	/* Protects the pad config */
 };
 
 static inline struct vsp1_entity *to_vsp1_entity(struct v4l2_subdev *subdev)

drivers/media/platform/vsp1/vsp1_hsit.c

@@ -71,10 +71,15 @@ static int hsit_set_format(struct v4l2_subdev *subdev,
 	struct vsp1_hsit *hsit = to_hsit(subdev);
 	struct v4l2_subdev_pad_config *config;
 	struct v4l2_mbus_framefmt *format;
+	int ret = 0;
+
+	mutex_lock(&hsit->entity.lock);
 
 	config = vsp1_entity_get_pad_config(&hsit->entity, cfg, fmt->which);
-	if (!config)
-		return -EINVAL;
+	if (!config) {
+		ret = -EINVAL;
+		goto done;
+	}
 
 	format = vsp1_entity_get_pad_format(&hsit->entity, config, fmt->pad);
 
@@ -83,7 +88,7 @@ static int hsit_set_format(struct v4l2_subdev *subdev,
 		 * modified.
 		 */
 		fmt->format = *format;
-		return 0;
+		goto done;
 	}
 
 	format->code = hsit->inverse ? MEDIA_BUS_FMT_AHSV8888_1X32
@@ -104,7 +109,9 @@ static int hsit_set_format(struct v4l2_subdev *subdev,
 	format->code = hsit->inverse ? MEDIA_BUS_FMT_ARGB8888_1X32
 		     : MEDIA_BUS_FMT_AHSV8888_1X32;
 
-	return 0;
+done:
+	mutex_unlock(&hsit->entity.lock);
+	return ret;
 }
 
 static const struct v4l2_subdev_pad_ops hsit_pad_ops = {

drivers/media/platform/vsp1/vsp1_lif.c

@@ -66,10 +66,15 @@ static int lif_set_format(struct v4l2_subdev *subdev,
 	struct vsp1_lif *lif = to_lif(subdev);
 	struct v4l2_subdev_pad_config *config;
 	struct v4l2_mbus_framefmt *format;
+	int ret = 0;
+
+	mutex_lock(&lif->entity.lock);
 
 	config = vsp1_entity_get_pad_config(&lif->entity, cfg, fmt->which);
-	if (!config)
-		return -EINVAL;
+	if (!config) {
+		ret = -EINVAL;
+		goto done;
+	}
 
 	/* Default to YUV if the requested format is not supported. */
 	if (fmt->format.code != MEDIA_BUS_FMT_ARGB8888_1X32 &&
@@ -83,7 +88,7 @@ static int lif_set_format(struct v4l2_subdev *subdev,
 		 * format.
 		 */
 		fmt->format = *format;
-		return 0;
+		goto done;
 	}
 
 	format->code = fmt->format.code;
@@ -101,7 +106,9 @@ static int lif_set_format(struct v4l2_subdev *subdev,
 					    LIF_PAD_SOURCE);
 	*format = fmt->format;
 
-	return 0;
+done:
+	mutex_unlock(&lif->entity.lock);
+	return ret;
 }
 
 static const struct v4l2_subdev_pad_ops lif_pad_ops = {

drivers/media/platform/vsp1/vsp1_lut.c

@@ -124,10 +124,15 @@ static int lut_set_format(struct v4l2_subdev *subdev,
 	struct vsp1_lut *lut = to_lut(subdev);
 	struct v4l2_subdev_pad_config *config;
 	struct v4l2_mbus_framefmt *format;
+	int ret = 0;
+
+	mutex_lock(&lut->entity.lock);
 
 	config = vsp1_entity_get_pad_config(&lut->entity, cfg, fmt->which);
-	if (!config)
-		return -EINVAL;
+	if (!config) {
+		ret = -EINVAL;
+		goto done;
+	}
 
 	/* Default to YUV if the requested format is not supported. */
 	if (fmt->format.code != MEDIA_BUS_FMT_ARGB8888_1X32 &&
@@ -140,7 +145,7 @@ static int lut_set_format(struct v4l2_subdev *subdev,
 	if (fmt->pad == LUT_PAD_SOURCE) {
 		/* The LUT output format can't be modified. */
 		fmt->format = *format;
-		return 0;
+		goto done;
 	}
 
 	format->code = fmt->format.code;
@@ -158,7 +163,9 @@ static int lut_set_format(struct v4l2_subdev *subdev,
 					    LUT_PAD_SOURCE);
 	*format = fmt->format;
 
-	return 0;
+done:
+	mutex_unlock(&lut->entity.lock);
+	return ret;
 }
 
 /* -----------------------------------------------------------------------------

drivers/media/platform/vsp1/vsp1_rwpf.c

@@ -67,10 +67,15 @@ static int vsp1_rwpf_set_format(struct v4l2_subdev *subdev,
 	struct v4l2_subdev_pad_config *config;
 	struct v4l2_mbus_framefmt *format;
 	struct v4l2_rect *crop;
+	int ret = 0;
+
+	mutex_lock(&rwpf->entity.lock);
 
 	config = vsp1_entity_get_pad_config(&rwpf->entity, cfg, fmt->which);
-	if (!config)
-		return -EINVAL;
+	if (!config) {
+		ret = -EINVAL;
+		goto done;
+	}
 
 	/* Default to YUV if the requested format is not supported. */
 	if (fmt->format.code != MEDIA_BUS_FMT_ARGB8888_1X32 &&
@@ -85,7 +90,7 @@ static int vsp1_rwpf_set_format(struct v4l2_subdev *subdev,
 		 */
 		format->code = fmt->format.code;
 		fmt->format = *format;
-		return 0;
+		goto done;
 	}
 
 	format->code = fmt->format.code;
@@ -110,7 +115,9 @@ static int vsp1_rwpf_set_format(struct v4l2_subdev *subdev,
 					    RWPF_PAD_SOURCE);
 	*format = fmt->format;
 
-	return 0;
+done:
+	mutex_unlock(&rwpf->entity.lock);
+	return ret;
 }
 
 static int vsp1_rwpf_get_selection(struct v4l2_subdev *subdev,
@@ -120,14 +127,19 @@ static int vsp1_rwpf_get_selection(struct v4l2_subdev *subdev,
 	struct vsp1_rwpf *rwpf = to_rwpf(subdev);
 	struct v4l2_subdev_pad_config *config;
 	struct v4l2_mbus_framefmt *format;
+	int ret = 0;
 
 	/* Cropping is implemented on the sink pad. */
 	if (sel->pad != RWPF_PAD_SINK)
 		return -EINVAL;
 
+	mutex_lock(&rwpf->entity.lock);
+
 	config = vsp1_entity_get_pad_config(&rwpf->entity, cfg, sel->which);
-	if (!config)
-		return -EINVAL;
+	if (!config) {
+		ret = -EINVAL;
+		goto done;
+	}
 
 	switch (sel->target) {
 	case V4L2_SEL_TGT_CROP:
@@ -144,10 +156,13 @@ static int vsp1_rwpf_get_selection(struct v4l2_subdev *subdev,
 		break;
 
 	default:
-		return -EINVAL;
+		ret = -EINVAL;
+		break;
 	}
 
-	return 0;
+done:
+	mutex_unlock(&rwpf->entity.lock);
+	return ret;
 }
 
 static int vsp1_rwpf_set_selection(struct v4l2_subdev *subdev,
@@ -158,6 +173,7 @@ static int vsp1_rwpf_set_selection(struct v4l2_subdev *subdev,
 	struct v4l2_subdev_pad_config *config;
 	struct v4l2_mbus_framefmt *format;
 	struct v4l2_rect *crop;
+	int ret = 0;
 
 	/* Cropping is implemented on the sink pad. */
 	if (sel->pad != RWPF_PAD_SINK)
@@ -166,9 +182,13 @@ static int vsp1_rwpf_set_selection(struct v4l2_subdev *subdev,
 	if (sel->target != V4L2_SEL_TGT_CROP)
 		return -EINVAL;
 
+	mutex_lock(&rwpf->entity.lock);
+
 	config = vsp1_entity_get_pad_config(&rwpf->entity, cfg, sel->which);
-	if (!config)
-		return -EINVAL;
+	if (!config) {
+		ret = -EINVAL;
+		goto done;
+	}
 
 	/* Make sure the crop rectangle is entirely contained in the image. The
 	 * WPF top and left offsets are limited to 255.
@@ -206,7 +226,9 @@ static int vsp1_rwpf_set_selection(struct v4l2_subdev *subdev,
 	format->width = crop->width;
 	format->height = crop->height;
 
-	return 0;
+done:
+	mutex_unlock(&rwpf->entity.lock);
+	return ret;
 }
 
 const struct v4l2_subdev_pad_ops vsp1_rwpf_pad_ops = {

drivers/media/platform/vsp1/vsp1_sru.c

@@ -128,6 +128,7 @@ static int sru_enum_frame_size(struct v4l2_subdev *subdev,
 	struct vsp1_sru *sru = to_sru(subdev);
 	struct v4l2_subdev_pad_config *config;
 	struct v4l2_mbus_framefmt *format;
+	int ret = 0;
 
 	config = vsp1_entity_get_pad_config(&sru->entity, cfg, fse->which);
 	if (!config)
@@ -135,8 +136,12 @@ static int sru_enum_frame_size(struct v4l2_subdev *subdev,
 
 	format = vsp1_entity_get_pad_format(&sru->entity, config, SRU_PAD_SINK);
 
-	if (fse->index || fse->code != format->code)
-		return -EINVAL;
+	mutex_lock(&sru->entity.lock);
+
+	if (fse->index || fse->code != format->code) {
+		ret = -EINVAL;
+		goto done;
+	}
 
 	if (fse->pad == SRU_PAD_SINK) {
 		fse->min_width = SRU_MIN_SIZE;
@@ -156,7 +161,9 @@ static int sru_enum_frame_size(struct v4l2_subdev *subdev,
 		}
 	}
 
-	return 0;
+done:
+	mutex_unlock(&sru->entity.lock);
+	return ret;
 }
 
 static void sru_try_format(struct vsp1_sru *sru,
@@ -217,10 +224,15 @@ static int sru_set_format(struct v4l2_subdev *subdev,
 	struct vsp1_sru *sru = to_sru(subdev);
 	struct v4l2_subdev_pad_config *config;
 	struct v4l2_mbus_framefmt *format;
+	int ret = 0;
+
+	mutex_lock(&sru->entity.lock);
 
 	config = vsp1_entity_get_pad_config(&sru->entity, cfg, fmt->which);
-	if (!config)
-		return -EINVAL;
+	if (!config) {
+		ret = -EINVAL;
+		goto done;
+	}
 
 	sru_try_format(sru, config, fmt->pad, &fmt->format);
 
@@ -236,7 +248,9 @@ static int sru_set_format(struct v4l2_subdev *subdev,
 		sru_try_format(sru, config, SRU_PAD_SOURCE, format);
 	}
 
-	return 0;
+done:
+	mutex_unlock(&sru->entity.lock);
+	return ret;
 }
 
 static const struct v4l2_subdev_pad_ops sru_pad_ops = {

drivers/media/platform/vsp1/vsp1_uds.c

@@ -133,6 +133,7 @@ static int uds_enum_frame_size(struct v4l2_subdev *subdev,
 	struct vsp1_uds *uds = to_uds(subdev);
 	struct v4l2_subdev_pad_config *config;
 	struct v4l2_mbus_framefmt *format;
+	int ret = 0;
 
 	config = vsp1_entity_get_pad_config(&uds->entity, cfg, fse->which);
 	if (!config)
@@ -141,8 +142,12 @@ static int uds_enum_frame_size(struct v4l2_subdev *subdev,
 	format = vsp1_entity_get_pad_format(&uds->entity, config,
 					    UDS_PAD_SINK);
 
-	if (fse->index || fse->code != format->code)
-		return -EINVAL;
+	mutex_lock(&uds->entity.lock);
+
+	if (fse->index || fse->code != format->code) {
+		ret = -EINVAL;
+		goto done;
+	}
 
 	if (fse->pad == UDS_PAD_SINK) {
 		fse->min_width = UDS_MIN_SIZE;
@@ -156,7 +161,9 @@ static int uds_enum_frame_size(struct v4l2_subdev *subdev,
 				  &fse->max_height);
 	}
 
-	return 0;
+done:
+	mutex_unlock(&uds->entity.lock);
+	return ret;
 }
 
 static void uds_try_format(struct vsp1_uds *uds,
@@ -202,10 +209,15 @@ static int uds_set_format(struct v4l2_subdev *subdev,
 	struct vsp1_uds *uds = to_uds(subdev);
 	struct v4l2_subdev_pad_config *config;
 	struct v4l2_mbus_framefmt *format;
+	int ret = 0;
+
+	mutex_lock(&uds->entity.lock);
 
 	config = vsp1_entity_get_pad_config(&uds->entity, cfg, fmt->which);
-	if (!config)
-		return -EINVAL;
+	if (!config) {
+		ret = -EINVAL;
+		goto done;
+	}
 
 	uds_try_format(uds, config, fmt->pad, &fmt->format);
 
@@ -221,7 +233,9 @@ static int uds_set_format(struct v4l2_subdev *subdev,
 		uds_try_format(uds, config, UDS_PAD_SOURCE, format);
 	}
 
-	return 0;
+done:
+	mutex_unlock(&uds->entity.lock);
+	return ret;
 }
 
 /* -----------------------------------------------------------------------------