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Commit 466cae66 authored by Sakari Ailus's avatar Sakari Ailus Committed by Mauro Carvalho Chehab
Browse files

media: v4l: async: Ensure only unique fwnodes are registered to notifiers 



While registering a notifier, check that each newly added fwnode is
unique, and return an error if it is not. Also check that a newly added
notifier does not have the same fwnodes twice.

Signed-off-by: default avatarSakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: default avatarHans Verkuil <hans.verkuil@cisco.com>
Acked-by: default avatarNiklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: default avatarSebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@s-opensource.com>
parent 2cab00bb

drivers/media/v4l2-core/v4l2-async.c

+79 −7
Original line number Diff line number Diff line
@@ -308,8 +308,71 @@ static void v4l2_async_notifier_unbind_all_subdevs( 
	notifier->parent = NULL;

}



/* See if an fwnode can be found in a notifier's lists. */

static bool __v4l2_async_notifier_fwnode_has_async_subdev(

	struct v4l2_async_notifier *notifier, struct fwnode_handle *fwnode)

{

	struct v4l2_async_subdev *asd;

	struct v4l2_subdev *sd;



	list_for_each_entry(asd, &notifier->waiting, list) {

		if (asd->match_type != V4L2_ASYNC_MATCH_FWNODE)

			continue;



		if (asd->match.fwnode.fwnode == fwnode)

			return true;

	}



	list_for_each_entry(sd, &notifier->done, async_list) {

		if (WARN_ON(!sd->asd))

			continue;



		if (sd->asd->match_type != V4L2_ASYNC_MATCH_FWNODE)

			continue;



		if (sd->asd->match.fwnode.fwnode == fwnode)

			return true;

	}



	return false;

}



/*

 * Find out whether an async sub-device was set up for an fwnode already or

 * whether it exists in a given notifier before @this_index.

 */

static bool v4l2_async_notifier_fwnode_has_async_subdev(

	struct v4l2_async_notifier *notifier, struct fwnode_handle *fwnode,

	unsigned int this_index)

{

	unsigned int j;



	lockdep_assert_held(&list_lock);



	/* Check that an fwnode is not being added more than once. */

	for (j = 0; j < this_index; j++) {

		struct v4l2_async_subdev *asd = notifier->subdevs[this_index];

		struct v4l2_async_subdev *other_asd = notifier->subdevs[j];



		if (other_asd->match_type == V4L2_ASYNC_MATCH_FWNODE &&

		    asd->match.fwnode.fwnode ==

		    other_asd->match.fwnode.fwnode)

			return true;

	}



	/* Check than an fwnode did not exist in other notifiers. */

	list_for_each_entry(notifier, &notifier_list, list)

		if (__v4l2_async_notifier_fwnode_has_async_subdev(

			    notifier, fwnode))

			return true;



	return false;

}



static int __v4l2_async_notifier_register(struct v4l2_async_notifier *notifier)

{

	struct device *dev =

		notifier->v4l2_dev ? notifier->v4l2_dev->dev : NULL;

	struct v4l2_async_subdev *asd;

	int ret;

	int i;
@@ -320,6 +383,8 @@ static int __v4l2_async_notifier_register(struct v4l2_async_notifier *notifier) 
	INIT_LIST_HEAD(&notifier->waiting);

	INIT_LIST_HEAD(&notifier->done);



	mutex_lock(&list_lock);



	for (i = 0; i < notifier->num_subdevs; i++) {

		asd = notifier->subdevs[i];
@@ -327,25 +392,31 @@ static int __v4l2_async_notifier_register(struct v4l2_async_notifier *notifier) 
		case V4L2_ASYNC_MATCH_CUSTOM:

		case V4L2_ASYNC_MATCH_DEVNAME:

		case V4L2_ASYNC_MATCH_I2C:

			break;

		case V4L2_ASYNC_MATCH_FWNODE:

			if (v4l2_async_notifier_fwnode_has_async_subdev(

				    notifier, asd->match.fwnode.fwnode, i)) {

				dev_err(dev,

					"fwnode has already been registered or in notifier's subdev list\n");

				ret = -EEXIST;

				goto err_unlock;

			}

			break;

		default:

			dev_err(notifier->v4l2_dev ? notifier->v4l2_dev->dev : NULL,

				"Invalid match type %u on %p\n",

			dev_err(dev, "Invalid match type %u on %p\n",

				asd->match_type, asd);

			return -EINVAL;

			ret = -EINVAL;

			goto err_unlock;

		}

		list_add_tail(&asd->list, &notifier->waiting);

	}



	mutex_lock(&list_lock);



	ret = v4l2_async_notifier_try_all_subdevs(notifier);

	if (ret)

	if (ret < 0)

		goto err_unbind;



	ret = v4l2_async_notifier_try_complete(notifier);

	if (ret)

	if (ret < 0)

		goto err_unbind;



	/* Keep also completed notifiers on the list */
@@ -361,6 +432,7 @@ static int __v4l2_async_notifier_register(struct v4l2_async_notifier *notifier) 
	 */

	v4l2_async_notifier_unbind_all_subdevs(notifier);



err_unlock:

	mutex_unlock(&list_lock);



	return ret;