From 466cae66eaa13c4895a80c19d7d8d3019c46ae6b Mon Sep 17 00:00:00 2001 From: Sakari Ailus Date: Wed, 20 Sep 2017 03:51:54 -0400 Subject: [PATCH] media: v4l: async: Ensure only unique fwnodes are registered to notifiers MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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: Sakari Ailus Acked-by: Hans Verkuil Acked-by: Niklas Söderlund Reviewed-by: Sebastian Reichel Signed-off-by: Mauro Carvalho Chehab --- drivers/media/v4l2-core/v4l2-async.c | 86 +++++++++++++++++++++++++--- 1 file changed, 79 insertions(+), 7 deletions(-) diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c index ed539c4fd5dc..57bd54016064 100644 --- a/drivers/media/v4l2-core/v4l2-async.c +++ b/drivers/media/v4l2-core/v4l2-async.c @@ -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, ¬ifier->waiting, list) { + if (asd->match_type != V4L2_ASYNC_MATCH_FWNODE) + continue; + + if (asd->match.fwnode.fwnode == fwnode) + return true; + } + + list_for_each_entry(sd, ¬ifier->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, ¬ifier_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(¬ifier->waiting); INIT_LIST_HEAD(¬ifier->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, ¬ifier->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; -- 2.45.2