Commit fc490717 authored Aug 11, 2016 by Sakari Ailus Committed by Mauro Carvalho Chehab Aug 24, 2016

[media] v4l: Do not allow re-registering sub-devices



Albeit not prohibited explicitly, re-registering sub-devices generated a
big, loud warning which quite likely soon was followed by a crash. What
followed was re-initialising a media entity, driver's registered() callback
being called and re-adding a list entry to a list.

Prevent this by returning an error if a sub-device is already registered.

[mchehab@s-opensource.com: reorder logic to check if !sd before dereferencing it]
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

parent 6a21b728

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

+1 −4

Original line number	Diff line number	Diff line
		@@ -160,12 +160,9 @@ int v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
		int err;

		/* Check for valid input */
		if (v4l2_dev == NULL \|\| sd == NULL \|\| !sd->name[0])
		if (!v4l2_dev \|\| !sd \|\| sd->v4l2_dev \|\| !sd->name[0])
		return -EINVAL;

		/* Warn if we apparently re-register a subdev */
		WARN_ON(sd->v4l2_dev != NULL);

		/*
		* The reason to acquire the module here is to avoid unloading
		* a module of sub-device which is registered to a media

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