From fc49071766ed371268cc03b868cf97f21ad3f273 Mon Sep 17 00:00:00 2001 From: Sakari Ailus <sakari.ailus@linux.intel.com> Date: Thu, 11 Aug 2016 07:18:37 -0300 Subject: [PATCH] [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> --- drivers/media/v4l2-core/v4l2-device.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/drivers/media/v4l2-core/v4l2-device.c b/drivers/media/v4l2-core/v4l2-device.c index 06fa5f1b2cff..62bbed76dbbc 100644 --- a/drivers/media/v4l2-core/v4l2-device.c +++ b/drivers/media/v4l2-core/v4l2-device.c @@ -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