From: Sylwester Nawrocki Date: Fri, 31 May 2013 14:37:25 +0000 (-0300) Subject: [media] exynos4-is: Add locking at fimc(-lite) subdev unregistered handler X-Git-Tag: firefly_0821_release~176^2~3573^2~1793 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=26d63d13da2c7de2547f6f455ae20045285dfeb8;p=firefly-linux-kernel-4.4.55.git [media] exynos4-is: Add locking at fimc(-lite) subdev unregistered handler Protect the fimc/fimc-lite video nodes unregistration with their video lock. This prevents a kernel crash when e.g. udev opens a video node right after the driver registers it and then the driver tries to unregister it and defers its probing. Using video_is_unregistered() together with the video mutex allows safe unregistration of the video nodes at any time. Signed-off-by: Sylwester Nawrocki Signed-off-by: Kyungmin Park Signed-off-by: Mauro Carvalho Chehab --- diff --git a/drivers/media/platform/exynos4-is/fimc-capture.c b/drivers/media/platform/exynos4-is/fimc-capture.c index 33c6a2f0ad74..1578aa4e4bb5 100644 --- a/drivers/media/platform/exynos4-is/fimc-capture.c +++ b/drivers/media/platform/exynos4-is/fimc-capture.c @@ -1855,6 +1855,8 @@ static void fimc_capture_subdev_unregistered(struct v4l2_subdev *sd) if (fimc == NULL) return; + mutex_lock(&fimc->lock); + fimc_unregister_m2m_device(fimc); vdev = &fimc->vid_cap.ve.vdev; @@ -1866,6 +1868,8 @@ static void fimc_capture_subdev_unregistered(struct v4l2_subdev *sd) } kfree(fimc->vid_cap.ctx); fimc->vid_cap.ctx = NULL; + + mutex_unlock(&fimc->lock); } static const struct v4l2_subdev_internal_ops fimc_capture_sd_internal_ops = { diff --git a/drivers/media/platform/exynos4-is/fimc-lite.c b/drivers/media/platform/exynos4-is/fimc-lite.c index 24e2a0f8797a..3f76f8abc4b3 100644 --- a/drivers/media/platform/exynos4-is/fimc-lite.c +++ b/drivers/media/platform/exynos4-is/fimc-lite.c @@ -1300,11 +1300,15 @@ static void fimc_lite_subdev_unregistered(struct v4l2_subdev *sd) if (fimc == NULL) return; + mutex_lock(&fimc->lock); + if (video_is_registered(&fimc->ve.vdev)) { video_unregister_device(&fimc->ve.vdev); media_entity_cleanup(&fimc->ve.vdev.entity); fimc->ve.pipe = NULL; } + + mutex_unlock(&fimc->lock); } static const struct v4l2_subdev_internal_ops fimc_lite_subdev_internal_ops = {