[media] exynos4-is: Add locking at fimc(-lite) subdev unregistered handler (26d63d13) · Commits · 戴 / test

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 <s.nawrocki@samsung.com> Signed-off-by:

Kyungmin Park <kyungmin.park@samsung.com> Signed-off-by:

Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/platform/exynos4-is/fimc-capture.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -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 = {

drivers/media/platform/exynos4-is/fimc-lite.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -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 = {

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