[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 <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/platform/exynos4-is/fimc-capture.c b/drivers/media/platform/exynos4-is/fimc-capture.c
index 33c6a2f..1578aa4 100644
--- a/drivers/media/platform/exynos4-is/fimc-capture.c
+++ b/drivers/media/platform/exynos4-is/fimc-capture.c
@@ -1855,6 +1855,8 @@
if (fimc == NULL)
return;
+ mutex_lock(&fimc->lock);
+
fimc_unregister_m2m_device(fimc);
vdev = &fimc->vid_cap.ve.vdev;
@@ -1866,6 +1868,8 @@
}
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 24e2a0f..3f76f8a 100644
--- a/drivers/media/platform/exynos4-is/fimc-lite.c
+++ b/drivers/media/platform/exynos4-is/fimc-lite.c
@@ -1300,11 +1300,15 @@
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 = {