diff mbox series

[RESEND,drm-misc-next,5/7] drm/arm/hdlcd: use drm_dev_unplug()

Message ID 20220905152719.128539-6-dakr@redhat.com (mailing list archive)
State New, archived
Headers show
Series drm/arm/hdlcd: use drm managed resources | expand

Commit Message

Danilo Krummrich Sept. 5, 2022, 3:27 p.m. UTC 
When the driver is unbound, there might still be users in userspace
having an open fd and are calling into the driver.

While this is fine for drm managed resources, it is not for resources
bound to the device/driver lifecycle, e.g. clocks or MMIO mappings.

To prevent use-after-free issues we need to protect those resources with
drm_dev_enter() and drm_dev_exit(). This does only work if we indicate
that the drm device was unplugged, hence use drm_dev_unplug() instead of
drm_dev_unregister().

Protecting the particular resources with drm_dev_enter()/drm_dev_exit()
is handled by subsequent patches.

Signed-off-by: Danilo Krummrich <dakr@redhat.com>
---
 drivers/gpu/drm/arm/hdlcd_drv.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/gpu/drm/arm/hdlcd_drv.c b/drivers/gpu/drm/arm/hdlcd_drv.c
index 120c87934a91..e41def6d47cc 100644
--- a/drivers/gpu/drm/arm/hdlcd_drv.c
+++ b/drivers/gpu/drm/arm/hdlcd_drv.c
@@ -325,7 +325,7 @@  static void hdlcd_drm_unbind(struct device *dev)
 	struct drm_device *drm = dev_get_drvdata(dev);
 	struct hdlcd_drm_private *hdlcd = drm_to_hdlcd_priv(drm);
 
-	drm_dev_unregister(drm);
+	drm_dev_unplug(drm);
 	drm_kms_helper_poll_fini(drm);
 	component_unbind_all(dev, drm);
 	of_node_put(hdlcd->crtc.port);