Commit 981f0929 authored by Simon Ser's avatar Simon Ser
Browse files

drm: hide unregistered connectors from GETCONNECTOR IOCTL 



When registering a connector, the kernel sends a hotplug uevent in
drm_connector_register(). When unregistering a connector, drivers
are expected to send a uevent as well. However, user-space has no way
to figure out that the connector isn't registered anymore: it'll still
be reported in GETCONNECTOR IOCTLs.

The documentation for DRM_CONNECTOR_UNREGISTERED states:

> The connector […] has since been unregistered and removed from
> userspace, or the connector was unregistered before it had a chance
> to be exposed to userspace

Signed-off-by: default avatarSimon Ser <contact@emersion.fr>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: default avatarLyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220801133754.461037-1-contact@emersion.fr
parent e71a8ebb

drivers/gpu/drm/drm_mode_config.c

+3 −0
Original line number Diff line number Diff line
@@ -151,6 +151,9 @@ int drm_mode_getresources(struct drm_device *dev, void *data, 
	count = 0;

	connector_id = u64_to_user_ptr(card_res->connector_id_ptr);

	drm_for_each_connector_iter(connector, &conn_iter) {

		if (connector->registration_state != DRM_CONNECTOR_REGISTERED)

			continue;



		/* only expose writeback connectors if userspace understands them */

		if (!file_priv->writeback_connectors &&

		    (connector->connector_type == DRM_MODE_CONNECTOR_WRITEBACK))