[PATCH AUTOSEL 4.19 04/10] drm: hide unregistered connectors from GETCONNECTOR IOCTL
Sasha Levin
sashal at kernel.org
Sun Oct 9 23:57:39 UTC 2022
From: Simon Ser <contact at emersion.fr>
[ Upstream commit 981f09295687f856d5345e19c7084aca481c1395 ]
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: Simon Ser <contact at emersion.fr>
Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
Cc: Jani Nikula <jani.nikula at intel.com>
Reviewed-by: Lyude Paul <lyude at redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220801133754.461037-1-contact@emersion.fr
Signed-off-by: Sasha Levin <sashal at kernel.org>
---
drivers/gpu/drm/drm_mode_config.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/gpu/drm/drm_mode_config.c b/drivers/gpu/drm/drm_mode_config.c
index 21e353bd3948..acbe78f6e0d1 100644
--- a/drivers/gpu/drm/drm_mode_config.c
+++ b/drivers/gpu/drm/drm_mode_config.c
@@ -145,6 +145,9 @@ 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))
--
2.35.1
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