Le mer. 20 janv. 2021 à 17:03, Daniel Vetter <dan...@ffwll.ch> a
écrit :
On Wed, Jan 20, 2021 at 1:35 PM Paul Cercueil <p...@crapouillou.net>
wrote:
If we don't call drm_connector_cleanup() manually in
panel_bridge_detach(), the connector will be cleaned up with the
other
DRM objects in the call to drm_mode_config_cleanup(). However,
since our
drm_connector is devm-allocated, by the time
drm_mode_config_cleanup()
will be called, our connector will be long gone. Therefore, the
connector must be cleaned up when the bridge is detached to avoid
use-after-free conditions.
For -fixes this sounds ok, but for -next I think switching to drmm_
would be much better.
The API would need to change to have access to the drm_device struct,
though. That would be quite a big patch, there are a few dozens source
files that use this API already.
Cheers,
-Paul
v2: Cleanup connector only if it was created
Fixes: 13dfc0540a57 ("drm/bridge: Refactor out the panel wrapper
from the lvds-encoder bridge.")
Cc: <sta...@vger.kernel.org> # 4.12+
Cc: Andrzej Hajda <a.ha...@samsung.com>
Cc: Neil Armstrong <narmstr...@baylibre.com>
Cc: Laurent Pinchart <laurent.pinch...@ideasonboard.com>
Cc: Jonas Karlman <jo...@kwiboo.se>
Cc: Jernej Skrabec <jernej.skra...@siol.net>
Signed-off-by: Paul Cercueil <p...@crapouillou.net>
---
drivers/gpu/drm/bridge/panel.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/gpu/drm/bridge/panel.c
b/drivers/gpu/drm/bridge/panel.c
index 0ddc37551194..df86b0ee0549 100644
--- a/drivers/gpu/drm/bridge/panel.c
+++ b/drivers/gpu/drm/bridge/panel.c
@@ -87,6 +87,12 @@ static int panel_bridge_attach(struct drm_bridge
*bridge,
static void panel_bridge_detach(struct drm_bridge *bridge)
{
+ struct panel_bridge *panel_bridge =
drm_bridge_to_panel_bridge(bridge);
+ struct drm_connector *connector = &panel_bridge->connector;
+
+ /* Cleanup the connector if we know it was initialized */
+ if (!!panel_bridge->connector.dev)
+ drm_connector_cleanup(connector);
}
static void panel_bridge_pre_enable(struct drm_bridge *bridge)
--
2.29.2
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
