From: Daniel Vetter Date: Fri, 14 Jun 2019 06:17:23 +0000 (+0200) Subject: drm/kms: Catch mode_object lifetime errors X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=4f5368b5541a902f6596558b05f5c21a9770dd32;p=openwrt%2Fstaging%2Fblogic.git drm/kms: Catch mode_object lifetime errors Only dynamic mode objects, i.e. those which are refcounted and have a free callback, can be added while the overall drm_device is visible to userspace. All others must be added before drm_dev_register and removed after drm_dev_unregister. Small issue around drivers still using the load/unload callbacks, we need to make sure we set dev->registered so that load/unload code in these callbacks doesn't trigger false warnings. Only a small adjustement in drm_dev_register was needed. Motivated by some irc discussions about object ids of dynamic objects like blobs become invalid, and me going on a bit an audit spree. Reviewed-by: Sean Paul Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20190614061723.1173-1-daniel.vetter@ffwll.ch --- diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c index fe0ce86c280f..c1671ff0f1eb 100644 --- a/drivers/gpu/drm/drm_drv.c +++ b/drivers/gpu/drm/drm_drv.c @@ -990,14 +990,14 @@ int drm_dev_register(struct drm_device *dev, unsigned long flags) if (ret) goto err_minors; - dev->registered = true; - if (dev->driver->load) { ret = dev->driver->load(dev, flags); if (ret) goto err_minors; } + dev->registered = true; + if (drm_core_check_feature(dev, DRIVER_MODESET)) drm_modeset_register_all(dev); diff --git a/drivers/gpu/drm/drm_mode_object.c b/drivers/gpu/drm/drm_mode_object.c index 1c6e51135962..c355ba8e6d5d 100644 --- a/drivers/gpu/drm/drm_mode_object.c +++ b/drivers/gpu/drm/drm_mode_object.c @@ -42,6 +42,8 @@ int __drm_mode_object_add(struct drm_device *dev, struct drm_mode_object *obj, { int ret; + WARN_ON(dev->registered && !obj_free_cb); + mutex_lock(&dev->mode_config.idr_mutex); ret = idr_alloc(&dev->mode_config.object_idr, register_obj ? obj : NULL, 1, 0, GFP_KERNEL); @@ -102,6 +104,8 @@ void drm_mode_object_register(struct drm_device *dev, void drm_mode_object_unregister(struct drm_device *dev, struct drm_mode_object *object) { + WARN_ON(dev->registered && !object->free_cb); + mutex_lock(&dev->mode_config.idr_mutex); if (object->id) { idr_remove(&dev->mode_config.object_idr, object->id);