drm/kms: Catch mode_object lifetime errors (4f5368b5) · Commits · 戴 / test

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 <sean@poorly.run> Signed-off-by:

Daniel Vetter <daniel.vetter@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20190614061723.1173-1-daniel.vetter@ffwll.ch

drivers/gpu/drm/drm_drv.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -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);

drivers/gpu/drm/drm_mode_object.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -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);

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