diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c index adb9eda4fa1a..d47aa774d64b 100644 --- a/drivers/gpu/drm/drm_gem.c +++ b/drivers/gpu/drm/drm_gem.c @@ -308,23 +308,26 @@ int drm_gem_dumb_destroy(struct drm_file *file, EXPORT_SYMBOL(drm_gem_dumb_destroy); /** - * Create a handle for this object. This adds a handle reference - * to the object, which includes a regular reference count. Callers - * will likely want to dereference the object afterwards. + * drm_gem_handle_create_tail - internal functions to create a handle + * + * This expects the dev->object_name_lock to be held already and will drop it + * before returning. Used to avoid races in establishing new handles when + * importing an object from either an flink name or a dma-buf. */ int -drm_gem_handle_create(struct drm_file *file_priv, - struct drm_gem_object *obj, - u32 *handlep) +drm_gem_handle_create_tail(struct drm_file *file_priv, + struct drm_gem_object *obj, + u32 *handlep) { struct drm_device *dev = obj->dev; int ret; + WARN_ON(!mutex_is_locked(&dev->object_name_lock)); + /* * Get the user-visible handle using idr. Preload and perform * allocation under our spinlock. */ - mutex_lock(&dev->object_name_lock); idr_preload(GFP_KERNEL); spin_lock(&file_priv->table_lock); @@ -351,6 +354,21 @@ drm_gem_handle_create(struct drm_file *file_priv, return 0; } + +/** + * Create a handle for this object. This adds a handle reference + * to the object, which includes a regular reference count. Callers + * will likely want to dereference the object afterwards. + */ +int +drm_gem_handle_create(struct drm_file *file_priv, + struct drm_gem_object *obj, + u32 *handlep) +{ + mutex_lock(&obj->dev->object_name_lock); + + return drm_gem_handle_create_tail(file_priv, obj, handlep); +} EXPORT_SYMBOL(drm_gem_handle_create); @@ -627,13 +645,15 @@ drm_gem_open_ioctl(struct drm_device *dev, void *data, mutex_lock(&dev->object_name_lock); obj = idr_find(&dev->object_name_idr, (int) args->name); - if (obj) + if (obj) { drm_gem_object_reference(obj); - mutex_unlock(&dev->object_name_lock); - if (!obj) + } else { + mutex_unlock(&dev->object_name_lock); return -ENOENT; + } - ret = drm_gem_handle_create(file_priv, obj, &handle); + /* drm_gem_handle_create_tail unlocks dev->object_name_lock. */ + ret = drm_gem_handle_create_tail(file_priv, obj, &handle); drm_gem_object_unreference_unlocked(obj); if (ret) return ret; diff --git a/include/drm/drmP.h b/include/drm/drmP.h index bf058470a0fd..063eac31b97b 100644 --- a/include/drm/drmP.h +++ b/include/drm/drmP.h @@ -1575,6 +1575,9 @@ drm_gem_object_unreference_unlocked(struct drm_gem_object *obj) } } +int drm_gem_handle_create_tail(struct drm_file *file_priv, + struct drm_gem_object *obj, + u32 *handlep); int drm_gem_handle_create(struct drm_file *file_priv, struct drm_gem_object *obj, u32 *handlep);