diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c index dcbd2f559e39..b8a8132becef 100644 --- a/drivers/gpu/drm/drm_gem.c +++ b/drivers/gpu/drm/drm_gem.c @@ -154,7 +154,7 @@ void drm_gem_private_object_init(struct drm_device *dev, obj->filp = NULL; kref_init(&obj->refcount); - atomic_set(&obj->handle_count, 0); + obj->handle_count = 0; obj->size = size; } EXPORT_SYMBOL(drm_gem_private_object_init); @@ -218,11 +218,9 @@ static void drm_gem_object_handle_free(struct drm_gem_object *obj) struct drm_device *dev = obj->dev; /* Remove any name for this object */ - spin_lock(&dev->object_name_lock); if (obj->name) { idr_remove(&dev->object_name_idr, obj->name); obj->name = 0; - spin_unlock(&dev->object_name_lock); /* * The object name held a reference to this object, drop * that now. @@ -230,15 +228,13 @@ static void drm_gem_object_handle_free(struct drm_gem_object *obj) * This cannot be the last reference, since the handle holds one too. */ kref_put(&obj->refcount, drm_gem_object_ref_bug); - } else - spin_unlock(&dev->object_name_lock); - + } } void drm_gem_object_handle_unreference_unlocked(struct drm_gem_object *obj) { - if (WARN_ON(atomic_read(&obj->handle_count) == 0)) + if (WARN_ON(obj->handle_count == 0)) return; /* @@ -247,8 +243,11 @@ drm_gem_object_handle_unreference_unlocked(struct drm_gem_object *obj) * checked for a name */ - if (atomic_dec_and_test(&obj->handle_count)) + spin_lock(&obj->dev->object_name_lock); + if (--obj->handle_count == 0) drm_gem_object_handle_free(obj); + spin_unlock(&obj->dev->object_name_lock); + drm_gem_object_unreference_unlocked(obj); } @@ -326,17 +325,21 @@ drm_gem_handle_create(struct drm_file *file_priv, * allocation under our spinlock. */ idr_preload(GFP_KERNEL); + spin_lock(&dev->object_name_lock); spin_lock(&file_priv->table_lock); ret = idr_alloc(&file_priv->object_idr, obj, 1, 0, GFP_NOWAIT); - + drm_gem_object_reference(obj); + obj->handle_count++; spin_unlock(&file_priv->table_lock); + spin_unlock(&dev->object_name_lock); idr_preload_end(); - if (ret < 0) + if (ret < 0) { + drm_gem_object_handle_unreference_unlocked(obj); return ret; + } *handlep = ret; - drm_gem_object_handle_reference(obj); if (dev->driver->gem_open_object) { ret = dev->driver->gem_open_object(obj, file_priv); @@ -577,6 +580,12 @@ drm_gem_flink_ioctl(struct drm_device *dev, void *data, idr_preload(GFP_KERNEL); spin_lock(&dev->object_name_lock); + /* prevent races with concurrent gem_close. */ + if (obj->handle_count == 0) { + ret = -ENOENT; + goto err; + } + if (!obj->name) { ret = idr_alloc(&dev->object_name_idr, obj, 1, 0, GFP_NOWAIT); if (ret < 0) diff --git a/drivers/gpu/drm/drm_info.c b/drivers/gpu/drm/drm_info.c index 9f8fc4c328c9..5351e811c421 100644 --- a/drivers/gpu/drm/drm_info.c +++ b/drivers/gpu/drm/drm_info.c @@ -207,7 +207,7 @@ static int drm_gem_one_name_info(int id, void *ptr, void *data) seq_printf(m, "%6d %8zd %7d %8d\n", obj->name, obj->size, - atomic_read(&obj->handle_count), + obj->handle_count, atomic_read(&obj->refcount.refcount)); return 0; } diff --git a/drivers/gpu/drm/exynos/exynos_drm_gem.c b/drivers/gpu/drm/exynos/exynos_drm_gem.c index b904633863e8..f3c6f40666e1 100644 --- a/drivers/gpu/drm/exynos/exynos_drm_gem.c +++ b/drivers/gpu/drm/exynos/exynos_drm_gem.c @@ -136,7 +136,7 @@ void exynos_drm_gem_destroy(struct exynos_drm_gem_obj *exynos_gem_obj) obj = &exynos_gem_obj->base; buf = exynos_gem_obj->buffer; - DRM_DEBUG_KMS("handle count = %d\n", atomic_read(&obj->handle_count)); + DRM_DEBUG_KMS("handle count = %d\n", obj->handle_count); /* * do not release memory region from exporter. diff --git a/include/drm/drmP.h b/include/drm/drmP.h index 1a7a78fdb4b7..57dce6081d73 100644 --- a/include/drm/drmP.h +++ b/include/drm/drmP.h @@ -615,8 +615,16 @@ struct drm_gem_object { /** Reference count of this object */ struct kref refcount; - /** Handle count of this object. Each handle also holds a reference */ - atomic_t handle_count; /* number of handles on this object */ + /** + * handle_count - gem file_priv handle count of this object + * + * Each handle also holds a reference. Note that when the handle_count + * drops to 0 any global names (e.g. the id in the flink namespace) will + * be cleared. + * + * Protected by dev->object_name_lock. + * */ + unsigned handle_count; /** Related drm device */ struct drm_device *dev; @@ -1572,13 +1580,6 @@ int drm_gem_handle_create(struct drm_file *file_priv, u32 *handlep); int drm_gem_handle_delete(struct drm_file *filp, u32 handle); -static inline void -drm_gem_object_handle_reference(struct drm_gem_object *obj) -{ - drm_gem_object_reference(obj); - atomic_inc(&obj->handle_count); -} - void drm_gem_object_handle_unreference_unlocked(struct drm_gem_object *obj); void drm_gem_free_mmap_offset(struct drm_gem_object *obj);