It published the gem object to userspace, by that point other threads can guess the id and start using it. And gem IDs are _very_ easy to guess (it's just an idr).
Since gem objects is the only thing we allow drivers to create themselves (all the kms/prime/syncobj stuff is handled by the core) no other functions seem to be in need of this clarification.
Motivated by reviewing the xen-front kms driver.
Cc: Oleksandr Andrushchenko oleksandr_andrushchenko@epam.com Signed-off-by: Daniel Vetter daniel.vetter@intel.com --- drivers/gpu/drm/drm_gem.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c index 4975ba9a7bc8..4a16d7b26c89 100644 --- a/drivers/gpu/drm/drm_gem.c +++ b/drivers/gpu/drm/drm_gem.c @@ -436,9 +436,12 @@ drm_gem_handle_create_tail(struct drm_file *file_priv, * @obj: object to register * @handlep: pionter to return the created handle to the caller * - * 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. + * 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. + * + * Since this publishes @obj to userspace it must be fully set up by this point, + * drivers must call this last in their buffer object creation callbacks. */ int drm_gem_handle_create(struct drm_file *file_priv, struct drm_gem_object *obj,