drm/gem: handlecount isn't really a kref so don't make it one.

There were lots of places being inconsistent since handle count
looked like a kref but it really wasn't.

Fix this my just making handle count an atomic on the object,
and have it increase the normal object kref.

Now i915/radeon/nouveau drivers can drop the normal reference on
userspace object creation, and have the handle hold it.

This patch fixes a memory leak or corruption on unload, because
the driver had no way of knowing if a handle had been actually
added for this object, and the fbcon object needed to know this
to clean itself up properly.

Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 2 insertions, 6 deletions

diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
index 6fe2cd298c12..f7e61be8430a 100644
--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -148,7 +148,7 @@ int drm_gem_object_init(struct drm_device *dev,
                 return -ENOMEM;
 
         kref_init(&obj->refcount);
-        kref_init(&obj->handlecount);
+        atomic_set(&obj->handle_count, 0);
         obj->size = size;
 
         atomic_inc(&dev->object_count);
@@ -496,12 +496,8 @@ static void drm_gem_object_ref_bug(struct kref *list_kref)
  * called before drm_gem_object_free or we'll be touching
  * freed memory
  */
-void
-drm_gem_object_handle_free(struct kref *kref)
+void drm_gem_object_handle_free(struct drm_gem_object *obj)
 {
-        struct drm_gem_object *obj = container_of(kref,
-                                                  struct drm_gem_object,
-                                                  handlecount);
         struct drm_device *dev = obj->dev;
 
         /* Remove any name for this object */