drm: Do not leak a new reference for flink() on an existing name

The name table should only hold a single reference, so avoid leaking
additional references for secondary calls to flink().

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Dave Airlie <airlied@linux.ie>

1 files changed, 16 insertions, 17 deletions

diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
index e5a8ebf9a662..5dad6b9d0dec 100644
--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -301,27 +301,25 @@ again:
         }
 
         spin_lock(&dev->object_name_lock);
-        if (obj->name) {
-                args->name = obj->name;
+        if (!obj->name) {
+                ret = idr_get_new_above(&dev->object_name_idr, obj, 1,
+                                        &obj->name);
+                args->name = (uint64_t) obj->name;
                 spin_unlock(&dev->object_name_lock);
-                return 0;
-        }
-        ret = idr_get_new_above(&dev->object_name_idr, obj, 1,
-                                 &obj->name);
-        spin_unlock(&dev->object_name_lock);
-        if (ret == -EAGAIN)
-                goto again;
 
-        if (ret != 0)
-                goto err;
+                if (ret == -EAGAIN)
+                        goto again;
 
-        /*
-         * Leave the reference from the lookup around as the
-         * name table now holds one
-         */
-        args->name = (uint64_t) obj->name;
+                if (ret != 0)
+                        goto err;
 
-        return 0;
+                /* Allocate a reference for the name table.  */
+                drm_gem_object_reference(obj);
+        } else {
+                args->name = (uint64_t) obj->name;
+                spin_unlock(&dev->object_name_lock);
+                ret = 0;
+        }
 
 err:
         mutex_lock(&dev->struct_mutex);
@@ -452,6 +450,7 @@ drm_gem_object_handle_free(struct kref *kref)
         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