1 files changed, 21 insertions, 3 deletions

diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
index d47aa774d64b..4b3c533be859 100644
--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -195,9 +195,14 @@ drm_gem_remove_prime_handles(struct drm_gem_object *obj, struct drm_file *filp)
                 drm_prime_remove_buf_handle(&filp->prime,
                                 obj->import_attach->dmabuf);
         }
-        if (obj->export_dma_buf) {
+
+        /*
+         * Note: obj->dma_buf can't disappear as long as we still hold a
+         * handle reference in obj->handle_count.
+         */
+        if (obj->dma_buf) {
                 drm_prime_remove_buf_handle(&filp->prime,
-                                obj->export_dma_buf);
+                                obj->dma_buf);
         }
 }
 
@@ -231,6 +236,15 @@ static void drm_gem_object_handle_free(struct drm_gem_object *obj)
         }
 }
 
+static void drm_gem_object_exported_dma_buf_free(struct drm_gem_object *obj)
+{
+        /* Unbreak the reference cycle if we have an exported dma_buf. */
+        if (obj->dma_buf) {
+                dma_buf_put(obj->dma_buf);
+                obj->dma_buf = NULL;
+        }
+}
+
 static void
 drm_gem_object_handle_unreference_unlocked(struct drm_gem_object *obj)
 {
@@ -244,8 +258,10 @@ drm_gem_object_handle_unreference_unlocked(struct drm_gem_object *obj)
         */
 
         mutex_lock(&obj->dev->object_name_lock);
-        if (--obj->handle_count == 0)
+        if (--obj->handle_count == 0) {
                 drm_gem_object_handle_free(obj);
+                drm_gem_object_exported_dma_buf_free(obj);
+        }
         mutex_unlock(&obj->dev->object_name_lock);
 
         drm_gem_object_unreference_unlocked(obj);
@@ -712,6 +728,8 @@ drm_gem_release(struct drm_device *dev, struct drm_file *file_private)
 void
 drm_gem_object_release(struct drm_gem_object *obj)
 {
+        WARN_ON(obj->dma_buf);
+
         if (obj->filp)
             fput(obj->filp);
 }