drm/i915: Fix potential AB-BA deadlock in i915_gem_execbuffer()

[net-next-2.6.git] / drivers / gpu / drm / i915 / i915_gem.c

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 55f4c060fa01d83b8f066376431e1a02803e0f4c..ff0d94dd35505c794ba92580ddeb9510ff829de8 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2634,15 +2634,6 @@ i915_gem_execbuffer(struct drm_device *dev, void *data,
 
        i915_verify_inactive(dev, __FILE__, __LINE__);
 
-       /* Copy the new buffer offsets back to the user's exec list. */
-       ret = copy_to_user((struct drm_i915_relocation_entry __user *)
-                          (uintptr_t) args->buffers_ptr,
-                          exec_list,
-                          sizeof(*exec_list) * args->buffer_count);
-       if (ret)
-               DRM_ERROR("failed to copy %d exec entries "
-                         "back to user (%d)\n",
-                          args->buffer_count, ret);
 err:
        for (i = 0; i < pinned; i++)
                i915_gem_object_unpin(object_list[i]);
@@ -2652,6 +2643,18 @@ err:
 
        mutex_unlock(&dev->struct_mutex);
 
+       if (!ret) {
+               /* Copy the new buffer offsets back to the user's exec list. */
+               ret = copy_to_user((struct drm_i915_relocation_entry __user *)
+                                  (uintptr_t) args->buffers_ptr,
+                                  exec_list,
+                                  sizeof(*exec_list) * args->buffer_count);
+               if (ret)
+                       DRM_ERROR("failed to copy %d exec entries "
+                                 "back to user (%d)\n",
+                                 args->buffer_count, ret);
+       }
+
 pre_mutex_err:
        drm_free(object_list, sizeof(*object_list) * args->buffer_count,
                 DRM_MEM_DRIVER);