drm/qxl: Propagate correctly errors from qxlhw_handle_to_bo

This function could return a NULL pointer in case of handle not
present and in case of out of memory conditions however caller
function always returned EINVAL error hiding a possible ENOMEM.
This patch change the function to return the error instead to
be able to propagate the error instead of assuming EINVAL.

Signed-off-by: Frediano Ziglio <fziglio@redhat.com>
Reviewed-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/qxl/qxl_ioctl.c

@@ -107,9 +107,9 @@ apply_surf_reloc(struct qxl_device *qdev, struct qxl_reloc_info *info)
 }
 
 /* return holding the reference to this object */
-static struct qxl_bo *qxlhw_handle_to_bo(struct qxl_device *qdev,
-					 struct drm_file *file_priv, uint64_t handle,
-					 struct qxl_release *release)
+static int qxlhw_handle_to_bo(struct qxl_device *qdev,
+			      struct drm_file *file_priv, uint64_t handle,
+			      struct qxl_release *release, struct qxl_bo **qbo_p)
 {
 	struct drm_gem_object *gobj;
 	struct qxl_bo *qobj;
@@ -117,16 +117,17 @@ static struct qxl_bo *qxlhw_handle_to_bo(struct qxl_device *qdev,
 
 	gobj = drm_gem_object_lookup(qdev->ddev, file_priv, handle);
 	if (!gobj)
-		return NULL;
+		return -EINVAL;
 
 	qobj = gem_to_qxl_bo(gobj);
 
 	ret = qxl_release_list_add(release, qobj);
 	drm_gem_object_unreference_unlocked(gobj);
 	if (ret)
-		return NULL;
+		return ret;
 
-	return qobj;
+	*qbo_p = qobj;
+	return 0;
 }
 
 /*
@@ -219,13 +220,10 @@ static int qxl_process_single_command(struct qxl_device *qdev,
 		reloc_info[i].type = reloc.reloc_type;
 
 		if (reloc.dst_handle) {
-			reloc_info[i].dst_bo = qxlhw_handle_to_bo(qdev, file_priv,
-								  reloc.dst_handle, release);
-			if (!reloc_info[i].dst_bo) {
-				ret = -EINVAL;
-				reloc_info[i].src_bo = NULL;
+			ret = qxlhw_handle_to_bo(qdev, file_priv, reloc.dst_handle, release,
+						 &reloc_info[i].dst_bo);
+			if (ret)
 				goto out_free_bos;
-			}
 			reloc_info[i].dst_offset = reloc.dst_offset;
 		} else {
 			reloc_info[i].dst_bo = cmd_bo;
@@ -234,14 +232,11 @@ static int qxl_process_single_command(struct qxl_device *qdev,
 		num_relocs++;
 
 		/* reserve and validate the reloc dst bo */
-		if (reloc.reloc_type == QXL_RELOC_TYPE_BO || reloc.src_handle > 0) {
-			reloc_info[i].src_bo =
-				qxlhw_handle_to_bo(qdev, file_priv,
-						   reloc.src_handle, release);
-			if (!reloc_info[i].src_bo) {
-				ret = -EINVAL;
+		if (reloc.reloc_type == QXL_RELOC_TYPE_BO || reloc.src_handle) {
+			ret = qxlhw_handle_to_bo(qdev, file_priv, reloc.src_handle, release,
+						 &reloc_info[i].src_bo);
+			if (ret)
 				goto out_free_bos;
-			}
 			reloc_info[i].src_offset = reloc.src_offset;
 		} else {
 			reloc_info[i].src_bo = NULL;