[PATCH 04/18] software_node: Enforce parent before child ordering of nodes array for software_node_register_nodes()

[Daniel Scally <djrscally@xxxxxxxxx>]

Registering software_nodes with the .parent member set to point to a
currently unregistered software_node has the potential for problems,
so enforce parent -> child ordering in arrays passed to this function.

Suggested-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Signed-off-by: Daniel Scally <djrscally@xxxxxxxxx>
---
Changes since RFC v3:

	Patch introduced

 drivers/base/swnode.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/base/swnode.c b/drivers/base/swnode.c
index 615a0c93e116..af7930b3679e 100644
--- a/drivers/base/swnode.c
+++ b/drivers/base/swnode.c
@@ -700,14 +700,21 @@ int software_node_register_nodes(const struct software_node *nodes)
 	int i;
 
 	for (i = 0; nodes[i].name; i++) {
+		if (nodes[i].parent)
+			if (!software_node_to_swnode(nodes[i].parent)) {
+				ret = -EINVAL;
+				goto err_unregister_nodes;
+			}
+
 		ret = software_node_register(&nodes[i]);
-		if (ret) {
-			software_node_unregister_nodes(nodes);
-			return ret;
-		}
+		if (ret)
+			goto err_unregister_nodes;
 	}
 
 	return 0;
+err_unregister_nodes:
+	software_node_unregister_nodes(nodes);
+	return ret;
 }
 EXPORT_SYMBOL_GPL(software_node_register_nodes);
 
-- 
2.25.1