of: detect invalid phandle in overlay

Overlays are not allowed to modify phandle values of previously existing
nodes because there is no information available to allow fixup up
properties that use the previously existing phandle.

Signed-off-by: Frank Rowand <frank.rowand@sony.com>
Signed-off-by: Rob Herring <robh@kernel.org>

diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c
index 7827786718d815c0a92a026b5b07cf8d61b6f542..c0e4ee1cd1bad5a57bf8ecb13edbfcdfe7bc2d47 100644 (file)
--- a/drivers/of/overlay.c
+++ b/drivers/of/overlay.c
@@ -132,6 +132,10 @@ static int of_overlay_apply_single_device_node(struct of_overlay *ov,
        /* NOTE: Multiple mods of created nodes not supported */
        tchild = of_get_child_by_name(target, cname);
        if (tchild != NULL) {
+               /* new overlay phandle value conflicts with existing value */
+               if (child->phandle)
+                       return -EINVAL;
+
                /* apply overlay recursively */
                ret = of_overlay_apply_one(ov, tchild, child);
                of_node_put(tchild);