[PATCH 5.10 074/142] ARM: zImage: atags_to_fdt: Fix node names on added root nodes

[Greg Kroah-Hartman]

From: Rob Herring <robh@xxxxxxxxxx>

commit 30596ae0547dbda469d31a2678d9072fb0a3fa27 upstream.

Commit 7536c7e03e74 ("of/fdt: Remove redundant kbasename function
call") exposed a bug creating DT nodes in the ATAGS to DT fixup code.
Non-existent nodes would mistaken get created with a leading '/'. The
problem was fdt_path_offset() takes a full path while creating a node
with fdt_add_subnode() takes just the basename.

Since this we only add root child nodes, we can just skip over the '/'.

Fixes: 7536c7e03e74 ("of/fdt: Remove redundant kbasename function call")
Reported-by: Chris Packham <chris.packham@xxxxxxxxxxxxxxxxxxx>
Cc: Qi Zheng <arch0.zheng@xxxxxxxxx>
Cc: Russell King <linux@xxxxxxxxxxxxxxx>
Signed-off-by: Rob Herring <robh@xxxxxxxxxx>
Tested-by: Chris Packham <chris.packham@xxxxxxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20210126023905.1631161-1-robh@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 arch/arm/boot/compressed/atags_to_fdt.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/arch/arm/boot/compressed/atags_to_fdt.c
+++ b/arch/arm/boot/compressed/atags_to_fdt.c
@@ -15,7 +15,8 @@ static int node_offset(void *fdt, const
 {
 	int offset = fdt_path_offset(fdt, node_path);
 	if (offset == -FDT_ERR_NOTFOUND)
-		offset = fdt_add_subnode(fdt, 0, node_path);
+		/* Add the node to root if not found, dropping the leading '/' */
+		offset = fdt_add_subnode(fdt, 0, node_path + 1);
 	return offset;
 }