On Tue, Nov 05, 2019 at 10:09:52AM +0200, Stefan Mavrodiev wrote:
> When libfdt applies overlay, which has aliases, they are added to
> the __symbols__ node. Since the overlay path is string, it ends with
> trailing zero. However, when calculating path length, this symbol should
> be excluded. The effect is, that the property is threated as integer
> instead of string.
>
> Here is a simple example. Using test/overlay_base:
> / {
> test-node {
> ...
> };
> __symbols__ {
> test = "/test-node";
> ...
> };
> };
>
> Compaling simple overlay with alias node:
> / {
> fragment@0 {
> target = <0xffffffff>;
> __overlay__ {
> foo {
> bar = "bar";
> phandle = <0x00000001>;
> };
> };
> };
> __symbols__ {
> foo = "/fragment@0/__overlay__/foo";
> };
> __fixups__ {
> test = "/fragment@0:target:0";
> };
> };
>
> After merge:
> / {
> ...
> __symbols__ {
> foo = <0x2f746573 0x742d6e6f 0x64652f66 0x6f6f0000>;
> ...
> };
> };
>
> You can see that the foo value is wrong. It's parsed as int, instead of string. Same
> test with the fix:
>
> / {
> ...
> __symbols__ {
> foo = "/test-node/foo";
> ...
> };
> };
>
> Signed-off-by: Stefan Mavrodiev <stefan@xxxxxxxxxx>
LGTM, but it'd be great if you could add a test case for this as well.
> ---
> libfdt/fdt_overlay.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/libfdt/fdt_overlay.c b/libfdt/fdt_overlay.c
> index be71873..b310e49 100644
> --- a/libfdt/fdt_overlay.c
> +++ b/libfdt/fdt_overlay.c
> @@ -752,7 +752,7 @@ static int overlay_symbol_update(void *fdt, void *fdto)
> if ((e - s) > len && (memcmp(s, "/__overlay__/", len) == 0)) {
> /* /<fragment-name>/__overlay__/<relative-subnode-path> */
> rel_path = s + len;
> - rel_path_len = e - rel_path;
> + rel_path_len = e - rel_path - 1;
> } else if ((e - s) == len
> && (memcmp(s, "/__overlay__", len - 1) == 0)) {
> /* /<fragment-name>/__overlay__ */
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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