Re: [PATCH 01/10] of: Fix alias name length calculating error in API of_find_node_opts_by_path()

[Rob Herring]

On Thu, Dec 5, 2024 at 6:53 PM Zijun Hu <zijun_hu@xxxxxxxxxx> wrote:
>
> From: Zijun Hu <quic_zijuhu@xxxxxxxxxxx>
>
> Alias name length calculated by of_find_node_opts_by_path() is wrong as
> explained below:
>
> Take "alias/serial@llc500:115200n8" as its @patch argument for an example
>       ^    ^             ^
>       0    5             19
>
> The right length of alias 'alias' is 5, but the API results in 19 which is
> obvious wrong.
>
> The wrong length will cause finding device node failure for such paths.
> Fix by using index of either '/' or ':' as the length who comes earlier.

Can you add a test case in the unittest for this.

>
> Fixes: 106937e8ccdc ("of: fix handling of '/' in options for of_find_node_by_path()")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Zijun Hu <quic_zijuhu@xxxxxxxxxxx>
> ---
>  drivers/of/base.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/of/base.c b/drivers/of/base.c
> index 7dc394255a0a14cd1aed02ec79c2f787a222b44c..9a9313183d1f1b61918fe7e6fa80c2726b099a1c 100644
> --- a/drivers/of/base.c
> +++ b/drivers/of/base.c
> @@ -893,10 +893,10 @@ struct device_node *of_find_node_opts_by_path(const char *path, const char **opt
>         /* The path could begin with an alias */
>         if (*path != '/') {
>                 int len;
> -               const char *p = separator;
> +               const char *p = strchrnul(path, '/');
>
> -               if (!p)
> -                       p = strchrnul(path, '/');
> +               if (separator && separator < p)
> +                       p = separator;
>                 len = p - path;
>
>                 /* of_aliases must not be NULL */
>
> --
> 2.34.1
>