Re: [PATCH 2/2] userns: declare the KUnit-visible helpers whenever KUnit is enabled

[Bill Wendling]

On Fri, Sep 11, 2026 at 5:59 AM Christian Brauner <brauner@xxxxxxxxxx> wrote:
>
> VISIBLE_IF_KUNIT drops the static qualifier whenever CONFIG_KUNIT is
> enabled but the prototypes for the two helpers it exposes are only
> declared when CONFIG_USER_NS_MAP_KUNIT_TEST is set.
>
>   kernel/user_namespace.c:787:22: warning: no previous prototype for 'insert_extent' [-Wmissing-prototypes]
>   kernel/user_namespace.c:860:22: warning: no previous prototype for 'sort_idmaps' [-Wmissing-prototypes]
>
> Guard the declarations on CONFIG_KUNIT so they match the definitions.
>
> Fixes: f6f1a2496ba5 ("userns: Add KUnit test suite for uid_gid_map")
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> Closes: https://lore.kernel.org/oe-kbuild-all/202609111048.yhHILE11-lkp@xxxxxxxxx/
> Closes: https://lore.kernel.org/oe-kbuild-all/202609111305.ta3EOA2x-lkp@xxxxxxxxx/
> Signed-off-by: Christian Brauner (Amutable) <brauner@xxxxxxxxxx>

Feel free to add:

Reviewed-by: Bill Wendling <morbo@xxxxxxxxxx>

-bw

> ---
>  include/linux/user_namespace.h | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h
> index 637cd7e91a45..91232053775d 100644
> --- a/include/linux/user_namespace.h
> +++ b/include/linux/user_namespace.h
> @@ -208,11 +208,11 @@ extern bool in_userns(const struct user_namespace *ancestor,
>  extern bool current_in_userns(const struct user_namespace *target_ns);
>  struct ns_common *ns_get_owner(struct ns_common *ns);
>
> -#if IS_ENABLED(CONFIG_USER_NS_MAP_KUNIT_TEST)
> +#if IS_ENABLED(CONFIG_KUNIT)
>  extern int uid_gid_map_insert_extent(struct uid_gid_map *map,
>                                      struct uid_gid_extent *extent);
>  extern int uid_gid_map_sort(struct uid_gid_map *map);
> -#endif /* CONFIG_USER_NS_MAP_KUNIT_TEST */
> +#endif /* CONFIG_KUNIT */
>
>  #else
>
> --
> 2.53.0
>