Re: [PATCH v7 6/8] modpost: Add modname to mod_device_table alias

[Nicolas Schier <nsc@kernel.org>]

On Mon, Aug 18, 2025 at 06:55:00PM +0200, Alexey Gladkov wrote:
> At this point, if a symbol is compiled as part of the kernel,
> information about which module the symbol belongs to is lost.
> 
> To save this it is possible to add the module name to the alias name.
> It's not very pretty, but it's possible for now.
> 
> Cc: Miguel Ojeda <ojeda@kernel.org>
> Cc: Andreas Hindborg <a.hindborg@kernel.org>
> Cc: Danilo Krummrich <dakr@kernel.org>
> Cc: Alex Gaynor <alex.gaynor@gmail.com>
> Cc: rust-for-linux@vger.kernel.org
> Signed-off-by: Alexey Gladkov <legion@kernel.org>
> Acked-by: Danilo Krummrich <dakr@kernel.org>
> ---
>  include/linux/module.h   | 14 +++++++++++++-
>  rust/kernel/device_id.rs |  8 ++++----
>  scripts/mod/file2alias.c | 18 ++++++++++++++----
>  3 files changed, 31 insertions(+), 9 deletions(-)
> 
...
> diff --git a/scripts/mod/file2alias.c b/scripts/mod/file2alias.c
> index 00586119a25b7..13021266a18f8 100644
> --- a/scripts/mod/file2alias.c
> +++ b/scripts/mod/file2alias.c
> @@ -1476,8 +1476,8 @@ void handle_moddevtable(struct module *mod, struct elf_info *info,
>  {
>  	void *symval;
>  	char *zeros = NULL;
> -	const char *type, *name;
> -	size_t typelen;
> +	const char *type, *name, *modname;
> +	size_t typelen, modnamelen;

when applying the patch-set onto kbuild-next, gcc refuses to build this patch
(this possibly killing future bisecting):

../scripts/mod/file2alias.c: In function ‘handle_moddevtable’:
../scripts/mod/file2alias.c:1480:25: error: variable ‘modnamelen’ set but not used [-Werror=unused-but-set-variable]
 1480 |         size_t typelen, modnamelen;
      |                         ^~~~~~~~~~
cc1: all warnings being treated as errors
make[2]: *** [../scripts/Makefile.host:131: scripts/mod/file2alias.o] Error 

(-Werror is on for userprogs, since commit
27758d8c2583d10472b745a43ff86fef96c11ef7)

Introduction of modnamelen has to be moved to the next patch.

Kind regards
Nicolas