On Mon, Jun 7, 2021 at 11:02 PM Mark Brown <broonie@xxxxxxxxxx> wrote:
>
> One common cause of modpost version generation failures is a failure to
> prototype exported assembly functions - the tooling requires this for
> exported functions even if they are not and should not be called from C
> code in order to do the version mangling for symbols. Unfortunately the
> error message is currently rather abstruse, simply saying that "version
> generation failed" and even diving into the code doesn't directly show
> what's going on since there's several steps between the problem and it
> being observed.
>
> Provide an explicit hint as to the likely cause of a version generation
> failure to help anyone who runs into this in future more readily diagnose
> and fix the problem.
>
> Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
> ---
Applied to linux-kbuild. Thanks.
>
> v2:
> - Reword and reformat error message.
> - Fix duplicated is.
>
> scripts/mod/modpost.c | 7 +++++--
> 1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
> index 3e623ccc020b..270a7df898e2 100644
> --- a/scripts/mod/modpost.c
> +++ b/scripts/mod/modpost.c
> @@ -660,8 +660,11 @@ static void handle_modversion(const struct module *mod,
> unsigned int crc;
>
> if (sym->st_shndx == SHN_UNDEF) {
> - warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n",
> - symname, mod->name, mod->is_vmlinux ? "" : ".ko");
> + warn("EXPORT symbol \"%s\" [%s%s] version ...\n"
> + "Is \"%s\" prototyped in <asm/asm-prototypes.h>?\n",
> + symname, mod->name, mod->is_vmlinux ? "" : ".ko",
> + symname);
> +
> return;
> }
>
> --
> 2.20.1
>
--
Best Regards
Masahiro Yamada
