Re: [PATCH v2 12/26] modpost: make sym_add_exported() always allocate a new symbol

Nick Desaulniers
2022-05-03T21:57:07Z

On Sun, May 1, 2022 at 1:42 AM Masahiro Yamada <masahiroy@kernel.org> wrote:
>
> Currently, sym_add_exported() does not allocate a symbol if the same
> name symbol already exists in the hash table.
>
> This does not reflect the real use cases. You can let an external
> module override the in-tree one. In this case, the external module
> will export the same name symbols as the in-tree one. However,
> modpost simply ignores those symbols, then Module.symvers for the
> external module loses its symbols.
>
> sym_add_exported() should allocate a new symbol.
>
> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Thanks for the patch!
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>

> ---
>
> (no changes since v1)
>
> scripts/mod/modpost.c | 10 ++++------
> 1 file changed, 4 insertions(+), 6 deletions(-)
>
> diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
> index 1f01fc942f94..c9b75697d0fc 100644
> --- a/scripts/mod/modpost.c
> +++ b/scripts/mod/modpost.c
> @@ -412,19 +412,17 @@ static struct symbol *sym_add_exported(const char *name, struct module *mod,
> {
> struct symbol *s = find_symbol(name);
>
> - if (!s) {
> - s = new_symbol(name, mod, export);
> - list_add_tail(&s->list, &mod->exported_symbols);
> - } else if (!external_module || s->module->is_vmlinux ||
> - s->module == mod) {
> + if (s && (!external_module || s->module->is_vmlinux || s->module == mod)) {
> error("%s: '%s' exported twice. Previous export was in %s%s\n",
> mod->name, name, s->module->name,
> s->module->is_vmlinux ? "" : ".ko");
> - return s;
> }
>
> + s = new_symbol(name, mod, export);
> s->module = mod;
> s->export = export;
> + list_add_tail(&s->list, &mod->exported_symbols);
> +
> return s;
> }
>
> --
> 2.32.0
>

--
Thanks,
~Nick Desaulniers