Re: [PATCH v5 02/21] modpost: remove fromsym info in __ex_table section mismatch warning

Nick Desaulniers
2023-05-17T18:53:24Z

On Sun, May 14, 2023 at 8:27 AM Masahiro Yamada <masahiroy@kernel.org> wrote:
>
> report_extable_warnings() prints "from" in a pretty form, but we know
> it is always located in the __ex_table section, i.e. a collection of
> struct exception_table_entry.

Would it still be helpful to have "from __ex_table" somewhere in the
error string that may be shown to developers?

>
> It is very likely to fail to get the symbol name and ends up with
> meaningless message:
>
> ... in reference from the (unknown reference) (unknown) to ...
>
> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
> ---
>
> scripts/mod/modpost.c | 11 ++---------
> 1 file changed, 2 insertions(+), 9 deletions(-)
>
> diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
> index ba4577aa4f1d..bbe066f7adbc 100644
> --- a/scripts/mod/modpost.c
> +++ b/scripts/mod/modpost.c
> @@ -1297,23 +1297,16 @@ static void report_extable_warnings(const char* modname, struct elf_info* elf,
> Elf_Rela* r, Elf_Sym* sym,
> const char* fromsec, const char* tosec)
> {
> - Elf_Sym* fromsym = find_elf_symbol2(elf, r->r_offset, fromsec);
> - const char* fromsym_name = sym_name(elf, fromsym);
> Elf_Sym* tosym = find_elf_symbol(elf, r->r_addend, sym);
> const char* tosym_name = sym_name(elf, tosym);
> - const char* from_pretty_name;
> - const char* from_pretty_name_p;
> const char* to_pretty_name;
> const char* to_pretty_name_p;
>
> - get_pretty_name(is_function(fromsym),
> - &from_pretty_name, &from_pretty_name_p);
> get_pretty_name(is_function(tosym),
> &to_pretty_name, &to_pretty_name_p);
>
> - warn("%s(%s+0x%lx): Section mismatch in reference from the %s %s%s to the %s %s:%s%s\n",
> - modname, fromsec, (long)r->r_offset, from_pretty_name,
> - fromsym_name, from_pretty_name_p,
> + warn("%s(%s+0x%lx): Section mismatch in reference to the %s %s:%s%s\n",
> + modname, fromsec, (long)r->r_offset,
> to_pretty_name, tosec, tosym_name, to_pretty_name_p);
>
> if (!match(tosec, mismatch->bad_tosec) &&
> --
> 2.39.2
>

--
Thanks,
~Nick Desaulniers