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

Masahiro Yamada
2023-05-20T13:12:08Z

On Thu, May 18, 2023 at 3:53 AM Nick Desaulniers
<ndesaulniers@google.com> wrote:
>
> 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?

See the code.

The variable, 'fromsec' (i.e. "__ex_table") is remaining.

It prints a warning message as you wish.

> >
> > 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

--
Best Regards
Masahiro Yamada