Re: [PATCH] readelf: Warn zero-sized relocation sections

["H.J. Lu" <hjl.tools@gmail.com>]

On Tue, Apr 14, 2020 at 5:42 AM Jan Beulich <jbeulich@suse.com> wrote:
>
> On 14.04.2020 14:25, H.J. Lu via Binutils wrote:
> > Older linkers may fail with zero-sized relocation section in section
> > group.
> >
> >       PR ld/25767
> >       * readelf.c (process_section_headers): Warn zero-sized
> >       relocation sections.
>
> Zero-sized sections of whatever kind are perfectly fine in ELF. I
> see no reason why one would want to see a warning for such by
> default.

Linkers older than 2.35 may fail with

./ld: BFD (GNU Binutils) 2.34.50.20200402 assertion fail
/export/gnu/import/git/gitlab/x86-binutils/bfd/elf.c:3652

> Jan
>
> > ---
> >  binutils/readelf.c | 14 ++++++++++++--
> >  1 file changed, 12 insertions(+), 2 deletions(-)
> >
> > diff --git a/binutils/readelf.c b/binutils/readelf.c
> > index cd456b0290..535d47a58e 100644
> > --- a/binutils/readelf.c
> > +++ b/binutils/readelf.c
> > @@ -6315,9 +6315,19 @@ process_section_headers (Filedata * filedata)
> >        else if (section->sh_type == SHT_GROUP)
> >       CHECK_ENTSIZE_VALUES (section, i, GRP_ENTRY_SIZE, GRP_ENTRY_SIZE);
> >        else if (section->sh_type == SHT_REL)
> > -     CHECK_ENTSIZE (section, i, Rel);
> > +     {
> > +       CHECK_ENTSIZE (section, i, Rel);
> > +       if (section->sh_size == 0)
> > +         warn (_("Section '%s': zero-sized relocation section\n"),
> > +               name);
> > +     }
> >        else if (section->sh_type == SHT_RELA)
> > -     CHECK_ENTSIZE (section, i, Rela);
> > +     {
> > +       CHECK_ENTSIZE (section, i, Rela);
> > +       if (section->sh_size == 0)
> > +         warn (_("Section '%s': zero-sized relocation section\n"),
> > +               name);
> > +     }
> >        else if ((do_debugging || do_debug_info || do_debug_abbrevs
> >               || do_debug_lines || do_debug_pubnames || do_debug_pubtypes
> >               || do_debug_aranges || do_debug_frames || do_debug_macinfo
> >
>


-- 
H.J.