Re: [RFC v5 04/57] objtool: check: Ignore empty alternative groups

[Julien Thierry]

On 1/21/20 4:30 PM, Josh Poimboeuf wrote:
> On Thu, Jan 09, 2020 at 04:02:07PM +0000, Julien Thierry wrote:
> > Atlernative section can contain entries for alternatives with no
> > instructions. Objtool will currently crash when handling such an entry.
> >
> > Just skip that entry, but still give a warning to discourage useless
> > entries.
> >
> > Signed-off-by: Julien Thierry <jthierry@xxxxxxxxxx>
> > ---
> >   tools/objtool/check.c | 7 +++++++
> >   1 file changed, 7 insertions(+)
> >
> > diff --git a/tools/objtool/check.c b/tools/objtool/check.c
> > index 5968e6f08891..27e5380e0e0b 100644
> > --- a/tools/objtool/check.c
> > +++ b/tools/objtool/check.c
> > @@ -866,6 +866,13 @@ static int add_special_section_alts(struct objtool_file *file)
> >   		}
> >   
> >   		if (special_alt->group) {
> > +			if (!special_alt->orig_len) {
> > +				WARN("empty alternative entry at %s+0x%lx",
> > +				     orig_insn->sec->name,
> > +				     orig_insn->offset);
> > +				continue;
> > +			}
> > +
>
> I think WARN_FUNC() can be used here instead.

I'll do that.

Thanks,

--
Julien Thierry