Re: linux-next: Tree for Nov 15 (objtool)

From: Josh Poimboeuf
Date: Fri Nov 15 2019 - 11:38:40 EST


On Fri, Nov 15, 2019 at 08:02:30AM -0800, Randy Dunlap wrote:
> On 11/15/19 12:05 AM, Stephen Rothwell wrote:
> > Hi all,
> >
> > Changes since 20191114:
> >
>
> on x86_64:
>
> already reported and Josh supplied a fix (yet unmerged),
> but this is still around:
>
> kernel/exit.o: warning: objtool: __x64_sys_exit_group()+0x14: unreachable instruction

My apologies, I have a growing backlog of objtool fixes which I hope to
post next week.

>
> new AFAIK:
>
> drivers/gpu/drm/bridge/cdns-dsi.o: warning: objtool: cdns_dsi_bridge_enable()+0x3e0: unreachable instruction
>
> obj file for latter one is attached.

This seems fishy. cdns_dsi_init_link() never returns, it always dies a
with UD2. I bet GCC decided that it always does a divide-by-zero, and
so it forces a crash as a result. Will try to dig deeper next week...

--
Josh