Re: [PATCH] x86/sev: Mark snp_abort() noreturn

Segher Boessenkool
2022-08-24T19:51:17Z

On Wed, Aug 24, 2022 at 11:44:35AM -0700, Nick Desaulniers wrote:
> On Wed, Aug 24, 2022 at 10:33 AM Segher Boessenkool
> <segher@kernel.crashing.org> wrote:
> > On Wed, Aug 24, 2022 at 05:24:20PM +0200, Borislav Petkov wrote:
> > > Mark both the function prototype and definition as noreturn in order to
> > > prevent the compiler from doing transformations which confuse objtool
> > > like so:
> > >
> > > vmlinux.o: warning: objtool: sme_enable+0x71: unreachable instruction
> >
> > Would -Wmissing-noreturn have caught this?
>
> Oh, that's shiny. Is that relatively new?

Relatively, yes.

commit 0ca3fb0a168e9db2bd5405855d3932f62b08b7c9
Author: Kaveh R. Ghazi <ghazi@caip.rutgers.edu>
Date: Tue Oct 20 07:32:08 1998 +0000

New warning, `missing-noreturn':

The alias -Wsuggest-attribute=noreturn is newer:

commit 94ee697923f5a93881edbc5e1b3f810b290f0fc7
Author: Manuel López-Ibáñez <manu@gcc.gnu.org>
Date: Sun Apr 29 09:15:30 2012 +0000

* common.opt (Wmissing-noreturn): Alias of -Wsuggest-attribute=noret

Segher