Re: [PATCH 1/2] x86: Simplify Retpoline thunk
From: Josh Poimboeuf
Date: Wed Apr 20 2022 - 12:01:22 EST
On Wed, Apr 20, 2022 at 05:51:16PM +0200, Peter Zijlstra wrote:
> On Wed, Apr 20, 2022 at 08:27:36AM -0700, Josh Poimboeuf wrote:
> > On Tue, Apr 19, 2022 at 10:41:10PM +0200, Peter Zijlstra wrote:
> > > Now that we rewrite all the indirect call sites, per commit:
> > >
> > > 750850090081 ("x86/alternative: Implement .retpoline_sites support")
> > >
> > > it doesn't make sense to have the retpoline thunks be an ALTERNATIVE_2
> > > that still includes a 'naked' indirect jump.
> > >
> > > (this accidentally 'defunnels' i386 by going back to full retpolines)
> >
> > So mitigations=off no longer works on i386?
>
> Also true I suppose... does anybody care? /me runs like heck.
>
> I'd hate to make all this more complicated just because i386 tho :/
Not that I care... but at least the commit log should own up to it :-)
--
Josh