linux-kernel - Re: [GIT PULL] objtool fixes

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <hon37m7rc4qn6a52btgbeplqmcd47wa4huehc4aoddgpqsgghk@vbfd6ma4lw6k>
Date: Thu, 3 Apr 2025 12:42:57 -0700
From: Josh Poimboeuf <jpoimboe@...nel.org>
To: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Ingo Molnar <mingo@...nel.org>, linux-kernel@...r.kernel.org, 
	Peter Zijlstra <a.p.zijlstra@...llo.nl>, Thomas Gleixner <tglx@...utronix.de>, 
	Borislav Petkov <bp@...en8.de>, Andrew Morton <akpm@...ux-foundation.org>
Subject: Re: [GIT PULL] objtool fixes

On Thu, Apr 03, 2025 at 12:12:44PM -0700, Linus Torvalds wrote:
> On Thu, 3 Apr 2025 at 11:24, Josh Poimboeuf <jpoimboe@...nel.org> wrote:
> >
> > There's also smap_save() / smap_restore().  For the latter we'd need to
> > look for alternatives with "push reg; popf", which is definitely not
> > SMAP-specific.  So we'd need to start reading feature bits again, which
> > ends up even worse than what we had before.
> 
> Now, I agree that smap_save / smap_restore might be worthy of an
> annotation, to show that "this is just a push/pop, but the intent is
> to save AC".
> 
> Would that be ok?

Yeah, that should be fine.

If we can keep the annotations for those other alternatives, that leaves
most of the benefits of the original patch intact.

The "nop with stac/clac" alternative check does look trivial enough.

-- 
Josh