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

Message-ID: <CAHk-=wh2WtMskQ7ASnDJ_n0ZJs4hueEXsurwQpEvzmx-aZKFag@mail.gmail.com>
Date: Thu, 3 Apr 2025 09:06:11 -0700
From: Linus Torvalds <torvalds@...ux-foundation.org>
To: Josh Poimboeuf <jpoimboe@...nel.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, 3 Apr 2025 at 08:43, Josh Poimboeuf <jpoimboe@...nel.org> wrote:
>
> # OBJTOOL ANNOTATION
> 911: .pushsection .discard.annotate_insn,"M",@progbits,8; .long 911b - .; .long 6; .popsection

Josh, what's wrong with just disassembling the damn instruction?

It's what objtool does.

By all means add annotations for when the kernel does something
*special*, and the annotation is "this violates the usual rules".
Those kinds of annotations make perfect sense, and are a "don't
complain about this, because I know I'm doing something odd".

So annotations for things like non-standard stack frames etc are a good thing.

But dammit, clac/stac is *not* that. Quite the reverse. clac/stac *is*
the usual rule. clac/stac *is* the annotation.

             Linus