linux-kernel - Re: [PATCH] x86/srso: Disable the mitigation on unaffected configurations

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: <20230814211727.GLZNqZ5+flxtyaDjMQ@fat_crate.local>
Date:   Mon, 14 Aug 2023 23:17:27 +0200
From:   Borislav Petkov <bp@...en8.de>
To:     Josh Poimboeuf <jpoimboe@...nel.org>
Cc:     Nikolay Borisov <nik.borisov@...e.com>, X86 ML <x86@...nel.org>,
        Josh Poimboeuf <jpoimboe@...hat.com>,
        LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] x86/srso: Disable the mitigation on unaffected
 configurations

On Mon, Aug 14, 2023 at 01:53:00PM -0700, Josh Poimboeuf wrote:
> cpu_smt_possible() already does that.

Ok.

> 2. ENUMERATION OF NEW CAPABILITIES

Yes, exactly. On the next page: "Hypervisor software should
synthesize... " I got confused initially too.

> Since technically the CPU is affected, I'm thinking it should say
> "Mitigation: SMT disabled" or such, instead of "Not affected".

Lemme see how ugly it becomes tomorrow.

> Hm?  You mean the *_NO ones that determine whether the BUG bits get set
> in the first place?  How do they print "Not affected"?

If SMT is disabled on those configurations, it is not affected. But ok,
"SMT disabled".

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette