linux-kernel - Re: [PATCH 09/22] x86/fpu: Add (__)make_fpregs

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]

Date:   Wed, 13 Feb 2019 10:30:25 +0100
From:   Borislav Petkov <bp@...en8.de>
To:     Sebastian Andrzej Siewior <bigeasy@...utronix.de>
Cc:     linux-kernel@...r.kernel.org, x86@...nel.org,
        Andy Lutomirski <luto@...nel.org>,
        Paolo Bonzini <pbonzini@...hat.com>,
        Radim Krčmář <rkrcmar@...hat.com>,
        kvm@...r.kernel.org, "Jason A. Donenfeld" <Jason@...c4.com>,
        Rik van Riel <riel@...riel.com>,
        Dave Hansen <dave.hansen@...ux.intel.com>
Subject: Re: [PATCH 09/22] x86/fpu: Add (__)make_fpregs_active helpers

On Thu, Feb 07, 2019 at 11:43:25AM +0100, Sebastian Andrzej Siewior wrote:
> They are accessible inside the region. But they should not be touched by
> context switch code (and later BH).
> Is that what you meant?

I just don't like that "changes" name. So when called, those functions
practically lock the FPU regs from being accessed by others. So with

fpregs_lock
fpregs_unlock

for example, is kinda clear what's going on and you don't have to wonder
what it does.

> No. I picked up the patches, that function was named like that. I kept
> it. That __ probably denotes that it is an internal function but then it
> has to be used outside (KVM) if they plan to "reload" registers (which
> happens if they switch between host/guest registers).

Ok, so you can drop the "__".

-- 
Regards/Gruss,
    Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.