linux-kernel - Re: [PATCH v9 12/26] x86/fpu/xstate: Use feature disable (XFD) to protect dynamic user state

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: <CAJvTdKnPMjY5iKaz+ch14Syc_=n2+xiTrBEK020XwkHGJQQWJw@mail.gmail.com>
Date:   Tue, 24 Aug 2021 18:51:40 -0400
From:   Len Brown <lenb@...nel.org>
To:     Borislav Petkov <bp@...en8.de>
Cc:     Thiago Macieira <thiago.macieira@...el.com>,
        "Chang S. Bae" <chang.seok.bae@...el.com>,
        Andy Lutomirski <luto@...nel.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...nel.org>, X86 ML <x86@...nel.org>,
        "Brown, Len" <len.brown@...el.com>,
        Dave Hansen <dave.hansen@...el.com>,
        "Liu, Jing2" <jing2.liu@...el.com>,
        "Ravi V. Shankar" <ravi.v.shankar@...el.com>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v9 12/26] x86/fpu/xstate: Use feature disable (XFD) to
 protect dynamic user state

On Wed, Aug 18, 2021 at 2:09 PM Borislav Petkov <bp@...en8.de> wrote:

> What relevance does the fact have for userspace whether the kernel
> supports XFD or not?

Right.
If user space needs to know that XFD exists, then we have done
something very wrong.

-- 
Len Brown, Intel Open Source Technology Center