linux-kernel - Re: [PATCH v7 18/18] x86/fsgsbase/64: Add documentation for FSGSBASE

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: <alpine.DEB.2.21.1906161805360.1760@nanos.tec.linutronix.de>
Date:   Sun, 16 Jun 2019 18:07:09 +0200 (CEST)
From:   Thomas Gleixner <tglx@...utronix.de>
To:     Randy Dunlap <rdunlap@...radead.org>
cc:     "Chang S. Bae" <chang.seok.bae@...el.com>,
        Andy Lutomirski <luto@...nel.org>,
        Ingo Molnar <mingo@...nel.org>,
        "H . Peter Anvin" <hpa@...or.com>, Andi Kleen <ak@...ux.intel.com>,
        Ravi Shankar <ravi.v.shankar@...el.com>,
        LKML <linux-kernel@...r.kernel.org>, x86@...nel.org,
        Jonathan Corbet <corbet@....net>
Subject: Re: [PATCH v7 18/18] x86/fsgsbase/64: Add documentation for
 FSGSBASE

On Sun, 16 Jun 2019, Randy Dunlap wrote:
> On 6/13/19 11:54 PM, Thomas Gleixner wrote:
> > +
> > +There exist two mechanisms to read and write the FS/FS base address:
> 
> should this be...                                   FS/GS

Indeed.

> > +FSGSBASE instructions enablement
> > +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> > + The instructions are enumerated in CPUID leaf 7, bit 0 of EBX. If
> > + available /proc/cpuinfo shows 'fsgsbase' in the flag entry of the CPUs.
> > +
> > + The availability of the instructions is not enabling them
> 
> prefer:                                  does not enable them

ok.

> > + automatically. The kernel has to enable them explicitely in CR4. The
> 
> typo:                                            explicitly

ok.

Randy, thanks for reviewing that!


       tglx