linux-kernel - Re: [PATCH v7 0/4] Enabling Ring 3 MONITOR/MWAIT feature for Knights Landing

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] [day] [month] [year] [list]

Message-ID: <20161203202751.GC13417@amd>
Date:   Sat, 3 Dec 2016 21:27:51 +0100
From:   Pavel Machek <pavel@....cz>
To:     Grzegorz Andrejczuk <grzegorz.andrejczuk@...el.com>
Cc:     tglx@...utronix.de, mingo@...hat.com, hpa@...or.com,
        x86@...nel.org, bp@...e.de, dave.hansen@...ux.intel.com,
        lukasz.daniluk@...el.com, james.h.cownie@...el.com,
        jacob.jun.pan@...el.com, Piotr.Luc@...el.com,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v7 0/4] Enabling Ring 3 MONITOR/MWAIT feature for Knights
 Landing

On Fri 2016-10-28 15:49:51, Grzegorz Andrejczuk wrote:
> These patches enable Intel Xeon Phi x200 feature to use MONITOR/MWAIT
> instruction in ring 3 (userspace) Patches set MSR 0x140 for all
logical CPUs.

> Then expose it as CPU feature and introduces elf HWCAP capability
>  for x86.

Elf hardware capability? Why do that? Normally CPU features go to
/proc/cpuinfo...

Plus... Can you elaborate on security effects of this? Does monitor
allow monitoring memory the current process can not write to? Is it
good idea to let userland process watch for NMIs?

									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

Download attachment "signature.asc" of type "application/pgp-signature" (182 bytes)