linux-kernel - Re: Sysenter crash with Nested Task Bit set

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: <450EECEC.207@goop.org>
Date:	Mon, 18 Sep 2006 12:01:00 -0700
From:	Jeremy Fitzhardinge <jeremy@...p.org>
To:	Andi Kleen <ak@...e.de>
CC:	Benjamin LaHaise <bcrl@...ck.org>,
	Linus Torvalds <torvalds@...l.org>,
	Andrew Morton <akpm@...l.org>,
	Chuck Ebbert <76306.1226@...puserve.com>,
	In Cognito <defend.the.world@...il.com>,
	linux-kernel <linux-kernel@...r.kernel.org>,
	Ingo Molnar <mingo@...e.hu>
Subject: Re: Sysenter crash with Nested Task Bit set

Andi Kleen wrote:
> Yes it's never fast, but on basically all non P4 CPUs it is still fast enough
> to not be a problem. I suppose it causes a trace cache flush or something like
> that there.

I don't think it's that bad, but it might cause a full pipeline flush.  
I seem to remember measuring its cost at about 50 cycles.

    J

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/