Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261464AbVENTtB (ORCPT ); Sat, 14 May 2005 15:49:01 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261475AbVENTtB (ORCPT ); Sat, 14 May 2005 15:49:01 -0400 Received: from pentafluge.infradead.org ([213.146.154.40]:57478 "EHLO pentafluge.infradead.org") by vger.kernel.org with ESMTP id S261464AbVENTs5 (ORCPT ); Sat, 14 May 2005 15:48:57 -0400 Subject: Re: Hyper-Threading Vulnerability From: Arjan van de Ven To: Lee Revell Cc: Alan Cox , Dave Jones , Matt Mackall , Andy Isaacson , Andi Kleen , "Richard F. Rebel" , Gabor MICSKO , Linux Kernel Mailing List , tytso@mit.edu In-Reply-To: <1116098504.9141.31.camel@mindpipe> References: <1115963481.1723.3.camel@alderaan.trey.hu> <1116009483.4689.803.camel@rebel.corp.whenu.com> <20050513190549.GB47131@muc.de> <20050513212620.GA12522@hexapodia.org> <20050513215905.GY5914@waste.org> <1116024419.20646.41.camel@localhost.localdomain> <1116025212.6380.50.camel@mindpipe> <20050513232708.GC13846@redhat.com> <1116027488.6380.55.camel@mindpipe> <1116084186.20545.47.camel@localhost.localdomain> <1116088229.8880.7.camel@mindpipe> <1116089068.6007.13.camel@laptopd505.fenrus.org> <1116093396.9141.11.camel@mindpipe> <1116093694.6007.15.camel@laptopd505.fenrus.org> <1116098504.9141.31.camel@mindpipe> Content-Type: text/plain Date: Sat, 14 May 2005 21:48:46 +0200 Message-Id: <1116100126.6007.17.camel@laptopd505.fenrus.org> Mime-Version: 1.0 X-Mailer: Evolution 2.0.4 (2.0.4-4) Content-Transfer-Encoding: 7bit X-Spam-Score: 3.7 (+++) X-Spam-Report: SpamAssassin version 2.63 on pentafluge.infradead.org summary: Content analysis details: (3.7 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- 1.1 RCVD_IN_DSBL RBL: Received via a relay in list.dsbl.org [] 2.5 RCVD_IN_DYNABLOCK RBL: Sent directly from dynamic IP address [80.57.133.107 listed in dnsbl.sorbs.net] 0.1 RCVD_IN_SORBS RBL: SORBS: sender is listed in SORBS [80.57.133.107 listed in dnsbl.sorbs.net] X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1408 Lines: 31 On Sat, 2005-05-14 at 15:21 -0400, Lee Revell wrote: > On Sat, 2005-05-14 at 20:01 +0200, Arjan van de Ven wrote: > > On Sat, 2005-05-14 at 13:56 -0400, Lee Revell wrote: > > > On Sat, 2005-05-14 at 18:44 +0200, Arjan van de Ven wrote: > > > > then JACK is terminally broken if it doesn't have a fallback for non- > > > > rdtsc cpus. > > > > > > It does have a fallback, but the selection is done at compile time. It > > > uses rdtsc for all x86 CPUs except pre-i586 SMP systems. > > > > > > Maybe we should check at runtime, > > > > it's probably a sign that JACK isn't used on SMP systems much, at least > > not on the bigger systems (like IBM's x440's) where the tsc *will* > > differ wildly between cpus... > > Correct. The only bug reports we have seen related to the use of the > TSC is due to CPU frequency scaling. The fix is to not use it - people > who want to use their PC as a DSP for audio probably don't want their > processor slowing down anyway. it's a matter of time (my estimate is a year or two) before processors get variable frequencies based on temperature targets etc... and then rdtsc is really useless for this kind of thing.. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/