Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261641AbVEOOVj (ORCPT ); Sun, 15 May 2005 10:21:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261650AbVEOOVj (ORCPT ); Sun, 15 May 2005 10:21:39 -0400 Received: from artax.karlin.mff.cuni.cz ([195.113.31.125]:9652 "EHLO artax.karlin.mff.cuni.cz") by vger.kernel.org with ESMTP id S261641AbVEOOVg (ORCPT ); Sun, 15 May 2005 10:21:36 -0400 Date: Sun, 15 May 2005 16:21:36 +0200 (CEST) From: Mikulas Patocka To: Andi Kleen Cc: linux-kernel@vger.kernel.org Subject: Re: Hyper-Threading Vulnerability In-Reply-To: <20050515141207.GB94354@muc.de> Message-ID: References: <1115963481.1723.3.camel@alderaan.trey.hu> <20050513211609.75216bf8.diegocg@gmail.com> <20050515095446.GE68736@muc.de> <20050515141207.GB94354@muc.de> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1720 Lines: 47 On Sun, 15 May 2005, Andi Kleen wrote: > On Sun, May 15, 2005 at 03:51:05PM +0200, Mikulas Patocka wrote: > > > > > > On Sun, 15 May 2005, Andi Kleen wrote: > > > > > On Fri, May 13, 2005 at 09:16:09PM +0200, Diego Calleja wrote: > > > > El Fri, 13 May 2005 20:03:58 +0200, > > > > Andi Kleen escribi?: > > > > > > > > > > > > > This is not a kernel problem, but a user space problem. The fix > > > > > is to change the user space crypto code to need the same number of cache line > > > > > accesses on all keys. > > > > > > > > > > > > However they've patched the FreeBSD kernel to "workaround?" it: > > > > ftp://ftp.freebsd.org/pub/FreeBSD/CERT/patches/SA-05:09/htt5.patch > > > > > > That's a similar stupid idea as they did with the disk write > > > cache (lowering the MTBFs of their disks by considerable factors, > > > which is much worse than the power off data loss problem) > > > Let's not go down this path please. > > > > What wrong did they do with disk write cache? > > They turned it off by default, which according to disk vendors > lowers the MTBF of your disk to a fraction of the original value. > > I bet the total amount of valuable data lost for FreeBSD users because > of broken disks is much much bigger than what they gained from not losing > in the rather hard to hit power off cases. > > -Andi BTW. Is there any blacklist of disks with broken FLUSH CACHE command? Or a list of companies that cheat in implementation of it? Mikulas - 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/