Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756157Ab2BWW1n (ORCPT ); Thu, 23 Feb 2012 17:27:43 -0500 Received: from 1wt.eu ([62.212.114.60]:62577 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754575Ab2BWW1m (ORCPT ); Thu, 23 Feb 2012 17:27:42 -0500 Date: Thu, 23 Feb 2012 23:27:33 +0100 From: Willy Tarreau To: Linus Torvalds Cc: Greg Kroah-Hartman , "H. Peter Anvin" , stable@vger.kernel.org, Raphael Prevost , Suresh Siddha , Linux Kernel Mailing List Subject: Re: [PATCH 0/5] i387: stable kernel backport Message-ID: <20120223222733.GB1306@1wt.eu> References: <20120222211928.GA4448@kroah.com> <20120222213253.GA25150@kroah.com> <20120223200905.GA5475@kroah.com> <4F46A1C4.90506@zytor.com> <20120223204832.GA30322@kroah.com> <4F46A6EC.8050804@zytor.com> <20120223211016.GA16275@kroah.com> <20120223215242.GA1306@1wt.eu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.3i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1535 Lines: 38 On Thu, Feb 23, 2012 at 02:11:48PM -0800, Linus Torvalds wrote: > On Thu, Feb 23, 2012 at 1:52 PM, Willy Tarreau wrote: > > > > I would test this too, but apart from ensuring my kernel still boots, > > how do I ensure the patches do really fix what the ought to fix ? I > > must admit I didn't catch the initial issue they were supposed to fix > > unfortunately :-/ > > Almost nobody did. > > This only happens on modern CPU's that support the new AES-NI > instructions, and only with a 32-bit kernel (although the very > unlikely preemption issues can happen on x86-64 too). And you need to > have the AES instructions called from interrupts, which probably only > happens with the mac80211 wireless networking stack. > > And even then you need WPA2 to trigger it (I guess AES is sometimes > used with "extended WPA1" too, but I dunno). > > So it's not impossible to trigger, but you do need to have a fairly > recent CPU that happily runs in 64-bit mode, and install a 32-bit > system on it. And it needs to use the right wireless setup. OK so indeed I will only be able to check that it boots :-/ > It's possible that the right solution for really older kernels is just > to say that AES_NI depends on X86_64. Might be a good idea ! Thanks for the explanation, Willy -- 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/