From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751130Ab1BEG05 (ORCPT ); Sat, 5 Feb 2011 01:26:57 -0500 Received: from terminus.zytor.com ([198.137.202.10]:40315 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750865Ab1BEG04 (ORCPT ); Sat, 5 Feb 2011 01:26:56 -0500 Message-ID: <4D4CED97.7060302@zytor.com> Date: Fri, 04 Feb 2011 22:26:31 -0800 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.13) Gecko/20101209 Fedora/3.1.7-0.35.b3pre.fc14 Thunderbird/3.1.7 MIME-Version: 1.0 To: Kees Cook CC: mingo@redhat.com, linux-kernel@vger.kernel.org, castet.matthieu@free.fr, tglx@linutronix.de, hpa@linux.intel.com Subject: Re: [tip:x86/urgent] x86-32: Make sure the stack is set up before we use it References: <4D41E86D.8060205@free.fr> <20110205021922.GP5503@outflux.net> <4D4CD411.6070800@zytor.com> <20110205053716.GR5503@outflux.net> In-Reply-To: <20110205053716.GR5503@outflux.net> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/04/2011 09:37 PM, Kees Cook wrote: > On Fri, Feb 04, 2011 at 08:37:37PM -0800, H. Peter Anvin wrote: >> On 02/04/2011 06:19 PM, Kees Cook wrote: >>> This works for me doing CPU hotplugging on ia32, but on x86_64 it hangs. >>> (Both boot, though.) >> >> I can't reproduce the failure here, and it's hard to see how this patch >> would make a significant change on 64 bits. Could you try reverting >> *only* the head_64.S hunk and try it on your platform again? > > With the head_64.S hunk dropped, it runs fine. My highly fine-tuned > test-case is: > > while :; do ls -la / -R >/dev/null 2>/dev/null; done & > while :; do echo 0 > /sys/devices/system/cpu/cpu1/online ; echo 1 > /sys/devices/system/cpu/cpu1/online ; done & > > Looks good from this end. Thanks! > OK, that bothers me, because it would seem that something is accessing data it shouldn't, but ok, it fixes it for now. I'll update it in -tip. -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.