From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752573Ab1AES6c (ORCPT ); Wed, 5 Jan 2011 13:58:32 -0500 Received: from smtp6-g21.free.fr ([212.27.42.6]:39224 "EHLO smtp6-g21.free.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752250Ab1AES6b convert rfc822-to-8bit (ORCPT ); Wed, 5 Jan 2011 13:58:31 -0500 Date: Wed, 5 Jan 2011 19:58:16 +0100 From: matthieu castet To: Lin Ming Cc: Andi Kleen , Peter Zijlstra , Siarhei Liakh , Xuxian Jiang , Ingo Molnar , Arjan van de Ven , lkml , tglx Subject: Re: -tip tree resume fail, bisect to 5bd5a45(x86: Add NX protection for kernel data) Message-ID: <20110105195816.31457a59@mat-laptop> In-Reply-To: <1293415850.2565.269.camel@minggr.sh.intel.com> References: <1290410581.2405.24.camel@minggr.sh.intel.com> <1290431008.2072.119.camel@laptop> <1290443379.4cea9a73cd9ce@imp.free.fr> <1290443758.2072.318.camel@laptop> <20101122164247.GC21836@basil.fritz.box> <20101123235527.54293b59@mat-laptop> <20101126183144.300a71a4@mat-laptop> <1291093230.2405.191.camel@minggr.sh.intel.com> <20101224182644.062bdb3f@mat-laptop> <1293415850.2565.269.camel@minggr.sh.intel.com> X-Mailer: Claws Mail 3.7.6 (GTK+ 2.22.0; i486-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Le Mon, 27 Dec 2010 10:10:50 +0800, Lin Ming a écrit : > On Sat, 2010-12-25 at 01:26 +0800, matthieu castet wrote: > > Hi, > > > > Le Tue, 30 Nov 2010 13:00:30 +0800, > > Lin Ming a écrit : > > > > > On Sat, 2010-11-27 at 01:31 +0800, mat wrote: > > > > Le Tue, 23 Nov 2010 23:55:27 +0100, > > > > mat a écrit : > > > > > > > > > Le Mon, 22 Nov 2010 17:42:47 +0100, > > > > > Andi Kleen a écrit : > > > > > > > > > > > > That seems to be a S3 specific code path, that won't fix > > > > > > > anything. Simply do: > > > > > > > > > > > > > > echo 0 > /sys/devices/system/cpu/cpu1/online; > > > > > > > echo 1 > /sys/devices/system/cpu/cpu1/online; > > > > > > > > > > > > > > and your machine will explode.. > > > > > > > > > > > > The SMP startup trampoline is copied I believe > > > > > > and only executed in real mode without page tables. > > > > > > > > > > > > So it's perhaps not the trampoline, but the early startup > > > > > > code that ends up being broken. > > > > > yes : > > > > > acpi wakeup code and smp trampoline are copied in low memory > > > > > (first 1MB). > > > > > > > > > > So they can't end up int the kernel data mapping ? > > > > > > > > > > So it should something else. > > > > > > > > > > I will try to investigate on this. > > > > > > > > > Unfortunately on my laptop supporting NX, suspend to ram seems > > > > broken (even without this patch) and I got only one core, so I > > > > am unable to test it. > > > > > > > > Does cpu suspend/resume is broken ? Or it is only S3 ? > > > > > > > > If yes, are there any interesting trace if we suspend only one > > > > core with sysfs. > > > > > > echo 0 > /sys/devices/system/cpu/cpu1/online; > > > echo 1 > /sys/devices/system/cpu/cpu1/online; > > > > > > then machine just reboots... > > > > > Ok, > > > > could you try the attached patch ? > > Unfortunately, it does not work against current tip/master(1f7107c8). > > Lin Ming > Thanks for the testing. For the record I did some tests. - The x86_32 cpu hotplug is working fine. - On x86_64 we crash between the cpu1 is wakeup and before trampoline jump to start_secondary A difference between 32 and 64 bit is that head_32.S use initial_page_table mmu table then switch to swapper_pg_dir while 64 bit version use init_level4_pgt for trampoline, head and kernel. But I fail to see where setting NX is level3_kernel_pgt aera can make the resume fail. When we enable NX we are in .text section (head_64). Matthieu