From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933874Ab0HLPql (ORCPT ); Thu, 12 Aug 2010 11:46:41 -0400 Received: from s15228384.onlinehome-server.info ([87.106.30.177]:50559 "EHLO mail.x86-64.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759992Ab0HLPqj (ORCPT ); Thu, 12 Aug 2010 11:46:39 -0400 Date: Thu, 12 Aug 2010 17:47:56 +0200 From: Borislav Petkov To: "H. Peter Anvin" Cc: Joerg Roedel , "Roedel, Joerg" , "mingo@elte.hu" , "tglx@linutronix.de" , "Herrmann3, Andreas" , "Seidel, Conny" , "Sarathy, Bhavna" , "greg@kroah.com" , "x86@kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH 1/2] x86-32: Fix crashes with CPU hotplug on AMD machines Message-ID: <20100812154756.GD2070@aftab> References: <1280940316-7966-1-git-send-email-bp@amd64.org> <1280940316-7966-2-git-send-email-bp@amd64.org> <4C59F24B.1010702@zytor.com> <20100805074503.GI18307@amd.com> <4C5AC736.20903@zytor.com> <20100812144142.GY23755@8bytes.org> <4C64148D.5080305@zytor.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4C64148D.5080305@zytor.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "H. Peter Anvin" Date: Thu, Aug 12, 2010 at 11:34:37AM -0400 > On 08/12/2010 07:41 AM, Joerg Roedel wrote: > > On Thu, Aug 05, 2010 at 07:14:14AM -0700, H. Peter Anvin wrote: > >> On 08/05/2010 12:45 AM, Roedel, Joerg wrote: > >> Correct, again. It's unclear to me if we can get away with the very > >> simple 64-bit approach -- in particular, not including all the 1:1 > >> mappings in the kernel -- for all future users, though. > > > > Yeah, We could probably use the same symbol names for the trampoline and > > the swapper page-table on 32 and 64 bit and merge the code that handles > > it between the architectures. Shouldn't be too difficult. We cook > > something up :-) > > But do you mind to take this patch first? It fixes the occurence of an > > erratum on AMD hardware, it is a quite simple fix compared to the rework > > suggested. In fact, I would like to have a simple patch to fix the > > problem first (and backport it as necessary) and then go the way to > > rework the current code differences between 32 and 64 bit. > > > > Agreed. I do have a concern about the kernel page tables not being > synchronized into trampoline_pg_dir (it's only an issue for 32-bit > !PAE), so at the very least we need to keep an eye out for it... I've been working on what you suggested and the patch boots on a 32-bit PAE kernel but keeps rebooting on non-PAE after setting the stack_start on the AP. I could send it out later for you to look at, if you like - you should be able to spot what I'm missing :)... -- Regards/Gruss, Boris. Advanced Micro Devices GmbH Einsteinring 24, 85609 Dornach General Managers: Alberto Bozzo, Andrew Bowd Registration: Dornach, Gemeinde Aschheim, Landkreis Muenchen Registergericht Muenchen, HRB Nr. 43632