From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754011AbYLDMWk (ORCPT ); Thu, 4 Dec 2008 07:22:40 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751214AbYLDMWb (ORCPT ); Thu, 4 Dec 2008 07:22:31 -0500 Received: from one.firstfloor.org ([213.235.205.2]:50535 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751188AbYLDMWa (ORCPT ); Thu, 4 Dec 2008 07:22:30 -0500 Date: Thu, 4 Dec 2008 13:33:35 +0100 From: Andi Kleen To: Wu Fengguang Cc: Andi Kleen , LKML , Ingo Molnar , Andrew Morton , Jack Steiner , Yinghai Lu Subject: Re: 2.6.28-rc6: early panic with boot option "nosmp" Message-ID: <20081204123335.GP6703@one.firstfloor.org> References: <20081204022806.GA29293@localhost> <20081204101343.GO6703@one.firstfloor.org> <20081204120214.GA30833@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20081204120214.GA30833@localhost> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > The exception raised on dereferencing mpf or mpf_found. This obvious patch should fix it then. Does it? -- Fix early exception in __get_smp_config with nosmp Bail out early when there is no MP table. Reported by Wu Fengguang Signed-off-by: Andi Kleen --- arch/x86/kernel/mpparse.c | 3 +++ 1 file changed, 3 insertions(+) Index: linux-2.6.28-rc4-test/arch/x86/kernel/mpparse.c =================================================================== --- linux-2.6.28-rc4-test.orig/arch/x86/kernel/mpparse.c 2008-10-24 13:34:40.000000000 +0200 +++ linux-2.6.28-rc4-test/arch/x86/kernel/mpparse.c 2008-12-04 13:20:34.000000000 +0100 @@ -604,6 +604,9 @@ printk(KERN_INFO "Using ACPI for processor (LAPIC) " "configuration information\n"); + if (!mpf) + return; + printk(KERN_INFO "Intel MultiProcessor Specification v1.%d\n", mpf->mpf_specification); #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86_32)