From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932253AbZHUNg6 (ORCPT ); Fri, 21 Aug 2009 09:36:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932204AbZHUNg6 (ORCPT ); Fri, 21 Aug 2009 09:36:58 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:47101 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932179AbZHUNg5 (ORCPT ); Fri, 21 Aug 2009 09:36:57 -0400 Date: Fri, 21 Aug 2009 15:35:53 +0200 From: Ingo Molnar To: Xiao Guangrong , Thomas Gleixner , "H. Peter Anvin" , Yinghai Lu Cc: Andrew Morton , LKML , x86@kernel.org Subject: Re: [PATCH] x86: fix system die when load with "reservetop" parameter Message-ID: <20090821133553.GE10263@elte.hu> References: <4A8D402F.4080805@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4A8D402F.4080805@cn.fujitsu.com> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.5 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Xiao Guangrong wrote: > The system will die if the kernel is booted with "reservetop" > parameter, in present code, parse "reservetop" parameter after > early_ioremap_init(), and some function still use early_ioremap() > after it. btw., what are you using the 'reservetop' boot option for? > The problem is, "reservetop" parameter can modify 'FIXADDR_TOP', > then the virtual address got by early_ioremap() is base on old > 'FIXADDR_TOP', but the page mapping is base on new 'FIXADDR_TOP', > it will occur page fault, and the IDT is not prepare yet, so, the > system is dead. > > So, put parse_early_param() in the front of early_ioremap_init() > in this patch. > > Signed-off-by: Xiao Guangrong > --- > arch/x86/kernel/setup.c | 10 +++++----- > 1 files changed, 5 insertions(+), 5 deletions(-) Does this bug trigger in 2.6.30 too? I'm quite nervous about doing this change so late in the .31 cycle, we've got a hundred early parameters that now get executed much earlier than before. No way can i test all of them and others testing it (like in your case) takes time to trickle through. So unless this is a .31 regression i'd be inclined to queue it up for .32. Ingo