From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753255AbZHXS2G (ORCPT ); Mon, 24 Aug 2009 14:28:06 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753238AbZHXS2D (ORCPT ); Mon, 24 Aug 2009 14:28:03 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:38011 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753176AbZHXS17 (ORCPT ); Mon, 24 Aug 2009 14:27:59 -0400 Date: Mon, 24 Aug 2009 20:27:13 +0200 From: Ingo Molnar To: Yinghai Lu Cc: Hugh Dickins , Linus Torvalds , Zachary Amsden , "H. Peter Anvin" , Xiao Guangrong , Andrew Morton , linux-kernel@vger.kernel.org Subject: Re: linux-next: reservetop fix disables mem= Message-ID: <20090824182713.GB9785@elte.hu> References: <4A92D029.8090807@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4A92D029.8090807@kernel.org> 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 * Yinghai Lu wrote: > Hugh Dickins wrote: > > I find the "mem=" boot parameter disabled in today's linux-next: > > reverting the tip commit below fixes that. > > > > Hugh > > > > From: Xiao Guangrong > > Date: Thu, 20 Aug 2009 12:23:11 +0000 (+0800) > > Subject: x86: Fix system crash when loading with "reservetop" parameter > > X-Git-Url: http://git.kernel.org/?p=linux%2Fkernel%2Fgit%2Fmingo%2Flinux-2.6-x86.git;a=commitdiff_plain;h=8126dec32738421afa362114337331337b4be17f > > > > x86: Fix system crash when loading with "reservetop" parameter > > > > 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. > > > > 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 > > Cc: yinghai@kernel.org > > Cc: Andrew Morton > > LKML-Reference: <4A8D402F.4080805@cn.fujitsu.com> > > Signed-off-by: Ingo Molnar > > --- > > > > diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c > > index 63f32d2..02643cc 100644 > > --- a/arch/x86/kernel/setup.c > > +++ b/arch/x86/kernel/setup.c > > @@ -711,6 +711,11 @@ void __init setup_arch(char **cmdline_p) > > printk(KERN_INFO "Command line: %s\n", boot_command_line); > > #endif > > > > + strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE); > > + *cmdline_p = command_line; > > + > > + parse_early_param(); > > + > > /* VMI may relocate the fixmap; do this before touching ioremap area */ > > vmi_init(); > > > > @@ -793,11 +798,6 @@ void __init setup_arch(char **cmdline_p) > > #endif > > #endif > > > > - strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE); > > - *cmdline_p = command_line; > > - > > - parse_early_param(); > > - > > #ifdef CONFIG_X86_64 > > check_efer(); > > #endif > > yes, that patch will break other built-in command too. > > need drop that patch. done. Was nervous about the patch already: http://lkml.org/lkml/2009/8/21/127 > also the problem was caused by vmi patch, and that commit should > be reverted. > > commit ae8d04e2ecbb233926860e9ce145eac19c7835dc > Author: Zachary Amsden > Date: Sat Dec 13 12:36:58 2008 -0800 > > x86 Fix VMI crash on boot in 2.6.28-rc8 > > VMI initialiation can relocate the fixmap, causing early_ioremap to > malfunction if it is initialized before the relocation. To fix this, > VMI activation is split into two phases; the detection, which must > happen before setting up ioremap, and the activation, which must happen > after parsing early boot parameters. > > This fixes a crash on boot when VMI is enabled under VMware. > > Signed-off-by: Zachary Amsden > Signed-off-by: Linus Torvalds > > diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c > index 9d5674f..bdec76e 100644 > --- a/arch/x86/kernel/setup.c > +++ b/arch/x86/kernel/setup.c > @@ -794,6 +794,9 @@ void __init setup_arch(char **cmdline_p) > printk(KERN_INFO "Command line: %s\n", boot_command_line); > #endif > > + /* VMI may relocate the fixmap; do this before touching ioremap area */ > + vmi_init(); > + > early_cpu_init(); > early_ioremap_init(); > > @@ -880,13 +883,8 @@ void __init setup_arch(char **cmdline_p) > check_efer(); > #endif > > -#if defined(CONFIG_VMI) && defined(CONFIG_X86_32) > - /* > - * Must be before kernel pagetables are setup > - * or fixmap area is touched. > - */ > - vmi_init(); > -#endif > + /* Must be before kernel pagetables are setup */ > + vmi_activate(); > > /* after early param, so could get panic from serial */ > reserve_early_setup_data(); > > > and according to > http://lkml.org/lkml/2008/12/10/388 > http://lkml.org/lkml/2008/12/10/456 > > Zachary should split reserve_top_address() to two functions... > before sending that patch to Linus mind looking at this yourself if interested? Zachary has not been active for quite some time. Ingo