Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757962AbZIPAYS (ORCPT ); Tue, 15 Sep 2009 20:24:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753787AbZIPAYL (ORCPT ); Tue, 15 Sep 2009 20:24:11 -0400 Received: from mk-filter-3-a-1.mail.uk.tiscali.com ([212.74.100.54]:19717 "EHLO mk-filter-3-a-1.mail.uk.tiscali.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753141AbZIPAYK (ORCPT ); Tue, 15 Sep 2009 20:24:10 -0400 X-Trace: 259194392/mk-filter-3.mail.uk.tiscali.com/B2C/$b2c-THROTTLED-DYNAMIC/b2c-CUSTOMER-DYNAMIC-IP/79.69.4.183/None/hugh.dickins@tiscali.co.uk X-SBRS: None X-RemoteIP: 79.69.4.183 X-IP-MAIL-FROM: hugh.dickins@tiscali.co.uk X-SMTP-AUTH: X-MUA: X-IP-BHB: Once X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: ApsEAIjMr0pPRQS3/2dsb2JhbACBU94KhBcF X-IronPort-AV: E=Sophos;i="4.44,393,1249254000"; d="scan'208";a="259194392" Date: Wed, 16 Sep 2009 01:23:26 +0100 (BST) From: Hugh Dickins X-X-Sender: hugh@sister.anvils To: Ingo Molnar cc: Yinghai Lu , 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= In-Reply-To: <20090824182713.GB9785@elte.hu> Message-ID: References: <4A92D029.8090807@kernel.org> <20090824182713.GB9785@elte.hu> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5442 Lines: 149 On Mon, 24 Aug 2009, Ingo Molnar wrote: > * 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: Somehow it seems to have undropped itself, so mem= stopped working again in recent mmotm/linux-next; and it looks like today the undropped patch has made its way to Linus - I've not built current git to check, but I think you'll find mem= is now broken there. Hugh > > 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/