Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751380AbZISRzo (ORCPT ); Sat, 19 Sep 2009 13:55:44 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751247AbZISRzo (ORCPT ); Sat, 19 Sep 2009 13:55:44 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:46591 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750828AbZISRzn (ORCPT ); Sat, 19 Sep 2009 13:55:43 -0400 Date: Sat, 19 Sep 2009 19:55:04 +0200 From: Ingo Molnar To: Hugh Dickins Cc: Yinghai Lu , 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: <20090919175504.GJ5366@elte.hu> References: <4A92D029.8090807@kernel.org> <20090824182713.GB9785@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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 Content-Length: 3437 Lines: 88 * Hugh Dickins wrote: > 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. I thoroughly zapped it. Do you know about any commit ID where it snuck in? 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/