Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752015AbZISSIy (ORCPT ); Sat, 19 Sep 2009 14:08:54 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751738AbZISSIw (ORCPT ); Sat, 19 Sep 2009 14:08:52 -0400 Received: from hera.kernel.org ([140.211.167.34]:46214 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751668AbZISSIv (ORCPT ); Sat, 19 Sep 2009 14:08:51 -0400 Message-ID: <4AB51DFD.2000904@kernel.org> Date: Sat, 19 Sep 2009 11:07:57 -0700 From: Yinghai Lu User-Agent: Thunderbird 2.0.0.23 (X11/20090817) MIME-Version: 1.0 To: Ingo Molnar CC: Hugh Dickins , Linus Torvalds , "H. Peter Anvin" , Thomas Gleixner , Andrew Morton , linux-kernel@vger.kernel.org Subject: Re: linux-next: reservetop fix disables mem= References: <4A92D029.8090807@kernel.org> <20090824182713.GB9785@elte.hu> <20090919175504.GJ5366@elte.hu> <4AB51CA2.9010608@kernel.org> In-Reply-To: <4AB51CA2.9010608@kernel.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3432 Lines: 100 Yinghai Lu wrote: > Ingo Molnar wrote: >> I thoroughly zapped it. Do you know about any commit ID where it snuck >> in? > > after close looking, it will break > 1. some cpu feature in early stage too, like cpu_has_x2apic > 2. will break built-in-command line > 3. will break other memmap= and mem= > 4. early_dbgp and early_console that will use early_ioremap to access mmio (?) > > YH > > commit 8126dec32738421afa362114337331337b4be17f > Author: Xiao Guangrong > Date: Thu Aug 20 20:23:11 2009 +0800 > > 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 > after revet it, it seem mem=32g etc still broken, maybe some other commit about x86 platform support from Thomas broke it. YH --- arch/x86/kernel/setup.c | 30 +++++++++++++++--------------- 1 file changed, 15 insertions(+), 15 deletions(-) Index: linux-2.6/arch/x86/kernel/setup.c =================================================================== --- linux-2.6.orig/arch/x86/kernel/setup.c +++ linux-2.6/arch/x86/kernel/setup.c @@ -697,21 +697,6 @@ 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; - -#ifdef CONFIG_X86_64 - /* - * Must call this twice: Once just to detect whether hardware doesn't - * support NX (so that the early EHCI debug console setup can safely - * call set_fixmap(), and then again after parsing early parameters to - * honor the respective command line option. - */ - check_efer(); -#endif - - parse_early_param(); - /* VMI may relocate the fixmap; do this before touching ioremap area */ vmi_init(); @@ -794,6 +779,21 @@ void __init setup_arch(char **cmdline_p) #endif #endif + strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE); + *cmdline_p = command_line; + +#ifdef CONFIG_X86_64 + /* + * Must call this twice: Once just to detect whether hardware doesn't + * support NX (so that the early EHCI debug console setup can safely + * call set_fixmap(), and then again after parsing early parameters to + * honor the respective command line option. + */ + check_efer(); +#endif + + parse_early_param(); + #ifdef CONFIG_X86_64 check_efer(); #endif -- 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/