Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762788AbYBWGTw (ORCPT ); Sat, 23 Feb 2008 01:19:52 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757936AbYBWGTa (ORCPT ); Sat, 23 Feb 2008 01:19:30 -0500 Received: from mx3.mail.elte.hu ([157.181.1.138]:34042 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757488AbYBWGT3 (ORCPT ); Sat, 23 Feb 2008 01:19:29 -0500 Date: Sat, 23 Feb 2008 07:18:56 +0100 From: Ingo Molnar To: James Morris Cc: Sam Ravnborg , Linus Torvalds , linux-kernel@vger.kernel.org, Arjan van de Ven , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" Subject: Re: Regression [Was: Boot hang with stack protector on x86_64] Message-ID: <20080223061856.GA26185@elte.hu> References: <20080222075950.GB2660@uranus.ravnborg.org> <20080222093621.GG327@elte.hu> <20080222121751.GA17889@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) X-ELTE-VirusStatus: clean 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=3.2.3 -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: 1404 Lines: 43 James, could you try the fix below ontop of x86.git#testing, does it solve your boot hang? Ingo ---------------> Subject: x86: stackprotector fix: do not zap %gs From: Ingo Molnar Date: Sat Feb 23 07:06:55 CET 2008 pda_init() puts 0 into %gs - that's wrong because any %gs access will fault from now on and we already have a dummy PDA set up that can be accessed just fine. This normally does not matter because almost nothing accesses %gs this early ... but the stackprotector now does to read the canary ... Signed-off-by: Ingo Molnar --- arch/x86/kernel/setup64.c | 2 -- 1 file changed, 2 deletions(-) Index: linux-x86.q/arch/x86/kernel/setup64.c =================================================================== --- linux-x86.q.orig/arch/x86/kernel/setup64.c +++ linux-x86.q/arch/x86/kernel/setup64.c @@ -165,8 +165,6 @@ void pda_init(int cpu) { struct x8664_pda *pda = cpu_pda(cpu); - /* Setup up data that may be needed in __get_free_pages early */ - asm volatile("movl %0,%%fs ; movl %0,%%gs" :: "r" (0)); /* Memory clobbers used to order PDA accessed */ mb(); wrmsrl(MSR_GS_BASE, pda); -- 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/