From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756043AbZBJORU (ORCPT ); Tue, 10 Feb 2009 09:17:20 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754450AbZBJORH (ORCPT ); Tue, 10 Feb 2009 09:17:07 -0500 Received: from hera.kernel.org ([140.211.167.34]:45581 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754595AbZBJORE (ORCPT ); Tue, 10 Feb 2009 09:17:04 -0500 Message-ID: <49918C3C.8030208@kernel.org> Date: Tue, 10 Feb 2009 23:16:28 +0900 From: Tejun Heo User-Agent: Thunderbird 2.0.0.19 (X11/20081227) MIME-Version: 1.0 To: Ingo Molnar CC: hpa@zytor.com, jeremy@goop.org, tglx@linutronix.de, linux-kernel@vger.kernel.org, x86@kernel.org, rusty@rustcorp.com.au Subject: Re: [PATCHSET x86/master] add stack protector support for x86_32 References: <1234186798-16820-1-git-send-email-tj@kernel.org> <20090209135557.GB14785@elte.hu> <20090209141209.GA24323@elte.hu> <499186FB.4070506@kernel.org> In-Reply-To: <499186FB.4070506@kernel.org> X-Enigmail-Version: 0.95.7 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.0 (hera.kernel.org [127.0.0.1]); Tue, 10 Feb 2009 14:16:41 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Tejun Heo wrote: > Ingo Molnar wrote: >> * Ingo Molnar wrote: >> >>> [...] I might not get around testing it today and pushing it out into tip:master, >>> but i pushed out the core/percpu bits, should you queue up further changes. >> ok, activated it for -tip testing, and there's a 64-bit build failure caused by >> it: >> >> arch/x86/kernel/head64.o: In function `x86_64_start_reservations': >> head64.c:(.init.text+0x26): undefined reference to `__stack_chk_guard' >> head64.c:(.init.text+0xc2): undefined reference to `__stack_chk_guard' >> arch/x86/kernel/head64.o: In function `x86_64_start_kernel': >> head64.c:(.init.text+0x104): undefined reference to `__stack_chk_guard' >> head64.c:(.init.text+0x1cd): undefined reference to `__stack_chk_guard' >> arch/x86/kernel/head.o: In function `reserve_ebda_region': >> head.c:(.init.text+0xb): undefined reference to `__stack_chk_guard' >> arch/x86/kernel/head.o:head.c:(.init.text+0x87): more undefined references to >> `__stack_chk_guard' follow > > Call to __stack_chk_guard is probably generated automatically. > Strangely, my gcc only generates calls to __stack_chk_fail. > > > gcc --version > gcc (SUSE Linux) 4.3.2 [gcc-4_3-branch revision 141291] > Copyright (C) 2008 Free Software Foundation, Inc. > This is free software; see the source for copying conditions. There is NO > warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. > > nm build/vmlinux|grep __stack_chk_ > 00000000f0fdf6cb A __crc___stack_chk_fail > ffffffff80d53e50 r __kcrctab___stack_chk_fail > ffffffff80d5ff81 r __kstrtab___stack_chk_fail > ffffffff80d3d140 r __ksymtab___stack_chk_fail > ffffffff80248619 T __stack_chk_fail > > I'll try other compilers but which version are you using? The > difference is that before the patchset, -fno-stack-protector was > always added whether stackprotector was enabled or not so this problem > wasn't visible (at the cost of bogus stackprotector of course). We'll > probably need to add __stack_chk_guard or disable if gcc generates > such symbol. I'll play with different gccs. Can't reproduce with gcc-4.1 or 4.2. Any chance you're using distcc w/ a build machine w/ glibc < 2.4? __stack_chk_guard is the symbol gcc fetches stack canary from if TLS is not supported, so somehow gcc thought that TLS wasn't available while building head64. Thanks. -- tejun