From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756185AbZBJO1L (ORCPT ); Tue, 10 Feb 2009 09:27:11 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754082AbZBJO0y (ORCPT ); Tue, 10 Feb 2009 09:26:54 -0500 Received: from hera.kernel.org ([140.211.167.34]:43876 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754650AbZBJO0x (ORCPT ); Tue, 10 Feb 2009 09:26:53 -0500 Message-ID: <49918E86.4020304@kernel.org> Date: Tue, 10 Feb 2009 23:26:14 +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> <49918C3C.8030208@kernel.org> <20090210142026.GD16147@elte.hu> In-Reply-To: <20090210142026.GD16147@elte.hu> 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 14:26:27 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Ingo Molnar wrote: >>> 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. > > yeah - i also used distcc. Maybe the nostackp makefile magic gets confused > about that? It seems that even with the same gcc versions, gcc built against libc w/o TLS support generates __stack_chk_guard, so if you mix the two flavors, the has-stack-protector check can be compiled on machines w/ TLS while some other files end up being built on machines w/o TLS support thus circumventing the support check. Can you please see whether non-distcc build fails too? Thanks. -- tejun