From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935219AbYEBN4v (ORCPT ); Fri, 2 May 2008 09:56:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S934567AbYEBN4h (ORCPT ); Fri, 2 May 2008 09:56:37 -0400 Received: from pasmtpa.tele.dk ([80.160.77.114]:60658 "EHLO pasmtpA.tele.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934255AbYEBN4g (ORCPT ); Fri, 2 May 2008 09:56:36 -0400 Date: Fri, 2 May 2008 15:57:08 +0200 From: Sam Ravnborg To: Alistair John Strachan Cc: Chris Knadle , Andrew Morton , Adrian Bunk , venkatesh.pallipadi@intel.com, davem@davemloft.net, trini@kernel.crashing.org, mingo@elte.hu, tglx@linutronix.de, hpa@zytor.com, linux-kernel@vger.kernel.org, suresh.b.siddha@intel.com, Linus Torvalds Subject: Re: huge gcc 4.1.{0,1} __weak problem Message-ID: <20080502135708.GA22929@uranus.ravnborg.org> References: <20080501235558.GA20637@orac.ofobscurity.com> <200805021055.10602.alistair@devzero.co.uk> <20080502104348.GC20741@uranus.ravnborg.org> <200805021248.56797.alistair@devzero.co.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200805021248.56797.alistair@devzero.co.uk> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, May 02, 2008 at 12:48:55PM +0100, Alistair John Strachan wrote: > On Friday 02 May 2008 11:43:48 Sam Ravnborg wrote: > [snip] > > > > > It's __GNUC_PATCHLEVEL__, I believe. > > > > > > > > > > So yes, we can distinguish 4.1.2 (good, and very common) from > > > > > 4.1.{0,1} (bad, and rather uncommon). > > > > > And yes, considering that 4.1.1 (and even more so 4.1.0) should be > > > > > rare to begin with, I think it's better to just not support it. > > > > > > > > > > Linus > > > > > > > > Unfortunately Debian Stable (i.e. Etch), which is relatively popular > > > > for server use, is still using 4.1.1 :-( (The current gcc package is > > > > gcc-4.1.1-21) > > > > > > > > I have not looked to see if Debian Stable's gcc-4.1.1-21 has been > > > > patched for the currently discussed __weak bug. > > > > > > I checked and it has been patched in 4.1.1-21. This would make checking > > > for 4.1.1 via __GNUC_PATCHLEVEL__ potentially invalid, as patched distro > > > compilers may (and in this case do) have this fixed. > > > > Is it possible to cook up a small sample file we could build as part > > of the kernel build. If it fails => error out. > > If someone comes up with the code I shall try to integrate it > > in the build system. > > The GCC PR has a test case for this regression which might be usable. > > http://gcc.gnu.org/viewcvs/branches/gcc-4_1-branch/gcc/testsuite/gcc.dg/tree-ssa/pr27781.c?view=markup&pathrev=114852 OK, can anyone confirm that this fails to build which a buggy gcc: void __attribute__((weak)) func(void) { /* no code */ } int main() { func(); return 0; } Sam