Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753875AbYLZRFa (ORCPT ); Fri, 26 Dec 2008 12:05:30 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752614AbYLZRFM (ORCPT ); Fri, 26 Dec 2008 12:05:12 -0500 Received: from E23SMTP06.au.ibm.com ([202.81.18.175]:46057 "EHLO e23smtp06.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752598AbYLZRFL (ORCPT ); Fri, 26 Dec 2008 12:05:11 -0500 Date: Fri, 26 Dec 2008 22:34:52 +0530 From: Kamalesh Babulal To: Ingo Molnar Cc: Sam Ravnborg , Yinghai Lu , David Howells , Andrew Morton , Stephen Rothwell , linux-next@vger.kernel.org, LKML , mel@csn.ul.ie Subject: Re: [BUG] next-20081216 - WARNING: at kernel/smp.c:333 smp_call_function_mask Message-ID: <20081226170452.GC5100@linux.vnet.ibm.com> Reply-To: Kamalesh Babulal References: <494C0BF0.3080109@kernel.org> <20081223132127.GA5450@linux.vnet.ibm.com> <495153A4.5060201@kernel.org> <20081224163400.GA11562@linux.vnet.ibm.com> <49529CE1.4040005@kernel.org> <20081226091217.GA5100@linux.vnet.ibm.com> <4954AC7B.3020603@kernel.org> <20081226102716.GA31450@uranus.ravnborg.org> <20081226152804.GB5100@linux.vnet.ibm.com> <20081226153318.GA4514@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <20081226153318.GA4514@elte.hu> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3136 Lines: 99 * Ingo Molnar [2008-12-26 16:33:18]: > > * Kamalesh Babulal wrote: > > > * Sam Ravnborg [2008-12-26 11:27:16]: > > > > > On Fri, Dec 26, 2008 at 02:05:47AM -0800, Yinghai Lu wrote: > > > > Kamalesh Babulal wrote: > > > > > * Yinghai Lu [2008-12-24 12:34:41]: > > > > > > > > > >> -- > > > > > > > > > > After the applying the patch, the kernel panic's with the same backtrace. The > > > > > box is running Fedora 5 on it. > > > > > > > > > > > > > please try... > > > > Ingo, do we need to switch to use #idef and inline function instead? > > > > > > I recall David Howells had a similar issue with the bootparamter patch set. > > > The workaround he used was to add a barrier(); call in the weak function > > > to avoid the inline. > > > > > > [full context kept as I added David to to: list]. > > > Sam > > > > > > > Hi Yinghai, > > > > Thanks, after applying the patch, the kernel boot's up fine. > > how about the patch below, does that work too? (after removing Yinghai's > patch) > > Ingo Hi Ingo, Kernel crashes with the same trace, after the applying the patch. > > -------------> > From 0d41e654c877a0de441448ca2f63a72ed11c5d84 Mon Sep 17 00:00:00 2001 > From: Ingo Molnar > Date: Fri, 26 Dec 2008 14:39:51 +0100 > Subject: [PATCH] kbuild, sparseirq: work around GCC bug with __weak aliases > > Impact: fix panic on null pointer with sparseirq > > Certain versions of GCC inline the weak global functions. > Work it around by marking __weak functions as noinline. > > Signed-off-by: Ingo Molnar > --- > include/linux/compiler-gcc.h | 8 +++++++- > 1 files changed, 7 insertions(+), 1 deletions(-) > > diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h > index 5c8351b..1ad72e6 100644 > --- a/include/linux/compiler-gcc.h > +++ b/include/linux/compiler-gcc.h > @@ -41,11 +41,17 @@ > > #define __deprecated __attribute__((deprecated)) > #define __packed __attribute__((packed)) > -#define __weak __attribute__((weak)) > #define __naked __attribute__((naked)) > #define __noreturn __attribute__((noreturn)) > > /* > + * Mark weak aliases also noinline, because some GCC versions > + * incorrectly inline weak aliases (even when a non-weak variant > + * is there) and thus cause crashes: > + */ > +#define __weak __attribute__((weak)) noinline > + > +/* > * From the GCC manual: > * > * Many functions have no effects except the return value and their > -- > 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/ -- Thanks & Regards, Kamalesh Babulal, Linux Technology Center, IBM, ISTL. -- 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/