Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754511AbYHXPBC (ORCPT ); Sun, 24 Aug 2008 11:01:02 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751560AbYHXPA4 (ORCPT ); Sun, 24 Aug 2008 11:00:56 -0400 Received: from bu3sch.de ([62.75.166.246]:47643 "EHLO vs166246.vserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751045AbYHXPAz (ORCPT ); Sun, 24 Aug 2008 11:00:55 -0400 From: Michael Buesch To: Andreas Schwab Subject: Re: Random crashes with 2.6.27-rc3 on PPC Date: Sun, 24 Aug 2008 17:00:22 +0200 User-Agent: KMail/1.9.6 (enterprise 0.20070907.709405) Cc: benh@kernel.crashing.org, linuxppc-dev@ozlabs.org, Linus Torvalds , linux-kernel References: <200808231610.46473.mb@bu3sch.de> <200808241544.12412.mb@bu3sch.de> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200808241700.22815.mb@bu3sch.de> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1577 Lines: 41 On Sunday 24 August 2008 16:46:38 Andreas Schwab wrote: > Michael Buesch writes: > > > The following workaround seems to fix the crashes on powerpc. > > However, this patch is clearly not what we want for other architectures, > > as they might need -fno-omit-frame-pointer to function properly. > > This has a better chance to be accepted. :-) > > diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug > index 8b5a7d3..f9a2e48 100644 > --- a/lib/Kconfig.debug > +++ b/lib/Kconfig.debug > @@ -394,7 +394,7 @@ config LOCKDEP > bool > depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT > select STACKTRACE > - select FRAME_POINTER if !X86 && !MIPS > + select FRAME_POINTER if !X86 && !MIPS && !PPC > select KALLSYMS > select KALLSYMS_ALL This is not what my patch is doing. Your patch always forces FRAME_POINTER off. At least as far as lockdep is concerned. What about other parts of the kernel that enable FRAME_POINTER? I think this should be fixed in the makefile by substitution of -fno-omit-frame-pointer on PPC (and probably depending on the compiler version). Otherwise, if somebody else decides to do select FRAME_POINTER in some other code, the bug will reappear. I'm also not sure if it's desired to always force FRAME_POINTER off. -- Greetings Michael. -- 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/