Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753016AbYFRIfg (ORCPT ); Wed, 18 Jun 2008 04:35:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751394AbYFRIf2 (ORCPT ); Wed, 18 Jun 2008 04:35:28 -0400 Received: from mtagate7.de.ibm.com ([195.212.29.156]:7469 "EHLO mtagate7.de.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751372AbYFRIf1 (ORCPT ); Wed, 18 Jun 2008 04:35:27 -0400 Message-ID: <4858C8CC.4040407@de.ibm.com> Date: Wed, 18 Jun 2008 10:35:24 +0200 From: Peter Oberparleiter User-Agent: Thunderbird 2.0.0.4 (X11/20070604) MIME-Version: 1.0 To: Mariusz Kozlowski , Andrew Morton CC: linux-mm@kvack.org, balbir@linux.vnet.ibm.com, linux-kernel@vger.kernel.org, Peter Oberparleiter Subject: Re: 2.6.26-rc5-mm1 References: <200806180026.27247.m.kozlowski@tuxland.pl> In-Reply-To: <200806180026.27247.m.kozlowski@tuxland.pl> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3006 Lines: 92 Mariusz Kozlowski wrote: > After a few hours and tons of reboots I narrowed it down to > arch/x86/kernel/Makefile: > > a) works > obj-y += tsc_$(BITS).o io_delay.o rtc.o > GCOV_tsc_$(BITS).o := n > #GCOV_io_delay.o := n > #GCOV_rtc.o := n > > b) doesn't work > obj-y += tsc_$(BITS).o io_delay.o rtc.o > #GCOV_tsc_$(BITS).o := n > #GCOV_io_delay.o := n > #GCOV_rtc.o := n > > and that points to arch/x86/kernel/tsc_64.c Excellent work! I had a quick look at that file and couldn't identify any obvious reason (for a non-x84 developer) why it shouldn't work with -fprofile-arcs. There are some comments in the corresponding Makefile though that indicate that tsc_64.o is a bit picky with regards to CFLAGS (no -pg, -fno-stack-protector) so I think it's safe to simply exclude those files from profiling. Based on your findings, the following patch should be applied to -mm. Thanks again for your effort. -- [PATCH] gcov: fix run-time error on x86_64 From: Peter Oberparleiter Disable profiling of tsc_$(BITS).o to fix a run-time error when using CONFIG_GCOV_PROFILE_ALL on x86_64: bash[498] segfault at ffffffff80868b58 ip ffffffffff600412 sp 7fffa3d010f0 error 7 init[1] segfault at ffffffff80868b58 ip ffffffffff600412 sp 7fff9e97f640 error 7 init[1] segfault at ffffffff80868b58 ip ffffffffff600412 sp 7fff9e97eed0 error 7 Kernel panic - not syncing: Attemted to kill init! Pid 1, comm: init Not tainted 2.6.26-rc5-mm1 #1 m.kozlowski@tuxland.pl wrote: > After a few hours and tons of reboots I narrowed it down to > arch/x86/kernel/Makefile: > > a) works > obj-y += tsc_$(BITS).o io_delay.o rtc.o > GCOV_tsc_$(BITS).o := n > #GCOV_io_delay.o := n > #GCOV_rtc.o := n > > b) doesn't work > obj-y += tsc_$(BITS).o io_delay.o rtc.o > #GCOV_tsc_$(BITS).o := n > #GCOV_io_delay.o := n > #GCOV_rtc.o := n > > and that points to arch/x86/kernel/tsc_64.c Reported-by: Mariusz Kozlowski Reported-by: Balbir Singh Signed-off-by: Peter Oberparleiter --- arch/x86/kernel/Makefile | 3 +++ 1 file changed, 3 insertions(+) Index: linux-2.6.26-rc5-mm3/arch/x86/kernel/Makefile =================================================================== --- linux-2.6.26-rc5-mm3.orig/arch/x86/kernel/Makefile +++ linux-2.6.26-rc5-mm3/arch/x86/kernel/Makefile @@ -13,6 +13,9 @@ CFLAGS_REMOVE_tsc_32.o = -pg CFLAGS_REMOVE_rtc.o = -pg endif +GCOV_tsc_32.o := n +GCOV_tsc_64.o := n + # # vsyscalls (which work on the user stack) should have # no stack-protector checks: -- 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/