Messages in this thread Patch in this message | | | Date | Wed, 18 Jun 2008 10:35:24 +0200 | From | Peter Oberparleiter <> | Subject | Re: 2.6.26-rc5-mm1 |
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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 <peter.oberparleiter@de.ibm.com>
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 <m.kozlowski@tuxland.pl> Reported-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
--- 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:
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