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authorIngo Molnar <mingo@elte.hu>2008-07-11 15:09:15 +0200
committerIngo Molnar <mingo@elte.hu>2008-07-11 15:09:15 +0200
commit3d0decc4f49e8645cd6369b02ed076bebd3d61ad (patch)
treee5777e66ce903f19a06fb429516b2960f261b2a1 /arch/x86
parentf361a450bf1ad14e2b003217dbf3958638631265 (diff)
x86: fix tsc unification buglet with ftrace and stackprotector
Yinghai Lu reported crashes on 64-bit x86: BUG: unable to handle kernel NULL pointer dereference at 0000000000000000 IP: [<ffffffff80253b17>] hrtick_start_fair+0x89/0x173 [...] And with a long session of debugging and a lot of difficulty, tracked it down to this commit: ---------------> 8fbbc4b45ce3e4c0eeb15004c79c72b6896a79c2 is first bad commit commit 8fbbc4b45ce3e4c0eeb15004c79c72b6896a79c2 Author: Alok Kataria <akataria@vmware.com> Date: Tue Jul 1 11:43:34 2008 -0700 x86: merge tsc_init and clocksource code <-------------- The problem is that the TSC unification missed these Makefile rules in arch/x86/kernel/Makefile: # Do not profile debug and lowlevel utilities CFLAGS_REMOVE_tsc_64.o = -pg CFLAGS_REMOVE_tsc_32.o = -pg ... CFLAGS_tsc_64.o := $(nostackp) ... which rules make sure that various instrumentation and debugging facilities are disabled for code that might end up in a VDSO - such as the TSC code. Reported-and-bisected-by: Yinghai Lu <yhlu.kernel@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Conflicts: Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/kernel/Makefile2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 59b14c940a2..4033d8dc745 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -13,7 +13,7 @@ CPPFLAGS_vmlinux.lds += -U$(UTS_MACHINE)
nostackp := $(call cc-option, -fno-stack-protector)
CFLAGS_vsyscall_64.o := $(PROFILING) -g0 $(nostackp)
CFLAGS_hpet.o := $(nostackp)
-CFLAGS_tsc_64.o := $(nostackp)
+CFLAGS_tsc.o := $(nostackp)
obj-y := process_$(BITS).o signal_$(BITS).o entry_$(BITS).o
obj-y += traps_$(BITS).o irq_$(BITS).o