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| author | Tony Breeds <tony@bakeyournoodle.com> | 2008-09-02 16:50:38 +1000 |
|---|---|---|
| committer | Paul Mackerras <paulus@samba.org> | 2008-09-03 20:53:34 +1000 |
| commit | 7563dc64585324f443f5ac107eb6d89ee813a2d2 (patch) | |
| tree | ad97560d4280d844ff5a2c0c574962ef4fefa671 /arch/powerpc/Makefile | |
| parent | 303996dace16894710a5291327eeb79afdb8ed12 (diff) | |
| download | op-kernel-dev-7563dc64585324f443f5ac107eb6d89ee813a2d2.zip op-kernel-dev-7563dc64585324f443f5ac107eb6d89ee813a2d2.tar.gz | |
powerpc: Work around gcc's -fno-omit-frame-pointer bug
This bug is causing random crashes
(http://bugzilla.kernel.org/show_bug.cgi?id=11414).
-fno-omit-frame-pointer is only needed on powerpc when -pg is also
supplied, and there is a gcc bug that causes incorrect code generation
on 32-bit powerpc when -fno-omit-frame-pointer is used---it uses stack
locations below the stack pointer, which is not allowed by the ABI
because those locations can and sometimes do get corrupted by an
interrupt.
This ensures that CONFIG_FRAME_POINTER is only selected by ftrace.
When CONFIG_FTRACE is enabled we also pass -mno-sched-epilog to work
around the gcc codegen bug.
Patch based on work by:
Andreas Schwab <schwab@suse.de>
Segher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: Tony Breeds <tony@bakeyournoodle.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'arch/powerpc/Makefile')
| -rw-r--r-- | arch/powerpc/Makefile | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile index 9155c93..c6be19e 100644 --- a/arch/powerpc/Makefile +++ b/arch/powerpc/Makefile @@ -116,6 +116,11 @@ ifeq ($(CONFIG_6xx),y) KBUILD_CFLAGS += -mcpu=powerpc endif +# Work around a gcc code-gen bug with -fno-omit-frame-pointer. +ifeq ($(CONFIG_FTRACE),y) +KBUILD_CFLAGS += -mno-sched-epilog +endif + cpu-as-$(CONFIG_4xx) += -Wa,-m405 cpu-as-$(CONFIG_6xx) += -Wa,-maltivec cpu-as-$(CONFIG_POWER4) += -Wa,-maltivec |
