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authorTony Breeds <tony@bakeyournoodle.com>2008-09-02 16:50:38 +1000
committerPaul Mackerras <paulus@samba.org>2008-09-03 20:53:34 +1000
commit7563dc64585324f443f5ac107eb6d89ee813a2d2 (patch)
treead97560d4280d844ff5a2c0c574962ef4fefa671
parent303996dace16894710a5291327eeb79afdb8ed12 (diff)
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>
-rw-r--r--arch/powerpc/Makefile5
-rw-r--r--arch/powerpc/kernel/Makefile7
-rw-r--r--arch/powerpc/platforms/powermac/Makefile2
-rw-r--r--lib/Kconfig.debug6
4 files changed, 13 insertions, 7 deletions
diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index 9155c9312c1..c6be19e9cea 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
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index 64f5948ebc9..946daea780f 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -14,12 +14,13 @@ endif
ifdef CONFIG_FTRACE
# Do not trace early boot code
-CFLAGS_REMOVE_cputable.o = -pg
-CFLAGS_REMOVE_prom_init.o = -pg
+CFLAGS_REMOVE_cputable.o = -pg -mno-sched-epilog
+CFLAGS_REMOVE_prom_init.o = -pg -mno-sched-epilog
+CFLAGS_REMOVE_btext.o = -pg -mno-sched-epilog
ifdef CONFIG_DYNAMIC_FTRACE
# dynamic ftrace setup.
-CFLAGS_REMOVE_ftrace.o = -pg
+CFLAGS_REMOVE_ftrace.o = -pg -mno-sched-epilog
endif
endif
diff --git a/arch/powerpc/platforms/powermac/Makefile b/arch/powerpc/platforms/powermac/Makefile
index 58ecdd72630..be60d64be7a 100644
--- a/arch/powerpc/platforms/powermac/Makefile
+++ b/arch/powerpc/platforms/powermac/Makefile
@@ -2,7 +2,7 @@ CFLAGS_bootx_init.o += -fPIC
ifdef CONFIG_FTRACE
# Do not trace early boot code
-CFLAGS_REMOVE_bootx_init.o = -pg
+CFLAGS_REMOVE_bootx_init.o = -pg -mno-sched-epilog
endif
obj-y += pic.o setup.o time.o feature.o pci.o \
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 8b5a7d304a5..0b504814e37 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
@@ -676,13 +676,13 @@ config FAULT_INJECTION_STACKTRACE_FILTER
depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
depends on !X86_64
select STACKTRACE
- select FRAME_POINTER
+ select FRAME_POINTER if !PPC
help
Provide stacktrace filter for fault-injection capabilities
config LATENCYTOP
bool "Latency measuring infrastructure"
- select FRAME_POINTER if !MIPS
+ select FRAME_POINTER if !MIPS && !PPC
select KALLSYMS
select KALLSYMS_ALL
select STACKTRACE