diff options
| -rw-r--r-- | arch/powerpc/Kconfig | 19 | ||||
| -rw-r--r-- | arch/powerpc/Makefile | 15 | ||||
| -rwxr-xr-x | arch/powerpc/scripts/gcc-check-mprofile-kernel.sh | 23 |
3 files changed, 57 insertions, 0 deletions
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index e4824fd04bb7..91da283cd658 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -94,6 +94,7 @@ config PPC select OF_RESERVED_MEM select HAVE_FTRACE_MCOUNT_RECORD select HAVE_DYNAMIC_FTRACE + select HAVE_DYNAMIC_FTRACE_WITH_REGS if MPROFILE_KERNEL select HAVE_FUNCTION_TRACER select HAVE_FUNCTION_GRAPH_TRACER select SYSCTL_EXCEPTION_TRACE @@ -373,6 +374,24 @@ config PPC_TRANSACTIONAL_MEM ---help--- Support user-mode Transactional Memory on POWERPC. +config DISABLE_MPROFILE_KERNEL + bool "Disable use of mprofile-kernel for kernel tracing" + depends on PPC64 && CPU_LITTLE_ENDIAN + default y + help + Selecting this options disables use of the mprofile-kernel ABI for + kernel tracing. That will cause options such as live patching + (CONFIG_LIVEPATCH) which depend on CONFIG_DYNAMIC_FTRACE_WITH_REGS to + be disabled also. + + If you have a toolchain which supports mprofile-kernel, then you can + enable this. Otherwise leave it disabled. If you're not sure, say + "N". + +config MPROFILE_KERNEL + depends on PPC64 && CPU_LITTLE_ENDIAN + def_bool !DISABLE_MPROFILE_KERNEL + config IOMMU_HELPER def_bool PPC64 diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile index 96efd8213c1c..f4e49a4153cb 100644 --- a/arch/powerpc/Makefile +++ b/arch/powerpc/Makefile @@ -133,6 +133,21 @@ else CFLAGS-$(CONFIG_GENERIC_CPU) += -mcpu=powerpc64 endif +ifdef CONFIG_MPROFILE_KERNEL + ifeq ($(shell $(srctree)/arch/powerpc/scripts/gcc-check-mprofile-kernel.sh $(CC) -I$(srctree)/include -D__KERNEL__),OK) + CC_FLAGS_FTRACE := -pg -mprofile-kernel + KBUILD_CPPFLAGS += -DCC_USING_MPROFILE_KERNEL + else + # If the user asked for mprofile-kernel but the toolchain doesn't + # support it, emit a warning and deliberately break the build later + # with mprofile-kernel-not-supported. We would prefer to make this an + # error right here, but then the user would never be able to run + # oldconfig to change their configuration. + $(warning Compiler does not support mprofile-kernel, set CONFIG_DISABLE_MPROFILE_KERNEL) + CC_FLAGS_FTRACE := -mprofile-kernel-not-supported + endif +endif + CFLAGS-$(CONFIG_CELL_CPU) += $(call cc-option,-mcpu=cell) CFLAGS-$(CONFIG_POWER4_CPU) += $(call cc-option,-mcpu=power4) CFLAGS-$(CONFIG_POWER5_CPU) += $(call cc-option,-mcpu=power5) diff --git a/arch/powerpc/scripts/gcc-check-mprofile-kernel.sh b/arch/powerpc/scripts/gcc-check-mprofile-kernel.sh new file mode 100755 index 000000000000..c658d8cf760b --- /dev/null +++ b/arch/powerpc/scripts/gcc-check-mprofile-kernel.sh @@ -0,0 +1,23 @@ +#!/bin/bash + +set -e +set -o pipefail + +# To debug, uncomment the following line +# set -x + +# Test whether the compile option -mprofile-kernel exists and generates +# profiling code (ie. a call to _mcount()). +echo "int func() { return 0; }" | \ + $* -S -x c -O2 -p -mprofile-kernel - -o - 2> /dev/null | \ + grep -q "_mcount" + +# Test whether the notrace attribute correctly suppresses calls to _mcount(). + +echo -e "#include <linux/compiler.h>\nnotrace int func() { return 0; }" | \ + $* -S -x c -O2 -p -mprofile-kernel - -o - 2> /dev/null | \ + grep -q "_mcount" && \ + exit 1 + +echo "OK" +exit 0 |