[PATCH v3 4/7] arm64: ftrace: allow for tracing leaf functions
From: AKASHI Takahiro <hidden>
Date: 2015-10-08 10:03:41
Also in:
lkml
Subsystem:
arm64 port (aarch64 architecture), the rest · Maintainers:
Catalin Marinas, Will Deacon, Linus Torvalds
CONFIG_FRAME_POINTER is always enabled on arm64, adding -fno-omit-frame-pointer, while ftrace, CONFIG_FUNCTION_TRACER, adds -pg to KBUILD_CFLAGS. The combination of these options, however, does not implicitly enables -fno-omit-leaf-frame-pointer option, and no leaf functions are actually traced under ftrace. This patch allows for tracing leaf functions by adding -fno-omit-leaf-frame-pointer option, but does it only when CONFIG_STACK_TRACER is configured because it will increase the kernel size and add extra instructions on runtime. Signed-off-by: AKASHI Takahiro <redacted> --- arch/arm64/Makefile | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
index f9914d7..71cad91 100644
--- a/arch/arm64/Makefile
+++ b/arch/arm64/Makefile@@ -28,6 +28,11 @@ endif KBUILD_CFLAGS += -mgeneral-regs-only $(lseinstr) KBUILD_AFLAGS += $(lseinstr) +ifdef CONFIG_STACK_TRACER +ifdef CONFIG_FRAME_POINTER +KBUILD_CFLAGS += -mno-omit-leaf-frame-pointer +endif +endif ifeq ($(CONFIG_CPU_BIG_ENDIAN), y) KBUILD_CPPFLAGS += -mbig-endian
--
1.7.9.5