powerpc: Enable GCOV

Make it possible to enable GCOV code coverage measurement on powerpc.

Lightly tested on 64-bit, seems to work as expected.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

5 files changed, 13 insertions, 1 deletions

diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index 035946f9d5fb..720e8c3b8e94 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -115,6 +115,13 @@ ifneq ($(CONFIG_XMON)$(CONFIG_KEXEC),)
 obj-y                           += ppc_save_regs.o
 endif
 
+# Disable GCOV in odd or sensitive code
+GCOV_PROFILE_prom_init.o := n
+GCOV_PROFILE_ftrace.o := n
+GCOV_PROFILE_machine_kexec_64.o := n
+GCOV_PROFILE_machine_kexec_32.o := n
+GCOV_PROFILE_kprobes.o := n
+
 extra-$(CONFIG_PPC_FPU)         += fpu.o
 extra-$(CONFIG_ALTIVEC)         += vector.o
 extra-$(CONFIG_PPC64)           += entry_64.o
diff --git a/arch/powerpc/kernel/vdso32/Makefile b/arch/powerpc/kernel/vdso32/Makefile
index c3d57bd01a88..b54b81688132 100644
--- a/arch/powerpc/kernel/vdso32/Makefile
+++ b/arch/powerpc/kernel/vdso32/Makefile
@@ -12,6 +12,7 @@ endif
 targets := $(obj-vdso32) vdso32.so vdso32.so.dbg
 obj-vdso32 := $(addprefix $(obj)/, $(obj-vdso32))
 
+GCOV_PROFILE := n
 
 EXTRA_CFLAGS := -shared -fno-common -fno-builtin
 EXTRA_CFLAGS += -nostdlib -Wl,-soname=linux-vdso32.so.1 \
diff --git a/arch/powerpc/kernel/vdso64/Makefile b/arch/powerpc/kernel/vdso64/Makefile
index fa7f1b8f3e50..dd0c8e936775 100644
--- a/arch/powerpc/kernel/vdso64/Makefile
+++ b/arch/powerpc/kernel/vdso64/Makefile
@@ -7,6 +7,8 @@ obj-vdso64 = sigtramp.o gettimeofday.o datapage.o cacheflush.o note.o
 targets := $(obj-vdso64) vdso64.so vdso64.so.dbg
 obj-vdso64 := $(addprefix $(obj)/, $(obj-vdso64))
 
+GCOV_PROFILE := n
+
 EXTRA_CFLAGS := -shared -fno-common -fno-builtin
 EXTRA_CFLAGS += -nostdlib -Wl,-soname=linux-vdso64.so.1 \
                 $(call ld-option, -Wl$(comma)--hash-style=sysv)
diff --git a/arch/powerpc/xmon/Makefile b/arch/powerpc/xmon/Makefile
index 85ab97ab840a..faa81b6a6612 100644
--- a/arch/powerpc/xmon/Makefile
+++ b/arch/powerpc/xmon/Makefile
@@ -2,6 +2,8 @@
 
 subdir-ccflags-$(CONFIG_PPC_WERROR) := -Werror
 
+GCOV_PROFILE := n
+
 ifdef CONFIG_PPC64
 EXTRA_CFLAGS += -mno-minimal-toc
 endif
diff --git a/kernel/gcov/Kconfig b/kernel/gcov/Kconfig
index 22e9dcfaa3d3..654efd09f6a9 100644
--- a/kernel/gcov/Kconfig
+++ b/kernel/gcov/Kconfig
@@ -34,7 +34,7 @@ config GCOV_KERNEL
 config GCOV_PROFILE_ALL
         bool "Profile entire Kernel"
         depends on GCOV_KERNEL
-        depends on S390 || X86
+        depends on S390 || X86 || (PPC && EXPERIMENTAL)
         default n
         ---help---
         This options activates profiling for the entire kernel.