When ftrace is enabled and we build with gcc-4.7 or older, we
get a warning for each file on architectures that select
CONFIG_LD_DEAD_CODE_DATA_ELIMINATION:
warning: -ffunction-sections disabled; it makes profiling impossible [enabled
by default]
This turns off function sections in that specific case, leaving
it enabled for all other configurations.
Fixes: b67067f1176d ("kbuild: allow archs to select link dead code/data
elimination")
Signed-off-by: Arnd Bergmann <a...@arndb.de>
Cc: Namhyung Kim <namhyung.with.f...@gmail.com>
---
v2: accidentally resend the same patch as before
v3: send the exact same patch once more, without doing the change I wanted
v4: actually fixed version number in check as pointed out by Namhyung Kim (I
hope)
---
Makefile | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/Makefile b/Makefile
index 6e7e644a0b84..3a964fa3a787 100644
--- a/Makefile
+++ b/Makefile
@@ -662,7 +662,11 @@ KBUILD_CFLAGS += -Wextra
KBUILD_CFLAGS += $(call cc-disable-warning,frame-address,)
ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
+ifdef CONFIG_FUNCTION_TRACER
+KBUILD_CFLAGS += $(call cc-ifversion, -ge,0408,$(call
cc-option,-ffunction-sections,))
+else
KBUILD_CFLAGS += $(call cc-option,-ffunction-sections,)
+endif
KBUILD_CFLAGS += $(call cc-option,-fdata-sections,)
endif
--
2.9.0
