From: Vasily Gorbik gor@linux.ibm.com
commit 07d0408120216b60625c9a5b8012d1c3a907984d upstream.
Currently if CONFIG_FTRACE_MCOUNT_RECORD is enabled -mrecord-mcount compiler flag support is tested for every Makefile.
Top 4 cc-option usages: 511 -mrecord-mcount 11 -fno-stack-protector 9 -Wno-override-init 2 -fsched-pressure
To address that move cc-option from scripts/Makefile.build to top Makefile and export CC_USING_RECORD_MCOUNT to be used in original place.
While doing that also add -mrecord-mcount to CC_FLAGS_FTRACE (if gcc actually supports it).
Link: http://lkml.kernel.org/r/patch-2.thread-aa7b8d.git-de935bace15a.your-ad-here...
Acked-by: Andi Kleen ak@linux.intel.com Signed-off-by: Vasily Gorbik gor@linux.ibm.com Signed-off-by: Steven Rostedt (VMware) rostedt@goodmis.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- Makefile | 7 +++++++ scripts/Makefile.build | 9 +++------ 2 files changed, 10 insertions(+), 6 deletions(-)
--- a/Makefile +++ b/Makefile @@ -762,6 +762,13 @@ ifdef CONFIG_FUNCTION_TRACER ifndef CC_FLAGS_FTRACE CC_FLAGS_FTRACE := -pg endif +ifdef CONFIG_FTRACE_MCOUNT_RECORD + # gcc 5 supports generating the mcount tables directly + ifeq ($(call cc-option-yn,-mrecord-mcount),y) + CC_FLAGS_FTRACE += -mrecord-mcount + export CC_USING_RECORD_MCOUNT := 1 + endif +endif export CC_FLAGS_FTRACE ifdef CONFIG_HAVE_FENTRY CC_USING_FENTRY := $(call cc-option, -mfentry -DCC_USING_FENTRY) --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -222,11 +222,8 @@ cmd_modversions_c = \ endif
ifdef CONFIG_FTRACE_MCOUNT_RECORD -# gcc 5 supports generating the mcount tables directly -ifneq ($(call cc-option,-mrecord-mcount,y),y) -KBUILD_CFLAGS += -mrecord-mcount -else -# else do it all manually +ifndef CC_USING_RECORD_MCOUNT +# compiler will not generate __mcount_loc use recordmcount or recordmcount.pl ifdef BUILD_C_RECORDMCOUNT ifeq ("$(origin RECORDMCOUNT_WARN)", "command line") RECORDMCOUNT_FLAGS = -w @@ -255,7 +252,7 @@ cmd_record_mcount = \ "$(CC_FLAGS_FTRACE)" ]; then \ $(sub_cmd_record_mcount) \ fi; -endif # -record-mcount +endif # CC_USING_RECORD_MCOUNT endif
ifdef CONFIG_STACK_VALIDATION