ftrace: allow architectures to specify ftrace compile options
If the kernel is compiled with function tracer support the -pg compile option
is passed to gcc to generate extra code into the prologue of each function.
This patch replaces the "open-coded" -pg compile flag with a CC_FLAGS_FTRACE
makefile variable which architectures can override if a different option
should be used for code generation.
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/Makefile b/Makefile
index fd80c6e..11c6fe8 100644
--- a/Makefile
+++ b/Makefile
@@ -724,10 +724,14 @@
endif
ifdef CONFIG_FUNCTION_TRACER
+ifndef CC_FLAGS_FTRACE
+CC_FLAGS_FTRACE := -pg
+endif
+export CC_FLAGS_FTRACE
ifdef CONFIG_HAVE_FENTRY
CC_USING_FENTRY := $(call cc-option, -mfentry -DCC_USING_FENTRY)
endif
-KBUILD_CFLAGS += -pg $(CC_USING_FENTRY)
+KBUILD_CFLAGS += $(CC_FLAGS_FTRACE) $(CC_USING_FENTRY)
KBUILD_AFLAGS += $(CC_USING_FENTRY)
ifdef CONFIG_DYNAMIC_FTRACE
ifdef CONFIG_HAVE_C_RECORDMCOUNT
diff --git a/kernel/Makefile b/kernel/Makefile
index a59481a..13af308 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -13,8 +13,8 @@
ifdef CONFIG_FUNCTION_TRACER
# Do not trace debug files and internal ftrace files
-CFLAGS_REMOVE_cgroup-debug.o = -pg
-CFLAGS_REMOVE_irq_work.o = -pg
+CFLAGS_REMOVE_cgroup-debug.o = $(CC_FLAGS_FTRACE)
+CFLAGS_REMOVE_irq_work.o = $(CC_FLAGS_FTRACE)
endif
# cond_syscall is currently not LTO compatible
diff --git a/kernel/events/Makefile b/kernel/events/Makefile
index 103f5d1..2925188 100644
--- a/kernel/events/Makefile
+++ b/kernel/events/Makefile
@@ -1,5 +1,5 @@
ifdef CONFIG_FUNCTION_TRACER
-CFLAGS_REMOVE_core.o = -pg
+CFLAGS_REMOVE_core.o = $(CC_FLAGS_FTRACE)
endif
obj-y := core.o ring_buffer.o callchain.o
diff --git a/kernel/locking/Makefile b/kernel/locking/Makefile
index 8541bfd..4caca3f 100644
--- a/kernel/locking/Makefile
+++ b/kernel/locking/Makefile
@@ -2,10 +2,10 @@
obj-y += mutex.o semaphore.o rwsem.o mcs_spinlock.o
ifdef CONFIG_FUNCTION_TRACER
-CFLAGS_REMOVE_lockdep.o = -pg
-CFLAGS_REMOVE_lockdep_proc.o = -pg
-CFLAGS_REMOVE_mutex-debug.o = -pg
-CFLAGS_REMOVE_rtmutex-debug.o = -pg
+CFLAGS_REMOVE_lockdep.o = $(CC_FLAGS_FTRACE)
+CFLAGS_REMOVE_lockdep_proc.o = $(CC_FLAGS_FTRACE)
+CFLAGS_REMOVE_mutex-debug.o = $(CC_FLAGS_FTRACE)
+CFLAGS_REMOVE_rtmutex-debug.o = $(CC_FLAGS_FTRACE)
endif
obj-$(CONFIG_DEBUG_MUTEXES) += mutex-debug.o
diff --git a/kernel/sched/Makefile b/kernel/sched/Makefile
index ab32b7b..46be870 100644
--- a/kernel/sched/Makefile
+++ b/kernel/sched/Makefile
@@ -1,5 +1,5 @@
ifdef CONFIG_FUNCTION_TRACER
-CFLAGS_REMOVE_clock.o = -pg
+CFLAGS_REMOVE_clock.o = $(CC_FLAGS_FTRACE)
endif
ifneq ($(CONFIG_SCHED_OMIT_FRAME_POINTER),y)
diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile
index 67d6369..9a7e0e6 100644
--- a/kernel/trace/Makefile
+++ b/kernel/trace/Makefile
@@ -3,11 +3,11 @@
ifdef CONFIG_FUNCTION_TRACER
ORIG_CFLAGS := $(KBUILD_CFLAGS)
-KBUILD_CFLAGS = $(subst -pg,,$(ORIG_CFLAGS))
+KBUILD_CFLAGS = $(subst $(CC_FLAGS_FTRACE),,$(ORIG_CFLAGS))
ifdef CONFIG_FTRACE_SELFTEST
# selftest needs instrumentation
-CFLAGS_trace_selftest_dynamic.o = -pg
+CFLAGS_trace_selftest_dynamic.o = $(CC_FLAGS_FTRACE)
obj-y += trace_selftest_dynamic.o
endif
endif
diff --git a/lib/Makefile b/lib/Makefile
index 3c3b30b..f3f73e5 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -4,7 +4,7 @@
ifdef CONFIG_FUNCTION_TRACER
ORIG_CFLAGS := $(KBUILD_CFLAGS)
-KBUILD_CFLAGS = $(subst -pg,,$(ORIG_CFLAGS))
+KBUILD_CFLAGS = $(subst $(CC_FLAGS_FTRACE),,$(ORIG_CFLAGS))
endif
lib-y := ctype.o string.o vsprintf.o cmdline.o \
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 649ce68..01df30a 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -234,8 +234,9 @@
"$(if $(part-of-module),1,0)" "$(@)";
recordmcount_source := $(srctree)/scripts/recordmcount.pl
endif
-cmd_record_mcount = \
- if [ "$(findstring -pg,$(_c_flags))" = "-pg" ]; then \
+cmd_record_mcount = \
+ if [ "$(findstring $(CC_FLAGS_FTRACE),$(_c_flags))" = \
+ "$(CC_FLAGS_FTRACE)" ]; then \
$(sub_cmd_record_mcount) \
fi;
endif