From 2f4df0017baedd535254d987c6b10f855f1fb11f Mon Sep 17 00:00:00 2001 From: Vasily Gorbik Date: Mon, 6 Aug 2018 15:17:46 +0200 Subject: tracing: Add -mcount-nop option support -mcount-nop gcc option generates the calls to the profiling functions as nops which allows to avoid patching mcount jump with NOP instructions initially. -mcount-nop gcc option will be activated if platform selects HAVE_NOP_MCOUNT and gcc actually supports it. In addition to that CC_USING_NOP_MCOUNT is defined and could be used by architectures to adapt ftrace patching behavior. Link: http://lkml.kernel.org/r/patch-3.thread-aa7b8d.git-e02ed2dc082b.your-ad-here.call-01533557518-ext-9465@work.hours Signed-off-by: Vasily Gorbik Signed-off-by: Steven Rostedt (VMware) --- Makefile | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'Makefile') diff --git a/Makefile b/Makefile index 2c92ebf59a34..c5b0cd7f3c2a 100644 --- a/Makefile +++ b/Makefile @@ -749,6 +749,12 @@ ifdef CONFIG_FTRACE_MCOUNT_RECORD CC_FLAGS_FTRACE += -mrecord-mcount export CC_USING_RECORD_MCOUNT := 1 endif + ifdef CONFIG_HAVE_NOP_MCOUNT + ifeq ($(call cc-option-yn, -mnop-mcount),y) + CC_FLAGS_FTRACE += -mnop-mcount + CC_FLAGS_USING += -DCC_USING_NOP_MCOUNT + endif + endif endif ifdef CONFIG_HAVE_FENTRY ifeq ($(call cc-option-yn, -mfentry),y) -- cgit v1.2.3-55-g7522