Commit 85356f80 authored by Steven Rostedt's avatar Steven Rostedt Committed by Steven Rostedt
Browse files

kbuild/recordmcount: Add RECORDMCOUNT_WARN to warn about mcount callers 



When mcount is called in a section that ftrace will not modify it into
a nop, we want to warn about this. But not warn about this always. Now
if the user builds the kernel with the option RECORDMCOUNT_WARN=1 then
the build will warn about mcount callers that are ignored and will just
waste execution time.

Acked-by: default avatarMichal Marek <mmarek@suse.cz>
Cc: linux-kbuild@vger.kernel.org
Link: http://lkml.kernel.org/r/20110421023738.714956282@goodmis.org


Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent dfad3d59

Makefile

+1 −0
Original line number Diff line number Diff line
@@ -1268,6 +1268,7 @@ help: 
	@echo  '  make C=1   [targets] Check all c source with $$CHECK (sparse by default)'

	@echo  '  make C=2   [targets] Force check of all c source with $$CHECK'

	@echo  '  make W=1   [targets] Enable extra gcc checks'

	@echo  '  make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'

	@echo  ''

	@echo  'Execute "make" or "make all" to build all targets marked with [*] '

	@echo  'For further info see the ./README file'

scripts/Makefile.build

+4 −1
Original line number Diff line number Diff line
@@ -244,13 +244,16 @@ endif 


ifdef CONFIG_FTRACE_MCOUNT_RECORD

ifdef BUILD_C_RECORDMCOUNT

ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")

  RECORDMCOUNT_FLAGS = -w

endif

# Due to recursion, we must skip empty.o.

# The empty.o file is created in the make process in order to determine

#  the target endianness and word size. It is made before all other C

#  files, including recordmcount.

sub_cmd_record_mcount =					\

	if [ $(@) != "scripts/mod/empty.o" ]; then	\

		$(objtree)/scripts/recordmcount "$(@)";	\

		$(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)";	\

	fi;

else

sub_cmd_record_mcount = set -e ; perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \

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