From: Steven Rostedt <srostedt@xxxxxxxxxx> 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: Michal Marek <mmarek@xxxxxxx> Cc: linux-kbuild@xxxxxxxxxxxxxxx Link: http://lkml.kernel.org/r/20110421023738.714956282@xxxxxxxxxxx Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx> --- Makefile | 1 + scripts/Makefile.build | 5 ++++- 2 files changed, 5 insertions(+), 1 deletions(-) diff --git a/Makefile b/Makefile index 41ea6fb..e7d01ad 100644 --- a/Makefile +++ b/Makefile @@ -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' diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 7d3f903..6165622 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -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; recordmcount_source := $(srctree)/scripts/recordmcount.c \ $(srctree)/scripts/recordmcount.h -- 1.7.4.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
