CC_FLAGS_FTRACE may contain trailing whitespace that interferes with findstring. For example, commit 6977f95e63b9 ("powerpc: avoid -mno-sched-epilog on GCC 4.9 and newer") introduced a change such that on my ppc64le box, CC_FLAGS_FTRACE="-pg -mprofile-kernel ". (Note the trailing space.) When cmd_record_mcount is now invoked, findstring fails as the ftrace flags were found at very end of _c_flags, without the trailing space. _c_flags=" ... -pg -mprofile-kernel" CC_FLAGS_FTRACE="-pg -mprofile-kernel " ^ findstring is looking for this extra space Remove the redundant whitespaces from CC_FLAGS_FTRACE in cmd_record_mcount to avoid this problem. Fixes: 6977f95e63b9 ("powerpc: avoid -mno-sched-epilog on GCC 4.9 and newer"). Signed-off-by: Joe Lawrence <joe.lawrence@xxxxxxxxxx> --- Standard disclaimer: I'm not a kbuild expert, but this works around the problem I reported where ftrace and livepatch self-tests were failing as specified object files were not run through the recordmcount.pl script: ppc64le: ftrace self-tests and $(CC_FLAGS_FTRACE) broken? https://lists.ozlabs.org/pipermail/linuxppc-dev/2019-March/187298.html scripts/Makefile.build | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 2554a15ecf2b..74d402b5aa3c 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -199,10 +199,10 @@ sub_cmd_record_mcount = perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \ "$(if $(part-of-module),1,0)" "$(@)"; recordmcount_source := $(srctree)/scripts/recordmcount.pl endif # BUILD_C_RECORDMCOUNT -cmd_record_mcount = \ - if [ "$(findstring $(CC_FLAGS_FTRACE),$(_c_flags))" = \ - "$(CC_FLAGS_FTRACE)" ]; then \ - $(sub_cmd_record_mcount) \ +cmd_record_mcount = \ + if [ "$(findstring $(strip $(CC_FLAGS_FTRACE)),$(_c_flags))" = \ + "$(strip $(CC_FLAGS_FTRACE))" ]; then \ + $(sub_cmd_record_mcount) \ fi endif # CC_USING_RECORD_MCOUNT endif # CONFIG_FTRACE_MCOUNT_RECORD -- 2.20.1