[tip:perf/core] objtool: Avoid checking code drift on busybox's diff

[tip-bot for Arnaldo Carvalho de Melo]

Commit-ID:  1a4bf28573c82b4cbeb4e8d3326b24a93ed64c8e
Gitweb:     http://git.kernel.org/tip/1a4bf28573c82b4cbeb4e8d3326b24a93ed64c8e
Author:     Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
AuthorDate: Wed, 13 Jul 2016 15:33:54 -0300
Committer:  Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Wed, 13 Jul 2016 23:08:54 -0300

objtool: Avoid checking code drift on busybox's diff

That doesn't have -I to match lines.

Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Wang Nan <wangnan0@xxxxxxxxxx>
Link: http://lkml.kernel.org/n/tip-1zqv1h6okt70e2huokkdtf1u@xxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
 tools/objtool/Makefile | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/tools/objtool/Makefile b/tools/objtool/Makefile
index f094f3c..9a3110c 100644
--- a/tools/objtool/Makefile
+++ b/tools/objtool/Makefile
@@ -41,8 +41,11 @@ include $(srctree)/tools/build/Makefile.include
 $(OBJTOOL_IN): fixdep FORCE
 	@$(MAKE) $(build)=objtool
 
+# Busybox's diff doesn't have -I, avoid warning in that case
+#
 $(OBJTOOL): $(LIBSUBCMD) $(OBJTOOL_IN)
-	@(test -d ../../kernel -a -d ../../tools -a -d ../objtool && (( \
+	@(diff -I 2>&1 | grep -q 'option requires an argument' && \
+	test -d ../../kernel -a -d ../../tools -a -d ../objtool && (( \
 	diff -I'^#include' arch/x86/insn/insn.c ../../arch/x86/lib/insn.c >/dev/null && \
 	diff -I'^#include' arch/x86/insn/inat.c ../../arch/x86/lib/inat.c >/dev/null && \
 	diff arch/x86/insn/x86-opcode-map.txt ../../arch/x86/lib/x86-opcode-map.txt >/dev/null && \