From c2bb9e32e2315971a8535fee77335c04a739d71d Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 20 Apr 2016 11:32:35 -0400 Subject: objtool: Fix Makefile to properly see if libelf is supported When doing a make allmodconfig, I hit the following compile error: In file included from builtin-check.c:32:0: elf.h:22:18: fatal error: gelf.h: No such file or directory compilation terminated. ... Digging into it, it appears that the $(shell ..) command in the Makefile does not give the proper result when it fails to find -lelf, and continues to compile objtool. Instead, use the "try-run" makefile macro to perform the test. This gives a proper result for both cases. Signed-off-by: Steven Rostedt Acked-by: Josh Poimboeuf Cc: Andrew Morton Cc: Andy Lutomirski Cc: Arnaldo Carvalho de Melo Cc: Bernd Petrovitsch Cc: Borislav Petkov Cc: Chris J Arges Cc: Jiri Slaby Cc: Linus Torvalds Cc: Michal Marek Cc: Namhyung Kim Cc: Pedro Alves Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: live-patching@vger.kernel.org Fixes: 442f04c34a1a4 ("objtool: Add tool to perform compile-time stack metadata validation") Link: http://lkml.kernel.org/r/20160420153234.GA24032@home.goodmis.org Signed-off-by: Ingo Molnar --- Makefile | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'Makefile') diff --git a/Makefile b/Makefile index 1d0aef03eae7..70ca38ef9f4b 100644 --- a/Makefile +++ b/Makefile @@ -1008,7 +1008,8 @@ prepare0: archprepare FORCE prepare: prepare0 prepare-objtool ifdef CONFIG_STACK_VALIDATION - has_libelf := $(shell echo "int main() {}" | $(HOSTCC) -xc -o /dev/null -lelf - &> /dev/null && echo 1 || echo 0) + has_libelf := $(call try-run,\ + echo "int main() {}" | $(HOSTCC) -xc -o /dev/null -lelf -,1,0) ifeq ($(has_libelf),1) objtool_target := tools/objtool FORCE else -- cgit v1.2.3