From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932595AbcCCRkk (ORCPT ); Thu, 3 Mar 2016 12:40:40 -0500 Received: from mx1.redhat.com ([209.132.183.28]:39459 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754309AbcCCRki (ORCPT ); Thu, 3 Mar 2016 12:40:38 -0500 From: Josh Poimboeuf To: Ingo Molnar Cc: Stephen Rothwell , linux-next@vger.kernel.org, linux-kernel@vger.kernel.org, linux@roeck-us.net, Andrew Morton , live-patching@vger.kernel.org, Sudip Mukherjee Subject: [PATCH] objtool: Warn if libelf is missing Date: Thu, 3 Mar 2016 11:39:30 -0600 Message-Id: <8c27fe00face60f42e888ddb3142c97e45223165.1457026550.git.jpoimboe@redhat.com> In-Reply-To: <20160303143527.GA2348@treble.redhat.com> References: <20160303143527.GA2348@treble.redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org With CONFIG_STACK_VALIDATION enabled, if the host system doesn't have a development version of libelf installed, the build fails with errors like: elf.h:22:18: fatal error: gelf.h: No such file or directory compilation terminated. Instead of failing to build, instead just print a warning and disable stack validation. Signed-off-by: Josh Poimboeuf --- Based on tip/master. Makefile | 13 ++++++++++++- scripts/Makefile.build | 2 ++ 2 files changed, 14 insertions(+), 1 deletion(-) diff --git a/Makefile b/Makefile index 750df29..1fd8328 100644 --- a/Makefile +++ b/Makefile @@ -998,8 +998,19 @@ prepare0: archprepare FORCE # All the preparing.. prepare: prepare0 prepare-objtool +ifdef CONFIG_STACK_VALIDATION + has_libelf := $(shell echo "int main() {}" | $(HOSTCC) -xc -o /dev/null -lelf - &> /dev/null && echo 1 || echo 0) + ifeq ($(has_libelf),1) + objtool_target := tools/objtool FORCE + else + $(warning "Cannot use CONFIG_STACK_VALIDATION, please install libelf-dev or elfutils-libelf-devel") + SKIP_STACK_VALIDATION := 1 + export SKIP_STACK_VALIDATION + endif +endif + PHONY += prepare-objtool -prepare-objtool: $(if $(CONFIG_STACK_VALIDATION), tools/objtool FORCE) +prepare-objtool: $(objtool_target) # Generate some files # --------------------------------------------------------------------------- diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 130a452..e1bc190 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -242,6 +242,7 @@ cmd_record_mcount = \ endif ifdef CONFIG_STACK_VALIDATION +ifneq ($(SKIP_STACK_VALIDATION),1) __objtool_obj := $(objtree)/tools/objtool/objtool @@ -260,6 +261,7 @@ objtool_obj = $(if $(patsubst y%,, \ $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \ $(__objtool_obj)) +endif # SKIP_STACK_VALIDATION endif # CONFIG_STACK_VALIDATION define rule_cc_o_c -- 2.4.3