Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753070AbbDTSkK (ORCPT ); Mon, 20 Apr 2015 14:40:10 -0400 Received: from services.gouders.net ([141.101.32.176]:55013 "EHLO services.gouders.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751443AbbDTSkH (ORCPT ); Mon, 20 Apr 2015 14:40:07 -0400 From: Dirk Gouders To: Ingo Molnar Cc: Arnaldo Carvalho de Melo , Peter Zijlstra , Paul Mackerras , Ingo Molnar , linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] tools/lib/api/Makefile: Add feature check for _FORTIFY_SOURCE In-Reply-To: <20150420181631.GA19378@gmail.com> (Ingo Molnar's message of "Mon, 20 Apr 2015 20:16:31 +0200") References: <20150420181631.GA19378@gmail.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.4 (gnu/linux) Date: Mon, 20 Apr 2015 20:34:07 +0200 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1773 Lines: 51 Ingo Molnar writes: > * Dirk Gouders wrote: > >> For example on Gentoo systems where _FORTIFY_SOURCE is set by default, >> `make -C tools/perf' fails, because of the macro being redefined. >> >> Fix that by a feature-check analogous to tools/perf/config/Makefile. >> >> Signed-off-by: Dirk Gouders >> --- >> tools/lib/api/Makefile | 9 ++++++++- >> 1 file changed, 8 insertions(+), 1 deletion(-) >> >> diff --git a/tools/lib/api/Makefile b/tools/lib/api/Makefile >> index d8fe29f..acf9097 100644 >> --- a/tools/lib/api/Makefile >> +++ b/tools/lib/api/Makefile >> @@ -16,7 +16,14 @@ MAKEFLAGS += --no-print-directory >> LIBFILE = $(OUTPUT)libapi.a >> >> CFLAGS := $(EXTRA_WARNINGS) $(EXTRA_CFLAGS) >> -CFLAGS += -ggdb3 -Wall -Wextra -std=gnu99 -Werror -O6 -D_FORTIFY_SOURCE=2 -fPIC >> +CFLAGS += -ggdb3 -Wall -Wextra -std=gnu99 -Werror -O6 -fPIC >> + >> +ifeq ($(DEBUG),0) >> + ifeq ($(feature-fortify-source), 1) >> + CFLAGS += -D_FORTIFY_SOURCE=2 >> + endif >> +endif > > So how about undefining it instead and re-defining it as > _FORTIFY_SOURCE=2? > > Just in case a distro sets a weaker version - lets not accept that > weaker setting. We've always had the stronger version of it. Yes, I was suggesting something similar (but without founded reasoning), some time ago [1]. Would the "undefining-approch" mean that we should modify the handling of _FORTIFY_SOURCE in tools/perf/config/Makefile as well? Dirk [1] https://lkml.org/lkml/2013/5/22/186 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/