Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754066AbaGCA5s (ORCPT ); Wed, 2 Jul 2014 20:57:48 -0400 Received: from smtp.outflux.net ([198.145.64.163]:34351 "EHLO smtp.outflux.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753920AbaGCA5r (ORCPT ); Wed, 2 Jul 2014 20:57:47 -0400 Date: Wed, 2 Jul 2014 17:57:19 -0700 From: Kees Cook To: Randy Dunlap Cc: akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-next@vger.kernel.org, sfr@canb.auug.org.au, mhocko@suse.cz, Andi Kleen Subject: Re: mmotm 2014-07-02-15-07 uploaded (stack protector) Message-ID: <20140703005719.GJ5412@outflux.net> References: <53b482d3.gR7nYB/K7hPREviI%akpm@linux-foundation.org> <53B493E2.2030905@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <53B493E2.2030905@infradead.org> Organization: Outflux X-HELO: www.outflux.net Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Randy, And to explain more specifically what's happening: On Wed, Jul 02, 2014 at 04:21:06PM -0700, Randy Dunlap wrote: > config-r8736:CONFIG_CC_STACKPROTECTOR_STRONG=y > [...] > build-r8736.out:/local/lnx/MM/mmotm-2014-0702-1507/Makefile:662: Cannot use CONFIG_CC_STACKPROTECTOR_STRONG: -fstack-protector-strong not supported by compiler > build-r8736.out:/local/lnx/MM/mmotm-2014-0702-1507/Makefile:662: Cannot use CONFIG_CC_STACKPROTECTOR_STRONG: -fstack-protector-strong not supported by compiler > gcc: error: unrecognized command line option '-fstack-protector-strong' That makes sense: a feature that requires a specific compiler version was chosen, so you get a warning and a failed build. (The first warning was during the .config parsing pass, the second warning was during the binary build pass.) > config-r8737:# CONFIG_CC_STACKPROTECTOR_STRONG is not set > [...] > build-r8737.out:/local/lnx/MM/mmotm-2014-0702-1507/Makefile:662: Cannot use CONFIG_CC_STACKPROTECTOR_STRONG: -fstack-protector-strong not supported by compiler This is the same issue: the prior .config was still there with STRONG set, but after finishing the new .config parsing pass, everything is happy for the binary build pass. And, I assume, the r8737 didn't fail to build. The trouble seems to be how kbuild handle .config changes, but I was never able to sort it out. -Kees -- Kees Cook @outflux.net -- 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/