From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C8508C43382 for ; Wed, 26 Sep 2018 18:38:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0B8B321546 for ; Wed, 26 Sep 2018 18:38:53 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0B8B321546 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.crashing.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727285AbeI0AxH (ORCPT ); Wed, 26 Sep 2018 20:53:07 -0400 Received: from gate.crashing.org ([63.228.1.57]:48524 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726127AbeI0AxH (ORCPT ); Wed, 26 Sep 2018 20:53:07 -0400 Received: from gate.crashing.org (localhost.localdomain [127.0.0.1]) by gate.crashing.org (8.14.1/8.14.1) with ESMTP id w8QHbphO017440; Wed, 26 Sep 2018 12:37:52 -0500 Received: (from segher@localhost) by gate.crashing.org (8.14.1/8.14.1/Submit) id w8QHbjIp017396; Wed, 26 Sep 2018 12:37:45 -0500 X-Authentication-Warning: gate.crashing.org: segher set sender to segher@kernel.crashing.org using -f Date: Wed, 26 Sep 2018 12:37:44 -0500 From: Segher Boessenkool To: Christophe LEROY Cc: Russell Currey , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Andrew Donnellan , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 2/2] powerpc/64: add stack protector support Message-ID: <20180926173744.GN23155@gate.crashing.org> References: <2b934594d21ade67a4092637cf9e6b7d2d131187.1537801613.git.christophe.leroy@c-s.fr> <0797fc91-6400-2508-1cc0-4bba78aafbbb@c-s.fr> <30fb4e6b-0981-c53c-a1db-94138eaad268@c-s.fr> <20180926092806.GM23155@gate.crashing.org> <284752d1-6c32-bdca-72d3-4d8616b26fbf@c-s.fr> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <284752d1-6c32-bdca-72d3-4d8616b26fbf@c-s.fr> User-Agent: Mutt/1.4.2.3i Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Sep 26, 2018 at 11:41:26AM +0200, Christophe LEROY wrote: > Le 26/09/2018 à 11:28, Segher Boessenkool a écrit : > >On Wed, Sep 26, 2018 at 09:58:30AM +0200, Christophe LEROY wrote: > >>Segher, any idea about this problem ? > > > >>>>arch/powerpc/platforms/powermac/bootx_init.o: In function > >>>>`bootx_printf': > >>>>/var/lib/jenkins-slave/workspace/snowpatch/snowpatch-linux- > >>>>sparse/linux/arch/powerpc/platforms/powermac/bootx_init.c:88: > >>>>undefined reference to `__stack_chk_fail_local' > > > >Are you building as PIC? Are you linking libssp_nonshared.a? Why not? > > Spotted, thanks. > > arch/powerpc/platforms/powermac/Makefile contains: > > CFLAGS_bootx_init.o += -fPIC > > Does it mean we should add -lssp_nonshared to LDFLAGS_vmlinux ? Something like that. > Or maybe stack protection on bootx_init doesn't make much sense and we > could just do the following ? > > CFLAGS_bootx_init.o += -fPIC $(call cc-option, > -fno-stack-protector) But more likely this. Why does it use -fPIC? If it is only boot-time init (which the name suggests) then disabling ssp makes a lot of sense. Segher