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=-8.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 798A7C2D0C3 for ; Wed, 18 Dec 2019 08:12:15 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 46FC2218AC for ; Wed, 18 Dec 2019 08:12:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="WT0D+obG" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 46FC2218AC Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:50774 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ihURK-0003FV-FV for qemu-devel@archiver.kernel.org; Wed, 18 Dec 2019 03:12:14 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:51457) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ihUQd-0002oP-A4 for qemu-devel@nongnu.org; Wed, 18 Dec 2019 03:11:32 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ihUQb-0008Uv-BR for qemu-devel@nongnu.org; Wed, 18 Dec 2019 03:11:30 -0500 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:48428 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ihUQb-0008R8-7F for qemu-devel@nongnu.org; Wed, 18 Dec 2019 03:11:29 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1576656687; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:openpgp:openpgp; bh=tVhKJEuSPLOXhaKPiHrpLwAD8wgUZoTebgN9SwCdQW8=; b=WT0D+obGb/flw8+AO2WxBwtwFf6Wbv9E7zq37IbN6DF2g2sHE7pW29OveZZ5Heh27xNiI6 r3lReK5FAcw+9mrGCL95OK101XnIihJOhjnOSiT1u67ZlgsBbkjm43G2m5TbmjANHLhXTP bpSoPGDGAXRpcbV20h7FmCmfc2tObU0= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-427-tivi4ZyKOWiRwLVpABYDjg-1; Wed, 18 Dec 2019 03:11:26 -0500 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 141D61800D42; Wed, 18 Dec 2019 08:11:25 +0000 (UTC) Received: from thuth.remote.csb (ovpn-116-150.ams2.redhat.com [10.36.116.150]) by smtp.corp.redhat.com (Postfix) with ESMTPS id EB05C60C18; Wed, 18 Dec 2019 08:11:20 +0000 (UTC) Subject: Re: [PATCH 5/7] configure: Unnest detection of -z,relro and -z,now To: Richard Henderson , qemu-devel@nongnu.org References: <20191218031920.6414-1-richard.henderson@linaro.org> <20191218031920.6414-6-richard.henderson@linaro.org> From: Thomas Huth Openpgp: preference=signencrypt Message-ID: <881dff30-a729-6d7b-f823-5f136125ac0b@redhat.com> Date: Wed, 18 Dec 2019 09:11:19 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <20191218031920.6414-6-richard.henderson@linaro.org> Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-MC-Unique: tivi4ZyKOWiRwLVpABYDjg-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 207.211.31.120 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: berrange@redhat.com, i@maskray.me, philmd@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 18/12/2019 04.19, Richard Henderson wrote: > There is nothing about these options that is related to PIE. > Nor is there anything that specifically ties them to each other. > Use them unconditionally. > > Signed-off-by: Richard Henderson > --- > configure | 13 ++++++++++--- > 1 file changed, 10 insertions(+), 3 deletions(-) > > diff --git a/configure b/configure > index 972ce7396f..f8981eec15 100755 > --- a/configure > +++ b/configure > @@ -2034,9 +2034,6 @@ if test "$pie" != "no" ; then > QEMU_CFLAGS="-fPIE -DPIE $QEMU_CFLAGS" > LDFLAGS="-pie $LDFLAGS" > pie="yes" > - if compile_prog "" "-Wl,-z,relro -Wl,-z,now" ; then > - LDFLAGS="-Wl,-z,relro -Wl,-z,now $LDFLAGS" > - fi > else > if test "$pie" = "yes"; then > error_exit "PIE not available due to missing toolchain support" > @@ -2047,6 +2044,16 @@ if test "$pie" != "no" ; then > fi > fi > > +# Detect support for DT_BIND_NOW. > +if compile_prog "" "-Wl,-z,now" ; then > + LDFLAGS="-Wl,-z,now $LDFLAGS" > +fi > + > +# Detect support for PT_GNU_RELRO. > +if compile_prog "" "-Wl,-z,relro" ; then > + LDFLAGS="-Wl,-z,relro $LDFLAGS" > +fi Looking at https://mudongliang.github.io/2016/07/11/relro-a-not-so-well-known-memory-corruption-mitigation-technique.html the idea of specifying these two options together was likely to get "Full RELRO" instead of only "Partial RELRO". Thus, does it make sense to have "-Wl,-z,now" without "-Wl,-z,relro" in QEMU? Or should this rather check whether both are possible, then use both, otherwise just try to use "relro" alone? Thomas