From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 34165 invoked by alias); 14 Jul 2017 07:46:23 -0000 Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org Received: (qmail 34036 invoked by uid 89); 14 Jul 2017 07:46:22 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.9 required=5.0 tests=BAYES_00,RP_MATCHES_RCVD,SPF_HELO_PASS autolearn=ham version=3.3.2 spammy=HContent-Transfer-Encoding:8bit X-HELO: mx1.redhat.com Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Fri, 14 Jul 2017 07:46:20 +0000 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id DBAEA3B71F; Fri, 14 Jul 2017 07:46:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com DBAEA3B71F Authentication-Results: ext-mx06.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx06.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=law@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com DBAEA3B71F Received: from localhost.localdomain (ovpn-116-196.phx2.redhat.com [10.3.116.196]) by smtp.corp.redhat.com (Postfix) with ESMTP id 886DD65E84; Fri, 14 Jul 2017 07:46:18 +0000 (UTC) Subject: Re: [PATCH][RFA/RFC] Stack clash mitigation patch 01/08 To: Jakub Jelinek , Segher Boessenkool Cc: "gcc-patches@gcc.gnu.org >> gcc-patches" References: <93ce7fc1-e41e-282f-a574-234a83d57d7d@redhat.com> <20170713003157.GW13471@gate.crashing.org> <470c6af6-0c13-34fb-8ccb-7c31d24181f2@redhat.com> <20170713213201.GI13471@gate.crashing.org> <20170714074026.GX2123@tucnak> From: Jeff Law Message-ID: <0a705e61-90e4-134c-815e-986f9343dfd4@redhat.com> Date: Fri, 14 Jul 2017 07:46:00 -0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 MIME-Version: 1.0 In-Reply-To: <20170714074026.GX2123@tucnak> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-IsSubscribed: yes X-SW-Source: 2017-07/txt/msg00802.txt.bz2 On 07/14/2017 01:40 AM, Jakub Jelinek wrote: > On Thu, Jul 13, 2017 at 04:32:02PM -0500, Segher Boessenkool wrote: >> I don't think it should be inside -fstack-check at all. Sure, the >> mechanisms implementing it overlap a bit (more on some targets, less >> on others), but how will a user ask for clash protection _and_ for >> stack checking? > > Are we willing to implement that? What would we do in that case? I'd change every existing target that has a backend stack probing implementatoin to use a moving-sp style. ie, allocate page, probe page, allocate page, probe page. We'd then want to use the -fstack-check routines rather than the new routines. But in the end I don't think using the options together makes all that much sense. We really should look at -fstack-check as Ada specific, even though its implementation is in the target files and middle end. Jeff