From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 26796 invoked by alias); 25 Jan 2018 16:40:55 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Received: (qmail 26786 invoked by uid 89); 25 Jan 2018 16:40:55 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.8 required=5.0 tests=AWL,BAYES_00,FREEMAIL_FROM,RCVD_IN_DNSWL_NONE,SPF_PASS autolearn=ham version=3.3.2 spammy=HX-Google-Smtp-Source:AH8x224, Hx-languages-length:2720, urgent X-HELO: mail-oi0-f49.google.com X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=Pk6lVs+bQOFTL/tZjufVTSho0Wux9IjcbuXFhw/mg6M=; b=PWFZY+ITuM61GnYYCOQUfoglOsrZ7/X4upRTyO9+11g8XOn14kX3v5VAXHyoSnT4Ac 4D7uZUy8m8s+a/13ZPc05EHTN7aKLICV4YnHVH0TgNbM2EadVmg7UC9dOSMq0xyEsidk y2LDOnYYAx5BPGNSMtzOyoO/q0oj5n13grkiiMXU2FEoa3G84MPmXhhauIipkOqPNn9W ZfUqWgkS2DUg6hvezFCMM8XphqXzue5L4naihGKvJl6MGGMSVxXGcyxalgvqn2MoFlhj 83hi9HYF9+tDCxl4Gy32KMWuwd7fW+q6awC4Huf4VN77u8wNz2qlwT8LTAhLTSo++Vn3 hN0g== X-Gm-Message-State: AKwxytcVSTsNrweyseeDdTy6C8k1RzAwdOdzJP1B3cmSUEWsbE+X78p0 dBLcYzoQUXAR1VBOFiBW1t3/GRQY5oeBCmZNNBk= X-Google-Smtp-Source: AH8x224+3F51H69zG24PkYjL5hX514VzRsuS9D1fwCAh295tAQ32DvUR2etv6gkHOhfjmrQkFvGBurTL8/xn1dQrYig= X-Received: by 10.202.213.144 with SMTP id m138mr11347487oig.192.1516898452415; Thu, 25 Jan 2018 08:40:52 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <889d278f-ae40-9feb-8b71-194f009b62d1@redhat.com> References: <20180125014816.GA5754@altlinux.org> <30596304-a38e-1102-156f-85f67bd4d40e@redhat.com> <889d278f-ae40-9feb-8b71-194f009b62d1@redhat.com> From: "H.J. Lu" Date: Thu, 25 Jan 2018 16:40:00 -0000 Message-ID: Subject: Re: [PATCH] Revert Intel CET changes to __jmp_buf_tag (Bug 22743) To: "Carlos O'Donell" Cc: Zack Weinberg , Florian Weimer , "Senkevich, Andrew" , Andreas Schwab , GNU C Library Content-Type: text/plain; charset="UTF-8" X-SW-Source: 2018-01/txt/msg00825.txt.bz2 On Thu, Jan 25, 2018 at 8:36 AM, Carlos O'Donell wrote: > On 01/25/2018 08:28 AM, H.J. Lu wrote: >> On Thu, Jan 25, 2018 at 8:22 AM, Zack Weinberg wrote: >>> On Thu, Jan 25, 2018 at 10:33 AM, H.J. Lu wrote: >>>> On Thu, Jan 25, 2018 at 6:55 AM, Zack Weinberg wrote: >>>>> In my opinion, the fact that you two are having this argument >>>>> reinforces Carlos' position: the original patch should be reverted and >>>>> we should figure out what to do in 2.28 when we're not under time >>>>> pressure. HJ, do you have some concrete external reason why you must >>>>> have this new feature in 2.27? If so, please tell us what it is. To >>>>> me it doesn't seem urgent. >>>> >>>> My question is if we are going to fix it at all. If yes, why not 2.27. >>>> Both approaches are opaque to users. They can't tell the difference. >>> >>> My concerns are entirely based on timing: specifically, you seem to be >>> in a rush to squeak under the 2.27 deadline. Rushing leads to >>> mistakes. >> >> The main issue for this one is testcase. Once a testcase is found, we >> know how to avoid the issue. >> >>> This seems like the sort of thing that could reasonably be backported >>> to the release branch(es) ... *after* we have calmly, without rushing, >>> figured out the correct fix in mainline. >>> >> >> I am fine with reverting my patch only on 2.27 branch, not on master. > > This does not make sense. The revert on master would last for as long as > you have to come up with a patch that works and everyone accepts and has > consensus. We have 2 proposals, one with a patch and one without. How long should it take to make a decision? > You checked these patches in without consensus, and instead of waiting > or pinging for review, you checked them in. > > For x86_64 there is no machine maintainer, it requires community consensus, Do we need/want machine maintainers for x86-64 (i386)? > the port is too important not to get serious community review. > > They changes had negative ABI consequences, and now you have several > people interested in making sure future patches don't break ABI. There are no arguments here. > You have drawn attention to this work and now you have to reach consensus > on a solution for a primary architecture which is very important to all of > us in the downstream distributions. More time is required to make these > patches work. > > I see no clear argument for why this needs to be in 2.27. That is fine with me. > I will be reverting the patches in the next 8 hours. We need this on master so that we can work on CET support. -- H.J.