From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on archive.lwn.net X-Spam-Level: X-Spam-Status: No, score=-5.8 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham autolearn_force=no version=3.4.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by archive.lwn.net (Postfix) with ESMTP id DB59C7DE78 for ; Mon, 7 May 2018 19:14:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752719AbeEGTOb (ORCPT ); Mon, 7 May 2018 15:14:31 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:50556 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752099AbeEGTOa (ORCPT ); Mon, 7 May 2018 15:14:30 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id A517784257; Mon, 7 May 2018 19:14:29 +0000 (UTC) Received: from llong.remote.csb (ovpn-120-35.rdu2.redhat.com [10.10.120.35]) by smtp.corp.redhat.com (Postfix) with ESMTP id 01C972024CA1; Mon, 7 May 2018 19:14:28 +0000 (UTC) Subject: Re: [PATCH v6 0/8] ipc: Clamp *mni to the real IPCMNI limit & increase that limit To: "Eric W. Biederman" Cc: "Luis R. Rodriguez" , Kees Cook , Andrew Morton , Jonathan Corbet , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-doc@vger.kernel.org, Al Viro , Matthew Wilcox References: <1524862838-8247-1-git-send-email-longman@redhat.com> <87po2ex0k6.fsf@xmission.com> <5aac35f0-77e3-5693-ddf0-a03695ff1192@redhat.com> <87tvrqf66r.fsf@xmission.com> From: Waiman Long Organization: Red Hat Message-ID: Date: Mon, 7 May 2018 15:14:28 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.0 MIME-Version: 1.0 In-Reply-To: <87tvrqf66r.fsf@xmission.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Content-Language: en-US X-Scanned-By: MIMEDefang 2.78 on 10.11.54.4 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Mon, 07 May 2018 19:14:29 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Mon, 07 May 2018 19:14:29 +0000 (UTC) for IP:'10.11.54.4' DOMAIN:'int-mx04.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'longman@redhat.com' RCPT:'' Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On 05/02/2018 11:06 AM, Eric W. Biederman wrote: > >>> and or users that may or may not exist. If you can find something that >>> will care sure. We need to avoid breaking userspace and causing >>> regressions. However as this stands it looks you are making maintenance >>> of the kernel more difficult to avoid having to look to see if there are >>> monsters under the bed. >> I shall admit that it can be hard to find applications that will >> explicitly need that as we usually don't have access to the applications >> that the customers have. It is more a correctness issue where the >> existing code is kind of lying about what can actually be supported. I >> just want to make the users more aware of what the right limits are. > You presume the kernel is lying to applications. I admit the kernel > can lie to applications. I don't see any evidence that the kernel is > actually doing so. So far (to me) it looks like a large number of sysv > shared memory segments is not particulalry common. > > So I would not be at all surprised if no regressions would be generated > if you simply deny setting the value past the maximum. Maybe you are right. I will update the patchset to fail the update if the range is exceeded since I had added option of extending the limit if the users choose to do so. Cheers, Longman -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html