From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 41057 invoked by alias); 8 Jun 2017 16:19:35 -0000 Mailing-List: contact gnu-gabi-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Post: List-Help: List-Subscribe: Sender: gnu-gabi-owner@sourceware.org Received: (qmail 41039 invoked by uid 89); 8 Jun 2017 16:19:33 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Checked: by ClamAV 0.99.2 on sourceware.org X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.9 required=5.0 tests=AWL,BAYES_00,FREEMAIL_FROM,RCVD_IN_DNSWL_NONE,SPF_PASS autolearn=ham version=3.3.2 spammy=5c, theme, 07-Jun-2017, 07-jun-2017 X-Spam-Status: No, score=-1.9 required=5.0 tests=AWL,BAYES_00,FREEMAIL_FROM,RCVD_IN_DNSWL_NONE,SPF_PASS autolearn=ham version=3.3.2 X-Spam-Checker-Version: SpamAssassin 3.3.2 (2011-06-06) on sourceware.org X-Spam-Level: X-HELO: mail-ot0-f194.google.com Received: from mail-ot0-f194.google.com (HELO mail-ot0-f194.google.com) (74.125.82.194) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Thu, 08 Jun 2017 16:19:32 +0000 Received: by mail-ot0-f194.google.com with SMTP id t31so3918880ota.2 for ; Thu, 08 Jun 2017 09:19:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=reply-to:subject:references:to:cc:from:organization:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding; bh=G7krXSgW/yHqC1naSemurdczGmljLnRfFSAwRkD9SkU=; b=h/yIDyG4sVZAniKn/iNuZ6EHI3qljrcD+C7vfAaJK1x8k4j6krQ+7ROt+Wm1dp/D33 /LCdoqQCZYpoaMratb0K40G7mHu+wqw6di5j8wmPvxUVvMklQSrNU9WoirAomEZNVoQk Bh9Xz2XPqQhBxp3F5d2PNQKok4v9+wgWa9CWLiuQxugQd8Uoz3UpFGyOdV9NvgCJ5cZb 4rPGRl7rbBkG0C1odXgtUpux9oyN9aMkvat2c2M/EmqgfQMe3wZlAjlxDeEjV+pSu/Ue 0Ea8TG4hzTqsU/3Oje7d9nVxVTjYquOlMOW0utYuGnKDRMVrQwgb/q7RW3BfNdiLwOxX 4Nqw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:reply-to:subject:references:to:cc:from :organization:message-id:date:user-agent:mime-version:in-reply-to :content-transfer-encoding; bh=G7krXSgW/yHqC1naSemurdczGmljLnRfFSAwRkD9SkU=; b=e1dlRt03YWhqTMwm22dysps85nXip2cjY3Ah8ywj0sQkxULuEGhsynS6IaLeG7vQ5H OpNZMPoZy8TGVWpLVR+OaEGG7sJ4zO7JpCHRyU45TOoo772WlYFRWeYhu8NUlOUuhPdt JlmfZFAhpjMJ1ubs3QKr3hVjR0sPeNOIN4yQonM6/dtu54x31jBZ4nJdA/qM1151rcqc 3S94SVrPV9TpVNtnIS/OzRNfQTvPd1RzVG73elszrF5nQyOEboAvNNT3XR9eYxG82nSD OBvJZEOkTN82t9l74nIafpbsl5NLVK3fh2Z21RYH6jMLbRlNsit/UiQdxY/DZ5jlFZYn PvlA== X-Gm-Message-State: AKS2vOyRznufU/MvjX6XoTC5mjiui6To5LF7BeKzkobGFs22IIQ4QHj3 t6h6iFLmxrNt0AZoXow= X-Received: by 10.157.16.102 with SMTP id o35mr6820241oto.192.1496938775225; Thu, 08 Jun 2017 09:19:35 -0700 (PDT) Received: from [192.168.1.2] ([103.16.201.114]) by smtp.gmail.com with ESMTPSA id p3sm2833841ota.51.2017.06.08.09.19.32 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 08 Jun 2017 09:19:34 -0700 (PDT) Reply-To: hegdesmailbox@gmail.com Subject: Re: gABI extension proposal: PT_SHMMAP References: <5d71c4e4-19d2-3861-e212-5e86d29c53fc@zytor.com> To: Cary Coutant , James Y Knight Cc: "H. Peter Anvin" , gnu-gabi@sourceware.org From: Suprateeka R Hegde Organization: HEGDESASPECT Message-ID: Date: Sun, 01 Jan 2017 00:00:00 -0000 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-Antivirus: Avast (VPS 170607-0, 07-06-2017), Outbound message X-Antivirus-Status: Clean X-IsSubscribed: yes X-SW-Source: 2017-q2/txt/msg00025.txt.bz2 On 07-Jun-2017 10:40 PM, H. Peter Anvin wrote: > Any particular reason that you feel this is not generally useful? 1. The use case provided looks extremely specific to Linux. AFAIK, none of the unix like HP-UX, Solaris or AIX need this requirement. 2. This looks so specific to a runtime loader that it can be as well handled as a special case in GNU mmap system (may be in ld.so). 3. Assuming Cary is right in understanding that you want a writable but still sharable page, such features are not even provided by some of the legacy unix kernels. 4. Eventually there can be many such flags if we start going with specific claims. For instance there was a request for PF_NOREAD/SHF_NOREAD that would help some archs (STM?) to protect code from being read. 5. Why dont we try to fit this proposal under the bigger one - program properties - proposed by H.J. ? The theme there is to pass such information to runtime. 6. Lastly, the proposal looks incomplete: 5-a. The hex value for the proposed flag is missing 5-b. The proposal should be sent to Generic SYS-V ABI group and not GNU-GABI alone. 5-c. The complete semantics of this flag in a standard form. The semantics should talk about what is mandatory, what is optional. Is the current/existing UNIX should be changed to honor this flag or is this optional? -- Supra