Received: by 2002:ac0:a582:0:0:0:0:0 with SMTP id m2-v6csp848572imm; Fri, 5 Oct 2018 12:54:15 -0700 (PDT) X-Google-Smtp-Source: ACcGV62QNvkY64dJRHTxvtueSvtuLrbuUf76XP4g5YooztP8ttUNYIKnOoM6abR3MyMVW9c7TLwV X-Received: by 2002:a63:f005:: with SMTP id k5-v6mr11564109pgh.259.1538769255132; Fri, 05 Oct 2018 12:54:15 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1538769255; cv=none; d=google.com; s=arc-20160816; b=PNhFopYI81gQntfxXPON4VbiQPz73ZKzwt7HLfUETD0mvvAlS2tWHjdvBu4q2STL9Z r6aaPVsS3uC88DjqpoR40E0I2QoaagvLLaOlofnjSz/Sh6iixXB52JGEfY0SCI/N0pYw WY48waT8EmfX6C3/EGMmiMXc4KPGO47+rb7a/BAvM5pLrQ2RrxhzwL61LHtEqpcJ/y8C 151+dvKF0lrlZYdtq7lYqpX017ITME/Mb8Aw/NVTbJ7q+aVdqB6qiTyepmKcoh06F/td Kgbv8OSu0JH+O5AuYihj3YDI//S7MD+P286Znj0z34cspBv7JsaPCk+p6VSsjL//BbcJ r2xw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:content-transfer-encoding:mime-version :references:in-reply-to:message-id:subject:cc:to:from:date; bh=Oqf06Rt2sxBFnjtTK5PgktSaPZRVJ5jKLXj10uzhcMY=; b=uZ06dIk7OU+WHaEQp3mKTuhb2XQJZjXV5Z0ypN2tALx73xd4Mnxnz/i7aZxItuJdXZ /TgCuhPlxpZ2TbPvJcF7FCTYgkVAyx3sWHQe9+pwxuDaOBiqfe48QiAeugUL3l9D0iL7 VtNOOrle13gWFT1rlNilx0ObRj/sVWLiY7/9ICR2q+RU9ND1S6XLmH812GfV5OlHBu3k KCpdDTgPNFt1iNI9bwz7Bq9Ayq7Z5X7WBtryp1cpQCnLa4K/Zh0RiSpq2LJ3/PY7UqcF LP0QmHATS8uOxt5LRzJ3LPUrKcNve9mUIol8Uti3WS350RAxLEyo+Se2bf8Iom4wceDa cHsQ== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id x13-v6si8110545pgq.357.2018.10.05.12.53.59; Fri, 05 Oct 2018 12:54:15 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728611AbeJFCyH (ORCPT + 99 others); Fri, 5 Oct 2018 22:54:07 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:36800 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728061AbeJFCyH (ORCPT ); Fri, 5 Oct 2018 22:54:07 -0400 Received: from akpm3.svl.corp.google.com (unknown [104.133.8.65]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id 1FDC26822; Fri, 5 Oct 2018 19:53:41 +0000 (UTC) Date: Fri, 5 Oct 2018 12:53:39 -0700 From: Andrew Morton To: "Joel Fernandes (Google)" Cc: linux-kernel@vger.kernel.org, kernel-team@android.com, jreck@google.com, john.stultz@linaro.org, tkjos@google.com, gregkh@linuxfoundation.org, Al Viro , "J. Bruce Fields" , Jeff Layton , Khalid Aziz , linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Mike Kravetz Subject: Re: [PATCH RFC] mm: Add an fs-write seal to memfd Message-Id: <20181005125339.f6febfd3fcfdc69c6f408c50@linux-foundation.org> In-Reply-To: <20181005192727.167933-1-joel@joelfernandes.org> References: <20181005192727.167933-1-joel@joelfernandes.org> X-Mailer: Sylpheed 3.6.0 (GTK+ 2.24.31; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 5 Oct 2018 12:27:27 -0700 "Joel Fernandes (Google)" wrote: > To support the usecase, this patch adds a new F_SEAL_FS_WRITE seal which > prevents any future mmap and write syscalls from succeeding while > keeping the existing mmap active. The following program shows the seal > working in action: Please be prepared to create a manpage patch for this one.