From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D9CCCC4346E for ; Fri, 25 Sep 2020 02:34:52 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 8824D20888 for ; Fri, 25 Sep 2020 02:34:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="WFFhYRtU"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="t2Am+bOL" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8824D20888 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:Mime-Version:References:In-Reply-To:Message-Id: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=67TI/jMsL+YM2kndcorAo0SZ3nSs+Gs4cQnklwBVY4E=; b=WFFhYRtUtCYStJjsAaMtqtWxu ElbToDfm0QvhKsY5cfi7MpjjkfvgEQasmmamd0C8BFnFilYXuLZE2tfqsVd1dT7kq36EVfPXYbyeb enMRVfl0m21RaNAGhL99MViwPg/5tnLBwuYPA3RgNQXqKFo5rvLY66hB0QGTxqbP+B67phCExhCC/ LINXIGAgAwNrmeidPP1CCL/uN7WxGQtRKKUxCtMS1fALBLgd59+haN/s3uPEr2swQWBaokMcyhxbx 9607WD2ukE7caniexu4xzv4gtOw9s/NvvOm3q33Dc6jJUHzx7VFDTwrRW0pXa46H4hgRoslfmJDx0 TAhc6F5KA==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kLdZG-0005Jr-Gh; Fri, 25 Sep 2020 02:34:38 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kLdZB-0005HW-MV; Fri, 25 Sep 2020 02:34:34 +0000 Received: from X1 (unknown [104.245.68.101]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 6CF7620888; Fri, 25 Sep 2020 02:34:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601001271; bh=Smg4DQZKLT8m1LXboOjRbYbEEA4933QtuIJr9GOx1d4=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=t2Am+bOL7aQc+oLElXbYFnp8Y1wlGgthaRTiSGvzkHwzblFnwyTLhHkGuKwh6cPPK dGNyh6ea1G8zhcYz+2jZ/HAlJJzZS2Hb5uMncrKXCFHO9WgB/ShnWeWBcyoD4aVexB fTMs8EfOHnI33GKShzqA790tDOYNu8QPGgMsLH84= Date: Thu, 24 Sep 2020 19:34:28 -0700 From: Andrew Morton To: Mike Rapoport Subject: Re: [PATCH v6 0/6] mm: introduce memfd_secret system call to create "secret" memory areas Message-Id: <20200924193428.6642e0cc3436bb67ddf8024a@linux-foundation.org> In-Reply-To: <20200924132904.1391-1-rppt@kernel.org> References: <20200924132904.1391-1-rppt@kernel.org> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.32; x86_64-pc-linux-gnu) Mime-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200924_223433_857559_60345E40 X-CRM114-Status: GOOD ( 24.59 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , David Hildenbrand , Peter Zijlstra , Catalin Marinas , Dave Hansen , linux-mm@kvack.org, Will Deacon , linux-kselftest@vger.kernel.org, "H. Peter Anvin" , Christopher Lameter , Idan Yaniv , Thomas Gleixner , Elena Reshetova , linux-arch@vger.kernel.org, Tycho Andersen , linux-nvdimm@lists.01.org, Shuah Khan , x86@kernel.org, Matthew Wilcox , Mike Rapoport , Ingo Molnar , Michael Kerrisk , Arnd Bergmann , James Bottomley , Borislav Petkov , Alexander Viro , Andy Lutomirski , Paul Walmsley , "Kirill A. Shutemov" , Dan Williams , linux-arm-kernel@lists.infradead.org, linux-api@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, Palmer Dabbelt , linux-fsdevel@vger.kernel.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org On Thu, 24 Sep 2020 16:28:58 +0300 Mike Rapoport wrote: > From: Mike Rapoport > > Hi, > > This is an implementation of "secret" mappings backed by a file descriptor. > I've dropped the boot time reservation patch for now as it is not strictly > required for the basic usage and can be easily added later either with or > without CMA. > > ... > > The file descriptor backing secret memory mappings is created using a > dedicated memfd_secret system call The desired protection mode for the > memory is configured using flags parameter of the system call. The mmap() > of the file descriptor created with memfd_secret() will create a "secret" > memory mapping. The pages in that mapping will be marked as not present in > the direct map and will have desired protection bits set in the user page > table. For instance, current implementation allows uncached mappings. > > Although normally Linux userspace mappings are protected from other users, > such secret mappings are useful for environments where a hostile tenant is > trying to trick the kernel into giving them access to other tenants > mappings. > > Additionally, the secret mappings may be used as a mean to protect guest > memory in a virtual machine host. > > For demonstration of secret memory usage we've created a userspace library > [1] that does two things: the first is act as a preloader for openssl to I can find no [1]. I'm not a fan of the enumerated footnote thing. Why not inline the url right here so readers don't need to jump around? _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv