From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f177.google.com (mail-pf0-f177.google.com [209.85.192.177]) by kanga.kvack.org (Postfix) with ESMTP id C105A6B0254 for ; Mon, 7 Mar 2016 12:46:19 -0500 (EST) Received: by mail-pf0-f177.google.com with SMTP id x188so59628845pfb.2 for ; Mon, 07 Mar 2016 09:46:19 -0800 (PST) Received: from mga04.intel.com (mga04.intel.com. [192.55.52.120]) by mx.google.com with ESMTP id lm9si4346403pab.142.2016.03.07.09.46.18 for ; Mon, 07 Mar 2016 09:46:18 -0800 (PST) Subject: Re: [PATCH v2] sparc64: Add support for Application Data Integrity (ADI) References: <1456951177-23579-1-git-send-email-khalid.aziz@oracle.com> <20160305.230702.1325379875282120281.davem@davemloft.net> <56DD9949.1000106@oracle.com> <56DD9E94.70201@oracle.com> <56DDA6FD.4040404@oracle.com> From: Dave Hansen Message-ID: <56DDBE68.6080709@linux.intel.com> Date: Mon, 7 Mar 2016 09:46:16 -0800 MIME-Version: 1.0 In-Reply-To: <56DDA6FD.4040404@oracle.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Khalid Aziz , Andy Lutomirski , Rob Gardner Cc: David Miller , Jonathan Corbet , Andrew Morton , dingel@linux.vnet.ibm.com, zhenzhang.zhang@huawei.com, bob.picco@oracle.com, "Kirill A. Shutemov" , "Aneesh Kumar K.V" , Andrea Arcangeli , Arnd Bergmann , sparclinux@vger.kernel.org, Michal Hocko , chris.hyser@oracle.com, Richard Weinberger , Vlastimil Babka , Konstantin Khlebnikov , Oleg Nesterov , Greg Thelen , Jan Kara , xiexiuqi@huawei.com, Vineet.Gupta1@synopsys.com, Andrew Lutomirski , "Eric W. Biederman" , bsegall@google.com, Geert Uytterhoeven , Davidlohr Bueso , Alexey Dobriyan , "linux-doc@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , linux-arch , Linux API On 03/07/2016 08:06 AM, Khalid Aziz wrote: > Top 4-bits of sparc64 virtual address are used for version tag only when > a process has its PSTATE.mcde bit set and it is accessing a memory > region that has ADI enabled on it (TTE.mcd set) and a version tag was > set on the virtual address being accessed. These 4-bits retain their > original semantics in all other cases. OK, so this effectively reduces the address space of a process using the feature. Do we need to do anything explicit to keep an app from using that address space? Do we make sure the kernel doesn't place VMAs there? Do we respect mmap() hints that try to place memory there? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org