From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-oi0-f47.google.com (mail-oi0-f47.google.com [209.85.218.47]) by kanga.kvack.org (Postfix) with ESMTP id 4B02B6B0253 for ; Mon, 7 Mar 2016 18:35:23 -0500 (EST) Received: by mail-oi0-f47.google.com with SMTP id d205so91164036oia.0 for ; Mon, 07 Mar 2016 15:35:23 -0800 (PST) Received: from userp1040.oracle.com (userp1040.oracle.com. [156.151.31.81]) by mx.google.com with ESMTPS id k205si9182oib.149.2016.03.07.15.35.22 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 07 Mar 2016 15:35:22 -0800 (PST) Message-ID: <56DE100E.7030109@oracle.com> Date: Tue, 08 Mar 2016 10:34:38 +1100 From: James Morris MIME-Version: 1.0 Subject: Re: [PATCH v2] sparc64: Add support for Application Data Integrity (ADI) References: <56DDDA31.9090105@oracle.com> <56DDE783.8090009@oracle.com> <20160307.155810.587016604208120674.davem@davemloft.net> In-Reply-To: <20160307.155810.587016604208120674.davem@davemloft.net> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: David Miller , khalid.aziz@oracle.com Cc: luto@amacapital.net, corbet@lwn.net, akpm@linux-foundation.org, dingel@linux.vnet.ibm.com, bob.picco@oracle.com, kirill.shutemov@linux.intel.com, aneesh.kumar@linux.vnet.ibm.com, aarcange@redhat.com, arnd@arndb.de, sparclinux@vger.kernel.org, rob.gardner@oracle.com, mhocko@suse.cz, chris.hyser@oracle.com, richard@nod.at, vbabka@suse.cz, koct9i@gmail.com, oleg@redhat.com, gthelen@google.com, jack@suse.cz, xiexiuqi@huawei.com, Vineet.Gupta1@synopsys.com, luto@kernel.org, ebiederm@xmission.com, bsegall@google.com, geert@linux-m68k.org, dave@stgolabs.net, adobriyan@gmail.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-api@vger.kernel.org On 03/08/2016 07:58 AM, David Miller wrote: > From: Khalid Aziz > Date: Mon, 7 Mar 2016 13:41:39 -0700 > >> Shared data may not always be backed by a file. My understanding is >> one of the use cases is for in-memory databases. This shared space >> could also be used to hand off transactions in flight to other >> processes. These transactions in flight would not be backed by a >> file. Some of these use cases might not use shmfs even. Setting ADI >> bits at virtual address level catches all these cases since what backs >> the tagged virtual address can be anything - a mapped file, mmio >> space, just plain chunk of memory. > > Frankly the most interesting use case to me is simply finding bugs > and memory scribbles, and for that we're want to be able to ADI > arbitrary memory returned from malloc() and friends. > > I personally see ADI more as a debugging than a security feature, > but that's just my view. This is certainly a major use of the feature. The Solaris folks have made some interesting use of it here: https://docs.oracle.com/cd/E37069_01/html/E37085/gphwb.html -- 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