From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AH8x2268wBdwqejBIiEnzWQsDSmCxkY6rMl9RxL1P60lgLATOnP5QL8aao6M3UlvK7SCI5X4x2AN ARC-Seal: i=1; a=rsa-sha256; t=1517583678; cv=none; d=google.com; s=arc-20160816; b=UDDrjRanQhfTGtQLrl+58K73vXBCGtcV22YLb9weppI4FC8wdifrs84DtcVUEUHC7N nq2OmBxaRFf3/4LGE0rfSleJrNAFcjXB4v/jkILpo7hticlWmU1HFE9VgpcMMVpV2T/A cXn4IAT8eYwuOjpb6tZpzeGtviznedc1wezuAdRNLCvLzxRcsa2XY94d+hJ38QMCp22M kdhPziJkZrunp/uWPGPsGY5heAMFY14OP2ejswuwxJ4bGaQRCKsGeXqm1svyKbblu1qL fhR9PlovQgYdppY/3fXCKcDHX7/PkoehOhz2G5STAZkRedz37MmebpqbKtgeR7q/1ONI CSug== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:content-language:in-reply-to:mime-version :user-agent:date:message-id:organization:from:references:cc:to :subject:dkim-signature:arc-authentication-results; bh=THbGEkTK4KM0jZ4st5ttnjwlbXSnnOqwtPYkd5uZTEs=; b=aUzlIte+3/1WWfS715T1RFt32AXGobmq6kcDXeKHcR874e9SHSNx/YXuFLQ/S7NNYJ j0W0hl9TEjfj6Ldo2QNKklo7VzzdOwkaFpbbMrbb6oIF9tVaqPHLKr2EcickLzdrQDZN cVy+z5ienZdg6q6naWZY5Og9C8a621qKQWpwiAE2JoNcUhULblgv57Duj/1PRGRVuyhQ wC0mYqa7ZGgVZA/yx8eECwoGKCEq43jWrKmRcT6K4i/Pbq/eCEAmaw+eHQ2whWXbzrMB s1UTy4BmMKPLBD0qrmggumWXyF0oEcKE72sji09zwZ32+JiOSEWlnkGZw3aediq/MuR1 O8ow== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@oracle.com header.s=corp-2017-10-26 header.b=noFy5UQd; spf=pass (google.com: domain of khalid.aziz@oracle.com designates 156.151.31.85 as permitted sender) smtp.mailfrom=khalid.aziz@oracle.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=oracle.com Authentication-Results: mx.google.com; dkim=pass header.i=@oracle.com header.s=corp-2017-10-26 header.b=noFy5UQd; spf=pass (google.com: domain of khalid.aziz@oracle.com designates 156.151.31.85 as permitted sender) smtp.mailfrom=khalid.aziz@oracle.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=oracle.com Subject: Re: [PATCH v11 00/10] Application Data Integrity feature introduced by SPARC M7 To: "Eric W. Biederman" Cc: davem@davemloft.net, dave.hansen@linux.intel.com, aarcange@redhat.com, akpm@linux-foundation.org, allen.pais@oracle.com, anthony.yznaga@oracle.com, arnd@arndb.de, babu.moger@oracle.com, benh@kernel.crashing.org, bob.picco@oracle.com, bsingharora@gmail.com, corbet@lwn.net, dan.j.williams@intel.com, dave.jiang@intel.com, david.j.aldridge@oracle.com, elena.reshetova@intel.com, glx@linutronix.de, gregkh@linuxfoundation.org, hannes@cmpxchg.org, hillf.zj@alibaba-inc.com, hpa@zytor.com, hughd@google.com, imbrenda@linux.vnet.ibm.com, jack@suse.cz, jag.raman@oracle.com, jane.chu@oracle.com, jglisse@redhat.com, jroedel@suse.de, khalid@gonehiking.org, khandual@linux.vnet.ibm.com, kirill.shutemov@linux.intel.com, kstewart@linuxfoundation.org, ktkhai@virtuozzo.com, liam.merwick@oracle.com, linux-arch@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, linux@roeck-us.net, me@tobin.cc, mgorman@suse.de, mgorman@techsingularity.net, mhocko@suse.com, mike.kravetz@oracle.com, minchan@kernel.org, mingo@kernel.org, mingo@redhat.com, mpe@ellerman.id.au, nadav.amit@gmail.com, nagarathnam.muthusamy@oracle.com, nborisov@suse.com, n-horiguchi@ah.jp.nec.com, nick.alcock@oracle.com, nitin.m.gupta@oracle.com, ombredanne@nexb.com, pasha.tatashin@oracle.com, paulus@samba.org, pombredanne@nexb.com, punit.agrawal@arm.com, rob.gardner@oracle.com, ross.zwisler@linux.intel.com, shannon.nelson@oracle.com, shli@fb.com, sparclinux@vger.kernel.org, steven.sistare@oracle.com, tglx@linutronix.de, thomas.tai@oracle.com, tklauser@distanz.ch, tom.hromatka@oracle.com, vegard.nossum@oracle.com, vijay.ac.kumar@oracle.com, willy@infradead.org, x86@kernel.org, zi.yan@cs.rutgers.edu References: <87wozwi0p1.fsf@xmission.com> From: Khalid Aziz Organization: Oracle Corp Message-ID: <0f1bdb63-60d5-467c-a6a4-c06ba62b1f6e@oracle.com> Date: Fri, 2 Feb 2018 07:59:25 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.5.0 MIME-Version: 1.0 In-Reply-To: <87wozwi0p1.fsf@xmission.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=8792 signatures=668660 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=840 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1711220000 definitions=main-1802020184 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1591223715312130121?= X-GMAIL-MSGID: =?utf-8?q?1591301823912883287?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On 02/01/2018 07:29 PM, ebiederm@xmission.com wrote: > Khalid Aziz writes: > >> V11 changes: >> This series is same as v10 and was simply rebased on 4.15 kernel. Can >> mm maintainers please review patches 2, 7, 8 and 9 which are arch >> independent, and include/linux/mm.h and mm/ksm.c changes in patch 10 >> and ack these if everything looks good? > > I am a bit puzzled how this differs from the pkey's that other > architectures are implementing to achieve a similar result. > > I am a bit mystified why you don't store the tag in a vma > instead of inventing a new way to store data on page out. Hello Eric, As Steven pointed out, sparc sets tags per cacheline unlike pkey. This results in much finer granularity for tags that pkey and hence requires larger tag storage than what we can do in a vma. > > Can you please use force_sig_fault to send these signals instead > of force_sig_info. Emperically I have found that it is very > error prone to generate siginfo's by hand, especially on code > paths where several different si_codes may apply. So it helps > to go through a helper function to ensure the fiddly bits are > all correct. AKA the unused bits all need to be set to zero before > struct siginfo is copied to userspace. > What you say makes sense. I followed the same code as other fault handlers for sparc. I could change just the fault handlers for ADI related faults. Would it make more sense to change all the fault handlers in a separate patch and keep the code in arch/sparc/kernel/traps_64.c consistent? Dave M, do you have a preference? Thanks, Khalid