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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 6C226C73C6D for ; Wed, 10 Jul 2019 06:38:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 368532064A for ; Wed, 10 Jul 2019 06:38:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726793AbfGJGir (ORCPT ); Wed, 10 Jul 2019 02:38:47 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:59496 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725844AbfGJGir (ORCPT ); Wed, 10 Jul 2019 02:38:47 -0400 Received: from pps.filterd (m0098409.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x6A6bbtI101578 for ; Wed, 10 Jul 2019 02:38:46 -0400 Received: from e06smtp04.uk.ibm.com (e06smtp04.uk.ibm.com [195.75.94.100]) by mx0a-001b2d01.pphosted.com with ESMTP id 2tn7expxcn-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 10 Jul 2019 02:38:45 -0400 Received: from localhost by e06smtp04.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Wed, 10 Jul 2019 07:38:40 +0100 Received: from d06av24.portsmouth.uk.ibm.com (mk.ibm.com [9.149.105.60]) by b06cxnps4074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x6A6cdmo42074132 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 10 Jul 2019 06:38:40 GMT Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id D22FE4203F; Wed, 10 Jul 2019 06:38:39 +0000 (GMT) Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 6DD3842047; Wed, 10 Jul 2019 06:38:37 +0000 (GMT) Received: from [9.199.41.185] (unknown [9.199.41.185]) by d06av24.portsmouth.uk.ibm.com (Postfix) with ESMTP; Wed, 10 Jul 2019 06:38:37 +0000 (GMT) Subject: Re: [PATCH v3 2/3] Powerpc64/Watchpoint: Don't ignore extraneous exceptions To: Christophe Leroy Cc: mpe@ellerman.id.au, mikey@neuling.org, benh@kernel.crashing.org, paulus@samba.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, npiggin@gmail.com, naveen.n.rao@linux.vnet.ibm.com, Ravi Bangoria References: <20190710045445.31037-1-ravi.bangoria@linux.ibm.com> <20190710045445.31037-3-ravi.bangoria@linux.ibm.com> <1f3fd425-3d2f-8d18-eff1-01ca5b605ba0@c-s.fr> From: Ravi Bangoria Date: Wed, 10 Jul 2019 12:08:36 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: <1f3fd425-3d2f-8d18-eff1-01ca5b605ba0@c-s.fr> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 x-cbid: 19071006-0016-0000-0000-00000290D778 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19071006-0017-0000-0000-000032EE8E67 Message-Id: X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-07-10_03:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1907100081 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 7/10/19 11:57 AM, Christophe Leroy wrote: > > > Le 10/07/2019 à 06:54, Ravi Bangoria a écrit : >> On Powerpc64, watchpoint match range is double-word granular. On >> a watchpoint hit, DAR is set to the first byte of overlap between >> actual access and watched range. And thus it's quite possible that >> DAR does not point inside user specified range. Ex, say user creates >> a watchpoint with address range 0x1004 to 0x1007. So hw would be >> configured to watch from 0x1000 to 0x1007. If there is a 4 byte >> access from 0x1002 to 0x1005, DAR will point to 0x1002 and thus >> interrupt handler considers it as extraneous, but it's actually not, >> because part of the access belongs to what user has asked. So, let >> kernel pass it on to user and let user decide what to do with it >> instead of silently ignoring it. The drawback is, it can generate >> false positive events. > > Why adding some #ifdefs based on CONFIG_8xx ? I don't know how 8xx behaves so I'm keeping the current behavior(ignore extraneous exception) for 8xx. > > I see your commit log mentions 'Powerpc64'. What about BOOK3S/32 ? Hmm, I should not have mention 64 there. Yes, the change should cover both Books3S/64 and Book3S/32.