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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 2E3BEC46470 for ; Tue, 7 Aug 2018 12:33:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D92CD20989 for ; Tue, 7 Aug 2018 12:33:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D92CD20989 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.ibm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389189AbeHGOry (ORCPT ); Tue, 7 Aug 2018 10:47:54 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:50816 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727572AbeHGOry (ORCPT ); Tue, 7 Aug 2018 10:47:54 -0400 Received: from pps.filterd (m0098420.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w77CWsjs145465 for ; Tue, 7 Aug 2018 08:33:46 -0400 Received: from e06smtp02.uk.ibm.com (e06smtp02.uk.ibm.com [195.75.94.98]) by mx0b-001b2d01.pphosted.com with ESMTP id 2kq9fun8f7-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 07 Aug 2018 08:33:45 -0400 Received: from localhost by e06smtp02.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) Tue, 7 Aug 2018 13:33:34 +0100 Received: from d06av24.portsmouth.uk.ibm.com (d06av24.portsmouth.uk.ibm.com [9.149.105.60]) by b06cxnps3075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id w77CXYZQ39256196 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Tue, 7 Aug 2018 12:33:34 GMT Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id C9FD842042; Tue, 7 Aug 2018 15:33:42 +0100 (BST) Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 2834F4204B; Tue, 7 Aug 2018 15:33:32 +0100 (BST) Received: from [9.79.225.234] (unknown [9.79.225.234]) by d06av24.portsmouth.uk.ibm.com (Postfix) with ESMTP; Tue, 7 Aug 2018 15:33:31 +0100 (BST) Subject: Re: [PATCH v7 3/6] Uprobes: Support SDT markers having reference count (semaphore) To: Oleg Nesterov Cc: srikar@linux.vnet.ibm.com, rostedt@goodmis.org, mhiramat@kernel.org, liu.song.a23@gmail.com, peterz@infradead.org, mingo@redhat.com, acme@kernel.org, alexander.shishkin@linux.intel.com, jolsa@redhat.com, namhyung@kernel.org, linux-kernel@vger.kernel.org, ananth@linux.vnet.ibm.com, alexis.berlemont@gmail.com, naveen.n.rao@linux.vnet.ibm.com, linux-arm-kernel@lists.infradead.org, linux-mips@linux-mips.org, linux@armlinux.org.uk, ralf@linux-mips.org, paul.burton@mips.com, Ravi Bangoria References: <20180731035143.11942-1-ravi.bangoria@linux.ibm.com> <20180731035143.11942-4-ravi.bangoria@linux.ibm.com> <20180803112455.GA13794@redhat.com> <20180807113622.GC19831@redhat.com> From: Ravi Bangoria Date: Tue, 7 Aug 2018 18:03:20 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.8.0 MIME-Version: 1.0 In-Reply-To: <20180807113622.GC19831@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 x-cbid: 18080712-0008-0000-0000-0000025E6478 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18080712-0009-0000-0000-000021C669DD Message-Id: <4d1e2a17-14ba-f277-8e57-4a4573630ab2@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-08-07_05:,, 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=845 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1807170000 definitions=main-1808070127 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Oleg, >> I'm sorry. I didn't get this. How can uprobe go away without calling >> uprobe_unregister() >> -> rergister_for_each_vma() >> -> remove_breakpoint() >> And remove_breakpoint() will get called > > assuming that _unregister() will find the same vma with the probed insn. But > as I said, the application can munmap the probed page/vma. Got it now :) Thanks.