From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on archive.lwn.net X-Spam-Level: X-Spam-Status: No, score=-5.8 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham autolearn_force=no version=3.4.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by archive.lwn.net (Postfix) with ESMTP id 0E0A17D062 for ; Mon, 2 Jul 2018 16:02:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752228AbeGBQCO (ORCPT ); Mon, 2 Jul 2018 12:02:14 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:46772 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752288AbeGBQCM (ORCPT ); Mon, 2 Jul 2018 12:02:12 -0400 Received: from pps.filterd (m0098416.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w62G16sg063500 for ; Mon, 2 Jul 2018 12:02:12 -0400 Received: from e06smtp01.uk.ibm.com (e06smtp01.uk.ibm.com [195.75.94.97]) by mx0b-001b2d01.pphosted.com with ESMTP id 2jym8fqsyr-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 02 Jul 2018 12:02:11 -0400 Received: from localhost by e06smtp01.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) Mon, 2 Jul 2018 17:02:03 +0100 Received: from d06av23.portsmouth.uk.ibm.com (d06av23.portsmouth.uk.ibm.com [9.149.105.59]) by b06cxnps3074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id w62G22TZ27394104 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Mon, 2 Jul 2018 16:02:02 GMT Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 0BF61A4065; Mon, 2 Jul 2018 17:01:45 +0100 (BST) Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 268A3A404D; Mon, 2 Jul 2018 17:01:42 +0100 (BST) Received: from linux.vnet.ibm.com (unknown [9.40.192.68]) by d06av23.portsmouth.uk.ibm.com (Postfix) with SMTP; Mon, 2 Jul 2018 17:01:41 +0100 (BST) Date: Mon, 2 Jul 2018 09:01:58 -0700 From: Srikar Dronamraju To: Ravi Bangoria Cc: oleg@redhat.com, rostedt@goodmis.org, mhiramat@kernel.org, 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, corbet@lwn.net, linux-doc@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 Subject: Re: [PATCH v5 06/10] Uprobes: Support SDT markers having reference count (semaphore) Reply-To: Srikar Dronamraju References: <20180628052209.13056-1-ravi.bangoria@linux.ibm.com> <20180628052209.13056-7-ravi.bangoria@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <20180628052209.13056-7-ravi.bangoria@linux.ibm.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-TM-AS-GCONF: 00 x-cbid: 18070216-4275-0000-0000-000002945260 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18070216-4276-0000-0000-0000379BCCE4 Message-Id: <20180702160158.GD65296@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-07-02_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=996 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1806210000 definitions=main-1807020182 Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org > Implement the reference counter logic in core uprobe. User will be > able to use it from trace_uprobe as well as from kernel module. New > trace_uprobe definition with reference counter will now be: > > :[(ref_ctr_offset)] > > where ref_ctr_offset is an optional field. For kernel module, new > variant of uprobe_register() has been introduced: > > uprobe_register_refctr(inode, offset, ref_ctr_offset, consumer) > Sorry for bringing this again, but I would actually think the ref_ctr is a consumer property. i.e the ref_ctr_offset should be part of uprobe_consumer. The advantages of doing that would be 1. Dont need to expose uprobe structure and just update our uprobe_consumer which is already an exported structure. - Exporting uprobe structure would expose some of our internal implementation details, basically reduce the freedom of changing stuff internally. - we came up with uprobe_arch for the parts that we wanted to expose to archs. exposing uprobe and uprobe_arch looks weird. 2. ref_ctr_offset is necessarily a consumer property, its not a uprobe property at all. 3. We dont need to change/add new uprobe_register functions. The way I look at it is. Based on the ref_ctr_offset field in consumer, we update_ref_ctr() around install_breakpoint/remove_breakpoint. > +static int delayed_uprobe_add(struct uprobe *uprobe, struct mm_struct *mm) > +{ > + struct delayed_uprobe *du; > + > + if (delayed_uprobe_check(uprobe, mm)) > + return 0; > + > + du = kzalloc(sizeof(*du), GFP_KERNEL); > + if (!du) > + return -ENOMEM; > + > + du->uprobe = uprobe; > + du->mm = mm; > + list_add(&du->list, &delayed_uprobe_list); > + return 0; > +} > + If I understood the delayed_uprobe stuff, its when we could insert a breakpoint but the vma that has the ref_ctr_offset is not loaded. Is that correct? > > -- > 2.14.4 > -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html