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 51DCFC04EBF for ; Mon, 23 Sep 2019 10:43:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2D42720835 for ; Mon, 23 Sep 2019 10:43:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2439527AbfIWKnE (ORCPT ); Mon, 23 Sep 2019 06:43:04 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:3412 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2436836AbfIWKnE (ORCPT ); Mon, 23 Sep 2019 06:43:04 -0400 Received: from pps.filterd (m0098416.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x8NAcUXX088851 for ; Mon, 23 Sep 2019 06:43:01 -0400 Received: from e06smtp01.uk.ibm.com (e06smtp01.uk.ibm.com [195.75.94.97]) by mx0b-001b2d01.pphosted.com with ESMTP id 2v6vce0arx-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 23 Sep 2019 06:43:01 -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, 23 Sep 2019 11:42:56 +0100 Received: from d06av26.portsmouth.uk.ibm.com (d06av26.portsmouth.uk.ibm.com [9.149.105.62]) by b06cxnps4074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x8NAgttm22151420 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 23 Sep 2019 10:42:56 GMT Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id C007CAE056; Mon, 23 Sep 2019 10:42:55 +0000 (GMT) Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 54C2FAE055; Mon, 23 Sep 2019 10:42:54 +0000 (GMT) Received: from linux.vnet.ibm.com (unknown [9.122.211.102]) by d06av26.portsmouth.uk.ibm.com (Postfix) with SMTP; Mon, 23 Sep 2019 10:42:54 +0000 (GMT) Date: Mon, 23 Sep 2019 16:12:53 +0530 From: Srikar Dronamraju To: Steven Rostedt Cc: linux-kernel@vger.kernel.org, Ingo Molnar , Andrew Morton , Masami Hiramatsu , Naveen Rao , Ravi Bangoria Subject: Re: [for-next][PATCH 7/8] tracing/probe: Reject exactly same probe event Reply-To: Srikar Dronamraju References: <20190919232313.198902049@goodmis.org> <20190919232400.470062819@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <20190919232400.470062819@goodmis.org> User-Agent: Mutt/1.9.4 (2018-02-28) X-TM-AS-GCONF: 00 x-cbid: 19092310-4275-0000-0000-0000036A006D X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19092310-4276-0000-0000-0000387C7426 Message-Id: <20190923102035.GA30095@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-09-23_04:,, 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=8.0.1-1908290000 definitions=main-1909230107 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hey Masami, Steven > > +static bool trace_kprobe_has_same_kprobe(struct trace_kprobe *orig, > + struct trace_kprobe *comp) > +{ > + struct trace_probe_event *tpe = orig->tp.event; > + struct trace_probe *pos; > + int i; > + > + list_for_each_entry(pos, &tpe->probes, list) { > + orig = container_of(pos, struct trace_kprobe, tp); > + if (strcmp(trace_kprobe_symbol(orig), > + trace_kprobe_symbol(comp)) || > + trace_kprobe_offset(orig) != trace_kprobe_offset(comp)) > + continue; > + > + /* > + * trace_probe_compare_arg_type() ensured that nr_args and > + * each argument name and type are same. Let's compare comm. > + */ > + for (i = 0; i < orig->tp.nr_args; i++) { > + if (strcmp(orig->tp.args[i].comm, > + comp->tp.args[i].comm)) > + continue; In a nested loop, *continue* is going to continue iterating through the inner loop. In which case, continue is doing nothing here. I thought we should have used a goto instead. No? To me, continue as a last statement of a for loop always looks weird. > + } > + > + return true; > + } I think we need something like this: list_for_each_entry(pos, &tpe->probes, list) { orig = container_of(pos, struct trace_kprobe, tp); if (strcmp(trace_kprobe_symbol(orig), trace_kprobe_symbol(comp)) || trace_kprobe_offset(orig) != trace_kprobe_offset(comp)) continue; /* * trace_probe_compare_arg_type() ensured that nr_args and * each argument name and type are same. Let's compare comm. */ for (i = 0; i < orig->tp.nr_args; i++) { if (strcmp(orig->tp.args[i].comm, comp->tp.args[i].comm)) goto outer_loop; } return true; outer_loop: } > + > + return false; > +} > + > ...... > +static bool trace_uprobe_has_same_uprobe(struct trace_uprobe *orig, > + struct trace_uprobe *comp) > +{ > + struct trace_probe_event *tpe = orig->tp.event; > + struct trace_probe *pos; > + struct inode *comp_inode = d_real_inode(comp->path.dentry); > + int i; > + > + list_for_each_entry(pos, &tpe->probes, list) { > + orig = container_of(pos, struct trace_uprobe, tp); > + if (comp_inode != d_real_inode(orig->path.dentry) || > + comp->offset != orig->offset) > + continue; > + > + /* > + * trace_probe_compare_arg_type() ensured that nr_args and > + * each argument name and type are same. Let's compare comm. > + */ > + for (i = 0; i < orig->tp.nr_args; i++) { > + if (strcmp(orig->tp.args[i].comm, > + comp->tp.args[i].comm)) > + continue; Same as above. > + } > + > + return true; > + } > + > + return false; > +} > + -- Thanks and Regards Srikar Dronamraju