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=-11.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 563CDC433E2 for ; Fri, 10 Jul 2020 11:15:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 37A192076A for ; Fri, 10 Jul 2020 11:15:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727059AbgGJLPa (ORCPT ); Fri, 10 Jul 2020 07:15:30 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:64646 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726369AbgGJLP0 (ORCPT ); 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Fri, 10 Jul 2020 11:15:17 +0000 Received: from d06av21.portsmouth.uk.ibm.com (d06av21.portsmouth.uk.ibm.com [9.149.105.232]) by b06cxnps4074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 06ABFFmZ50266196 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 10 Jul 2020 11:15:15 GMT Received: from d06av21.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id E5D335205F; Fri, 10 Jul 2020 11:15:14 +0000 (GMT) Received: from linux.vnet.ibm.com (unknown [9.126.150.29]) by d06av21.portsmouth.uk.ibm.com (Postfix) with SMTP id 7782C5204F; Fri, 10 Jul 2020 11:15:13 +0000 (GMT) Date: Fri, 10 Jul 2020 16:45:12 +0530 From: Srikar Dronamraju To: Masami Hiramatsu Cc: Arnaldo Carvalho de Melo , Arnaldo Carvalho de Melo , Oleg Nesterov , linux-kernel@vger.kernel.org, Andi Kleen , Andi Kleen Subject: Re: [PATCH 4/4] perf-probe: Warn if the target function is GNU Indirect function Message-ID: <20200710111512.GK874@linux.vnet.ibm.com> Reply-To: Srikar Dronamraju References: <159428201109.56570.3802208017109058146.stgit@devnote2> <159428205174.56570.17588311835868886287.stgit@devnote2> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <159428205174.56570.17588311835868886287.stgit@devnote2> User-Agent: Mutt/1.10.1 (2018-07-13) X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235,18.0.687 definitions=2020-07-10_03:2020-07-10,2020-07-10 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 bulkscore=0 lowpriorityscore=0 priorityscore=1501 mlxscore=0 spamscore=0 malwarescore=0 mlxlogscore=999 phishscore=0 adultscore=0 suspectscore=0 impostorscore=0 clxscore=1011 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2007100074 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Masami Hiramatsu [2020-07-09 17:07:31]: > Reported-by: Andi Kleen > Signed-off-by: Masami Hiramatsu > --- > tools/perf/util/probe-event.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c > index 1e95a336862c..671176d39569 100644 > --- a/tools/perf/util/probe-event.c > +++ b/tools/perf/util/probe-event.c > @@ -379,6 +379,11 @@ static int find_alternative_probe_point(struct debuginfo *dinfo, > address = sym->start; > else > address = map->unmap_ip(map, sym->start) - map->reloc; > + if (sym->type == STT_GNU_IFUNC) { > + pr_warning("Warning: The probe address (0x%lx) is in a GNU indirect function.\n" > + "This may not work as you expected unless you intend to probe the indirect function.\n", > + (unsigned long)address); > + } Are these GNU indirect functions possible in kernel? If not we could move this warning under if (uprobes) Also instead of printing the address, can we print the pp->function? > break; > } > if (!address) { > -- Thanks and Regards Srikar Dronamraju