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=-5.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 97915C433E0 for ; Thu, 9 Jul 2020 14:45:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6C27F20672 for ; Thu, 9 Jul 2020 14:45:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=firstfloor.org header.i=@firstfloor.org header.b="qxKpfZaR" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727042AbgGIOp1 (ORCPT ); Thu, 9 Jul 2020 10:45:27 -0400 Received: from one.firstfloor.org ([193.170.194.197]:36222 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726410AbgGIOp1 (ORCPT ); Thu, 9 Jul 2020 10:45:27 -0400 Received: by one.firstfloor.org (Postfix, from userid 503) id C9F5F86731; Thu, 9 Jul 2020 16:36:54 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=firstfloor.org; s=mail; t=1594305414; bh=NFHVOQuc740DsnU3hI4JnpmsluKHMe7JTI/h4WcX4yw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=qxKpfZaR0f/XvTQvLBiUw9glLNQyIZoHiwSIQMsKSbL7iQYwANOkTAC1AJ/Xd+yf9 tbSaJDdmto+SmTfAQE1xS8nHgMyp+AKZ3sHuC0JE9QIJCjtcK0soNeleJWv9WoXwFd gGQbA3CPGu3owN5v8RcgGEqAWD415NIJDNaVvWT8= Date: Thu, 9 Jul 2020 07:36:54 -0700 From: Andi Kleen To: Masami Hiramatsu Cc: Arnaldo Carvalho de Melo , Arnaldo Carvalho de Melo , Oleg Nesterov , Srikar Dronamraju , 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: <20200709143654.pw2maoxivsjho6op@two.firstfloor.org> References: <159428201109.56570.3802208017109058146.stgit@devnote2> <159428205174.56570.17588311835868886287.stgit@devnote2> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <159428205174.56570.17588311835868886287.stgit@devnote2> User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > 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", I would say something like this. Consider identifying the final function used at run time and set the probe directly on that. I think that's more useful to the user. -Andi