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=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 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 67AC1C4360C for ; Fri, 27 Sep 2019 15:06:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3B04021841 for ; Fri, 27 Sep 2019 15:06:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727924AbfI0PGu (ORCPT ); Fri, 27 Sep 2019 11:06:50 -0400 Received: from mail.kernel.org ([198.145.29.99]:43856 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727120AbfI0PGu (ORCPT ); Fri, 27 Sep 2019 11:06:50 -0400 Received: from oasis.local.home (unknown [65.39.69.237]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 504942146E; Fri, 27 Sep 2019 15:06:48 +0000 (UTC) Date: Fri, 27 Sep 2019 11:06:43 -0400 From: Steven Rostedt To: Srikar Dronamraju Cc: LKML , Masami Hiramatsu , Naveen Rao , Ravi Bangoria Subject: Re: [PATCH] tracing/probe: Test nr_args match in looking for same probe events Message-ID: <20190927105019.661591cd@oasis.local.home> In-Reply-To: <20190927131458.GA19008@linux.vnet.ibm.com> References: <20190927055035.4c3abae9@oasis.local.home> <20190927131458.GA19008@linux.vnet.ibm.com> X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 27 Sep 2019 19:08:53 +0530 Srikar Dronamraju wrote: \> > --- > > kernel/trace/trace_kprobe.c | 2 ++ > > kernel/trace/trace_uprobe.c | 2 ++ > > 2 files changed, 4 insertions(+) > > > > diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c > > index 402dc3ce88d3..d2543a403f25 100644 > > --- a/kernel/trace/trace_kprobe.c > > +++ b/kernel/trace/trace_kprobe.c > > @@ -537,6 +537,8 @@ static bool trace_kprobe_has_same_kprobe(struct trace_kprobe *orig, > > > > list_for_each_entry(pos, &tpe->probes, list) { > > orig = container_of(pos, struct trace_kprobe, tp); > > + if (orig->tp.nr_args != comp->tp.nr_args) > > + continue; > > This has a side-effect where the newer probe has same argument commands, we > still end up appending the probe. ?? How so? If the two have the same number of arguments we do exactly what we did before this patch. Please explain to me how that side effect would happen? It basically is doing, "if the two probes do not have the same number of arguments, don't bother comparing, because they are different." -- Steve