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=-5.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_2 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 4F93AC433E3 for ; Wed, 15 Jul 2020 18:28:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3AFDE20672 for ; Wed, 15 Jul 2020 18:28:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726034AbgGOS2w (ORCPT ); Wed, 15 Jul 2020 14:28:52 -0400 Received: from mail.kernel.org ([198.145.29.99]:51606 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725992AbgGOS2v (ORCPT ); Wed, 15 Jul 2020 14:28:51 -0400 Received: from oasis.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (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 E88F72065F; Wed, 15 Jul 2020 18:28:50 +0000 (UTC) Date: Wed, 15 Jul 2020 14:28:49 -0400 From: Steven Rostedt To: ahmadkhorrami Cc: Linux-trace Users , lttng-dev@lists.lttng.org, Mathieu Desnoyers , =?UTF-8?B?SsOpcsOpbWll?= Galarneau , Namhyung Kim Subject: Re: Capturing User-Level Function Calls/Returns Message-ID: <20200715142849.0bfe909a@oasis.local.home> In-Reply-To: References: 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-trace-users-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-trace-users@vger.kernel.org On Wed, 15 Jul 2020 20:37:16 +0430 ahmadkhorrami wrote: > Hi, > What is the most efficient way to capture occurrence of a function > call/return of a binary program in userspace? > It seems the answer is Uprobes. 1) Am I right? > But Uprobes use "int" instruction which leads to a switch into kernel > mode. 2) Wouldn't it be better to avoid this transition? > I'm looking forward to your reply and will be happy to read your > opinions. > Regards. Hi, I believe LTTng has utilities that can help you trace user space programs. I think there's also a users ftrace like utility that Namhyung was working on. But I don't know where in the development that is. -- Steve