From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sebastian Andrzej Siewior Subject: Re: Enabling function trace on call during module init Date: Fri, 11 Oct 2013 12:15:31 +0200 Message-ID: <20131011101531.GD6983@linutronix.de> References: <20130907204811.5d52a6b1@gandalf.local.home> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Cc: Venkat Subbiah , linux-rt-users@vger.kernel.org To: Steven Rostedt Return-path: Received: from www.linutronix.de ([62.245.132.108]:60254 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752191Ab3JKKPd (ORCPT ); Fri, 11 Oct 2013 06:15:33 -0400 Content-Disposition: inline In-Reply-To: <20130907204811.5d52a6b1@gandalf.local.home> Sender: linux-rt-users-owner@vger.kernel.org List-ID: * Steven Rostedt | 2013-09-07 20:48:11 [-0400]: >You wont be able to trace any function that is annotated with "__init", >or even "__exit". That's because the init section does not have a >standard way of cleaning them up (for boot, modules are different, but >are still affected by it). Is this even required / wanted? Usually the module just hooks itself into subsystem like pci_register_driver() and is usually not interresting. The interresting part starts from ->probe() (I think) and this is captured, right? >As ftrace modifies code, and it modifies locations of functions, it can >not safely modify code that suddenly disappeared without it knowing it, >otherwise you may end up with broken NIC cards. Hmmm. This sounds like you know what you are talking about :) >-- Steve Sebastian