From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754397AbbAVEXl (ORCPT ); Wed, 21 Jan 2015 23:23:41 -0500 Received: from zeniv.linux.org.uk ([195.92.253.2]:47309 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750940AbbAVEXf (ORCPT ); Wed, 21 Jan 2015 23:23:35 -0500 Date: Thu, 22 Jan 2015 04:23:30 +0000 From: Al Viro To: Greg Kroah-Hartman Cc: Steven Rostedt , linux-kernel@vger.kernel.org, Ingo Molnar , Andrew Morton Subject: Re: [RFC][PATCH 0/5] tracing: Add new file system tracefs Message-ID: <20150122042330.GU29656@ZenIV.linux.org.uk> References: <20150121171953.823177070@goodmis.org> <20150121230007.GA10389@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150121230007.GA10389@kroah.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 22, 2015 at 07:00:07AM +0800, Greg Kroah-Hartman wrote: > On Wed, Jan 21, 2015 at 12:19:53PM -0500, Steven Rostedt wrote: > > > > There has been complaints that tracing is tied too much to debugfs, > > as there are systems that would like to perform tracing, but do > > not mount debugfs for security reasons. That is because any subsystem > > may use debugfs for debugging, and these interfaces are not always > > tested for security. > > > > Creating a new tracefs that the tracing directory will now be attached > > to allows system admins the ability to access the tracing directory > > without the need to mount debugfs. > > Yeah! > > Any chance you can use kernfs as your "basis" for this filesystem > instead of having to roll all of your own functions? I'm slowly working > on moving debugfs to it, and it should save a lot of code there, as well > as fixing some "problems" we have in debugfs file lifetimes when things > are removed from the system. I would recommend against that - kernfs is overburdened by their need to accomodate cgroup weirdness. IMO it's not a good model for anything, other than an anti-hard-drugs poster ("don't shoot that shit, or you might end up hallucinating _this_").