From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752221AbcAEPZu (ORCPT ); Tue, 5 Jan 2016 10:25:50 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:33512 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751509AbcAEPZs (ORCPT ); Tue, 5 Jan 2016 10:25:48 -0500 Date: Tue, 5 Jan 2016 07:25:47 -0800 From: Greg KH To: Pierre Paul MINGOT Cc: "Austin S. Hemmelgarn" , jslaby@suse.cz, linux-kernel@vger.kernel.org Subject: Re: [PATCH] Add possibility to set /dev/tty number Message-ID: <20160105152547.GC7251@kroah.com> References: <20160104154305.GA24533@kroah.com> <568AA47D.6010604@gmail.com> <20160104171121.GA25961@kroah.com> <568ABCBD.3070909@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 05, 2016 at 09:51:14AM +0100, Pierre Paul MINGOT wrote: > In industrial sector, for obvious security and safety reasons we want > configure our system and have a full control of the devices within it. > So unused or dummy devices are not wanted , not nice to have. > One way to achieve this goal is to have a full picture of the devices > in our system and then identified which type of applications can run > and then safety or security potential risks. Base on this analysis we > can put in place mandatory actions to fix the risks. > An other interest for reduce dummy /dev devices is hot-plug device > creation detection through inotify or udev. Indeed, we can configure > udev or inotify for monitoring the /dev directory and notify watched > dedicated events. lesser the devices in /dev is better the response > is. This aspect is crucial for RTOS with very high time constraint > near of microseconds. It's the case for example for a system with > Linux RT Patch or Xenomai. I don't understand how reducing the number of vt devices makes anything more or less secure, or better yet, more responsive. Please provide specific details showing how this happens. thanks, greg k-h