From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1422662AbWGJPWA (ORCPT ); Mon, 10 Jul 2006 11:22:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1422660AbWGJPWA (ORCPT ); Mon, 10 Jul 2006 11:22:00 -0400 Received: from caramon.arm.linux.org.uk ([212.18.232.186]:42762 "EHLO caramon.arm.linux.org.uk") by vger.kernel.org with ESMTP id S1422661AbWGJPV6 (ORCPT ); Mon, 10 Jul 2006 11:21:58 -0400 Date: Mon, 10 Jul 2006 16:21:47 +0100 From: Russell King To: Valdis.Kletnieks@vt.edu Cc: Alan Cox , Jon Smirl , "Antonino A. Daplas" , "H. Peter Anvin" , Greg KH , lkml , Andrew Morton Subject: Re: [PATCH] Clean up old names in tty code to current names Message-ID: <20060710152146.GA18728@flint.arm.linux.org.uk> Mail-Followup-To: Valdis.Kletnieks@vt.edu, Alan Cox , Jon Smirl , "Antonino A. Daplas" , "H. Peter Anvin" , Greg KH , lkml , Andrew Morton References: <1152524657.27368.108.camel@localhost.localdomain> <9e4733910607100541i744dd744n16c35c50dae1e98d@mail.gmail.com> <1152537049.27368.119.camel@localhost.localdomain> <9e4733910607100603r5ae1a21ex1a2fa0f045424fd1@mail.gmail.com> <1152539034.27368.124.camel@localhost.localdomain> <9e4733910607100707g4810a86boa93a5b6b0b1a8d0a@mail.gmail.com> <44B26752.9000507@gmail.com> <9e4733910607100757t4ddfaf93l1723580de551529b@mail.gmail.com> <1152544746.27368.134.camel@localhost.localdomain> <200607101510.k6AFAWND006142@turing-police.cc.vt.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200607101510.k6AFAWND006142@turing-police.cc.vt.edu> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 10, 2006 at 11:10:32AM -0400, Valdis.Kletnieks@vt.edu wrote: > On Mon, 10 Jul 2006 16:19:06 BST, Alan Cox said: > > Ar Llu, 2006-07-10 am 10:57 -0400, ysgrifennodd Jon Smirl: > > > > A few apps do rely on /proc/tty/drivers for the major-minor > > > > to device name mapping. /dev/vc/0 does not exist (unless > > > > created manually) without devfs. > > > > > > This is why I questioned if /proc/tty was really in use, it contains > > > an entry that is obviously wrong for my system. > > > > Which tools already know about. What is so hard to understand about the > > idea that pointless random changes break stuff and don't fix things. > > On the other hand, a case can be made that if userspace already knows about > the fact the thing is totally broken Maybe - what if userspace is looking up /dev/tty0 in /proc/tty/drivers and happens to know that it's called /dev/vc/0, because it's working around this known idiosyncrasy of the kernel ? If you change tty/drivers to be the more correct /dev/tty0, such a program would needlessly break. > fixing it won't break anything. How can you be certain - I think that's Alan's point (if it isn't, that's my point.) The answer is you can't, so in order to maintain ABI compatibility (and yes, this *IS* part of the kernel ABI) it must be left exactly as-is. > The only case is that some *already* terminally broken stuff may break > further. That "terminally broken stuff" might just happen to work with today's kernels. Even so, that's no reason to pile in additional user-visible changes which could potentially have adverse effects. -- Russell King Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/ maintainer of: 2.6 Serial core