From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dmitry Torokhov Subject: Re: [RFC] Input: implement sysrq as an input handler Date: Thu, 15 Apr 2010 22:33:05 -0700 Message-ID: <20100416053305.GC1078@core.coreip.homeip.net> References: <20100317061952.GA19789@core.coreip.homeip.net> <20100319000043.GC12017@khazad-dum.debian.net> <20100319000931.GA5671@core.coreip.homeip.net> <20100319160641.GC16743@khazad-dum.debian.net> <20100319180314.GB12143@core.coreip.homeip.net> <20100320025329.GA2468@khazad-dum.debian.net> <20100322045910.GE31621@core.coreip.homeip.net> <20100401133454.GA1291@ucw.cz> <20100401154212.GA7900@core.coreip.homeip.net> <20100404132734.GB1346@ucw.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-yw0-f194.google.com ([209.85.211.194]:47906 "EHLO mail-yw0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753124Ab0DPFdM (ORCPT ); Fri, 16 Apr 2010 01:33:12 -0400 Content-Disposition: inline In-Reply-To: <20100404132734.GB1346@ucw.cz> Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: Pavel Machek Cc: Henrique de Moraes Holschuh , Linux Input , LKML , Jason Wessel On Sun, Apr 04, 2010 at 03:27:34PM +0200, Pavel Machek wrote: > Hi! > > > > If userspace disables sysrq during normal operation, that makes it > > > useless. > > > > > > If normal user could do that, that's a security problem. > > > > > > > Yes, and...? This patch does not change the way one enables, disables, > > intercepts, etc. SysRq and SAK compared to how it was handled when SysRq > > was part of keyboard _input handler_. The only thisng this patch does is > > moving the code into a _separate_ input handler. > > Yep, that was just a note. > > > > > The problem is that device does not know what SysRq and especially SAK are. > > > > User can reassign key codes and key symbols easily. > > > > > > That was not case in original implementation; it had hardcoded keymap. > > > > The earth was also flat back then and the only keyboard was AT one. SAK > > was always part of keymap so could be reassinged at any time. > > Well, there are two SAKs. > > One SAK -- in keymap, is remappable and always was. > > Second, sysrq-saK -- is (was?) hardcoded and not affected by > keymap. Please don't change that. Can I change Alt? Just saying... ;) Anyway, yes, it was hardcodced in 2.4. It also was only working on AT keyboards, and now we support much wider range. -- Dmitry