Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262833AbVDHNSG (ORCPT ); Fri, 8 Apr 2005 09:18:06 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262827AbVDHNLc (ORCPT ); Fri, 8 Apr 2005 09:11:32 -0400 Received: from nevyn.them.org ([66.93.172.17]:12764 "EHLO nevyn.them.org") by vger.kernel.org with ESMTP id S262805AbVDHNF3 (ORCPT ); Fri, 8 Apr 2005 09:05:29 -0400 Date: Fri, 8 Apr 2005 09:05:22 -0400 From: Daniel Jacobowitz To: "Richard B. Johnson" Cc: Jan Harkes , Linux kernel Subject: Re: Linux-2.6.11 can't disable CAD Message-ID: <20050408130522.GA32099@nevyn.them.org> Mail-Followup-To: "Richard B. Johnson" , Jan Harkes , Linux kernel References: <20050407202059.GA414@delft.aura.cs.cmu.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.8i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1714 Lines: 42 On Thu, Apr 07, 2005 at 04:50:32PM -0400, Richard B. Johnson wrote: > On Thu, 7 Apr 2005, Jan Harkes wrote: > > >On Thu, Apr 07, 2005 at 11:16:14AM -0400, Richard B. Johnson wrote: > >>In the not-too distant past, one could disable Ctl-Alt-DEL. > >>Can't do it anymore. > >... > >>Observe that reboot() returns 0 and `strace` understands what > >>parameters were passed. The result is that, if I hit Ctl-Alt-Del, > >>`init` will still execute the shutdown-order (INIT 0). > > > >Actually, if CAD is enabled in the kernel, it will just reboot. > >If CAD is disabled in the kernel a SIGINT is sent to pid 1 (/sbin/init). > > > > No, that's not how it ever worked. There are parameters that are > available in the reboot-system call that define the operation that > will occur when the 3-finger salute occurs. > > Execute man 2 reboot. Take your own advice. From the man page: LINUX_REBOOT_CMD_CAD_ON (RB_ENABLE_CAD, 0x89abcdef). CAD is enabled. This means that the CAD keystroke will immediately cause the action associated with LINUX_REBOOT_CMD_RESTART. LINUX_REBOOT_CMD_CAD_OFF (RB_DISABLE_CAD, 0). CAD is disabled. This means that the CAD keystroke will cause a SIGINT signal to be sent to init (process 1), whereupon this process may decide upon a proper action (maybe: kill all processes, sync, reboot). -- Daniel Jacobowitz CodeSourcery, LLC - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/