Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sat, 27 Apr 2002 15:11:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sat, 27 Apr 2002 15:10:59 -0400 Received: from ebiederm.dsl.xmission.com ([166.70.28.69]:33375 "EHLO frodo.biederman.org") by vger.kernel.org with ESMTP id ; Sat, 27 Apr 2002 15:10:59 -0400 To: Padraig Brady Cc: ebuddington@wesleyan.edu, linux-kernel@vger.kernel.org Subject: Re: Dissociating process from bin's filesystem In-Reply-To: <20020424224714.B19073@ma-northadams1b-46.bur.adelphia.net> <3CC7EBC3.6030707@antefacto.com> From: ebiederm@xmission.com (Eric W. Biederman) Date: 27 Apr 2002 13:03:11 -0600 Message-ID: Lines: 24 User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.1 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Padraig Brady writes: > I'm think this is not possible at the moment. > > The file of the executing process is in use as the backing store for > one or more live virtual memory areas, so changing it could > corrupt the processes using those areas. Hence you can't umount. > > Now the Mach kernel has a MAP_COPY flag to the mmap system call > which would do what you want, but this is mucho complex/messy, > so don't hold your breath for a linux implementation. > > A related note on shared libraries is you don't get the > "text file busy" message if you update them while they're in use, > like you do for executable files. The reason is MAP_DENYWRITE > is ignored for security reasons. I think Eric Biederman has > a workaround though? I played with it but could find nothing better than. chmod a-w file And it wasn't terribly important personally so I dropped it. Eric - 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/