From owner-cvs-src@FreeBSD.ORG Sat Aug 9 11:43:13 2008 Return-Path: Delivered-To: cvs-src@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 597F61065671; Sat, 9 Aug 2008 11:43:13 +0000 (UTC) (envelope-from peterjeremy@optushome.com.au) Received: from mail35.syd.optusnet.com.au (mail35.syd.optusnet.com.au [211.29.133.51]) by mx1.freebsd.org (Postfix) with ESMTP id D80478FC16; Sat, 9 Aug 2008 11:43:12 +0000 (UTC) (envelope-from peterjeremy@optushome.com.au) Received: from server.vk2pj.dyndns.org (c122-106-215-175.belrs3.nsw.optusnet.com.au [122.106.215.175]) by mail35.syd.optusnet.com.au (8.13.1/8.13.1) with ESMTP id m79Bh6L1004572 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Sat, 9 Aug 2008 21:43:07 +1000 Received: from server.vk2pj.dyndns.org (localhost.vk2pj.dyndns.org [127.0.0.1]) by server.vk2pj.dyndns.org (8.14.2/8.14.2) with ESMTP id m79Bh5Ur059389; Sat, 9 Aug 2008 21:43:05 +1000 (EST) (envelope-from peter@server.vk2pj.dyndns.org) Received: (from peter@localhost) by server.vk2pj.dyndns.org (8.14.2/8.14.2/Submit) id m79Bh5ac059388; Sat, 9 Aug 2008 21:43:05 +1000 (EST) (envelope-from peter) Date: Sat, 9 Aug 2008 21:43:05 +1000 From: Peter Jeremy To: Robert Watson Message-ID: <20080809114305.GV64458@server.vk2pj.dyndns.org> References: <200808081343.m78DhwYE068477@repoman.freebsd.org> <200808081226.32089.jhb@freebsd.org> <20080809001256.GL64458@server.vk2pj.dyndns.org> <20080809103338.GN97161@deviant.kiev.zoral.com.ua> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="oxV4ZoPwBLqAyY+a" Content-Disposition: inline In-Reply-To: X-PGP-Key: http://members.optusnet.com.au/peterjeremy/pubkey.asc User-Agent: Mutt/1.5.18 (2008-05-17) Cc: src-committers@freebsd.org, John Baldwin , cvs-src@freebsd.org, Ed Schouten , cvs-all@freebsd.org, Kostik Belousov Subject: Re: cvs commit: src/sys/dev/io iodev.c X-BeenThere: cvs-src@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: CVS commit messages for the src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 09 Aug 2008 11:43:13 -0000 --oxV4ZoPwBLqAyY+a Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On 2008-Aug-09 12:08:42 +0100, Robert Watson wrote: >While /dev/io appeals to the UNIX "everything is a file" sensibility, I th= ink=20 >the system calls we have for this on i386 are more conceptually coherent. IMO, /dev/io is inherently a kludge - it's really more a MAC issue than anything like a file. Whilst you get a FD by opening /dev/io, you never use that FD for anything other than passing to close(2). Instead, you are using a magic side-effect that allows you to execute 'in' and 'out' instructions whilst you hold that FD open. AFAIK, the sole reason for having it appear as a file is that (in the absence of a MAC framework), the filesystem provides the only mechanism for access control. IMHO, /dev/io should be deprecated in favour of something like the MAC framework. (Note that i386_{g,s}et_ioperm(2) are nor suitable in their current form because there is no mechanism for the system administrator to define access controls). --=20 Peter Jeremy Please excuse any delays as the result of my ISP's inability to implement an MTA that is either RFC2821-compliant or matches their claimed behaviour. --oxV4ZoPwBLqAyY+a Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (FreeBSD) iEYEARECAAYFAkidgskACgkQ/opHv/APuIcETwCeORGQSU0oEEgHv6XQJuP8i5Ru iqIAniji6aT47H7Yicrvkp8QeLNfkmQI =0tpO -----END PGP SIGNATURE----- --oxV4ZoPwBLqAyY+a--