From owner-freebsd-current@FreeBSD.ORG Wed Nov 22 21:45:23 2006 Return-Path: X-Original-To: freebsd-current@freebsd.org Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id B880916A4FF for ; Wed, 22 Nov 2006 21:45:23 +0000 (UTC) (envelope-from jb@what-creek.com) Received: from what-creek.com (what-creek.com [66.111.37.70]) by mx1.FreeBSD.org (Postfix) with ESMTP id 85FDD43F1B for ; Wed, 22 Nov 2006 21:40:18 +0000 (GMT) (envelope-from jb@what-creek.com) Received: by what-creek.com (Postfix, from userid 102) id 5012A140EC08; Wed, 22 Nov 2006 21:42:04 +0000 (GMT) Date: Wed, 22 Nov 2006 21:42:04 +0000 From: John Birrell To: "Devon H. O'Dell" Message-ID: <20061122214203.GA48004@what-creek.com> References: <2b22951e0611212109t69b01400q5eb0ba15b028ce68@mail.gmail.com> <20061122051359.GA42639@what-creek.com> <20061122165735.GA37930@xor.obsecurity.org> <1164216949.18579.19.camel@buffy.york.ac.uk> <9ab217670611221016q5bd1bf84v4ef878391eb2a67a@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <9ab217670611221016q5bd1bf84v4ef878391eb2a67a@mail.gmail.com> User-Agent: Mutt/1.4.2.1i Cc: freebsd-current@freebsd.org, "Cai, Quanqing" , Kris Kennaway Subject: Re: KDTRACE is gone? X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 22 Nov 2006 21:45:23 -0000 On Wed, Nov 22, 2006 at 01:16:17PM -0500, Devon H. O'Dell wrote: > Yeah, it could be done. However, the DTrace provider (providing BEGIN, > END, and ERROR, and code that allows for other providers to hook in) > is > 13,000 lines of code and comments, so it'd be a very non-trivial > task. The DTrace provider isn't actually relevent to this discussion. That is find staying as a kernel module and CDDL'd. The issue is the hooks that the DTrace modules register with. These are very small bits of BSD licensed code that I write, and which get added inline to existing BSD licensed sources like trap.c. These little bits of code tend to require calling the DTrace kernel API or methods and techniques defined by CDDL headers and not documented anywhere else. I have been very careful not to copy CDDL stuff into FreeBSD headers for fear of causing FreeBSD legal problems in future like the claims being made in the SCO vs IBM (Linux) litigation. Remember that the OpenSolaris source is based on System V and Sun Microsystems have extended it to include DTrace. I need to find an alternative to the KDTRACE implementation -- that's why I removed it for now. I want to come up with a functional equivalent to the Solaris DTrace implementation. Having it as an option (amongst a heap of other options) that a user /might/ choose to compile in, isn't a good design IMO. -- John Birrell