Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932233AbWLRXw6 (ORCPT ); Mon, 18 Dec 2006 18:52:58 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932313AbWLRXw6 (ORCPT ); Mon, 18 Dec 2006 18:52:58 -0500 Received: from ozlabs.org ([203.10.76.45]:51878 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932233AbWLRXw5 (ORCPT ); Mon, 18 Dec 2006 18:52:57 -0500 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <17799.10706.834077.676728@cargo.ozlabs.ibm.com> Date: Tue, 19 Dec 2006 10:52:50 +1100 From: Paul Mackerras To: Linus Torvalds Cc: Alexandre Oliva , Ricardo Galli , linux-kernel@vger.kernel.org Subject: Re: GPL only modules In-Reply-To: References: <200612161927.13860.gallir@gmail.com> X-Mailer: VM 7.19 under Emacs 21.4.1 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2094 Lines: 44 Linus Torvalds writes: > "Derivation" has nothing to do with "linking". Either it's derived or it > is not, and "linking" simply doesn't matter. It doesn't matter whether > it's static or dynamic. That's a detail that simply doesn't have anythign > at all to do with "derivative work". There is in fact a pretty substantial non-technical difference between static and dynamic linking. If I create a binary by static linking and I include some library, and I distribute that binary to someone else, the recipient doesn't need to have a separate copy of the library, because they get one in the binary. If on the other hand the binary is dynamically linked, then the recipient needs to get hold of a copy of the library from somewhere, implying that they need to have satisfied whatever license conditions the copyright owner of the library places on it, in order to have obtained their copy of the library legally. In other words, static linking gives the recipient a "free" copy of the library, but dynamic linking doesn't. That is why some companies' legal guidelines have quite different rules about the distribution of binaries, depending on whether they are statically or dynamically linked. If the library was a proprietary library, for which the copyright owner wanted to charge a per-copy fee, the owner would no doubt object to me distributing statically-linked binaries containing his library, but could conceivably be perfectly happy with me distributing binaries that have been dynamically linked against his library, since then anyone who wants to use my binary has to purchase a copy of his library from him. So therefore I don't think you can reasonably claim that static vs. dynamic linking is only a technical difference. There are clearly other differences when it comes to distribution of the resulting binaries. Paul. - 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/