Question Regarding GPL

Rick Moen rick at
Fri Jan 20 23:58:42 UTC 2006

Quoting Ben Tilly (btilly at

> I'm not sure whether you're agreeing or disagreeing with me.

Welcome to the law.  ;->

> It is obvious that a loadable module can be derivative of the Linux
> kernel.  Just start with a piece of the Linux kernel and make it into
> a loadable module.  The question is whether it is possible for a
> loadable module to not be derivative of the Linux kernel. 

Yes, very succinctly put.

> Linus's stated opinion is that it is possible.  My admittedly
> uninformed opinion is that he is right.

To my knowledge, his most recent statement was on 2002-10-17, as follows
(in part):  

  The _only_ thing that allows for non-GPL modules is copyright law, and
  in particular the "derived work" issue. A vendor who distributes non-GPL
  modules is _not_ protected by the module interface per se, and should
  feel very confident that they can show in a court of law that the code
  is not derived.  [...]

  The original binary-only modules were for things that were
  pre-existing works of code, i.e., drivers and filesystems ported 
  from other operating systems, which thus could clearly be argued 
  to not be derived works, and the original limited export table 
  also acted somewhat as a barrier to show a level of distance.

By "derived work", Torvalds meant "derivative work" as used as a term of
art within copyright law.

My point, in any event, was that the factual question would be resolved
by a court not by consulting Torvalds's or anyone else's opinions, but
(in USA jurisdictions) by applying the Altai test to the allegedly 
infringing code.

> Many people have released drivers that depend on that opinion being
> correct.

Note:  Torvalds's opinions on the matter have been known to change
dramatically, without advance notice.  Compare his 1995-12-17 and
2002-10-17 proclamations on LKML, as archived here:  "Proprietary Kernel
Modules" on

> What you've said is that the correct test to use is the one described
> in that decision.  I just read that decision, and I am left no more
> able to answer the fundamental question than I was before.

My old landlord and colleague Richard Couture had a saying -- harsh, 
but relevant:  "Sorry to hear about _your_ problem."  ;->  The relevant
test is the one that will be applied.  I'm just telling the truth.

[Micro Star decision:]

> I don't see the relevance.  U

Relevance is that non-literal copying can infringe, and that
copyright-encumbered content isn't necessarily limited to code.

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