Re: Dual-Licensing Linux Kernel with GPL V2 and GPL V3

David Woodhouse
2007-06-15T19:49:00Z

On Fri, 2007-06-15 at 11:23 -0700, Linus Torvalds wrote:
>
> On Fri, 15 Jun 2007, David Woodhouse wrote:
> >
> > Actually, I don't see where it explicitly states that it only covers
> > derived work.
>
> See "Section 0":
>
> The "Program", below, refers to any such program or work, and a
> "work based on the Program" means either the Program or any
> derivative work under copyright law:
>
> so yes, if you grepped for "derived work", you wouldn't have found it. The
> exact wording used in the license is "derivative work under copyright
> law".
>
> So the very *definition* of the word "Program" is indeed limited by the
> notion of "derived work" - as defined by copyright law, and NOT the GPLv2.

Yep. And §2 talks explicitly about independent and separate works when
they are distributed _with_ the Program, as part of a larger work based
on the Program.

> > The case which interests me most is when someone makes an embedded
> > device, for example a router -- and they distribute a 'blob' of
> > firmware for it, containing both the kernel a binary-only network driver
> > module. Again we have to ask ourselves "is this a work based on the
> > kernel?". Obviously there isn't a 'right' answer outside a court of law,
> > but personally I reckon it's a fairly safe bet that it _is_ going to be
> > considered to be a work based on Linux.
>
> Hey, I kind of disagree.
>
> What is a DVD? It's just a "blob" of a UDF image, potentially containing
> the Linux kernel.
>
> How is that different from a "blob" of some other kind of image (say, a
> cramfs or similar image) on a rom?
>
> What makes UDF so different from cramfs? What makes a DVD so different
> from a ROM chip? Why would copyright law care about one and not the other?

The differences are subtle, but they do exist. They're not really about
whether it's iso9660 or cramfs; it's about whether what you put on them
is a coherent work in its own right or just a bunch of bits which happen
to be thrown together onto the same medium.

And in the router case, there's little point to its existence without
the binary-only module. At least with the DVD it _can_ work without the
binary-only module. Although as I said, some distributors definitely
claim that the distribution is a 'coherent whole' too.

> So I really do _not_ think it's at all obvious. Personally, I think it's
> exactly the same case. Others disagree, but I've never really seen a good
> *reason* for them disagreeing.

It's a grey area, and nobody's 'right' until/unless a court decides. And
then only until/unless a higher court contradicts it. The reason I
jumped in was to point out that it isn't _just_ about whether the module
is a derived work or not. The GPL goes further than that.

--
dwmw2