Question Regarding GPL

Ben Tilly btilly at
Sat Jan 21 03:58:33 UTC 2006

On 1/20/06, Lawrence Rosen <lrosen at> wrote:
> Previous emails wrote:
> > > 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.
> <snip>
> I'm turning this back into a question more challenging for license-discuss:
> This entire issue of linking independent modules to Linux has bothered us
> all for way too long, and from what I read GPLv3 won't solve it--at least
> not yet. The GPL is ambiguous about such combinations, and regular
> pronouncements about it from the mountain top don't really help us achieve a
> common understanding among all the licensors and licensees in the world.

I don't see how the GPL can possibly address it given its current
structure.  The GPL is not a contract, it only applies if you do
something that requires permission under copyright law.  The question
is whether creating and using proprietary loadable modules is
something that requires permission under copyright law.

Rick's pointed to the decision at
which references Galoob, 964 F.2d at 967 saying that a derivative work
must exist in a "concrete or permanent form."  Apparently that
precedent found that copyright law did not apply to a situation where
a derivative work was created by modifying a program in memory.  My
understanding of that precedent says that if it is legal to create and
distribute a loadable module, copyright does not restrict one's
ability to load it into a running kernel.  (Though copyright would
come into play if one then saved a system image including the current
state of the modified kernel.)

Therefore end users do not generally need copyright permission to use
a loadable module that someone else has written.  The question
therefore comes down to whether copyright permission is needed to
write the loadable module in the first place.  If permission is
required then the GPL can and does address this - proprietary loadable
modules are not allowed.  If permission is not required then the GPL
can't possibly restrict this without completely changing the logic of
how it works.

> The language of OSL 3.0 § 1(a) and 1(b) attempts to solve the problem by
> separately granting a license to copy the Original Work and a license to
> create Derivative Works. These are the specific things you are authorized to
> do:
>    1(a): to reproduce the Original Work in copies, either alone or as part
>          of a collective work;
>    1(b): to translate, adapt, alter, transform, modify, or arrange the
>          Original Work, thereby creating derivative works ("Derivative
> Works")
>          based upon the Original Work;

According to the Microstar case it is possible to wind up with a
derivative work even though they did not translate, adapt, alter,
transform, modify, or arrange the Original Work.  Are those derivative
works banned by your license?

> So if Linux were licensed under OSL 3.0, linking a device driver to it would
> create either a collective work containing a copy of Linux and a copy of the
> driver or, if the driver was created by translating, adapting, altering,
> transforming, modifying, or arranging Linux, a derivative work of Linux. If
> the latter, source code would have to be disclosed. (See § 1(c).)

My understanding of Galoob says that there should be no copyright
issues involved with linking as long as the result is not saved.  But
I'm sure that Rick will come along shortly with a list of links to a
series of cases where judges looked at linking and came to the
opposite decision.

> Note that with such language, you'd never get into silly legal problems with
> pre-existing, independently-written copyrighted modules being declared
> derivative works of Linux simply because the works are linked together.

You'd still have the silly legal question we are discussing about
whether writing a work that uses Linux' published API for loadable
modules results in a derivative work.

Also your fix does the opposite of RMS and Eben want.  They want the
answer they gave at to
be true.

IMO licenses should do exactly what the authors want them to do to the
full extent allowed under the law.  That means that the GPLv3 should
satisfy the goals of the FSF.  Since it is their desire to provide
maximum encouragement to make software free (by their definition of
freedom), the GPLv3 should do exactly that.

I think that other people should use it only if the result meets their needs.

> Does anyone besides me think that similar language in GPLv3 would be
> helpful?

No, for both reasons that I gave.

1. As long as there is a factual question about when something is a
derivative work, there is a factual question about what the GPL says. 
In particular the question that I had is whether programming to Linux'
published API for creating a loadable module was sufficient to make
your code into a derivative work.  If it does, then your suggestion
does not make loadable modules legal.  It makes *loading* them legal,
but not the act of creating the thing to load.

2. The change runs counter to the stated goals of the FSF.


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