Re: MODULE_LICENSE and EXPORT_SYMBOL_GPL

Roy Murphy
2001-10-18T15:04:54Z

'Twas brillig when Keith Owens scrobe:
>EXPORT_SYMBOL_GPL
>
>Some kernel developers are unhappy with providing external interfaces
>to their code, only to see those interfaces being used by binary only
>modules. They view it as their work being appropriated. Whether you
>agree with that view or not is completely irrelevant, the person who
>owns the copyright decides how their work can be used.

The GPL takes its strength and power from Copyright Law. Copyright law
allows certain exclusive rights to authors. Among these are:
distribution, public performance and the preparation of derivative
works. Copyright Law (at least in the US) reserves certain rights to
the Public, notably the right to make Fair Uses. Because of Fair Use,
the statement above "the person who owns the copyright decides how
their work can be used." is demonstrably false in a US Copyright
context.

Some elements of authorship are copyrightable, other elements are not.
One clear exception in US Copyright Law is "methods of operation" which
are not copyrightable. The canonical example of this the pattern of a
standard transmission shift. The pattern, intimately tied to the
manner in which the device is used, has been standardized because its
design could be copied and used by all manufacturers.

Exported interfaces are "methods of operation" in the sense of US
Copyright Law. Copyright Law affords no protection to "methods of
operation". The GPL, which gains its strength from Copyright Law, also
has no rights in this area. If a GPLed module does not want other code
using its interfaces, they should not be exported.

This is an example of overreaching copyright control which is just as
aggregious as CSS on DVDs.