Cisco Cisco IPICS Release 2.1 Licensing Information

 to anybody else, feel free to do so. And if you want to argue legal

 points with me or point somehting out, I'm always interested. To a

 point ;-]

 

On Fri, 19 Oct 2001, Barnes wrote:

>

> I've been exchanging e-mail with Richard Stallman for a couple of

> weeks about the finer points of the GPL.

 

I feel your pain.

 

> I've have spent time pouring through mailing list archives, usenet,

> and web search engines to find out what's already been covered about

> your statement of allowing dynamically loaded kernel modules with

> proprietary code to co-exist with the Linux kernel.  So far I've

> been unable to find anything beyond vague statements attributed to

> you.  If these issues are addressed somewhere already, please refer

> me.

 

Well, it really boils down to the equivalent of "_all_ derived modules

have to be GPL'd". An external module doesn't really change the GPL in

that respect.

 

There are (mainly historical) examples of UNIX device drivers and some

UNIX filesystems that were pre-existing pieces of work, and which had

fairly well-defined and clear interfaces and that I personally could not

really consider any kind of "derived work" at all, and that were thus

acceptable. The clearest example of this is probably the AFS (the Andrew

Filesystem), but there have been various device drivers ported from SCO

too.

 

> Issue #1

> ========

> Currently the GPL version 2 license is the only license covering the

> Linux kernel.  I cannot find any alternative license explaining the

> loadable kernel module exception which makes your position difficult

> to legally analyze.

>

> There is a note at the top of www.kernel.org/pub/linux/kernel/COPYING,

> but that states "user programs" which would clearly not apply to

> kernel modules.

>

> Could you clarify in writing what the exception precisely states?

 

Well, there really is no exception. However, copyright law obviously

hinges on the definition of "derived work", and as such anything can

always be argued on that point.