Re: [PATCH] USB: mark USB drivers as being GPL only

["Chris Friesen" <cfriesen@nortel.com>]

David Newall wrote:
> That being said, a module can be written such 
> that it only dynamically links with the kernel.  Ndiswrapper is an 
> example of how this can be done: None of the drivers that work under 
> ndiswrapper make any direct use of the kernel, not in any way, indeed a 
> wrapper could be written for a different operating system.

The issue is all about "derivative works" in copyright law.

Ndiswrapper is in a good position because the closed-source drivers were 
originally written for another OS so it's pretty well impossible to 
argue that they are derived from linux.

However, if I were to write a new GPL shim and then a new closed-source 
module that uses the shim to access kernel symbols, it is entirely 
possible that a court could rule that my closed-source module is a 
derivative work of the linux kernel because it was written specifically 
to run on linux.

On the other hand if I were to sit down and write an OS-agnostic 
proprietary chunk of code, and then write a new GPL shim to use it under 
linux (and maybe other shim layers for other OS's as well), I _might_ be 
okay.  But I would have to be prepared to prove that the proprietary 
code was not derived from the Linux kernel.

Chris