Re: Linux GPL and binary module exception clause?

Linus Torvalds
2003-12-04T15:58:37Z

On Thu, 4 Dec 2003, Jason Kingsland wrote:
> > - anything that has knowledge of and plays with fundamental internal
> > Linux behaviour is clearly a derived work. If you need to muck around
> > with core code, you're derived, no question about it.
>
>
> If that is the case, why the introduction of EXPORT_SYMBOL_GPL and
> MODULE_LICENSE()?

It is really just documentation.

This is exactly so that it is more clear which cases are black-and-white,
and where people shouldn't even have to think about it for a single
second. It still doesn't make the gray area go away, but it limits it a
bit ("if you need this export, you're clearly doing something that
requires the GPL").

Note: since the kernel itself is under the GPL, clearly anybody can modify
the EXPORT_SYMBOL_GPL() line, and remove the _GPL part. That wouldn't be
against the license per se. But it doesn't make a module that needs that
symbol any less needful of the GPL - exactly because the thing is just a
big cluehint rather than anything else.

Linus