Re: Linux in a binary world... a doomsday scenario

Andrea Arcangeli
2005-12-06T00:53:45Z

On Mon, Dec 05, 2005 at 03:56:06PM -0800, Tim Bird wrote:
> If the GPL covers interface linkages (whether static or
> dynamic) then EXPORT_SYMBOL_GPL is redundant. If it does
> not, in all cases, then EXPORT_SYMBOL_GPL is, as
> an extension to GPL, therefore a GPL violation.

The last time I spoke with Linus about this, what I understood can be
described in two points:

1) EXPORT_SYMBOL_GPL is an hint: if you have to circumvent it, there are
high chances that you're creating a derivative of the linux kernel and
in turn there are high chances that you're illegal

2) The fact you're illegal or not, has nothing to do with the _GPL tag
in the exports, the illegal usage is when the module create a derivative
of the linux kernel.

Now I don't know for sure myself (I'm not a lawyer) what is a derivative
of the linux kernel (don't ask me), but the two above points are quite
clear to me.

I always thought the _GPL tag could have no direct legal implications
and Linus confirmed it. The kernel is GPL so everyone can modify the
exports or re-export symbols as usual, the exports are GPL code too. The
guy who re-exports or remove a _GPL tag is just modifying a GPL code, so
he's ok.

The _GPL tag is useful as an hint to binary only vendors as as such it
makes perfect sense.