Hi Jeff, On Wed, Nov 23, 2011 at 11:34 AM, Jeff Haran <jharan@bytemobile.com> wrote:
-----Original Message----- From: Greg KH [mailto:greg@kroah.com] Sent: Tuesday, November 22, 2011 2:44 PM To: Jeff Haran; Sengottuvelan S; Kernel Newbies Subject: Re: GPL-only symbol Error
On Tue, Nov 22, 2011 at 02:35:24PM -0800, Jeff Haran wrote:
I've seen others when faced with this who build their own kernels from sources just modify the problematic EXPORT_SYMBOL_GPL()s to EXPORT_SYMBOL()s. I don't know if that is legal. I wouldn't do it personally. Consult a lawyer before you go down that road.
It is not legal and companies have gotten into big trouble by trying to do that, or by creating "gpl-condom" kernel modules that wrap gpl-only symbols and export them again. Do not do that without the full buy-in from your legal department as they do not want to hear about it from an external query first.
Greg,
Just curious, can you provide links to these cases?
I've read the COPYING file at the top of the Linux source tree. I am not a lawyer, but I don't see anything in it that would prohibit somebody from taking the GPL kernel sources, changing the EXPORT_SYMBOL_GPL()s to EXPORT_SYMBOL()s, publishing that modified kernel source as required by the GPL license but then keep their module source that uses the now non-GPL symbols private. It seems like it should be prohibited in the spirit of open source, but I don't see any mention of these symbol declarations in the license.
The mere fact that the "gpl-condom" module links to EXPORT_SYMBOL_GPL functions make it, in and of itself, a GPL module ergo, there is no such thing as a "gpl-condom" module Regards, Graeme