I'm not a fan of Oracle'e, I'm not a fan of the copyrightability of APIs and I don't think Google should be found legally guilty of anything. That said, I think Google was ethically wrong in how they dealt with Sun and, following that, Oracle. Regardless, I'd say that adding GPL'd code in the kernel that changes the exportability of a symbol is just fine. Anyone is freely able to change GPL'd code and release it under the same license to do anything they like. They can remove EXPORT_SYMBOL_GPL completely if they want and then put a module on top of that. If you're willing to release and support that kernel, then you haven't _legally_ done anything wrong. Like Google though, I think you have ethical problems.