Re: [libgpiod][PATCH 6/6] core: add the kernel uapi header to the repository

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Thu, Jan 28, 2021 at 11:26:41AM +0800, Kent Gibson wrote:
> Bart and Dmitry: I submit that we are good to copy the headers into the
> repositories, but we should take a few steps just to make clear that we
> are in full compliance with the GPL v2.
> 
> Firstly, we are distributing the headers under Section 1 (distribution)
> of the GPL, so we should keep the headers in a separate directory that
> contains its own COPYING file as well as the GPL v2 and Linux syscall note
> - unless they are already available elsewhere in the repo.
> 
> The headers must be copied verbatim so as to not trigger Section 2
> (modification).  And it is probably good to include in the commit
> comment what kernel version or commit they were drawn from so that can
> be easily confirmed.
> 
> Section 3 still doesn't apply, as any resulting object code or
> executables are no more a derived work due to the availability of the
> header than they were previously.  And I don't think anyone is claiming
> that the repo itself is a derived work - in this context it is just a
> distribution medium.
> 
> The COPYING file, or equivalent, for the project should explicitly
> exclude any claim on the kernel header directory to make clear we are
> not trying to sublicense the headers as LGPL - which could breach
> Section 4.
> 
> Other than those points, I don't see anywhere we may be in breach.

That looks good, you should also consider following the REUSE
specification:
	https://reuse.software/
which recommends using a LICENSES/ directory for the different licenses
in your project and use SPDX lines at the top of your files to make
everything explicit.  The `reuse lint` command line tool should give you
lots of hints on good things to fix up in this area.

Good luck!

greg k-h