Add the full text of the CC-BY-4.0 license to the kernel tree as well as
the required tags for reference and tooling.
The license text was copied directly from the following url, but for
clarification a 'Creative Commons' was added before 'Attribution 4.0
International' in the first line:
https://creativecommons.org/licenses/by/4.0/legalcode.txt
CC-BY-4.0 is GPLv2 compatible, but when for example used for the
kernel's documentation it can easily happen that sphinx during
processing combines it with text or code from files using a more
restrictive license[1]. This bears pitfalls, hence point that risk out
and suggest to only use this license in combination with the GPLv2.
[1] https://lkml.kernel.org/r/20201201144314.GA14256@lst.de
Signed-off-by: Thorsten Leemhuis <linux@leemhuis.info>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
CC: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/7115b6c20ae3e6db0370fe4002dd586011205e1c.1607063223.git.linux@leemhuis.info
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Just like the CDDL the Apache license and the MPL must only be used as
a choice in additional to an GPL2 compatible license. Copy over the
boilerplate from the CDDL file to the other two after fixing it up to
make it clear the licenses need to be GPL2 compatible, not just the
more generic GPL compatible. For example the Apache 2 license is GPL3
compatible, but that doesn't matter for the kernel.
Also move these licenses to a separate directory and document the rules
in license-rules.rst.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
