Add the full text of the copyleft-next-0.3.1 license to the kernel
tree as well as the required tags for reference and tooling.
The license text was copied directly from the copyleft-next project's
git tree [0].
Discussion of using copyleft-next-0.3.1 on Linux started since June,
2016 [1]. In the end Linus' preference was to have drivers use
MODULE_LICENSE("GPL") to make it clear that the GPL applies when it
comes to Linux [2]. Additionally, even though copyleft-next-0.3.1 has
been found to be to be GPLv2 compatible by three attorneys at SUSE and
Redhat [3], to err on the side of caution we simply recommend to
always use the "OR" language for this license [4].
Even though it has been a goal of the project to be GPL-v2 compatible
to be certain in 2016 I asked for a clarification about what makes
copyleft-next GPLv2 compatible and also asked for a summary of
benefits. This prompted some small minor changes to make compatibility
even further clear and as of copyleft 0.3.1 compatibility should
be crystal clear [5].
The summary of why copyleft-next 0.3.1 is compatible with GPLv2
is explained as follows:
Like GPLv2, copyleft-next requires distribution of derivative works
("Derived Works" in copyleft-next 0.3.x) to be under the same license.
Ordinarily this would make the two licenses incompatible. However,
copyleft-next 0.3.1 says: "If the Derived Work includes material
licensed under the GPL, You may instead license the Derived Work under
the GPL." "GPL" is defined to include GPLv2.
In practice this means copyleft-next code in Linux may be licensed
under the GPL2, however there are additional obvious gains for
bringing contributions from Linux outbound where copyleft-next is
preferred. A summary of benefits why projects outside of Linux might
prefer to use copyleft-next >= 0.3.1 over GPLv2:
o It is much shorter and simpler
o It has an explicit patent license grant, unlike GPLv2
o Its notice preservation conditions are clearer
o More free software/open source licenses are compatible
with it (via section 4)
o The source code requirement triggered by binary distribution
is much simpler in a procedural sense
o Recipients potentially have a contract claim against distributors
who are noncompliant with the source code requirement
o There is a built-in inbound=outbound policy for upstream
contributions (cf. Apache License 2.0 section 5)
o There are disincentives to engage in the controversial practice
of copyleft/ proprietary dual-licensing
o In 15 years copyleft expires, which can be advantageous
for legacy code
o There are explicit disincentives to bringing patent infringement
claims accusing the licensed work of infringement (see 10b)
o There is a cure period for licensees who are not compliant
with the license (there is no cure opportunity in GPLv2)
o copyleft-next has a 'built-in or-later' provision
The first driver submission to Linux under this dual strategy was
lib/test_sysctl.c through commit 9308f2f9e7 ("test_sysctl: add
dedicated proc sysctl test driver") merged in July 2017. Shortly after
that I also added test_kmod through commit d9c6a72d6f ("kmod: add
test driver to stress test the module loader") in the same month. These
two drivers went in just a few months before the SPDX license practice
kicked in. In 2018 Kuno Woudt went through the process to get SPDX
identifiers for copyleft-next [6] [7]. Although there are SPDX tags
for copyleft-next-0.3.0, we only document use in Linux starting from
copyleft-next-0.3.1 which makes GPLv2 compatibility crystal clear.
This patch will let us update the two Linux selftest drivers in
subsequent patches with their respective SPDX license identifiers and
let us remove repetitive license boiler plate.
[0] https://github.com/copyleft-next/copyleft-next/blob/master/Releases/copyleft-next-0.3.1
[1] https://lore.kernel.org/lkml/1465929311-13509-1-git-send-email-mcgrof@kernel.org/
[2] https://lore.kernel.org/lkml/CA+55aFyhxcvD+q7tp+-yrSFDKfR0mOHgyEAe=f_94aKLsOu0Og@mail.gmail.com/
[3] https://lore.kernel.org/lkml/20170516232702.GL17314@wotan.suse.de/
[4] https://lkml.kernel.org/r/1495234558.7848.122.camel@linux.intel.com
[5] https://lists.fedorahosted.org/archives/list/copyleft-next@lists.fedorahosted.org/thread/JTGV56DDADWGKU7ZKTZA4DLXTGTLNJ57/#SQMDIKBRAVDOCT4UVNOOCRGBN2UJIKHZ
[6] https://spdx.org/licenses/copyleft-next-0.3.0.html
[7] https://spdx.org/licenses/copyleft-next-0.3.1.html
Cc: Goldwyn Rodrigues <rgoldwyn@suse.com>
Cc: Kuno Woudt <kuno@frob.nl>
Cc: Richard Fontana <fontana@sharpeleven.org>
Cc: copyleft-next@lists.fedorahosted.org
Cc: Ciaran Farrell <Ciaran.Farrell@suse.com>
Cc: Christopher De Nicolo <Christopher.DeNicolo@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Thorsten Leemhuis <linux@leemhuis.info>
Cc: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Tim Bird <tim.bird@sony.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A couple of exotic quote characters came in with this license text; they
can confuse software that is not expecting non-ASCII text. Switch to
normal quotes here, with no changes to the actual license text.
Reported-by: Rahul T R <r-ravikumar@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Thorsten Leemhuis <linux@leemhuis.info>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20210703012931.30604-1-nm@ti.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
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>
