On Fri, 16 Aug 2019 19:15:29 +0200 Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > On Fri, Aug 16, 2019 at 05:29:27PM +0200, Daniel Borkmann wrote: > > On 8/16/19 2:10 PM, Jesper Dangaard Brouer wrote: > > > On Thu, 15 Aug 2019 22:45:43 -0700 > > > Andrii Nakryiko <andriin@xxxxxx> wrote: > > > > > > > bpf_helpers.h and bpf_endian.h contain useful macros and BPF helper > > > > definitions essential to almost every BPF program. Which makes them > > > > useful not just for selftests. To be able to expose them as part of > > > > libbpf, though, we need them to be dual-licensed as LGPL-2.1 OR > > > > BSD-2-Clause. This patch updates licensing of those two files. > > > > > > I've already ACKed this, and is fine with (LGPL-2.1 OR BSD-2-Clause). > > > > > > I just want to understand, why "BSD-2-Clause" and not "Apache-2.0" ? > > > > > > The original argument was that this needed to be compatible with > > > "Apache-2.0", then why not simply add this in the "OR" ? > > > > It's use is discouraged in the kernel tree, see also LICENSES/dual/Apache-2.0 (below) and > > statement wrt compatibility from https://www.apache.org/licenses/GPL-compatibility.html: > > > > Valid-License-Identifier: Apache-2.0 > > SPDX-URL: https://spdx.org/licenses/Apache-2.0.html > > Usage-Guide: > > Do NOT use. The Apache-2.0 is not GPL2 compatible. [...] You didn't quote the continuation from LICENSES/dual/Apache-2.0 Usage-Guide: Do NOT use. The Apache-2.0 is not GPL2 compatible. It may only be used for dual-licensed files where the other license is GPL2 compatible. If you end up using this it MUST be used together with a GPL2 compatible license using "OR". The way I read it, is that you can use it with "OR", like: SPDX-License-Identifier: GPL-2.0 OR Apache-2.0 > That is correct, don't use Apache-2 code in the kernel please. Even as > a dual-license, it's a total mess. Good, I just wanted to understand why. > Having this be BSD-2 is actually better, as it should be fine to use > with Apache 2 code, right? Yes, that is also my understanding. And it better be as this is needed, as we want libbpf to be used by https://github.com/iovisor/bcc/ which is Apache-2.0. > Jesper, do you know of any license that BSD-2 is not compatible with > that is needed? No. -- Best regards, Jesper Dangaard Brouer MSc.CS, Principal Kernel Engineer at Red Hat LinkedIn: http://www.linkedin.com/in/brouer
