Re: [PATCH bpf-next] libbpf: relicense bpf_helpers.h and bpf_endian.h

[Daniel Borkmann <daniel@iogearbox.net>]

On 8/16/19 2:10 PM, Jesper Dangaard Brouer wrote:
> On Thu, 15 Aug 2019 22:45:43 -0700
> Andrii Nakryiko <andriin@fb.com> 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. [...]

>> Acked-by: Alexei Starovoitov <ast@kernel.org>
>> Acked-by: Hechao Li <hechaol@fb.com>
>> Acked-by: Martin KaFai Lau <kafai@fb.com>
>> Acked-by: Andrey Ignatov <rdna@fb.com>
>> Acked-by: Yonghong Song <yhs@fb.com>
>> Acked-by: Lawrence Brakmo <brakmo@fb.com>
>> Acked-by: Adam Barth <arb@fb.com>
>> Acked-by: Roman Gushchin <guro@fb.com>
>> Acked-by: Josef Bacik <jbacik@fb.com>
>> Acked-by: Joe Stringer <joe@wand.net.nz>
>> Acked-by: Daniel Borkmann <daniel@iogearbox.net>
>> Acked-by: Joel Fernandes (Google) <joel@joelfernandes.org>
>> Acked-by: David Ahern <dsahern@gmail.com>
>> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
> 
> Confirming I acked this.
> 
>> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
>> Acked-by: Lorenz Bauer <lmb@cloudflare.com>
>> Acked-by: Adrian Ratiu <adrian.ratiu@collabora.com>
>> Acked-by: Nikita V. Shirokov <tehnerd@tehnerd.com>
>> Acked-by: Willem de Bruijn <willemb@google.com>
>> Acked-by: Petar Penkov <ppenkov@google.com>
>> Acked-by: Teng Qin <palmtenor@gmail.com>
>> Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com>
>> Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
>> Cc: David S. Miller <davem@davemloft.net>
>> Cc: Michal Rostecki <mrostecki@opensuse.org>
>> Cc: John Fastabend <john.fastabend@gmail.com>
>> Cc: Sargun Dhillon <sargun@sargun.me>
>> Signed-off-by: Andrii Nakryiko <andriin@fb.com>
>> ---
>>   tools/testing/selftests/bpf/bpf_endian.h  | 2 +-
>>   tools/testing/selftests/bpf/bpf_helpers.h | 2 +-
>>   2 files changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/tools/testing/selftests/bpf/bpf_endian.h b/tools/testing/selftests/bpf/bpf_endian.h
>> index 05f036df8a4c..ff3593b0ae03 100644
>> --- a/tools/testing/selftests/bpf/bpf_endian.h
>> +++ b/tools/testing/selftests/bpf/bpf_endian.h
>> @@ -1,4 +1,4 @@
>> -/* SPDX-License-Identifier: GPL-2.0 */
>> +/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
>>   #ifndef __BPF_ENDIAN__
>>   #define __BPF_ENDIAN__
>>   
>> diff --git a/tools/testing/selftests/bpf/bpf_helpers.h b/tools/testing/selftests/bpf/bpf_helpers.h
>> index 8b503ea142f0..6c4930bc6e2e 100644
>> --- a/tools/testing/selftests/bpf/bpf_helpers.h
>> +++ b/tools/testing/selftests/bpf/bpf_helpers.h
>> @@ -1,4 +1,4 @@
>> -/* SPDX-License-Identifier: GPL-2.0 */
>> +/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
>>   #ifndef __BPF_HELPERS_H
>>   #define __BPF_HELPERS_H
>>   
> 
> 
>