d75fe9cb1d
libbpf and bpftool have been dual-licensed to facilitate inclusion in software that is not compatible with GPL2-only (ie: Apache2), but the samples are still GPL2-only. Given these files are samples, they get naturally copied around. For example, it is the case for samples/bpf/bpf_insn.h which was copied into the systemd tree: https://github.com/systemd/systemd/blob/main/src/shared/linux/bpf_insn.h Some more context on systemd's needs specifically: Most of systemd is (L)GPL2-or-later, which means there is no perceived incompatibility with Apache2 software and can thus be linked with OpenSSL 3.0. But given this GPL2-only header is included this is currently not possible. Dual-licensing this header solves this problem for us as we are scoping a move to OpenSSL 3.0, see: https://lists.freedesktop.org/archives/systemd-devel/2021-September/046882.html Dual-license this header as GPL-2.0-only OR BSD-2-Clause to follow the same licensing used by libbpf and bpftool: 1bc38b8ff6cc ("libbpf: relicense libbpf as LGPL-2.1 OR BSD-2-Clause") 907b22365115 ("tools: bpftool: dual license all files") Signed-off-by: Luca Boccassi <bluca@debian.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Simon Horman <simon.horman@corigine.com> Acked-by: Daniel Mack <daniel@zonque.org> Acked-by: Josef Bacik <josef@toxicpanda.com> Acked-by: Joe Stringer <joe@ovn.org> Acked-by: Chenbo Feng <fengc@google.com> Acked-by: Björn Töpel <bjorn@kernel.org> Acked-by: Magnus Karlsson <magnus.karlsson@intel.com> Acked-by: Brendan Jackman <jackmanb@google.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210923000540.47344-1-luca.boccassi@gmail.com
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.