Re: [PATCH v2 0/6] Add _opts variant for bpf_*_get_fd_by_id()

Jiri Olsa
2022-10-07T10:59:31Z

On Thu, Oct 06, 2022 at 01:07:30PM +0200, Roberto Sassu wrote:
> From: Roberto Sassu <roberto.sassu@huawei.com>
>
> Add the _opts variant for bpf_*_get_fd_by_id() functions, to be able to
> pass to the kernel more options, when requesting a fd of an eBPF object.
>
> Pass the options through a newly introduced structure,
> bpf_get_fd_by_id_opts, which currently contains open_flags (the other two
> members are for compatibility and for padding).
>
> open_flags allows the caller to request specific permissions to access a
> map (e.g. read-only). This is useful for example in the situation where a
> map is write-protected.
>
> Besides patches 2-6, which introduce the new variants and the data
> structure, patch 1 fixes the LIBBPF_1.0.0 declaration in libbpf.map.
>
> Changelog
>
> v1:
> - Don't CC stable kernel mailing list for patch 1 (suggested by Andrii)
> - Rename bpf_get_fd_opts struct to bpf_get_fd_by_id_opts (suggested by
> Andrii)
> - Move declaration of _opts variants after non-opts variants (suggested by
> Andrii)
> - Correctly initialize bpf_map_info, fix style issues, use map from
> skeleton, check valid fd in the test (suggested by Andrii)
> - Rename libbpf_get_fd_opts test to libbpf_get_fd_by_id_opts
>
> Roberto Sassu (6):
> libbpf: Fix LIBBPF_1.0.0 declaration in libbpf.map
> libbpf: Introduce bpf_get_fd_by_id_opts and
> bpf_map_get_fd_by_id_opts()
> libbpf: Introduce bpf_prog_get_fd_by_id_opts()
> libbpf: Introduce bpf_btf_get_fd_by_id_opts()
> libbpf: Introduce bpf_link_get_fd_by_id_opts()
> selftests/bpf: Add tests for _opts variants of bpf_*_get_fd_by_id()

it's not marked, but I'm assuming this goes to bpf-next, right?

anyway, lgtm

Acked-by: Jiri Olsa <jolsa@kernel.org>

thanks,
jirka

>
> tools/lib/bpf/bpf.c | 48 +++++++++-
> tools/lib/bpf/bpf.h | 16 ++++
> tools/lib/bpf/libbpf.map | 6 +-
> tools/testing/selftests/bpf/DENYLIST.s390x | 1 +
> .../bpf/prog_tests/libbpf_get_fd_by_id_opts.c | 87 +++++++++++++++++++
> .../bpf/progs/test_libbpf_get_fd_by_id_opts.c | 36 ++++++++
> 6 files changed, 189 insertions(+), 5 deletions(-)
> create mode 100644 tools/testing/selftests/bpf/prog_tests/libbpf_get_fd_by_id_opts.c
> create mode 100644 tools/testing/selftests/bpf/progs/test_libbpf_get_fd_by_id_opts.c
>
> --
> 2.25.1
>