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

From: Andrii Nakryiko
Date: Wed Oct 05 2022 - 19:14:40 EST


On Tue, Oct 4, 2022 at 6:18 AM Roberto Sassu
<roberto.sassu@xxxxxxxxxxxxxxx> wrote:
>
> From: Roberto Sassu <roberto.sassu@xxxxxxxxxx>
>
> NOTE: resending with libbpf_get_fd_opts test added to deny list for s390x.

it's not a resend if you change something in patches, it's a new
version, please mark it appropriately with v2 instead of [RESEND]

>
> 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 to
> the kernel.
>
> Pass the options through a newly introduced structure, bpf_get_fd_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.
>
> Roberto Sassu (6):
> libbpf: Fix LIBBPF_1.0.0 declaration in libbpf.map
> libbpf: Define bpf_get_fd_opts and introduce
> 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()
>
> tools/lib/bpf/bpf.c | 47 +++++++++-
> 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_opts.c | 88 +++++++++++++++++++
> .../bpf/progs/test_libbpf_get_fd_opts.c | 36 ++++++++
> 6 files changed, 189 insertions(+), 5 deletions(-)
> create mode 100644 tools/testing/selftests/bpf/prog_tests/libbpf_get_fd_opts.c
> create mode 100644 tools/testing/selftests/bpf/progs/test_libbpf_get_fd_opts.c
>
> --
> 2.25.1
>