[RESEND,0/6] Add _opts variant for bpf_*_get_fd_by_id()

Message

Roberto Sassu Oct. 4, 2022, 1:17 p.m. UTC

From: Roberto Sassu <[e-mail]>

NOTE: resending with libbpf_get_fd_opts test added to deny list for s390x.

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

Comments

Andrii Nakryiko Oct. 5, 2022, 11:14 p.m. UTC | #1

On Tue, Oct 4, 2022 at 6:18 AM Roberto Sassu
<[e-mail]> wrote:
>
> From: Roberto Sassu <[e-mail]>
>
> 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
>