linux

iv/linux

History

Andrii Nakryiko 87dbdc230d libbpf: Don't require full struct enum64 in UAPI headers

Drop the requirement for system-wide kernel UAPI headers to provide full
struct btf_enum64 definition. This is an unexpected requirement that
slipped in libbpf 1.0 and put unnecessary pressure ([0]) on users to have
a bleeding-edge kernel UAPI header from unreleased Linux 6.0.

To achieve this, we forward declare struct btf_enum64. But that's not
enough as there is btf_enum64_value() helper that expects to know the
layout of struct btf_enum64. So we get a bit creative with
reinterpreting memory layout as array of __u32 and accesing lo32/hi32
fields as array elements. Alternative way would be to have a local
pointer variable for anonymous struct with exactly the same layout as
struct btf_enum64, but that gets us into C++ compiler errors complaining
about invalid type casts. So play it safe, if ugly.

  [0] Closes: https://github.com/libbpf/libbpf/issues/562

Fixes: d90ec262b35b ("libbpf: Add enum64 support for btf_dump")
Reported-by: Toke Høiland-Jørgensen <toke@toke.dk>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Toke Høiland-Jørgensen <toke@toke.dk>
Link: https://lore.kernel.org/bpf/20220927042940.147185-1-andrii@kernel.org

2022-09-27 20:45:17 +02:00

api

Kbuild updates for v5.18

2022-03-31 11:59:03 -07:00

bpf

libbpf: Don't require full struct enum64 in UAPI headers

2022-09-27 20:45:17 +02:00

perf

libperf: Add a test case for read formats

2022-08-19 15:56:44 -03:00

subcmd

libsubcmd: Fix OPTION_GROUP sorting