Re: [PATCH v2 bpf-next 4/4] libbpf: deprecate bpf_program__get_prog_info_linear

["Toke Høiland-Jørgensen" <toke@redhat.com>]

Andrii Nakryiko <andrii.nakryiko@gmail.com> writes:

> On Mon, Oct 11, 2021 at 1:20 AM Dave Marchevsky <davemarchevsky@fb.com> wrote:
>>
>> As part of the road to libbpf 1.0, and discussed in libbpf issue tracker
>> [0], bpf_program__get_prog_info_linear and its associated structs and
>> helper functions should be deprecated. The functionality is too specific
>> to the needs of 'perf', and there's little/no out-of-tree usage to
>> preclude introduction of a more general helper in the future.
>>
>> [0] Closes: https://github.com/libbpf/libbpf/issues/313
>
> styling nit: don't know if it's described anywhere or not, but when
> people do references like this, they use 2 spaces of indentation. No
> idea how it came to be, but that's what I did for a while and see
> others doing the same.
>
>>
>> Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
>> ---
>>  tools/lib/bpf/libbpf.h | 3 +++
>>  1 file changed, 3 insertions(+)
>>
>> diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
>> index 89ca9c83ed4e..285008b46e1b 100644
>> --- a/tools/lib/bpf/libbpf.h
>> +++ b/tools/lib/bpf/libbpf.h
>> @@ -877,12 +877,15 @@ struct bpf_prog_info_linear {
>>         __u8                    data[];
>>  };
>>
>> +LIBBPF_DEPRECATED_SINCE(0, 7, "use a custom linear prog_info wrapper")
>>  LIBBPF_API struct bpf_prog_info_linear *
>>  bpf_program__get_prog_info_linear(int fd, __u64 arrays);
>>
>> +LIBBPF_DEPRECATED_SINCE(0, 7, "use a custom linear prog_info wrapper")
>>  LIBBPF_API void
>>  bpf_program__bpil_addr_to_offs(struct bpf_prog_info_linear *info_linear);
>>
>> +LIBBPF_DEPRECATED_SINCE(0, 7, "use a custom linear prog_info wrapper")
>
> we can actually deprecate all this starting from v0.6, because perf is
> building libbpf statically, so no worries about releases (also there
> are no replacement APIs we have to wait full release for)

Just FYI, we're also using this in libxdp, and that does link
dynamically to libbpf. It's not an issue to move away from it[0], but
perf is not the only user :)

-Toke

[0] Track that here: https://github.com/xdp-project/xdp-tools/issues/127