On 9/22/21 7:41 PM, Andrii Nakryiko wrote:
> Implement strict ELF section name handling for BPF programs. It utilizes
> `libbpf_set_strict_mode()` framework and adds new flag: LIBBPF_STRICT_SEC_NAME.
>
> If this flag is set, libbpf will enforce exact section name matching for
> a lot of program types that previously allowed just partial prefix
> match. E.g., if previously SEC("xdp_whatever_i_want") was allowed, now
> in strict mode only SEC("xdp") will be accepted, which makes SEC("")
> definitions cleaner and more structured. SEC() now won't be used as yet
> another way to uniquely encode BPF program identifier (for that
> C function name is better and is guaranteed to be unique within
> bpf_object). Now SEC() is strictly BPF program type and, depending on
> program type, extra load/attach parameter specification.
>
> Libbpf completely supports multiple BPF programs in the same ELF
> section, so multiple BPF programs of the same type/specification easily
> co-exist together within the same bpf_object scope.
>
> Additionally, a new (for now internal) convention is introduced: section
> name that can be a stand-alone exact BPF program type specificator, but
> also could have extra parameters after '/' delimiter. An example of such
> section is "struct_ops", which can be specified by itself, but also
> allows to specify the intended operation to be attached to, e.g.,
> "struct_ops/dctcp_init". Note, that "struct_ops_some_op" is not allowed.
> Such section definition is specified as "struct_ops+".
>
> This change is part of libbpf 1.0 effort ([0], [1]).
>
> [0] Closes: https://github.com/libbpf/libbpf/issues/271
> [1] https://github.com/libbpf/libbpf/wiki/Libbpf:-the-road-to-v1.0#stricter-and-more-uniform-bpf-program-section-name-sec-handling
>
> Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
> ---
Acked-by: Dave Marchevsky <davemarchevsky@xxxxxx>
