Commit f7310523 authored by Hengqi Chen's avatar Hengqi Chen Committed by Andrii Nakryiko
Browse files

libbpf: Support uniform BTF-defined key/value specification across all BPF maps 

A bunch of BPF maps do not support specifying BTF types for key and value.
This is non-uniform and inconvenient[0]. Currently, libbpf uses a retry
logic which removes BTF type IDs when BPF map creation failed. Instead
of retrying, this commit recognizes those specialized maps and removes
BTF type IDs when creating BPF map.

  [0] Closes: https://github.com/libbpf/libbpf/issues/355



Signed-off-by: default avatarHengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210930161456.3444544-2-hengqi.chen@gmail.com
parent 7bceeb95

tools/lib/bpf/libbpf.c

+24 −0
Original line number Diff line number Diff line
@@ -4669,6 +4669,30 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map, b 
			create_attr.inner_map_fd = map->inner_map_fd;

	}



	switch (def->type) {

	case BPF_MAP_TYPE_PERF_EVENT_ARRAY:

	case BPF_MAP_TYPE_CGROUP_ARRAY:

	case BPF_MAP_TYPE_STACK_TRACE:

	case BPF_MAP_TYPE_ARRAY_OF_MAPS:

	case BPF_MAP_TYPE_HASH_OF_MAPS:

	case BPF_MAP_TYPE_DEVMAP:

	case BPF_MAP_TYPE_DEVMAP_HASH:

	case BPF_MAP_TYPE_CPUMAP:

	case BPF_MAP_TYPE_XSKMAP:

	case BPF_MAP_TYPE_SOCKMAP:

	case BPF_MAP_TYPE_SOCKHASH:

	case BPF_MAP_TYPE_QUEUE:

	case BPF_MAP_TYPE_STACK:

	case BPF_MAP_TYPE_RINGBUF:

		create_attr.btf_fd = 0;

		create_attr.btf_key_type_id = 0;

		create_attr.btf_value_type_id = 0;

		map->btf_key_type_id = 0;

		map->btf_value_type_id = 0;

	default:

		break;

	}



	if (obj->gen_loader) {

		bpf_gen__map_create(obj->gen_loader, &create_attr, is_inner ? -1 : map - obj->maps);

		/* Pretend to have valid FD to pass various fd >= 0 checks.