Commit 9992d63e authored Oct 31, 2023 by Hengqi Chen Committed by Liu Jian Oct 31, 2023

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

mainline inclusion
from mainline-v5.16-rc1
commit f7310523
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I7DNAP
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=f731052325efc3726577feb743c7495f880ae07d

--------------------------------

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: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210930161456.3444544-2-hengqi.chen@gmail.com


(cherry picked from commit f7310523)
Signed-off-by: Liu Jian <liujian56@huawei.com>

Conflicts:
	tools/lib/bpf/libbpf.c

parent 276d5fca

tools/lib/bpf/libbpf.c

+24 −0

Original line number	Diff line number	Diff line
		@@ -4229,6 +4229,30 @@ static int bpf_object__create_map(struct bpf_object obj, struct bpf_map map)
		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;
		}

		map->fd = bpf_create_map_xattr(&create_attr);
		if (map->fd < 0 && (create_attr.btf_key_type_id \|\|
		create_attr.btf_value_type_id)) {