On 2/28/24 09:48, Andrii Nakryiko wrote:
On Mon, Feb 26, 2024 at 5:04 PM Kui-Feng Lee <thinker.li@xxxxxxxxx> wrote:For a struct_ops map, btf_value_type_id is the type ID of it's struct type. This value is required by bpftool to generate skeleton including pointers of shadow types. The code generator gets the type ID from bpf_map__btf_vaule_type_id() in order to get the type information of the struct type of a map. Signed-off-by: Kui-Feng Lee <thinker.li@xxxxxxxxx> --- tools/lib/bpf/libbpf.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index ef8fd20f33ca..465b50235a01 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -1229,6 +1229,7 @@ static int init_struct_ops_maps(struct bpf_object *obj, const char *sec_name, map->name = strdup(var_name); if (!map->name) return -ENOMEM; + map->btf_value_type_id = type_id;this part is goodmap->def.type = BPF_MAP_TYPE_STRUCT_OPS; map->def.key_size = sizeof(int); @@ -4818,7 +4819,9 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map, b if (obj->btf && btf__fd(obj->btf) >= 0) { create_attr.btf_fd = btf__fd(obj->btf); create_attr.btf_key_type_id = map->btf_key_type_id; - create_attr.btf_value_type_id = map->btf_value_type_id; + create_attr.btf_value_type_id = + def->type != BPF_MAP_TYPE_STRUCT_OPS ? + map->btf_value_type_id : 0;but here I think it's cleaner to reset create_attr.btf_value_type_id to zero a bit lower, see that we have special logic for PERF_EVENT_ARRAY, CGROUP_ARRAY and a bunch more maps. Just add a case for BPF_MAP_TYPE_STRUCT_OPS that will clear create_attr.btf_value_type_id only (keeping btf_fd and map->btf_value_Type_id intact)
No problem!
} if (bpf_map_type__is_map_in_map(def->type)) { -- 2.34.1
