libbpf: Support init of inner maps in light skeleton.

Add ability to initialize inner maps in light skeleton.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211201181040.23337-11-alexei.starovoitov@gmail.com
This commit is contained in:
Alexei Starovoitov 2021-12-01 10:10:33 -08:00 committed by Andrii Nakryiko
parent d0e928876e
commit be05c94476
3 changed files with 31 additions and 3 deletions

View file

@ -67,5 +67,6 @@ void bpf_gen__record_attach_target(struct bpf_gen *gen, const char *name, enum b
void bpf_gen__record_extern(struct bpf_gen *gen, const char *name, bool is_weak,
bool is_typeless, int kind, int insn_idx);
void bpf_gen__record_relo_core(struct bpf_gen *gen, const struct bpf_core_relo *core_relo);
void bpf_gen__populate_outer_map(struct bpf_gen *gen, int outer_map_idx, int key, int inner_map_idx);
#endif

View file

@ -1053,6 +1053,33 @@ void bpf_gen__map_update_elem(struct bpf_gen *gen, int map_idx, void *pvalue,
emit_check_err(gen);
}
void bpf_gen__populate_outer_map(struct bpf_gen *gen, int outer_map_idx, int slot,
int inner_map_idx)
{
int attr_size = offsetofend(union bpf_attr, flags);
int map_update_attr, key;
union bpf_attr attr;
memset(&attr, 0, attr_size);
pr_debug("gen: populate_outer_map: outer %d key %d inner %d\n",
outer_map_idx, slot, inner_map_idx);
key = add_data(gen, &slot, sizeof(slot));
map_update_attr = add_data(gen, &attr, attr_size);
move_blob2blob(gen, attr_field(map_update_attr, map_fd), 4,
blob_fd_array_off(gen, outer_map_idx));
emit_rel_store(gen, attr_field(map_update_attr, key), key);
emit_rel_store(gen, attr_field(map_update_attr, value),
blob_fd_array_off(gen, inner_map_idx));
/* emit MAP_UPDATE_ELEM command */
emit_sys_bpf(gen, BPF_MAP_UPDATE_ELEM, map_update_attr, attr_size);
debug_ret(gen, "populate_outer_map outer %d key %d inner %d",
outer_map_idx, slot, inner_map_idx);
emit_check_err(gen);
}
void bpf_gen__map_freeze(struct bpf_gen *gen, int map_idx)
{
int attr_size = offsetofend(union bpf_attr, map_fd);

View file

@ -4971,9 +4971,9 @@ static int init_map_in_map_slots(struct bpf_object *obj, struct bpf_map *map)
fd = bpf_map__fd(targ_map);
if (obj->gen_loader) {
pr_warn("// TODO map_update_elem: idx %td key %d value==map_idx %td\n",
map - obj->maps, i, targ_map - obj->maps);
return -ENOTSUP;
bpf_gen__populate_outer_map(obj->gen_loader,
map - obj->maps, i,
targ_map - obj->maps);
} else {
err = bpf_map_update_elem(map->fd, &i, &fd, 0);
}