Commit be05c944 authored by Alexei Starovoitov's avatar Alexei Starovoitov Committed by Andrii Nakryiko
Browse files

libbpf: Support init of inner maps in light skeleton. 



Add ability to initialize inner maps in light skeleton.

Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Acked-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211201181040.23337-11-alexei.starovoitov@gmail.com
parent d0e92887

tools/lib/bpf/bpf_gen_internal.h

+1 −0
Original line number Diff line number Diff line
@@ -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

tools/lib/bpf/gen_loader.c

+27 −0
Original line number Diff line number Diff line
@@ -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);

tools/lib/bpf/libbpf.c

+3 −3
Original line number Diff line number Diff line
@@ -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);

		}