From: Andrey Grafin conquistador@yandex-team.ru
[ Upstream commit f04deb90e516e8e48bf8693397529bc942a9e80b ]
This patch allows to auto create BPF_MAP_TYPE_ARRAY_OF_MAPS and BPF_MAP_TYPE_HASH_OF_MAPS with values of BPF_MAP_TYPE_PERF_EVENT_ARRAY by bpf_object__load().
Previous behaviour created a zero filled btf_map_def for inner maps and tried to use it for a map creation but the linux kernel forbids to create a BPF_MAP_TYPE_PERF_EVENT_ARRAY map with max_entries=0.
Fixes: 646f02ffdd49 ("libbpf: Add BTF-defined map-in-map support") Signed-off-by: Andrey Grafin conquistador@yandex-team.ru Signed-off-by: Andrii Nakryiko andrii@kernel.org Acked-by: Yonghong Song yonghong.song@linux.dev Acked-by: Hou Tao houtao1@huawei.com Link: https://lore.kernel.org/bpf/20240117130619.9403-1-conquistador@yandex-team.r... Signed-off-by: Alexei Starovoitov ast@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- tools/lib/bpf/libbpf.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 0c201f07d8aef..e45f831a12c2b 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -71,6 +71,7 @@
static struct bpf_map *bpf_object__add_map(struct bpf_object *obj); static bool prog_is_subprog(const struct bpf_object *obj, const struct bpf_program *prog); +static int map_set_def_max_entries(struct bpf_map *map);
static int __base_pr(enum libbpf_print_level level, const char *format, va_list args) @@ -4617,6 +4618,9 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map, b
if (bpf_map_type__is_map_in_map(def->type)) { if (map->inner_map) { + err = map_set_def_max_entries(map->inner_map); + if (err) + return err; err = bpf_object__create_map(obj, map->inner_map, true); if (err) { pr_warn("map '%s': failed to create inner map: %d\n",