selftest/bpf: Add map_in_maps with BPF_MAP_TYPE_PERF_EVENT_ARRAY values

Check that bpf_object__load() successfully creates map_in_maps
with BPF_MAP_TYPE_PERF_EVENT_ARRAY values.
These changes cover fix in the previous patch
"libbpf: Apply map_set_def_max_entries() for inner_maps on creation".

A command line output is:
- w/o fix
$ sudo ./test_maps
libbpf: map 'mim_array_pe': failed to create inner map: -22
libbpf: map 'mim_array_pe': failed to create: Invalid argument(-22)
libbpf: failed to load object './test_map_in_map.bpf.o'
Failed to load test prog

- with fix
$ sudo ./test_maps
...
test_maps: OK, 0 SKIPPED

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/20240117130619.9403-2-conquistador@yandex-team.ru
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 5 insertions, 1 deletions

diff --git a/tools/testing/selftests/bpf/test_maps.c b/tools/testing/selftests/bpf/test_maps.c
index 767e0693df10..dfbab214f4d1 100644
--- a/tools/testing/selftests/bpf/test_maps.c
+++ b/tools/testing/selftests/bpf/test_maps.c
@@ -1190,7 +1190,11 @@ static void test_map_in_map(void)
 		goto out_map_in_map;
 	}
 
-	bpf_object__load(obj);
+	err = bpf_object__load(obj);
+	if (err) {
+		printf("Failed to load test prog\n");
+		goto out_map_in_map;
+	}
 
 	map = bpf_object__find_map_by_name(obj, "mim_array");
 	if (!map) {