[PATCH bpf 2/2] selftests/bpf: Update map_in_map using map without BTF key/value info

[Hengqi Chen <hengqi.chen@xxxxxxxxx>]

Add a selftest to ensure that inner map without BTF key/value info
can coexist with inner map with BTF key/value info in the same map_in_map.

Signed-off-by: Hengqi Chen <hengqi.chen@xxxxxxxxx>
---
 .../selftests/bpf/prog_tests/btf_map_in_map.c | 27 +++++++++++++++++++
 .../selftests/bpf/progs/test_btf_map_in_map.c | 22 +++++++++++++++
 2 files changed, 49 insertions(+)

diff --git a/tools/testing/selftests/bpf/prog_tests/btf_map_in_map.c b/tools/testing/selftests/bpf/prog_tests/btf_map_in_map.c
index eb90a6b8850d..d34d91d6d9ca 100644
--- a/tools/testing/selftests/bpf/prog_tests/btf_map_in_map.c
+++ b/tools/testing/selftests/bpf/prog_tests/btf_map_in_map.c
@@ -154,6 +154,30 @@ static void test_diff_size(void)
 	test_btf_map_in_map__destroy(skel);
 }

+static void test_btf_key_value(void)
+{
+	struct test_btf_map_in_map *skel;
+	int err, map_fd1, map_fd2, zero = 0;
+
+	skel = test_btf_map_in_map__open_and_load();
+	if (CHECK(!skel, "skel_open", "failed to open&load skeleton\n"))
+		return;
+
+	map_fd1 = bpf_map__fd(skel->maps.inner);
+	err = bpf_map_update_elem(bpf_map__fd(skel->maps.outer), &zero, &map_fd1, 0);
+	CHECK(err, "update map_in_map using map with BTF key/value info",
+	      "cannot use inner map with BTF key/value info\n");
+
+	map_fd2 = bpf_map_create(BPF_MAP_TYPE_LRU_HASH, NULL, 4, 4, 1, NULL);
+	CHECK(map_fd2 < 0, "create map without BTF key/value info", "cannot create map\n");
+	err = bpf_map_update_elem(bpf_map__fd(skel->maps.outer), &zero, &map_fd2, 0);
+	CHECK(err, "update map_in_map using map without BTF key/value info",
+	      "cannot use inner map without BTF key/value info\n");
+
+	close(map_fd2);
+	test_btf_map_in_map__destroy(skel);
+}
+
 void test_btf_map_in_map(void)
 {
 	if (test__start_subtest("lookup_update"))
@@ -161,4 +185,7 @@ void test_btf_map_in_map(void)

 	if (test__start_subtest("diff_size"))
 		test_diff_size();
+
+	if (test__start_subtest("btf_key_value"))
+		test_btf_key_value();
 }
diff --git a/tools/testing/selftests/bpf/progs/test_btf_map_in_map.c b/tools/testing/selftests/bpf/progs/test_btf_map_in_map.c
index c218cf8989a9..8f7ca70496f2 100644
--- a/tools/testing/selftests/bpf/progs/test_btf_map_in_map.c
+++ b/tools/testing/selftests/bpf/progs/test_btf_map_in_map.c
@@ -118,6 +118,28 @@ struct outer_sockarr_sz1 {
 	.values = { (void *)&sockarr_sz1 },
 };

+struct inner_key {
+	__u32 x;
+};
+
+struct inner_value {
+	__u32 y;
+};
+
+struct inner {
+	__uint(type, BPF_MAP_TYPE_LRU_HASH);
+	__uint(max_entries, 1);
+	__type(key, struct inner_key);
+	__type(value, struct inner_value);
+} inner SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS);
+	__uint(max_entries, 1);
+	__type(key, __u32);
+	__array(values, struct inner);
+} outer SEC(".maps");
+
 int input = 0;

 SEC("raw_tp/sys_enter")
--
2.34.1