[PATCH v2 2/2] selftests/bpf: add test for percpu map flags combination

[Masoud Aghasi <maghasi@disroot.org>]

Add tests to exercise usage of a combination of flags for
percpu hash map updates.

Before the fix, these tests fail to respect user flags combination of
(BPF_F_CPU | BPF_EXIST). With the fix applied these tests pass.

Signed-off-by: Masoud Aghasi <maghasi@disroot.org>
---
 .../selftests/bpf/prog_tests/percpu_alloc.c   | 32 +++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/tools/testing/selftests/bpf/prog_tests/percpu_alloc.c b/tools/testing/selftests/bpf/prog_tests/percpu_alloc.c
index 7b4a1e24363b..e14a476da5c8 100644
--- a/tools/testing/selftests/bpf/prog_tests/percpu_alloc.c
+++ b/tools/testing/selftests/bpf/prog_tests/percpu_alloc.c
@@ -537,6 +537,34 @@ static void test_hash_cpu_flag(void)
 	test_map_op_cpu_flag(BPF_MAP_TYPE_HASH);
 }
 
+static void test_percpu_map_flags_combination(enum bpf_map_type map_type)
+{
+	u32 max_entries = 1;
+	u64 flags, val = 0;
+	int err, map_fd, key = 0;
+
+	map_fd = bpf_map_create(map_type, "test_flags_combo",
+				sizeof(int), sizeof(u64), max_entries, NULL);
+	if (!ASSERT_GE(map_fd, 0, "bpf_map_create"))
+		return;
+
+	flags = BPF_F_CPU | BPF_EXIST;
+	err = bpf_map_update_elem(map_fd, &key, &val, flags);
+	ASSERT_EQ(err, -ENOENT, "bpf_map_update_elem flags_combo");
+
+	close(map_fd);
+}
+
+static void test_percpu_hash_flags_combination(void)
+{
+	test_percpu_map_flags_combination(BPF_MAP_TYPE_PERCPU_HASH);
+}
+
+static void test_percpu_lru_hash_flags_combination(void)
+{
+	test_percpu_map_flags_combination(BPF_MAP_TYPE_LRU_PERCPU_HASH);
+}
+
 void test_percpu_alloc(void)
 {
 	if (test__start_subtest("array"))
@@ -565,4 +593,8 @@ void test_percpu_alloc(void)
 		test_array_cpu_flag();
 	if (test__start_subtest("cpu_flag_hash"))
 		test_hash_cpu_flag();
+	if (test__start_subtest("percpu_hash_flags_combination"))
+		test_percpu_hash_flags_combination();
+	if (test__start_subtest("percpu_lru_hash_flags_combination"))
+		test_percpu_lru_hash_flags_combination();
 }
-- 
2.47.3