selftest/bpf: extend the offload test with map checks

Check map device information is reported correctly, and perform
basic map operations.  Check device destruction gets rid of the
maps and map allocation failure path by telling netdevsim to
reject map offload via DebugFS.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

1 files changed, 34 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/sample_map_ret0.c b/tools/testing/selftests/bpf/sample_map_ret0.c
new file mode 100644
index 000000000000..0756303676ac
--- /dev/null
+++ b/tools/testing/selftests/bpf/sample_map_ret0.c
@@ -0,0 +1,34 @@
+/* SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) */
+#include <linux/bpf.h>
+#include "bpf_helpers.h"
+
+struct bpf_map_def SEC("maps") htab = {
+	.type = BPF_MAP_TYPE_HASH,
+	.key_size = sizeof(__u32),
+	.value_size = sizeof(long),
+	.max_entries = 2,
+};
+
+struct bpf_map_def SEC("maps") array = {
+	.type = BPF_MAP_TYPE_ARRAY,
+	.key_size = sizeof(__u32),
+	.value_size = sizeof(long),
+	.max_entries = 2,
+};
+
+/* Sample program which should always load for testing control paths. */
+SEC(".text") int func()
+{
+	__u64 key64 = 0;
+	__u32 key = 0;
+	long *value;
+
+	value = bpf_map_lookup_elem(&htab, &key);
+	if (!value)
+		return 1;
+	value = bpf_map_lookup_elem(&array, &key64);
+	if (!value)
+		return 1;
+
+	return 0;
+}