selftests/bpf: Add BTF.ext line/func info getter tests

Add selftests checking that line and func info retrieved by newly added
libbpf APIs are the same as returned by kernel via bpf_prog_get_info_by_fd.

Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250408234417.452565-3-mykyta.yatsenko5@gmail.com

1 files changed, 22 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/progs/test_btf_ext.c b/tools/testing/selftests/bpf/progs/test_btf_ext.c
new file mode 100644
index 000000000000..cdf20331db04
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_btf_ext.c
@@ -0,0 +1,22 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2025 Meta Platforms Inc. */
+
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include "bpf_misc.h"
+
+char _license[] SEC("license") = "GPL";
+
+__noinline static void f0(void)
+{
+	__u64 a = 1;
+
+	__sink(a);
+}
+
+SEC("xdp")
+__u64 global_func(struct xdp_md *xdp)
+{
+	f0();
+	return XDP_DROP;
+}