1 files changed, 78 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf4.c b/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf4.c
new file mode 100644
index 000000000000..a017d6b2f1dd
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf4.c
@@ -0,0 +1,78 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__uint(max_entries, 1);
+	__uint(key_size, sizeof(__u32));
+	__uint(value_size, sizeof(__u32));
+} nop_table SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_PROG_ARRAY);
+	__uint(max_entries, 3);
+	__uint(key_size, sizeof(__u32));
+	__uint(value_size, sizeof(__u32));
+} jmp_table SEC(".maps");
+
+int count = 0;
+int noise = 0;
+
+static __always_inline int subprog_noise(void)
+{
+	__u32 key = 0;
+
+	bpf_map_lookup_elem(&nop_table, &key);
+	return 0;
+}
+
+__noinline
+int subprog_tail_2(struct __sk_buff *skb)
+{
+	if (noise)
+		subprog_noise();
+	bpf_tail_call_static(skb, &jmp_table, 2);
+	return skb->len * 3;
+}
+
+__noinline
+int subprog_tail_1(struct __sk_buff *skb)
+{
+	bpf_tail_call_static(skb, &jmp_table, 1);
+	return skb->len * 2;
+}
+
+__noinline
+int subprog_tail(struct __sk_buff *skb)
+{
+	bpf_tail_call_static(skb, &jmp_table, 0);
+	return skb->len;
+}
+
+SEC("tc")
+int classifier_1(struct __sk_buff *skb)
+{
+	return subprog_tail_2(skb);
+}
+
+SEC("tc")
+int classifier_2(struct __sk_buff *skb)
+{
+	count++;
+	return subprog_tail_2(skb);
+}
+
+SEC("tc")
+int classifier_0(struct __sk_buff *skb)
+{
+	return subprog_tail_1(skb);
+}
+
+SEC("tc")
+int entry(struct __sk_buff *skb)
+{
+	return subprog_tail(skb);
+}
+
+char __license[] SEC("license") = "GPL";