tailcall_bpf2bpf_hierarchy1.c

 1// SPDX-License-Identifier: GPL-2.0
 2#include <linux/bpf.h>
 3#include <bpf/bpf_helpers.h>
 4#include "bpf_legacy.h"
 5#include "bpf_test_utils.h"
 6
 7struct {
 8	__uint(type, BPF_MAP_TYPE_PROG_ARRAY);
 9	__uint(max_entries, 1);
10	__uint(key_size, sizeof(__u32));
11	__uint(value_size, sizeof(__u32));
12} jmp_table SEC(".maps");
13
14int count = 0;
15
16static __noinline
17int subprog_tail(struct __sk_buff *skb)
18{
19	bpf_tail_call_static(skb, &jmp_table, 0);
20	return 0;
21}
22
23SEC("tc")
24int entry(struct __sk_buff *skb)
25{
26	int ret = 1;
27
28	clobber_regs_stack();
29
30	count++;
31	subprog_tail(skb);
32	subprog_tail(skb);
33
34	return ret;
35}
36
37char __license[] SEC("license") = "GPL";