xref: /OK3568_Linux_fs/kernel/tools/testing/selftests/bpf/progs/tailcall1.c (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun #include <linux/bpf.h>
3*4882a593Smuzhiyun 
4*4882a593Smuzhiyun #include <bpf/bpf_helpers.h>
5*4882a593Smuzhiyun 
6*4882a593Smuzhiyun struct {
7*4882a593Smuzhiyun 	__uint(type, BPF_MAP_TYPE_PROG_ARRAY);
8*4882a593Smuzhiyun 	__uint(max_entries, 3);
9*4882a593Smuzhiyun 	__uint(key_size, sizeof(__u32));
10*4882a593Smuzhiyun 	__uint(value_size, sizeof(__u32));
11*4882a593Smuzhiyun } jmp_table SEC(".maps");
12*4882a593Smuzhiyun 
13*4882a593Smuzhiyun #define TAIL_FUNC(x) 				\
14*4882a593Smuzhiyun 	SEC("classifier/" #x)			\
15*4882a593Smuzhiyun 	int bpf_func_##x(struct __sk_buff *skb)	\
16*4882a593Smuzhiyun 	{					\
17*4882a593Smuzhiyun 		return x;			\
18*4882a593Smuzhiyun 	}
19*4882a593Smuzhiyun TAIL_FUNC(0)
20*4882a593Smuzhiyun TAIL_FUNC(1)
21*4882a593Smuzhiyun TAIL_FUNC(2)
22*4882a593Smuzhiyun 
23*4882a593Smuzhiyun SEC("classifier")
entry(struct __sk_buff * skb)24*4882a593Smuzhiyun int entry(struct __sk_buff *skb)
25*4882a593Smuzhiyun {
26*4882a593Smuzhiyun 	/* Multiple locations to make sure we patch
27*4882a593Smuzhiyun 	 * all of them.
28*4882a593Smuzhiyun 	 */
29*4882a593Smuzhiyun 	bpf_tail_call_static(skb, &jmp_table, 0);
30*4882a593Smuzhiyun 	bpf_tail_call_static(skb, &jmp_table, 0);
31*4882a593Smuzhiyun 	bpf_tail_call_static(skb, &jmp_table, 0);
32*4882a593Smuzhiyun 	bpf_tail_call_static(skb, &jmp_table, 0);
33*4882a593Smuzhiyun 
34*4882a593Smuzhiyun 	bpf_tail_call_static(skb, &jmp_table, 1);
35*4882a593Smuzhiyun 	bpf_tail_call_static(skb, &jmp_table, 1);
36*4882a593Smuzhiyun 	bpf_tail_call_static(skb, &jmp_table, 1);
37*4882a593Smuzhiyun 	bpf_tail_call_static(skb, &jmp_table, 1);
38*4882a593Smuzhiyun 
39*4882a593Smuzhiyun 	bpf_tail_call_static(skb, &jmp_table, 2);
40*4882a593Smuzhiyun 	bpf_tail_call_static(skb, &jmp_table, 2);
41*4882a593Smuzhiyun 	bpf_tail_call_static(skb, &jmp_table, 2);
42*4882a593Smuzhiyun 	bpf_tail_call_static(skb, &jmp_table, 2);
43*4882a593Smuzhiyun 
44*4882a593Smuzhiyun 	return 3;
45*4882a593Smuzhiyun }
46*4882a593Smuzhiyun 
47*4882a593Smuzhiyun char __license[] SEC("license") = "GPL";
48*4882a593Smuzhiyun int _version SEC("version") = 1;
49