tailcall_bpf2bpf_hierarchy3.c

 1// SPDX-License-Identifier: GPL-2.0
 2#include <linux/bpf.h>
 3#include <bpf/bpf_helpers.h>
 4#include "bpf_misc.h"
 5#include "bpf_test_utils.h"
 6
 7int classifier_0(struct __sk_buff *skb);
 8
 9struct {
10	__uint(type, BPF_MAP_TYPE_PROG_ARRAY);
11	__uint(max_entries, 1);
12	__uint(key_size, sizeof(__u32));
13	__array(values, void (void));
14} jmp_table0 SEC(".maps") = {
15	.values = {
16		[0] = (void *) &classifier_0,
17	},
18};
19
20struct {
21	__uint(type, BPF_MAP_TYPE_PROG_ARRAY);
22	__uint(max_entries, 1);
23	__uint(key_size, sizeof(__u32));
24	__array(values, void (void));
25} jmp_table1 SEC(".maps") = {
26	.values = {
27		[0] = (void *) &classifier_0,
28	},
29};
30
31int count = 0;
32
33static __noinline
34int subprog_tail(struct __sk_buff *skb, void *jmp_table)
35{
36	bpf_tail_call_static(skb, jmp_table, 0);
37	return 0;
38}
39
40__auxiliary
41SEC("tc")
42int classifier_0(struct __sk_buff *skb)
43{
44	count++;
45	subprog_tail(skb, &jmp_table0);
46	subprog_tail(skb, &jmp_table1);
47	return count;
48}
49
50__success
51__retval(33)
52SEC("tc")
53int tailcall_bpf2bpf_hierarchy_3(struct __sk_buff *skb)
54{
55	int ret = 0;
56
57	clobber_regs_stack();
58
59	bpf_tail_call_static(skb, &jmp_table0, 0);
60
61	__sink(ret);
62	return ret;
63}
64
65char __license[] SEC("license") = "GPL";