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