1// SPDX-License-Identifier: GPL-2.0
2/* Copyright (c) 2022 Google */
3#include "vmlinux.h"
4#include <bpf/bpf_helpers.h>
5#include <bpf/bpf_tracing.h>
6
7struct bpf_testmod_btf_type_tag_1 {
8 int a;
9};
10
11struct bpf_testmod_btf_type_tag_2 {
12 struct bpf_testmod_btf_type_tag_1 *p;
13};
14
15__u64 g;
16
17SEC("fentry/bpf_testmod_test_btf_type_tag_percpu_1")
18int BPF_PROG(test_percpu1, struct bpf_testmod_btf_type_tag_1 *arg)
19{
20 g = arg->a;
21 return 0;
22}
23
24SEC("fentry/bpf_testmod_test_btf_type_tag_percpu_2")
25int BPF_PROG(test_percpu2, struct bpf_testmod_btf_type_tag_2 *arg)
26{
27 g = arg->p->a;
28 return 0;
29}
30
31/* trace_cgroup_mkdir(struct cgroup *cgrp, const char *path)
32 *
33 * struct cgroup_rstat_cpu {
34 * ...
35 * struct cgroup *updated_children;
36 * ...
37 * };
38 *
39 * struct cgroup {
40 * ...
41 * struct cgroup_rstat_cpu __percpu *rstat_cpu;
42 * ...
43 * };
44 */
45SEC("tp_btf/cgroup_mkdir")
46int BPF_PROG(test_percpu_load, struct cgroup *cgrp, const char *path)
47{
48 g = (__u64)cgrp->rstat_cpu->updated_children;
49 return 0;
50}
51
52SEC("tp_btf/cgroup_mkdir")
53int BPF_PROG(test_percpu_helper, struct cgroup *cgrp, const char *path)
54{
55 struct cgroup_rstat_cpu *rstat;
56 __u32 cpu;
57
58 cpu = bpf_get_smp_processor_id();
59 rstat = (struct cgroup_rstat_cpu *)bpf_per_cpu_ptr(cgrp->rstat_cpu, cpu);
60 if (rstat) {
61 /* READ_ONCE */
62 *(volatile int *)rstat;
63 }
64
65 return 0;
66}
67char _license[] SEC("license") = "GPL";
68

source code of linux/tools/testing/selftests/bpf/progs/btf_type_tag_percpu.c