1#include "bpf_experimental.h"
2
3struct val_t {
4 long b, c, d;
5};
6
7struct elem {
8 long sum;
9 struct val_t __percpu_kptr *pc;
10};
11
12struct {
13 __uint(type, BPF_MAP_TYPE_CGRP_STORAGE);
14 __uint(map_flags, BPF_F_NO_PREALLOC);
15 __type(key, int);
16 __type(value, struct elem);
17} cgrp SEC(".maps");
18
19const volatile int nr_cpus;
20
21/* Initialize the percpu object */
22SEC("fentry/bpf_fentry_test1")
23int BPF_PROG(test_cgrp_local_storage_1)
24{
25 struct task_struct *task;
26 struct val_t __percpu_kptr *p;
27 struct elem *e;
28
29 task = bpf_get_current_task_btf();
30 e = bpf_cgrp_storage_get(&cgrp, task->cgroups->dfl_cgrp, 0,
31 BPF_LOCAL_STORAGE_GET_F_CREATE);
32 if (!e)
33 return 0;
34
35 p = bpf_percpu_obj_new(struct val_t);
36 if (!p)
37 return 0;
38
39 p = bpf_kptr_xchg(&e->pc, p);
40 if (p)
41 bpf_percpu_obj_drop(p);
42
43 return 0;
44}
45
46/* Percpu data collection */
47SEC("fentry/bpf_fentry_test2")
48int BPF_PROG(test_cgrp_local_storage_2)
49{
50 struct task_struct *task;
51 struct val_t __percpu_kptr *p;
52 struct val_t *v;
53 struct elem *e;
54
55 task = bpf_get_current_task_btf();
56 e = bpf_cgrp_storage_get(&cgrp, task->cgroups->dfl_cgrp, 0, 0);
57 if (!e)
58 return 0;
59
60 p = e->pc;
61 if (!p)
62 return 0;
63
64 v = bpf_per_cpu_ptr(p, 0);
65 if (!v)
66 return 0;
67 v->c = 1;
68 v->d = 2;
69 return 0;
70}
71
72int cpu0_field_d, sum_field_c;
73int my_pid;
74
75/* Summarize percpu data collection */
76SEC("fentry/bpf_fentry_test3")
77int BPF_PROG(test_cgrp_local_storage_3)
78{
79 struct task_struct *task;
80 struct val_t __percpu_kptr *p;
81 struct val_t *v;
82 struct elem *e;
83 int i;
84
85 if ((bpf_get_current_pid_tgid() >> 32) != my_pid)
86 return 0;
87
88 task = bpf_get_current_task_btf();
89 e = bpf_cgrp_storage_get(&cgrp, task->cgroups->dfl_cgrp, 0, 0);
90 if (!e)
91 return 0;
92
93 p = e->pc;
94 if (!p)
95 return 0;
96
97 bpf_for(i, 0, nr_cpus) {
98 v = bpf_per_cpu_ptr(p, i);
99 if (v) {
100 if (i == 0)
101 cpu0_field_d = v->d;
102 sum_field_c += v->c;
103 }
104 }
105
106 return 0;
107}
108
109char _license[] SEC("license") = "GPL";
110

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