1// SPDX-License-Identifier: GPL-2.0
2/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */
3
4#include "vmlinux.h"
5#include <bpf/bpf_helpers.h>
6#include <bpf/bpf_tracing.h>
7
8char _license[] SEC("license") = "GPL";
9
10struct {
11 __uint(type, BPF_MAP_TYPE_CGRP_STORAGE);
12 __uint(map_flags, BPF_F_NO_PREALLOC);
13 __type(key, int);
14 __type(value, long);
15} map_a SEC(".maps");
16
17struct {
18 __uint(type, BPF_MAP_TYPE_CGRP_STORAGE);
19 __uint(map_flags, BPF_F_NO_PREALLOC);
20 __type(key, int);
21 __type(value, long);
22} map_b SEC(".maps");
23
24int target_hid = 0;
25bool is_cgroup1 = 0;
26
27struct cgroup *bpf_task_get_cgroup1(struct task_struct *task, int hierarchy_id) __ksym;
28void bpf_cgroup_release(struct cgroup *cgrp) __ksym;
29
30static void __on_update(struct cgroup *cgrp)
31{
32 long *ptr;
33
34 ptr = bpf_cgrp_storage_get(&map_a, cgrp, 0, BPF_LOCAL_STORAGE_GET_F_CREATE);
35 if (ptr)
36 *ptr += 1;
37
38 ptr = bpf_cgrp_storage_get(&map_b, cgrp, 0, BPF_LOCAL_STORAGE_GET_F_CREATE);
39 if (ptr)
40 *ptr += 1;
41}
42
43SEC("fentry/bpf_local_storage_update")
44int BPF_PROG(on_update)
45{
46 struct task_struct *task = bpf_get_current_task_btf();
47 struct cgroup *cgrp;
48
49 if (is_cgroup1) {
50 cgrp = bpf_task_get_cgroup1(task, target_hid);
51 if (!cgrp)
52 return 0;
53
54 __on_update(cgrp);
55 bpf_cgroup_release(cgrp);
56 return 0;
57 }
58
59 __on_update(cgrp: task->cgroups->dfl_cgrp);
60 return 0;
61}
62
63static void __on_enter(struct pt_regs *regs, long id, struct cgroup *cgrp)
64{
65 long *ptr;
66
67 ptr = bpf_cgrp_storage_get(&map_a, cgrp, 0, BPF_LOCAL_STORAGE_GET_F_CREATE);
68 if (ptr)
69 *ptr = 200;
70
71 ptr = bpf_cgrp_storage_get(&map_b, cgrp, 0, BPF_LOCAL_STORAGE_GET_F_CREATE);
72 if (ptr)
73 *ptr = 100;
74}
75
76SEC("tp_btf/sys_enter")
77int BPF_PROG(on_enter, struct pt_regs *regs, long id)
78{
79 struct task_struct *task = bpf_get_current_task_btf();
80 struct cgroup *cgrp;
81
82 if (is_cgroup1) {
83 cgrp = bpf_task_get_cgroup1(task, target_hid);
84 if (!cgrp)
85 return 0;
86
87 __on_enter(regs: regs, id: id, cgrp);
88 bpf_cgroup_release(cgrp);
89 return 0;
90 }
91
92 __on_enter(regs: regs, id: id, cgrp: task->cgroups->dfl_cgrp);
93 return 0;
94}
95

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