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
8 char _license[] SEC("license") = "GPL";
9
10 struct {
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
17 struct {
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
24 int target_hid = 0;
25 bool is_cgroup1 = 0;
26
27 struct cgroup *bpf_task_get_cgroup1(struct task_struct *task, int hierarchy_id) __ksym;
28 void bpf_cgroup_release(struct cgroup *cgrp) __ksym;
29
30 static 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
43 SEC("fentry/bpf_local_storage_update")
44 int 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(task->cgroups->dfl_cgrp);
60 return 0;
61 }
62
63 static 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
76 SEC("tp_btf/sys_enter")
77 int 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, id, cgrp);
88 bpf_cgroup_release(cgrp);
89 return 0;
90 }
91
92 __on_enter(regs, id, task->cgroups->dfl_cgrp);
93 return 0;
94 }
95
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