1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
|
// SPDX-License-Identifier: GPL-2.0
/* Copyright (C) 2023. Huawei Technologies Co., Ltd */
#include <linux/bpf.h>
#include <time.h>
#include <bpf/bpf_helpers.h>
#include "bpf_misc.h"
struct inner_map_type {
__uint(type, BPF_MAP_TYPE_ARRAY);
__uint(key_size, 4);
__uint(value_size, 4);
__uint(max_entries, 1);
} inner_map SEC(".maps");
struct {
__uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS);
__type(key, int);
__type(value, int);
__uint(max_entries, 1);
__array(values, struct inner_map_type);
} outer_array_map SEC(".maps") = {
.values = {
[0] = &inner_map,
},
};
struct {
__uint(type, BPF_MAP_TYPE_HASH_OF_MAPS);
__type(key, int);
__type(value, int);
__uint(max_entries, 1);
__array(values, struct inner_map_type);
} outer_htab_map SEC(".maps") = {
.values = {
[0] = &inner_map,
},
};
char _license[] SEC("license") = "GPL";
int tgid = 0;
static int acc_map_in_map(void *outer_map)
{
int i, key, value = 0xdeadbeef;
void *inner_map;
if ((bpf_get_current_pid_tgid() >> 32) != tgid)
return 0;
/* Find nonexistent inner map */
key = 1;
inner_map = bpf_map_lookup_elem(outer_map, &key);
if (inner_map)
return 0;
/* Find the old inner map */
key = 0;
inner_map = bpf_map_lookup_elem(outer_map, &key);
if (!inner_map)
return 0;
/* Wait for the old inner map to be replaced */
for (i = 0; i < 2048; i++)
bpf_map_update_elem(inner_map, &key, &value, 0);
return 0;
}
SEC("?kprobe/" SYS_PREFIX "sys_getpgid")
int access_map_in_array(void *ctx)
{
return acc_map_in_map(&outer_array_map);
}
SEC("?fentry.s/" SYS_PREFIX "sys_getpgid")
int sleepable_access_map_in_array(void *ctx)
{
return acc_map_in_map(&outer_array_map);
}
SEC("?kprobe/" SYS_PREFIX "sys_getpgid")
int access_map_in_htab(void *ctx)
{
return acc_map_in_map(&outer_htab_map);
}
SEC("?fentry.s/" SYS_PREFIX "sys_getpgid")
int sleepable_access_map_in_htab(void *ctx)
{
return acc_map_in_map(&outer_htab_map);
}
|
