1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */
3
4 #include "vmlinux.h"
5 #include <bpf/bpf_helpers.h>
6
7 #include "bpf_misc.h"
8
9 char _license[] SEC("license") = "GPL";
10
11 struct inner_array_type {
12 __uint(type, BPF_MAP_TYPE_ARRAY);
13 __uint(map_flags, BPF_F_MMAPABLE);
14 __type(key, __u32);
15 __type(value, __u64);
16 __uint(max_entries, 1);
17 } inner_array SEC(".maps");
18
19 struct {
20 __uint(type, BPF_MAP_TYPE_HASH_OF_MAPS);
21 __uint(key_size, 4);
22 __uint(value_size, 4);
23 __uint(max_entries, 1);
24 __array(values, struct inner_array_type);
25 } outer_map SEC(".maps");
26
27 int pid = 0;
28 __u64 match_value = 0x13572468;
29 bool done = false;
30 bool pid_match = false;
31 bool outer_map_match = false;
32
33 SEC("fentry/" SYS_PREFIX "sys_nanosleep")
34 int add_to_list_in_inner_array(void *ctx)
35 {
36 __u32 curr_pid, zero = 0;
37 struct bpf_map *map;
38 __u64 *value;
39
40 curr_pid = (u32)bpf_get_current_pid_tgid();
41 if (done || curr_pid != pid)
42 return 0;
43
44 pid_match = true;
45 map = bpf_map_lookup_elem(&outer_map, &curr_pid);
46 if (!map)
47 return 0;
48
49 outer_map_match = true;
50 value = bpf_map_lookup_elem(map, &zero);
51 if (!value)
52 return 0;
53
54 *value = match_value;
55 done = true;
56 return 0;
57 }
58
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.