1 | // SPDX-License-Identifier: GPL-2.0 |
2 | // Copyright (c) 2019 Facebook |
3 | |
4 | #include <linux/bpf.h> |
5 | #include <stdint.h> |
6 | #include <bpf/bpf_helpers.h> |
7 | |
8 | char _license[] SEC("license" ) = "GPL" ; |
9 | |
10 | struct { |
11 | __uint(type, BPF_MAP_TYPE_ARRAY); |
12 | __uint(map_flags, BPF_F_MMAPABLE | BPF_F_RDONLY_PROG); |
13 | __type(key, __u32); |
14 | __type(value, char); |
15 | } rdonly_map SEC(".maps" ); |
16 | |
17 | struct { |
18 | __uint(type, BPF_MAP_TYPE_ARRAY); |
19 | __uint(map_flags, BPF_F_MMAPABLE); |
20 | __type(key, __u32); |
21 | __type(value, __u64); |
22 | } data_map SEC(".maps" ); |
23 | |
24 | __u64 in_val = 0; |
25 | __u64 out_val = 0; |
26 | |
27 | SEC("raw_tracepoint/sys_enter" ) |
28 | int test_mmap(void *ctx) |
29 | { |
30 | int zero = 0, one = 1, two = 2, far = 1500; |
31 | __u64 val, *p; |
32 | |
33 | out_val = in_val; |
34 | |
35 | /* data_map[2] = in_val; */ |
36 | bpf_map_update_elem(&data_map, &two, (const void *)&in_val, 0); |
37 | |
38 | /* data_map[1] = data_map[0] * 2; */ |
39 | p = bpf_map_lookup_elem(&data_map, &zero); |
40 | if (p) { |
41 | val = (*p) * 2; |
42 | bpf_map_update_elem(&data_map, &one, &val, 0); |
43 | } |
44 | |
45 | /* data_map[far] = in_val * 3; */ |
46 | val = in_val * 3; |
47 | bpf_map_update_elem(&data_map, &far, &val, 0); |
48 | |
49 | return 0; |
50 | } |
51 | |
52 | |