1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* Copyright (c) 2022 Bytedance */ |
3 | |
4 | #include "vmlinux.h" |
5 | #include <bpf/bpf_helpers.h> |
6 | |
7 | __u64 percpu_array_elem_sum = 0; |
8 | __u64 percpu_hash_elem_sum = 0; |
9 | __u64 percpu_lru_hash_elem_sum = 0; |
10 | const volatile int nr_cpus; |
11 | const volatile int my_pid; |
12 | |
13 | struct { |
14 | __uint(type, BPF_MAP_TYPE_PERCPU_ARRAY); |
15 | __uint(max_entries, 1); |
16 | __type(key, __u32); |
17 | __type(value, __u64); |
18 | } percpu_array_map SEC(".maps" ); |
19 | |
20 | struct { |
21 | __uint(type, BPF_MAP_TYPE_PERCPU_HASH); |
22 | __uint(max_entries, 1); |
23 | __type(key, __u64); |
24 | __type(value, __u64); |
25 | } percpu_hash_map SEC(".maps" ); |
26 | |
27 | struct { |
28 | __uint(type, BPF_MAP_TYPE_LRU_PERCPU_HASH); |
29 | __uint(max_entries, 1); |
30 | __type(key, __u64); |
31 | __type(value, __u64); |
32 | } percpu_lru_hash_map SEC(".maps" ); |
33 | |
34 | struct read_percpu_elem_ctx { |
35 | void *map; |
36 | __u64 sum; |
37 | }; |
38 | |
39 | static int read_percpu_elem_callback(__u32 index, struct read_percpu_elem_ctx *ctx) |
40 | { |
41 | __u64 key = 0; |
42 | __u64 *value; |
43 | |
44 | value = bpf_map_lookup_percpu_elem(ctx->map, &key, index); |
45 | if (value) |
46 | ctx->sum += *value; |
47 | return 0; |
48 | } |
49 | |
50 | SEC("tp/syscalls/sys_enter_getuid" ) |
51 | int sysenter_getuid(const void *ctx) |
52 | { |
53 | struct read_percpu_elem_ctx map_ctx; |
54 | |
55 | if (my_pid != (bpf_get_current_pid_tgid() >> 32)) |
56 | return 0; |
57 | |
58 | map_ctx.map = &percpu_array_map; |
59 | map_ctx.sum = 0; |
60 | bpf_loop(nr_cpus, read_percpu_elem_callback, &map_ctx, 0); |
61 | percpu_array_elem_sum = map_ctx.sum; |
62 | |
63 | map_ctx.map = &percpu_hash_map; |
64 | map_ctx.sum = 0; |
65 | bpf_loop(nr_cpus, read_percpu_elem_callback, &map_ctx, 0); |
66 | percpu_hash_elem_sum = map_ctx.sum; |
67 | |
68 | map_ctx.map = &percpu_lru_hash_map; |
69 | map_ctx.sum = 0; |
70 | bpf_loop(nr_cpus, read_percpu_elem_callback, &map_ctx, 0); |
71 | percpu_lru_hash_elem_sum = map_ctx.sum; |
72 | |
73 | return 0; |
74 | } |
75 | |
76 | char _license[] SEC("license" ) = "GPL" ; |
77 | |