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
read_percpu_elem_callback(__u32 index,struct read_percpu_elem_ctx * ctx)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")
sysenter_getuid(const void * ctx)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