1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (c) 2020 Facebook
3 
4 #include <linux/ptrace.h>
5 #include <linux/bpf.h>
6 #include <bpf/bpf_helpers.h>
7 #include <bpf/bpf_tracing.h>
8 
9 #define VAR_NUM 2
10 
11 struct hmap_elem {
12 	struct bpf_spin_lock lock;
13 	int var[VAR_NUM];
14 };
15 
16 struct {
17 	__uint(type, BPF_MAP_TYPE_HASH);
18 	__uint(max_entries, 1);
19 	__type(key, __u32);
20 	__type(value, struct hmap_elem);
21 } hash_map SEC(".maps");
22 
23 SEC("freplace/handle_kprobe")
24 int new_handle_kprobe(struct pt_regs *ctx)
25 {
26 	struct hmap_elem zero = {}, *val;
27 	int key = 0;
28 
29 	val = bpf_map_lookup_elem(&hash_map, &key);
30 	if (!val)
31 		return 1;
32 	/* spin_lock in hash map */
33 	bpf_spin_lock(&val->lock);
34 	val->var[0] = 99;
35 	bpf_spin_unlock(&val->lock);
36 
37 	return 0;
38 }
39 
40 char _license[] SEC("license") = "GPL";
41