1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (c) 2019 Facebook
3 #include <linux/bpf.h>
4 #include <linux/version.h>
5 #include <bpf/bpf_helpers.h>
6
7 #define VAR_NUM 16
8
9 struct hmap_elem {
10 struct bpf_spin_lock lock;
11 int var[VAR_NUM];
12 };
13
14 struct {
15 __uint(type, BPF_MAP_TYPE_HASH);
16 __uint(max_entries, 1);
17 __type(key, __u32);
18 __type(value, struct hmap_elem);
19 } hash_map SEC(".maps");
20
21 struct array_elem {
22 struct bpf_spin_lock lock;
23 int var[VAR_NUM];
24 };
25
26 struct {
27 __uint(type, BPF_MAP_TYPE_ARRAY);
28 __uint(max_entries, 1);
29 __type(key, int);
30 __type(value, struct array_elem);
31 } array_map SEC(".maps");
32
33 SEC("cgroup/skb")
34 int bpf_map_lock_test(struct __sk_buff *skb)
35 {
36 struct hmap_elem *val;
37 int rnd = bpf_get_prandom_u32();
38 int key = 0, err = 1, i;
39 struct array_elem *q;
40
41 val = bpf_map_lookup_elem(&hash_map, &key);
42 if (!val)
43 goto err;
44 /* spin_lock in hash map */
45 bpf_spin_lock(&val->lock);
46 for (i = 0; i < VAR_NUM; i++)
47 val->var[i] = rnd;
48 bpf_spin_unlock(&val->lock);
49
50 /* spin_lock in array */
51 q = bpf_map_lookup_elem(&array_map, &key);
52 if (!q)
53 goto err;
54 bpf_spin_lock(&q->lock);
55 for (i = 0; i < VAR_NUM; i++)
56 q->var[i] = rnd;
57 bpf_spin_unlock(&q->lock);
58 err = 0;
59 err:
60 return err;
61 }
62 char _license[] SEC("license") = "GPL";
63
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