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// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2019 Facebook
#include <linux/bpf.h>
#include <linux/version.h>
#include <bpf/bpf_helpers.h>
#define VAR_NUM 16
struct hmap_elem {
struct bpf_spin_lock lock;
int var[VAR_NUM];
};
struct {
__uint(type, BPF_MAP_TYPE_HASH);
__uint(max_entries, 1);
__type(key, __u32);
__type(value, struct hmap_elem);
} hash_map SEC(".maps");
struct array_elem {
struct bpf_spin_lock lock;
int var[VAR_NUM];
};
struct {
__uint(type, BPF_MAP_TYPE_ARRAY);
__uint(max_entries, 1);
__type(key, int);
__type(value, struct array_elem);
} array_map SEC(".maps");
SEC("map_lock_demo")
int bpf_map_lock_test(struct __sk_buff *skb)
{
struct hmap_elem zero = {}, *val;
int rnd = bpf_get_prandom_u32();
int key = 0, err = 1, i;
struct array_elem *q;
val = bpf_map_lookup_elem(&hash_map, &key);
if (!val)
goto err;
/* spin_lock in hash map */
bpf_spin_lock(&val->lock);
for (i = 0; i < VAR_NUM; i++)
val->var[i] = rnd;
bpf_spin_unlock(&val->lock);
/* spin_lock in array */
q = bpf_map_lookup_elem(&array_map, &key);
if (!q)
goto err;
bpf_spin_lock(&q->lock);
for (i = 0; i < VAR_NUM; i++)
q->var[i] = rnd;
bpf_spin_unlock(&q->lock);
err = 0;
err:
return err;
}
char _license[] SEC("license") = "GPL";
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