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