63 lines · c
1// SPDX-License-Identifier: GPL-2.02// Copyright (c) 2019 Facebook3#include <linux/bpf.h>4#include <linux/version.h>5#include <bpf/bpf_helpers.h>6 7#define VAR_NUM 168 9struct hmap_elem {10 struct bpf_spin_lock lock;11 int var[VAR_NUM];12};13 14struct {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 21struct array_elem {22 struct bpf_spin_lock lock;23 int var[VAR_NUM];24};25 26struct {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 33SEC("cgroup/skb")34int 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;59err:60 return err;61}62char _license[] SEC("license") = "GPL";63