LXR linux/tools/testing/selftests/bpf/progs/test_map

   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
   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("map_lock_demo")
  34int bpf_map_lock_test(struct __sk_buff *skb)
  35{
  36        struct hmap_elem zero = {}, *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