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1// SPDX-License-Identifier: GPL-2.02/* Copyright (c) 2021 Facebook */3#include <linux/bpf.h>4#include <time.h>5#include <errno.h>6#include <bpf/bpf_helpers.h>7#include <bpf/bpf_tracing.h>8 9char _license[] SEC("license") = "GPL";10struct hmap_elem {11 int pad; /* unused */12 struct bpf_timer timer;13};14 15struct inner_map {16 __uint(type, BPF_MAP_TYPE_HASH);17 __uint(max_entries, 1024);18 __type(key, int);19 __type(value, struct hmap_elem);20} inner_htab SEC(".maps");21 22#define ARRAY_KEY 123#define ARRAY_KEY2 224#define HASH_KEY 123425 26struct outer_arr {27 __uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS);28 __uint(max_entries, 2);29 __uint(key_size, sizeof(int));30 __uint(value_size, sizeof(int));31 __array(values, struct inner_map);32} outer_arr SEC(".maps") = {33 .values = { [ARRAY_KEY] = &inner_htab },34};35 36__u64 err;37__u64 ok;38__u64 cnt;39 40/* callback for inner hash map */41static int timer_cb(void *map, int *key, struct hmap_elem *val)42{43 return 0;44}45 46SEC("fentry/bpf_fentry_test1")47int BPF_PROG(test1, int a)48{49 struct hmap_elem init = {};50 struct bpf_map *inner_map, *inner_map2;51 struct hmap_elem *val;52 int array_key = ARRAY_KEY;53 int array_key2 = ARRAY_KEY2;54 int hash_key = HASH_KEY;55 56 inner_map = bpf_map_lookup_elem(&outer_arr, &array_key);57 if (!inner_map)58 return 0;59 60 inner_map2 = bpf_map_lookup_elem(&outer_arr, &array_key2);61 if (!inner_map2)62 return 0;63 bpf_map_update_elem(inner_map, &hash_key, &init, 0);64 val = bpf_map_lookup_elem(inner_map, &hash_key);65 if (!val)66 return 0;67 68 bpf_timer_init(&val->timer, inner_map2, CLOCK_MONOTONIC);69 if (bpf_timer_set_callback(&val->timer, timer_cb))70 err |= 4;71 if (bpf_timer_start(&val->timer, 0, 0))72 err |= 8;73 return 0;74}75