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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 HASH_KEY 123424 25struct outer_arr {26 __uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS);27 __uint(max_entries, 2);28 __uint(key_size, sizeof(int));29 __uint(value_size, sizeof(int));30 __array(values, struct inner_map);31} outer_arr SEC(".maps") = {32 .values = { [ARRAY_KEY] = &inner_htab },33};34 35__u64 err;36__u64 ok;37__u64 cnt;38 39static int timer_cb1(void *map, int *key, struct hmap_elem *val);40 41static int timer_cb2(void *map, int *key, struct hmap_elem *val)42{43 cnt++;44 bpf_timer_set_callback(&val->timer, timer_cb1);45 if (bpf_timer_start(&val->timer, 1000, 0))46 err |= 1;47 ok |= 1;48 return 0;49}50 51/* callback for inner hash map */52static int timer_cb1(void *map, int *key, struct hmap_elem *val)53{54 cnt++;55 bpf_timer_set_callback(&val->timer, timer_cb2);56 if (bpf_timer_start(&val->timer, 1000, 0))57 err |= 2;58 /* Do a lookup to make sure 'map' and 'key' pointers are correct */59 bpf_map_lookup_elem(map, key);60 ok |= 2;61 return 0;62}63 64SEC("fentry/bpf_fentry_test1")65int BPF_PROG(test1, int a)66{67 struct hmap_elem init = {};68 struct bpf_map *inner_map;69 struct hmap_elem *val;70 int array_key = ARRAY_KEY;71 int hash_key = HASH_KEY;72 73 inner_map = bpf_map_lookup_elem(&outer_arr, &array_key);74 if (!inner_map)75 return 0;76 77 bpf_map_update_elem(inner_map, &hash_key, &init, 0);78 val = bpf_map_lookup_elem(inner_map, &hash_key);79 if (!val)80 return 0;81 82 bpf_timer_init(&val->timer, inner_map, CLOCK_MONOTONIC);83 if (bpf_timer_set_callback(&val->timer, timer_cb1))84 err |= 4;85 if (bpf_timer_start(&val->timer, 0, 0))86 err |= 8;87 return 0;88}89