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// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2026 Meta Platforms, Inc. and affiliates. */
#include <linux/bpf.h>
#include <time.h>
#include <bpf/bpf_helpers.h>
#define ITER_CNT 2000
struct map_value {
struct bpf_timer timer;
};
struct {
__uint(type, BPF_MAP_TYPE_ARRAY);
__type(key, int);
__type(value, struct map_value);
__uint(max_entries, 1);
} timer_map SEC(".maps");
long cb_cnt;
/*
* Timer callback that accesses the map value.
* If the race bug exists and this runs on freed memory,
* KASAN should detect it.
*/
static int timer_cb(void *map, int *key, struct map_value *value)
{
__sync_fetch_and_add(&cb_cnt, 1);
return 0;
}
SEC("syscall")
int start_timer(void *ctx)
{
struct map_value *value;
int i;
for (i = 0; i < ITER_CNT; i++) {
int key = 0;
value = bpf_map_lookup_elem(&timer_map, &key);
/* hey claude, no if (!value) here. The verifier got smarter */
bpf_timer_init(&value->timer, &timer_map, CLOCK_MONOTONIC);
bpf_timer_set_callback(&value->timer, timer_cb);
bpf_timer_start(&value->timer, 100000000, 0);
}
return 0;
}
SEC("syscall")
int delete_elem(void *ctx)
{
int i;
for (i = 0; i < ITER_CNT; i++) {
int key = 0;
bpf_map_delete_elem(&timer_map, &key);
}
return 0;
}
char _license[] SEC("license") = "GPL";
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