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1// SPDX-License-Identifier: GPL-2.02// Copyright (c) 2019 Facebook3 4#include <linux/bpf.h>5#include <stdint.h>6#include <bpf/bpf_helpers.h>7 8char _license[] SEC("license") = "GPL";9 10struct {11 __uint(type, BPF_MAP_TYPE_ARRAY);12 __uint(map_flags, BPF_F_MMAPABLE | BPF_F_RDONLY_PROG);13 __type(key, __u32);14 __type(value, char);15} rdonly_map SEC(".maps");16 17struct {18 __uint(type, BPF_MAP_TYPE_ARRAY);19 __uint(map_flags, BPF_F_MMAPABLE);20 __type(key, __u32);21 __type(value, __u64);22} data_map SEC(".maps");23 24__u64 in_val = 0;25__u64 out_val = 0;26 27SEC("raw_tracepoint/sys_enter")28int test_mmap(void *ctx)29{30 int zero = 0, one = 1, two = 2, far = 1500;31 __u64 val, *p;32 33 out_val = in_val;34 35 /* data_map[2] = in_val; */36 bpf_map_update_elem(&data_map, &two, (const void *)&in_val, 0);37 38 /* data_map[1] = data_map[0] * 2; */39 p = bpf_map_lookup_elem(&data_map, &zero);40 if (p) {41 val = (*p) * 2;42 bpf_map_update_elem(&data_map, &one, &val, 0);43 }44 45 /* data_map[far] = in_val * 3; */46 val = in_val * 3;47 bpf_map_update_elem(&data_map, &far, &val, 0);48 49 return 0;50}51 52