1 /* Copyright 2016 Netflix, Inc.
2 *
3 * This program is free software; you can redistribute it and/or
4 * modify it under the terms of version 2 of the GNU General Public
5 * License as published by the Free Software Foundation.
6 */
7 #include <linux/ptrace.h>
8 #include <uapi/linux/bpf.h>
9 #include <uapi/linux/bpf_perf_event.h>
10 #include <bpf/bpf_helpers.h>
11 #include <bpf/bpf_tracing.h>
12
13 #define MAX_IPS 8192
14
15 struct {
16 __uint(type, BPF_MAP_TYPE_HASH);
17 __type(key, u64);
18 __type(value, u32);
19 __uint(max_entries, MAX_IPS);
20 } ip_map SEC(".maps");
21
22 SEC("perf_event")
23 int do_sample(struct bpf_perf_event_data *ctx)
24 {
25 u64 ip;
26 u32 *value, init_val = 1;
27
28 ip = PT_REGS_IP(&ctx->regs);
29 value = bpf_map_lookup_elem(&ip_map, &ip);
30 if (value)
31 *value += 1;
32 else
33 /* E2BIG not tested for this example only */
34 bpf_map_update_elem(&ip_map, &ip, &init_val, BPF_NOEXIST);
35
36 return 0;
37 }
38 char _license[] SEC("license") = "GPL";
39
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