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
15struct {
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
22SEC("perf_event")
23int 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}
38char _license[] SEC("license") = "GPL";
39