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/version.h> 8 #include <linux/ptrace.h> 9 #include <uapi/linux/bpf.h> 10 #include <uapi/linux/bpf_perf_event.h> 11 #include "bpf_helpers.h" 12 13 #define MAX_IPS 8192 14 15 struct bpf_map_def SEC("maps") ip_map = { 16 .type = BPF_MAP_TYPE_HASH, 17 .key_size = sizeof(u64), 18 .value_size = sizeof(u32), 19 .max_entries = MAX_IPS, 20 }; 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