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/bpf_helpers.h> 12 #include <bpf/bpf_tracing.h> 13 14 #define MAX_IPS 8192 15 16 struct bpf_map_def SEC("maps") ip_map = { 17 .type = BPF_MAP_TYPE_HASH, 18 .key_size = sizeof(u64), 19 .value_size = sizeof(u32), 20 .max_entries = MAX_IPS, 21 }; 22 23 SEC("perf_event") 24 int do_sample(struct bpf_perf_event_data *ctx) 25 { 26 u64 ip; 27 u32 *value, init_val = 1; 28 29 ip = PT_REGS_IP(&ctx->regs); 30 value = bpf_map_lookup_elem(&ip_map, &ip); 31 if (value) 32 *value += 1; 33 else 34 /* E2BIG not tested for this example only */ 35 bpf_map_update_elem(&ip_map, &ip, &init_val, BPF_NOEXIST); 36 37 return 0; 38 } 39 char _license[] SEC("license") = "GPL"; 40