blob: 71a8ed32823ecc36cfc17b3ec519d611569dc7d6 [file] [log] [blame]
Alexei Starovoitov1c47910e2016-09-01 18:37:25 -07001/* Copyright (c) 2016 Facebook
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 <linux/version.h>
9#include <uapi/linux/bpf.h>
10#include <uapi/linux/bpf_perf_event.h>
11#include <uapi/linux/perf_event.h>
12#include "bpf_helpers.h"
13
14struct key_t {
15 char comm[TASK_COMM_LEN];
16 u32 kernstack;
17 u32 userstack;
18};
19
20struct bpf_map_def SEC("maps") counts = {
21 .type = BPF_MAP_TYPE_HASH,
22 .key_size = sizeof(struct key_t),
23 .value_size = sizeof(u64),
24 .max_entries = 10000,
25};
26
27struct bpf_map_def SEC("maps") stackmap = {
28 .type = BPF_MAP_TYPE_STACK_TRACE,
29 .key_size = sizeof(u32),
30 .value_size = PERF_MAX_STACK_DEPTH * sizeof(u64),
31 .max_entries = 10000,
32};
33
34#define KERN_STACKID_FLAGS (0 | BPF_F_FAST_STACK_CMP)
35#define USER_STACKID_FLAGS (0 | BPF_F_FAST_STACK_CMP | BPF_F_USER_STACK)
36
37SEC("perf_event")
38int bpf_prog1(struct bpf_perf_event_data *ctx)
39{
40 char fmt[] = "CPU-%d period %lld ip %llx";
41 u32 cpu = bpf_get_smp_processor_id();
42 struct key_t key;
43 u64 *val, one = 1;
44
45 if (ctx->sample_period < 10000)
46 /* ignore warmup */
47 return 0;
48 bpf_get_current_comm(&key.comm, sizeof(key.comm));
49 key.kernstack = bpf_get_stackid(ctx, &stackmap, KERN_STACKID_FLAGS);
50 key.userstack = bpf_get_stackid(ctx, &stackmap, USER_STACKID_FLAGS);
51 if ((int)key.kernstack < 0 && (int)key.userstack < 0) {
52 bpf_trace_printk(fmt, sizeof(fmt), cpu, ctx->sample_period,
53 ctx->regs.ip);
54 return 0;
55 }
56
57 val = bpf_map_lookup_elem(&counts, &key);
58 if (val)
59 (*val)++;
60 else
61 bpf_map_update_elem(&counts, &key, &one, BPF_NOEXIST);
62 return 0;
63}
64
65char _license[] SEC("license") = "GPL";