1 /* 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 <uapi/linux/bpf.h>
9 #include <uapi/linux/bpf_perf_event.h>
10 #include <uapi/linux/perf_event.h>
11 #include <bpf/bpf_helpers.h>
12 #include <bpf/bpf_tracing.h>
13
14 struct key_t {
15 char comm[TASK_COMM_LEN];
16 u32 kernstack;
17 u32 userstack;
18 };
19
20 struct {
21 __uint(type, BPF_MAP_TYPE_HASH);
22 __type(key, struct key_t);
23 __type(value, u64);
24 __uint(max_entries, 10000);
25 } counts SEC(".maps");
26
27 struct {
28 __uint(type, BPF_MAP_TYPE_STACK_TRACE);
29 __uint(key_size, sizeof(u32));
30 __uint(value_size, PERF_MAX_STACK_DEPTH * sizeof(u64));
31 __uint(max_entries, 10000);
32 } stackmap SEC(".maps");
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
37 SEC("perf_event")
bpf_prog1(struct bpf_perf_event_data * ctx)38 int bpf_prog1(struct bpf_perf_event_data *ctx)
39 {
40 char time_fmt1[] = "Time Enabled: %llu, Time Running: %llu";
41 char time_fmt2[] = "Get Time Failed, ErrCode: %d";
42 char addr_fmt[] = "Address recorded on event: %llx";
43 char fmt[] = "CPU-%d period %lld ip %llx";
44 u32 cpu = bpf_get_smp_processor_id();
45 struct bpf_perf_event_value value_buf;
46 struct key_t key;
47 u64 *val, one = 1;
48 int ret;
49
50 if (ctx->sample_period < 10000)
51 /* ignore warmup */
52 return 0;
53 bpf_get_current_comm(&key.comm, sizeof(key.comm));
54 key.kernstack = bpf_get_stackid(ctx, &stackmap, KERN_STACKID_FLAGS);
55 key.userstack = bpf_get_stackid(ctx, &stackmap, USER_STACKID_FLAGS);
56 if ((int)key.kernstack < 0 && (int)key.userstack < 0) {
57 bpf_trace_printk(fmt, sizeof(fmt), cpu, ctx->sample_period,
58 PT_REGS_IP(&ctx->regs));
59 return 0;
60 }
61
62 ret = bpf_perf_prog_read_value(ctx, (void *)&value_buf, sizeof(struct bpf_perf_event_value));
63 if (!ret)
64 bpf_trace_printk(time_fmt1, sizeof(time_fmt1), value_buf.enabled, value_buf.running);
65 else
66 bpf_trace_printk(time_fmt2, sizeof(time_fmt2), ret);
67
68 if (ctx->addr != 0)
69 bpf_trace_printk(addr_fmt, sizeof(addr_fmt), ctx->addr);
70
71 val = bpf_map_lookup_elem(&counts, &key);
72 if (val)
73 (*val)++;
74 else
75 bpf_map_update_elem(&counts, &key, &one, BPF_NOEXIST);
76 return 0;
77 }
78
79 char _license[] SEC("license") = "GPL";
80