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 <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/bpf_helpers.h>
13 #include <bpf/bpf_tracing.h>
14
15 struct key_t {
16 char comm[TASK_COMM_LEN];
17 u32 kernstack;
18 u32 userstack;
19 };
20
21 struct {
22 __uint(type, BPF_MAP_TYPE_HASH);
23 __type(key, struct key_t);
24 __type(value, u64);
25 __uint(max_entries, 10000);
26 } counts SEC(".maps");
27
28 struct {
29 __uint(type, BPF_MAP_TYPE_STACK_TRACE);
30 __uint(key_size, sizeof(u32));
31 __uint(value_size, PERF_MAX_STACK_DEPTH * sizeof(u64));
32 __uint(max_entries, 10000);
33 } stackmap SEC(".maps");
34
35 #define KERN_STACKID_FLAGS (0 | BPF_F_FAST_STACK_CMP)
36 #define USER_STACKID_FLAGS (0 | BPF_F_FAST_STACK_CMP | BPF_F_USER_STACK)
37
38 SEC("perf_event")
bpf_prog1(struct bpf_perf_event_data * ctx)39 int bpf_prog1(struct bpf_perf_event_data *ctx)
40 {
41 char time_fmt1[] = "Time Enabled: %llu, Time Running: %llu";
42 char time_fmt2[] = "Get Time Failed, ErrCode: %d";
43 char addr_fmt[] = "Address recorded on event: %llx";
44 char fmt[] = "CPU-%d period %lld ip %llx";
45 u32 cpu = bpf_get_smp_processor_id();
46 struct bpf_perf_event_value value_buf;
47 struct key_t key;
48 u64 *val, one = 1;
49 int ret;
50
51 if (ctx->sample_period < 10000)
52 /* ignore warmup */
53 return 0;
54 bpf_get_current_comm(&key.comm, sizeof(key.comm));
55 key.kernstack = bpf_get_stackid(ctx, &stackmap, KERN_STACKID_FLAGS);
56 key.userstack = bpf_get_stackid(ctx, &stackmap, USER_STACKID_FLAGS);
57 if ((int)key.kernstack < 0 && (int)key.userstack < 0) {
58 bpf_trace_printk(fmt, sizeof(fmt), cpu, ctx->sample_period,
59 PT_REGS_IP(&ctx->regs));
60 return 0;
61 }
62
63 ret = bpf_perf_prog_read_value(ctx, (void *)&value_buf, sizeof(struct bpf_perf_event_value));
64 if (!ret)
65 bpf_trace_printk(time_fmt1, sizeof(time_fmt1), value_buf.enabled, value_buf.running);
66 else
67 bpf_trace_printk(time_fmt2, sizeof(time_fmt2), ret);
68
69 if (ctx->addr != 0)
70 bpf_trace_printk(addr_fmt, sizeof(addr_fmt), ctx->addr);
71
72 val = bpf_map_lookup_elem(&counts, &key);
73 if (val)
74 (*val)++;
75 else
76 bpf_map_update_elem(&counts, &key, &one, BPF_NOEXIST);
77 return 0;
78 }
79
80 char _license[] SEC("license") = "GPL";
81
