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" ) |
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 | |