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_helpers.h" 13 14 struct key_t { 15 char comm[TASK_COMM_LEN]; 16 u32 kernstack; 17 u32 userstack; 18 }; 19 20 struct 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 27 struct 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 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 fmt[] = "CPU-%d period %lld ip %llx"; 43 u32 cpu = bpf_get_smp_processor_id(); 44 struct bpf_perf_event_value value_buf; 45 struct key_t key; 46 u64 *val, one = 1; 47 int ret; 48 49 if (ctx->sample_period < 10000) 50 /* ignore warmup */ 51 return 0; 52 bpf_get_current_comm(&key.comm, sizeof(key.comm)); 53 key.kernstack = bpf_get_stackid(ctx, &stackmap, KERN_STACKID_FLAGS); 54 key.userstack = bpf_get_stackid(ctx, &stackmap, USER_STACKID_FLAGS); 55 if ((int)key.kernstack < 0 && (int)key.userstack < 0) { 56 bpf_trace_printk(fmt, sizeof(fmt), cpu, ctx->sample_period, 57 PT_REGS_IP(&ctx->regs)); 58 return 0; 59 } 60 61 ret = bpf_perf_prog_read_value(ctx, (void *)&value_buf, sizeof(struct bpf_perf_event_value)); 62 if (!ret) 63 bpf_trace_printk(time_fmt1, sizeof(time_fmt1), value_buf.enabled, value_buf.running); 64 else 65 bpf_trace_printk(time_fmt2, sizeof(time_fmt2), ret); 66 67 val = bpf_map_lookup_elem(&counts, &key); 68 if (val) 69 (*val)++; 70 else 71 bpf_map_update_elem(&counts, &key, &one, BPF_NOEXIST); 72 return 0; 73 } 74 75 char _license[] SEC("license") = "GPL"; 76