tools/bpf/bpftool/map_perf_ring.c

   1 // SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
   2 /* Copyright (C) 2018 Netronome Systems, Inc. */
   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 <errno.h>
   8 #include <fcntl.h>
   9 #include <bpf/libbpf.h>
  10 #include <poll.h>
  11 #include <signal.h>
  12 #include <stdbool.h>
  13 #include <stdio.h>
  14 #include <stdlib.h>
  15 #include <string.h>
  16 #include <time.h>
  17 #include <unistd.h>
  18 #include <linux/bpf.h>
  19 #include <linux/perf_event.h>
  20 #include <sys/ioctl.h>
  21 #include <sys/mman.h>
  22 #include <sys/syscall.h>
  23
  24 #include <bpf/bpf.h>
  25
  26 #include "main.h"
  27
  28 #define MMAP_PAGE_CNT   16
  29
  30 static volatile bool stop;
  31
  32 struct perf_event_sample {
  33         struct perf_event_header header;
  34         __u64 time;
  35         __u32 size;
  36         unsigned char data[];
  37 };
  38
  39 struct perf_event_lost {
  40         struct perf_event_header header;
  41         __u64 id;
  42         __u64 lost;
  43 };
  44
  45 static void int_exit(int signo)
  46 {
  47         fprintf(stderr, "Stopping...\n");
  48         stop = true;
  49 }
  50
  51 struct event_pipe_ctx {
  52         bool all_cpus;
  53         int cpu;
  54         int idx;
  55 };
  56
  57 static enum bpf_perf_event_ret
  58 print_bpf_output(void *private_data, int cpu, struct perf_event_header *event)
  59 {
  60         struct perf_event_sample *e = container_of(event,
  61                                                    struct perf_event_sample,
  62                                                    header);
  63         struct perf_event_lost *lost = container_of(event,
  64                                                     struct perf_event_lost,
  65                                                     header);
  66         struct event_pipe_ctx *ctx = private_data;
  67         int idx = ctx->all_cpus ? cpu : ctx->idx;
  68
  69         if (json_output) {
  70                 jsonw_start_object(json_wtr);
  71                 jsonw_name(json_wtr, "type");
  72                 jsonw_uint(json_wtr, e->header.type);
  73                 jsonw_name(json_wtr, "cpu");
  74                 jsonw_uint(json_wtr, cpu);
  75                 jsonw_name(json_wtr, "index");
  76                 jsonw_uint(json_wtr, idx);
  77                 if (e->header.type == PERF_RECORD_SAMPLE) {
  78                         jsonw_name(json_wtr, "timestamp");
  79                         jsonw_uint(json_wtr, e->time);
  80                         jsonw_name(json_wtr, "data");
  81                         print_data_json(e->data, e->size);
  82                 } else if (e->header.type == PERF_RECORD_LOST) {
  83                         jsonw_name(json_wtr, "lost");
  84                         jsonw_start_object(json_wtr);
  85                         jsonw_name(json_wtr, "id");
  86                         jsonw_uint(json_wtr, lost->id);
  87                         jsonw_name(json_wtr, "count");
  88                         jsonw_uint(json_wtr, lost->lost);
  89                         jsonw_end_object(json_wtr);
  90                 }
  91                 jsonw_end_object(json_wtr);
  92         } else {
  93                 if (e->header.type == PERF_RECORD_SAMPLE) {
  94                         printf("== @%lld.%09lld CPU: %d index: %d =====\n",
  95                                e->time / 1000000000ULL, e->time % 1000000000ULL,
  96                                cpu, idx);
  97                         fprint_hex(stdout, e->data, e->size, " ");
  98                         printf("\n");
  99                 } else if (e->header.type == PERF_RECORD_LOST) {
 100                         printf("lost %lld events\n", lost->lost);
 101                 } else {
 102                         printf("unknown event type=%d size=%d\n",
 103                                e->header.type, e->header.size);
 104                 }
 105         }
 106
 107         return LIBBPF_PERF_EVENT_CONT;
 108 }
 109
 110 int do_event_pipe(int argc, char **argv)
 111 {
 112         struct perf_event_attr perf_attr = {
 113                 .sample_type = PERF_SAMPLE_RAW | PERF_SAMPLE_TIME,
 114                 .type = PERF_TYPE_SOFTWARE,
 115                 .config = PERF_COUNT_SW_BPF_OUTPUT,
 116                 .sample_period = 1,
 117                 .wakeup_events = 1,
 118         };
 119         struct bpf_map_info map_info = {};
 120         LIBBPF_OPTS(perf_buffer_raw_opts, opts);
 121         struct event_pipe_ctx ctx = {
 122                 .all_cpus = true,
 123                 .cpu = -1,
 124                 .idx = -1,
 125         };
 126         struct perf_buffer *pb;
 127         __u32 map_info_len;
 128         int err, map_fd;
 129
 130         map_info_len = sizeof(map_info);
 131         map_fd = map_parse_fd_and_info(&argc, &argv, &map_info, &map_info_len);
 132         if (map_fd < 0)
 133                 return -1;
 134
 135         if (map_info.type != BPF_MAP_TYPE_PERF_EVENT_ARRAY) {
 136                 p_err("map is not a perf event array");
 137                 goto err_close_map;
 138         }
 139
 140         while (argc) {
 141                 if (argc < 2) {
 142                         BAD_ARG();
 143                         goto err_close_map;
 144                 }
 145
 146                 if (is_prefix(*argv, "cpu")) {
 147                         char *endptr;
 148
 149                         NEXT_ARG();
 150                         ctx.cpu = strtoul(*argv, &endptr, 0);
 151                         if (*endptr) {
 152                                 p_err("can't parse %s as CPU ID", *argv);
 153                                 goto err_close_map;
 154                         }
 155
 156                         NEXT_ARG();
 157                 } else if (is_prefix(*argv, "index")) {
 158                         char *endptr;
 159
 160                         NEXT_ARG();
 161                         ctx.idx = strtoul(*argv, &endptr, 0);
 162                         if (*endptr) {
 163                                 p_err("can't parse %s as index", *argv);
 164                                 goto err_close_map;
 165                         }
 166
 167                         NEXT_ARG();
 168                 } else {
 169                         BAD_ARG();
 170                         goto err_close_map;
 171                 }
 172
 173                 ctx.all_cpus = false;
 174         }
 175
 176         if (!ctx.all_cpus) {
 177                 if (ctx.idx == -1 || ctx.cpu == -1) {
 178                         p_err("cpu and index must be specified together");
 179                         goto err_close_map;
 180                 }
 181         } else {
 182                 ctx.cpu = 0;
 183                 ctx.idx = 0;
 184         }
 185
 186         opts.cpu_cnt = ctx.all_cpus ? 0 : 1;
 187         opts.cpus = &ctx.cpu;
 188         opts.map_keys = &ctx.idx;
 189         pb = perf_buffer__new_raw(map_fd, MMAP_PAGE_CNT, &perf_attr,
 190                                   print_bpf_output, &ctx, &opts);
 191         if (!pb) {
 192                 p_err("failed to create perf buffer: %s (%d)",
 193                       strerror(errno), errno);
 194                 goto err_close_map;
 195         }
 196
 197         signal(SIGINT, int_exit);
 198         signal(SIGHUP, int_exit);
 199         signal(SIGTERM, int_exit);
 200
 201         if (json_output)
 202                 jsonw_start_array(json_wtr);
 203
 204         while (!stop) {
 205                 err = perf_buffer__poll(pb, 200);
 206                 if (err < 0 && err != -EINTR) {
 207                         p_err("perf buffer polling failed: %s (%d)",
 208                               strerror(errno), errno);
 209                         goto err_close_pb;
 210                 }
 211         }
 212
 213         if (json_output)
 214                 jsonw_end_array(json_wtr);
 215
 216         perf_buffer__free(pb);
 217         close(map_fd);
 218
 219         return 0;
 220
 221 err_close_pb:
 222         perf_buffer__free(pb);
 223 err_close_map:
 224         close(map_fd);
 225         return -1;
 226 }