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 event_ring_info {
  33         int fd;
  34         int key;
  35         unsigned int cpu;
  36         void *mem;
  37 };
  38
  39 struct perf_event_sample {
  40         struct perf_event_header header;
  41         __u64 time;
  42         __u32 size;
  43         unsigned char data[];
  44 };
  45
  46 struct perf_event_lost {
  47         struct perf_event_header header;
  48         __u64 id;
  49         __u64 lost;
  50 };
  51
  52 static void int_exit(int signo)
  53 {
  54         fprintf(stderr, "Stopping...\n");
  55         stop = true;
  56 }
  57
  58 struct event_pipe_ctx {
  59         bool all_cpus;
  60         int cpu;
  61         int idx;
  62 };
  63
  64 static enum bpf_perf_event_ret
  65 print_bpf_output(void *private_data, int cpu, struct perf_event_header *event)
  66 {
  67         struct perf_event_sample *e = container_of(event,
  68                                                    struct perf_event_sample,
  69                                                    header);
  70         struct perf_event_lost *lost = container_of(event,
  71                                                     struct perf_event_lost,
  72                                                     header);
  73         struct event_pipe_ctx *ctx = private_data;
  74         int idx = ctx->all_cpus ? cpu : ctx->idx;
  75
  76         if (json_output) {
  77                 jsonw_start_object(json_wtr);
  78                 jsonw_name(json_wtr, "type");
  79                 jsonw_uint(json_wtr, e->header.type);
  80                 jsonw_name(json_wtr, "cpu");
  81                 jsonw_uint(json_wtr, cpu);
  82                 jsonw_name(json_wtr, "index");
  83                 jsonw_uint(json_wtr, idx);
  84                 if (e->header.type == PERF_RECORD_SAMPLE) {
  85                         jsonw_name(json_wtr, "timestamp");
  86                         jsonw_uint(json_wtr, e->time);
  87                         jsonw_name(json_wtr, "data");
  88                         print_data_json(e->data, e->size);
  89                 } else if (e->header.type == PERF_RECORD_LOST) {
  90                         jsonw_name(json_wtr, "lost");
  91                         jsonw_start_object(json_wtr);
  92                         jsonw_name(json_wtr, "id");
  93                         jsonw_uint(json_wtr, lost->id);
  94                         jsonw_name(json_wtr, "count");
  95                         jsonw_uint(json_wtr, lost->lost);
  96                         jsonw_end_object(json_wtr);
  97                 }
  98                 jsonw_end_object(json_wtr);
  99         } else {
 100                 if (e->header.type == PERF_RECORD_SAMPLE) {
 101                         printf("== @%lld.%09lld CPU: %d index: %d =====\n",
 102                                e->time / 1000000000ULL, e->time % 1000000000ULL,
 103                                cpu, idx);
 104                         fprint_hex(stdout, e->data, e->size, " ");
 105                         printf("\n");
 106                 } else if (e->header.type == PERF_RECORD_LOST) {
 107                         printf("lost %lld events\n", lost->lost);
 108                 } else {
 109                         printf("unknown event type=%d size=%d\n",
 110                                e->header.type, e->header.size);
 111                 }
 112         }
 113
 114         return LIBBPF_PERF_EVENT_CONT;
 115 }
 116
 117 int do_event_pipe(int argc, char **argv)
 118 {
 119         struct perf_event_attr perf_attr = {
 120                 .sample_type = PERF_SAMPLE_RAW | PERF_SAMPLE_TIME,
 121                 .type = PERF_TYPE_SOFTWARE,
 122                 .config = PERF_COUNT_SW_BPF_OUTPUT,
 123                 .sample_period = 1,
 124                 .wakeup_events = 1,
 125         };
 126         struct bpf_map_info map_info = {};
 127         struct perf_buffer_raw_opts opts = {};
 128         struct event_pipe_ctx ctx = {
 129                 .all_cpus = true,
 130                 .cpu = -1,
 131                 .idx = -1,
 132         };
 133         struct perf_buffer *pb;
 134         __u32 map_info_len;
 135         int err, map_fd;
 136
 137         map_info_len = sizeof(map_info);
 138         map_fd = map_parse_fd_and_info(&argc, &argv, &map_info, &map_info_len);
 139         if (map_fd < 0)
 140                 return -1;
 141
 142         if (map_info.type != BPF_MAP_TYPE_PERF_EVENT_ARRAY) {
 143                 p_err("map is not a perf event array");
 144                 goto err_close_map;
 145         }
 146
 147         while (argc) {
 148                 if (argc < 2) {
 149                         BAD_ARG();
 150                         goto err_close_map;
 151                 }
 152
 153                 if (is_prefix(*argv, "cpu")) {
 154                         char *endptr;
 155
 156                         NEXT_ARG();
 157                         ctx.cpu = strtoul(*argv, &endptr, 0);
 158                         if (*endptr) {
 159                                 p_err("can't parse %s as CPU ID", *argv);
 160                                 goto err_close_map;
 161                         }
 162
 163                         NEXT_ARG();
 164                 } else if (is_prefix(*argv, "index")) {
 165                         char *endptr;
 166
 167                         NEXT_ARG();
 168                         ctx.idx = strtoul(*argv, &endptr, 0);
 169                         if (*endptr) {
 170                                 p_err("can't parse %s as index", *argv);
 171                                 goto err_close_map;
 172                         }
 173
 174                         NEXT_ARG();
 175                 } else {
 176                         BAD_ARG();
 177                         goto err_close_map;
 178                 }
 179
 180                 ctx.all_cpus = false;
 181         }
 182
 183         if (!ctx.all_cpus) {
 184                 if (ctx.idx == -1 || ctx.cpu == -1) {
 185                         p_err("cpu and index must be specified together");
 186                         goto err_close_map;
 187                 }
 188         } else {
 189                 ctx.cpu = 0;
 190                 ctx.idx = 0;
 191         }
 192
 193         opts.attr = &perf_attr;
 194         opts.event_cb = print_bpf_output;
 195         opts.ctx = &ctx;
 196         opts.cpu_cnt = ctx.all_cpus ? 0 : 1;
 197         opts.cpus = &ctx.cpu;
 198         opts.map_keys = &ctx.idx;
 199
 200         pb = perf_buffer__new_raw(map_fd, MMAP_PAGE_CNT, &opts);
 201         err = libbpf_get_error(pb);
 202         if (err) {
 203                 p_err("failed to create perf buffer: %s (%d)",
 204                       strerror(err), err);
 205                 goto err_close_map;
 206         }
 207
 208         signal(SIGINT, int_exit);
 209         signal(SIGHUP, int_exit);
 210         signal(SIGTERM, int_exit);
 211
 212         if (json_output)
 213                 jsonw_start_array(json_wtr);
 214
 215         while (!stop) {
 216                 err = perf_buffer__poll(pb, 200);
 217                 if (err < 0 && err != -EINTR) {
 218                         p_err("perf buffer polling failed: %s (%d)",
 219                               strerror(err), err);
 220                         goto err_close_pb;
 221                 }
 222         }
 223
 224         if (json_output)
 225                 jsonw_end_array(json_wtr);
 226
 227         perf_buffer__free(pb);
 228         close(map_fd);
 229
 230         return 0;
 231
 232 err_close_pb:
 233         perf_buffer__free(pb);
 234 err_close_map:
 235         close(map_fd);
 236         return -1;
 237 }