tools/perf/util/data-convert-json.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * JSON export.
   4  *
   5  * Copyright (C) 2021, CodeWeavers Inc. <nfraser@codeweavers.com>
   6  */
   7
   8 #include "data-convert.h"
   9
  10 #include <fcntl.h>
  11 #include <inttypes.h>
  12 #include <sys/stat.h>
  13 #include <unistd.h>
  14
  15 #include "linux/compiler.h"
  16 #include "linux/err.h"
  17 #include "util/auxtrace.h"
  18 #include "util/debug.h"
  19 #include "util/dso.h"
  20 #include "util/event.h"
  21 #include "util/evsel.h"
  22 #include "util/evlist.h"
  23 #include "util/header.h"
  24 #include "util/map.h"
  25 #include "util/session.h"
  26 #include "util/symbol.h"
  27 #include "util/thread.h"
  28 #include "util/tool.h"
  29
  30 #ifdef HAVE_LIBTRACEEVENT
  31 #include <traceevent/event-parse.h>
  32 #endif
  33
  34 struct convert_json {
  35         struct perf_tool tool;
  36         FILE *out;
  37         bool first;
  38         u64 events_count;
  39 };
  40
  41 // Outputs a JSON-encoded string surrounded by quotes with characters escaped.
  42 static void output_json_string(FILE *out, const char *s)
  43 {
  44         fputc('"', out);
  45         while (*s) {
  46                 switch (*s) {
  47
  48                 // required escapes with special forms as per RFC 8259
  49                 case '"':  fputs("\\\"", out); break;
  50                 case '\\': fputs("\\\\", out); break;
  51                 case '\b': fputs("\\b", out);  break;
  52                 case '\f': fputs("\\f", out);  break;
  53                 case '\n': fputs("\\n", out);  break;
  54                 case '\r': fputs("\\r", out);  break;
  55                 case '\t': fputs("\\t", out);  break;
  56
  57                 default:
  58                         // all other control characters must be escaped by hex code
  59                         if (*s <= 0x1f)
  60                                 fprintf(out, "\\u%04x", *s);
  61                         else
  62                                 fputc(*s, out);
  63                         break;
  64                 }
  65
  66                 ++s;
  67         }
  68         fputc('"', out);
  69 }
  70
  71 // Outputs an optional comma, newline and indentation to delimit a new value
  72 // from the previous one in a JSON object or array.
  73 static void output_json_delimiters(FILE *out, bool comma, int depth)
  74 {
  75         int i;
  76
  77         if (comma)
  78                 fputc(',', out);
  79         fputc('\n', out);
  80         for (i = 0; i < depth; ++i)
  81                 fputc('\t', out);
  82 }
  83
  84 // Outputs a printf format string (with delimiter) as a JSON value.
  85 __printf(4, 5)
  86 static void output_json_format(FILE *out, bool comma, int depth, const char *format, ...)
  87 {
  88         va_list args;
  89
  90         output_json_delimiters(out, comma, depth);
  91         va_start(args, format);
  92         vfprintf(out,  format, args);
  93         va_end(args);
  94 }
  95
  96 // Outputs a JSON key-value pair where the value is a string.
  97 static void output_json_key_string(FILE *out, bool comma, int depth,
  98                 const char *key, const char *value)
  99 {
 100         output_json_delimiters(out, comma, depth);
 101         output_json_string(out, key);
 102         fputs(": ", out);
 103         output_json_string(out, value);
 104 }
 105
 106 // Outputs a JSON key-value pair where the value is a printf format string.
 107 __printf(5, 6)
 108 static void output_json_key_format(FILE *out, bool comma, int depth,
 109                 const char *key, const char *format, ...)
 110 {
 111         va_list args;
 112
 113         output_json_delimiters(out, comma, depth);
 114         output_json_string(out, key);
 115         fputs(": ", out);
 116         va_start(args, format);
 117         vfprintf(out,  format, args);
 118         va_end(args);
 119 }
 120
 121 static void output_sample_callchain_entry(struct perf_tool *tool,
 122                 u64 ip, struct addr_location *al)
 123 {
 124         struct convert_json *c = container_of(tool, struct convert_json, tool);
 125         FILE *out = c->out;
 126
 127         output_json_format(out, false, 4, "{");
 128         output_json_key_format(out, false, 5, "ip", "\"0x%" PRIx64 "\"", ip);
 129
 130         if (al && al->sym && al->sym->namelen) {
 131                 struct dso *dso = al->map ? map__dso(al->map) : NULL;
 132
 133                 fputc(',', out);
 134                 output_json_key_string(out, false, 5, "symbol", al->sym->name);
 135
 136                 if (dso) {
 137                         const char *dso_name = dso->short_name;
 138
 139                         if (dso_name && strlen(dso_name) > 0) {
 140                                 fputc(',', out);
 141                                 output_json_key_string(out, false, 5, "dso", dso_name);
 142                         }
 143                 }
 144         }
 145
 146         output_json_format(out, false, 4, "}");
 147 }
 148
 149 static int process_sample_event(struct perf_tool *tool,
 150                                 union perf_event *event __maybe_unused,
 151                                 struct perf_sample *sample,
 152                                 struct evsel *evsel __maybe_unused,
 153                                 struct machine *machine)
 154 {
 155         struct convert_json *c = container_of(tool, struct convert_json, tool);
 156         FILE *out = c->out;
 157         struct addr_location al;
 158         u64 sample_type = __evlist__combined_sample_type(evsel->evlist);
 159         u8 cpumode = PERF_RECORD_MISC_USER;
 160
 161         addr_location__init(&al);
 162         if (machine__resolve(machine, &al, sample) < 0) {
 163                 pr_err("Sample resolution failed!\n");
 164                 addr_location__exit(&al);
 165                 return -1;
 166         }
 167
 168         ++c->events_count;
 169
 170         if (c->first)
 171                 c->first = false;
 172         else
 173                 fputc(',', out);
 174         output_json_format(out, false, 2, "{");
 175
 176         output_json_key_format(out, false, 3, "timestamp", "%" PRIi64, sample->time);
 177         output_json_key_format(out, true, 3, "pid", "%i", thread__pid(al.thread));
 178         output_json_key_format(out, true, 3, "tid", "%i", thread__tid(al.thread));
 179
 180         if ((sample_type & PERF_SAMPLE_CPU))
 181                 output_json_key_format(out, true, 3, "cpu", "%i", sample->cpu);
 182         else if (thread__cpu(al.thread) >= 0)
 183                 output_json_key_format(out, true, 3, "cpu", "%i", thread__cpu(al.thread));
 184
 185         output_json_key_string(out, true, 3, "comm", thread__comm_str(al.thread));
 186
 187         output_json_key_format(out, true, 3, "callchain", "[");
 188         if (sample->callchain) {
 189                 unsigned int i;
 190                 bool ok;
 191                 bool first_callchain = true;
 192
 193                 for (i = 0; i < sample->callchain->nr; ++i) {
 194                         u64 ip = sample->callchain->ips[i];
 195                         struct addr_location tal;
 196
 197                         if (ip >= PERF_CONTEXT_MAX) {
 198                                 switch (ip) {
 199                                 case PERF_CONTEXT_HV:
 200                                         cpumode = PERF_RECORD_MISC_HYPERVISOR;
 201                                         break;
 202                                 case PERF_CONTEXT_KERNEL:
 203                                         cpumode = PERF_RECORD_MISC_KERNEL;
 204                                         break;
 205                                 case PERF_CONTEXT_USER:
 206                                         cpumode = PERF_RECORD_MISC_USER;
 207                                         break;
 208                                 default:
 209                                         pr_debug("invalid callchain context: %"
 210                                                         PRId64 "\n", (s64) ip);
 211                                         break;
 212                                 }
 213                                 continue;
 214                         }
 215
 216                         if (first_callchain)
 217                                 first_callchain = false;
 218                         else
 219                                 fputc(',', out);
 220
 221                         addr_location__init(&tal);
 222                         ok = thread__find_symbol(al.thread, cpumode, ip, &tal);
 223                         output_sample_callchain_entry(tool, ip, ok ? &tal : NULL);
 224                         addr_location__exit(&tal);
 225                 }
 226         } else {
 227                 output_sample_callchain_entry(tool, sample->ip, &al);
 228         }
 229         output_json_format(out, false, 3, "]");
 230
 231 #ifdef HAVE_LIBTRACEEVENT
 232         if (sample->raw_data) {
 233                 int i;
 234                 struct tep_format_field **fields;
 235
 236                 fields = tep_event_fields(evsel->tp_format);
 237                 if (fields) {
 238                         i = 0;
 239                         while (fields[i]) {
 240                                 struct trace_seq s;
 241
 242                                 trace_seq_init(&s);
 243                                 tep_print_field(&s, sample->raw_data, fields[i]);
 244                                 output_json_key_string(out, true, 3, fields[i]->name, s.buffer);
 245
 246                                 i++;
 247                         }
 248                         free(fields);
 249                 }
 250         }
 251 #endif
 252         output_json_format(out, false, 2, "}");
 253         addr_location__exit(&al);
 254         return 0;
 255 }
 256
 257 static void output_headers(struct perf_session *session, struct convert_json *c)
 258 {
 259         struct stat st;
 260         struct perf_header *header = &session->header;
 261         int ret;
 262         int fd = perf_data__fd(session->data);
 263         int i;
 264         FILE *out = c->out;
 265
 266         output_json_key_format(out, false, 2, "header-version", "%u", header->version);
 267
 268         ret = fstat(fd, &st);
 269         if (ret >= 0) {
 270                 time_t stctime = st.st_mtime;
 271                 char buf[256];
 272
 273                 strftime(buf, sizeof(buf), "%FT%TZ", gmtime(&stctime));
 274                 output_json_key_string(out, true, 2, "captured-on", buf);
 275         } else {
 276                 pr_debug("Failed to get mtime of source file, not writing captured-on");
 277         }
 278
 279         output_json_key_format(out, true, 2, "data-offset", "%" PRIu64, header->data_offset);
 280         output_json_key_format(out, true, 2, "data-size", "%" PRIu64, header->data_size);
 281         output_json_key_format(out, true, 2, "feat-offset", "%" PRIu64, header->feat_offset);
 282
 283         output_json_key_string(out, true, 2, "hostname", header->env.hostname);
 284         output_json_key_string(out, true, 2, "os-release", header->env.os_release);
 285         output_json_key_string(out, true, 2, "arch", header->env.arch);
 286
 287         if (header->env.cpu_desc)
 288                 output_json_key_string(out, true, 2, "cpu-desc", header->env.cpu_desc);
 289
 290         output_json_key_string(out, true, 2, "cpuid", header->env.cpuid);
 291         output_json_key_format(out, true, 2, "nrcpus-online", "%u", header->env.nr_cpus_online);
 292         output_json_key_format(out, true, 2, "nrcpus-avail", "%u", header->env.nr_cpus_avail);
 293
 294         if (header->env.clock.enabled) {
 295                 output_json_key_format(out, true, 2, "clockid",
 296                                 "%u", header->env.clock.clockid);
 297                 output_json_key_format(out, true, 2, "clock-time",
 298                                 "%" PRIu64, header->env.clock.clockid_ns);
 299                 output_json_key_format(out, true, 2, "real-time",
 300                                 "%" PRIu64, header->env.clock.tod_ns);
 301         }
 302
 303         output_json_key_string(out, true, 2, "perf-version", header->env.version);
 304
 305         output_json_key_format(out, true, 2, "cmdline", "[");
 306         for (i = 0; i < header->env.nr_cmdline; i++) {
 307                 output_json_delimiters(out, i != 0, 3);
 308                 output_json_string(c->out, header->env.cmdline_argv[i]);
 309         }
 310         output_json_format(out, false, 2, "]");
 311 }
 312
 313 int bt_convert__perf2json(const char *input_name, const char *output_name,
 314                 struct perf_data_convert_opts *opts __maybe_unused)
 315 {
 316         struct perf_session *session;
 317         int fd;
 318         int ret = -1;
 319
 320         struct convert_json c = {
 321                 .tool = {
 322                         .sample         = process_sample_event,
 323                         .mmap           = perf_event__process_mmap,
 324                         .mmap2          = perf_event__process_mmap2,
 325                         .comm           = perf_event__process_comm,
 326                         .namespaces     = perf_event__process_namespaces,
 327                         .cgroup         = perf_event__process_cgroup,
 328                         .exit           = perf_event__process_exit,
 329                         .fork           = perf_event__process_fork,
 330                         .lost           = perf_event__process_lost,
 331 #ifdef HAVE_LIBTRACEEVENT
 332                         .tracing_data   = perf_event__process_tracing_data,
 333 #endif
 334                         .build_id       = perf_event__process_build_id,
 335                         .id_index       = perf_event__process_id_index,
 336                         .auxtrace_info  = perf_event__process_auxtrace_info,
 337                         .auxtrace       = perf_event__process_auxtrace,
 338                         .event_update   = perf_event__process_event_update,
 339                         .ordered_events = true,
 340                         .ordering_requires_timestamps = true,
 341                 },
 342                 .first = true,
 343                 .events_count = 0,
 344         };
 345
 346         struct perf_data data = {
 347                 .mode = PERF_DATA_MODE_READ,
 348                 .path = input_name,
 349                 .force = opts->force,
 350         };
 351
 352         if (opts->all) {
 353                 pr_err("--all is currently unsupported for JSON output.\n");
 354                 goto err;
 355         }
 356         if (opts->tod) {
 357                 pr_err("--tod is currently unsupported for JSON output.\n");
 358                 goto err;
 359         }
 360
 361         fd = open(output_name, O_CREAT | O_WRONLY | (opts->force ? O_TRUNC : O_EXCL), 0666);
 362         if (fd == -1) {
 363                 if (errno == EEXIST)
 364                         pr_err("Output file exists. Use --force to overwrite it.\n");
 365                 else
 366                         pr_err("Error opening output file!\n");
 367                 goto err;
 368         }
 369
 370         c.out = fdopen(fd, "w");
 371         if (!c.out) {
 372                 fprintf(stderr, "Error opening output file!\n");
 373                 close(fd);
 374                 goto err;
 375         }
 376
 377         session = perf_session__new(&data, &c.tool);
 378         if (IS_ERR(session)) {
 379                 fprintf(stderr, "Error creating perf session!\n");
 380                 goto err_fclose;
 381         }
 382
 383         if (symbol__init(&session->header.env) < 0) {
 384                 fprintf(stderr, "Symbol init error!\n");
 385                 goto err_session_delete;
 386         }
 387
 388         // The opening brace is printed manually because it isn't delimited from a
 389         // previous value (i.e. we don't want a leading newline)
 390         fputc('{', c.out);
 391
 392         // Version number for future-proofing. Most additions should be able to be
 393         // done in a backwards-compatible way so this should only need to be bumped
 394         // if some major breaking change must be made.
 395         output_json_format(c.out, false, 1, "\"linux-perf-json-version\": 1");
 396
 397         // Output headers
 398         output_json_format(c.out, true, 1, "\"headers\": {");
 399         output_headers(session, &c);
 400         output_json_format(c.out, false, 1, "}");
 401
 402         // Output samples
 403         output_json_format(c.out, true, 1, "\"samples\": [");
 404         perf_session__process_events(session);
 405         output_json_format(c.out, false, 1, "]");
 406         output_json_format(c.out, false, 0, "}");
 407         fputc('\n', c.out);
 408
 409         fprintf(stderr,
 410                         "[ perf data convert: Converted '%s' into JSON data '%s' ]\n",
 411                         data.path, output_name);
 412
 413         fprintf(stderr,
 414                         "[ perf data convert: Converted and wrote %.3f MB (%" PRIu64 " samples) ]\n",
 415                         (ftell(c.out)) / 1024.0 / 1024.0, c.events_count);
 416
 417         ret = 0;
 418 err_session_delete:
 419         perf_session__delete(session);
 420 err_fclose:
 421         fclose(c.out);
 422 err:
 423         return ret;
 424 }