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 fputc(',', out); 132 output_json_key_string(out, false, 5, "symbol", al->sym->name); 133 134 if (al->map && al->map->dso) { 135 const char *dso = al->map->dso->short_name; 136 137 if (dso && strlen(dso) > 0) { 138 fputc(',', out); 139 output_json_key_string(out, false, 5, "dso", dso); 140 } 141 } 142 } 143 144 output_json_format(out, false, 4, "}"); 145 } 146 147 static int process_sample_event(struct perf_tool *tool, 148 union perf_event *event __maybe_unused, 149 struct perf_sample *sample, 150 struct evsel *evsel __maybe_unused, 151 struct machine *machine) 152 { 153 struct convert_json *c = container_of(tool, struct convert_json, tool); 154 FILE *out = c->out; 155 struct addr_location al, tal; 156 u64 sample_type = __evlist__combined_sample_type(evsel->evlist); 157 u8 cpumode = PERF_RECORD_MISC_USER; 158 159 if (machine__resolve(machine, &al, sample) < 0) { 160 pr_err("Sample resolution failed!\n"); 161 return -1; 162 } 163 164 ++c->events_count; 165 166 if (c->first) 167 c->first = false; 168 else 169 fputc(',', out); 170 output_json_format(out, false, 2, "{"); 171 172 output_json_key_format(out, false, 3, "timestamp", "%" PRIi64, sample->time); 173 output_json_key_format(out, true, 3, "pid", "%i", al.thread->pid_); 174 output_json_key_format(out, true, 3, "tid", "%i", al.thread->tid); 175 176 if ((sample_type & PERF_SAMPLE_CPU)) 177 output_json_key_format(out, true, 3, "cpu", "%i", sample->cpu); 178 else if (al.thread->cpu >= 0) 179 output_json_key_format(out, true, 3, "cpu", "%i", al.thread->cpu); 180 181 output_json_key_string(out, true, 3, "comm", thread__comm_str(al.thread)); 182 183 output_json_key_format(out, true, 3, "callchain", "["); 184 if (sample->callchain) { 185 unsigned int i; 186 bool ok; 187 bool first_callchain = true; 188 189 for (i = 0; i < sample->callchain->nr; ++i) { 190 u64 ip = sample->callchain->ips[i]; 191 192 if (ip >= PERF_CONTEXT_MAX) { 193 switch (ip) { 194 case PERF_CONTEXT_HV: 195 cpumode = PERF_RECORD_MISC_HYPERVISOR; 196 break; 197 case PERF_CONTEXT_KERNEL: 198 cpumode = PERF_RECORD_MISC_KERNEL; 199 break; 200 case PERF_CONTEXT_USER: 201 cpumode = PERF_RECORD_MISC_USER; 202 break; 203 default: 204 pr_debug("invalid callchain context: %" 205 PRId64 "\n", (s64) ip); 206 break; 207 } 208 continue; 209 } 210 211 if (first_callchain) 212 first_callchain = false; 213 else 214 fputc(',', out); 215 216 ok = thread__find_symbol(al.thread, cpumode, ip, &tal); 217 output_sample_callchain_entry(tool, ip, ok ? &tal : NULL); 218 } 219 } else { 220 output_sample_callchain_entry(tool, sample->ip, &al); 221 } 222 output_json_format(out, false, 3, "]"); 223 224 #ifdef HAVE_LIBTRACEEVENT 225 if (sample->raw_data) { 226 int i; 227 struct tep_format_field **fields; 228 229 fields = tep_event_fields(evsel->tp_format); 230 if (fields) { 231 i = 0; 232 while (fields[i]) { 233 struct trace_seq s; 234 235 trace_seq_init(&s); 236 tep_print_field(&s, sample->raw_data, fields[i]); 237 output_json_key_string(out, true, 3, fields[i]->name, s.buffer); 238 239 i++; 240 } 241 free(fields); 242 } 243 } 244 #endif 245 output_json_format(out, false, 2, "}"); 246 return 0; 247 } 248 249 static void output_headers(struct perf_session *session, struct convert_json *c) 250 { 251 struct stat st; 252 struct perf_header *header = &session->header; 253 int ret; 254 int fd = perf_data__fd(session->data); 255 int i; 256 FILE *out = c->out; 257 258 output_json_key_format(out, false, 2, "header-version", "%u", header->version); 259 260 ret = fstat(fd, &st); 261 if (ret >= 0) { 262 time_t stctime = st.st_mtime; 263 char buf[256]; 264 265 strftime(buf, sizeof(buf), "%FT%TZ", gmtime(&stctime)); 266 output_json_key_string(out, true, 2, "captured-on", buf); 267 } else { 268 pr_debug("Failed to get mtime of source file, not writing captured-on"); 269 } 270 271 output_json_key_format(out, true, 2, "data-offset", "%" PRIu64, header->data_offset); 272 output_json_key_format(out, true, 2, "data-size", "%" PRIu64, header->data_size); 273 output_json_key_format(out, true, 2, "feat-offset", "%" PRIu64, header->feat_offset); 274 275 output_json_key_string(out, true, 2, "hostname", header->env.hostname); 276 output_json_key_string(out, true, 2, "os-release", header->env.os_release); 277 output_json_key_string(out, true, 2, "arch", header->env.arch); 278 279 output_json_key_string(out, true, 2, "cpu-desc", header->env.cpu_desc); 280 output_json_key_string(out, true, 2, "cpuid", header->env.cpuid); 281 output_json_key_format(out, true, 2, "nrcpus-online", "%u", header->env.nr_cpus_online); 282 output_json_key_format(out, true, 2, "nrcpus-avail", "%u", header->env.nr_cpus_avail); 283 284 if (header->env.clock.enabled) { 285 output_json_key_format(out, true, 2, "clockid", 286 "%u", header->env.clock.clockid); 287 output_json_key_format(out, true, 2, "clock-time", 288 "%" PRIu64, header->env.clock.clockid_ns); 289 output_json_key_format(out, true, 2, "real-time", 290 "%" PRIu64, header->env.clock.tod_ns); 291 } 292 293 output_json_key_string(out, true, 2, "perf-version", header->env.version); 294 295 output_json_key_format(out, true, 2, "cmdline", "["); 296 for (i = 0; i < header->env.nr_cmdline; i++) { 297 output_json_delimiters(out, i != 0, 3); 298 output_json_string(c->out, header->env.cmdline_argv[i]); 299 } 300 output_json_format(out, false, 2, "]"); 301 } 302 303 int bt_convert__perf2json(const char *input_name, const char *output_name, 304 struct perf_data_convert_opts *opts __maybe_unused) 305 { 306 struct perf_session *session; 307 int fd; 308 int ret = -1; 309 310 struct convert_json c = { 311 .tool = { 312 .sample = process_sample_event, 313 .mmap = perf_event__process_mmap, 314 .mmap2 = perf_event__process_mmap2, 315 .comm = perf_event__process_comm, 316 .namespaces = perf_event__process_namespaces, 317 .cgroup = perf_event__process_cgroup, 318 .exit = perf_event__process_exit, 319 .fork = perf_event__process_fork, 320 .lost = perf_event__process_lost, 321 #ifdef HAVE_LIBTRACEEVENT 322 .tracing_data = perf_event__process_tracing_data, 323 #endif 324 .build_id = perf_event__process_build_id, 325 .id_index = perf_event__process_id_index, 326 .auxtrace_info = perf_event__process_auxtrace_info, 327 .auxtrace = perf_event__process_auxtrace, 328 .event_update = perf_event__process_event_update, 329 .ordered_events = true, 330 .ordering_requires_timestamps = true, 331 }, 332 .first = true, 333 .events_count = 0, 334 }; 335 336 struct perf_data data = { 337 .mode = PERF_DATA_MODE_READ, 338 .path = input_name, 339 .force = opts->force, 340 }; 341 342 if (opts->all) { 343 pr_err("--all is currently unsupported for JSON output.\n"); 344 goto err; 345 } 346 if (opts->tod) { 347 pr_err("--tod is currently unsupported for JSON output.\n"); 348 goto err; 349 } 350 351 fd = open(output_name, O_CREAT | O_WRONLY | (opts->force ? O_TRUNC : O_EXCL), 0666); 352 if (fd == -1) { 353 if (errno == EEXIST) 354 pr_err("Output file exists. Use --force to overwrite it.\n"); 355 else 356 pr_err("Error opening output file!\n"); 357 goto err; 358 } 359 360 c.out = fdopen(fd, "w"); 361 if (!c.out) { 362 fprintf(stderr, "Error opening output file!\n"); 363 close(fd); 364 goto err; 365 } 366 367 session = perf_session__new(&data, &c.tool); 368 if (IS_ERR(session)) { 369 fprintf(stderr, "Error creating perf session!\n"); 370 goto err_fclose; 371 } 372 373 if (symbol__init(&session->header.env) < 0) { 374 fprintf(stderr, "Symbol init error!\n"); 375 goto err_session_delete; 376 } 377 378 // The opening brace is printed manually because it isn't delimited from a 379 // previous value (i.e. we don't want a leading newline) 380 fputc('{', c.out); 381 382 // Version number for future-proofing. Most additions should be able to be 383 // done in a backwards-compatible way so this should only need to be bumped 384 // if some major breaking change must be made. 385 output_json_format(c.out, false, 1, "\"linux-perf-json-version\": 1"); 386 387 // Output headers 388 output_json_format(c.out, true, 1, "\"headers\": {"); 389 output_headers(session, &c); 390 output_json_format(c.out, false, 1, "}"); 391 392 // Output samples 393 output_json_format(c.out, true, 1, "\"samples\": ["); 394 perf_session__process_events(session); 395 output_json_format(c.out, false, 1, "]"); 396 output_json_format(c.out, false, 0, "}"); 397 fputc('\n', c.out); 398 399 fprintf(stderr, 400 "[ perf data convert: Converted '%s' into JSON data '%s' ]\n", 401 data.path, output_name); 402 403 fprintf(stderr, 404 "[ perf data convert: Converted and wrote %.3f MB (%" PRIu64 " samples) ]\n", 405 (ftell(c.out)) / 1024.0 / 1024.0, c.events_count); 406 407 ret = 0; 408 err_session_delete: 409 perf_session__delete(session); 410 err_fclose: 411 fclose(c.out); 412 err: 413 return ret; 414 } 415