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