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