1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2008,2009, Steven Rostedt <srostedt@redhat.com> 4 */ 5 #include "util.h" 6 #include <dirent.h> 7 #include <mntent.h> 8 #include <stdio.h> 9 #include <stdlib.h> 10 #include <string.h> 11 #include <stdarg.h> 12 #include <sys/types.h> 13 #include <sys/stat.h> 14 #include <sys/wait.h> 15 #include <fcntl.h> 16 #include <unistd.h> 17 #include <errno.h> 18 #include <stdbool.h> 19 #include <linux/list.h> 20 #include <linux/kernel.h> 21 #include <linux/zalloc.h> 22 23 #include "../perf.h" 24 #include "trace-event.h" 25 #include <api/fs/tracing_path.h> 26 #include "evsel.h" 27 #include "debug.h" 28 29 #define VERSION "0.6" 30 31 static int output_fd; 32 33 34 int bigendian(void) 35 { 36 unsigned char str[] = { 0x1, 0x2, 0x3, 0x4, 0x0, 0x0, 0x0, 0x0}; 37 unsigned int *ptr; 38 39 ptr = (unsigned int *)(void *)str; 40 return *ptr == 0x01020304; 41 } 42 43 /* unfortunately, you can not stat debugfs or proc files for size */ 44 static int record_file(const char *file, ssize_t hdr_sz) 45 { 46 unsigned long long size = 0; 47 char buf[BUFSIZ], *sizep; 48 off_t hdr_pos = lseek(output_fd, 0, SEEK_CUR); 49 int r, fd; 50 int err = -EIO; 51 52 fd = open(file, O_RDONLY); 53 if (fd < 0) { 54 pr_debug("Can't read '%s'", file); 55 return -errno; 56 } 57 58 /* put in zeros for file size, then fill true size later */ 59 if (hdr_sz) { 60 if (write(output_fd, &size, hdr_sz) != hdr_sz) 61 goto out; 62 } 63 64 do { 65 r = read(fd, buf, BUFSIZ); 66 if (r > 0) { 67 size += r; 68 if (write(output_fd, buf, r) != r) 69 goto out; 70 } 71 } while (r > 0); 72 73 /* ugh, handle big-endian hdr_size == 4 */ 74 sizep = (char*)&size; 75 if (bigendian()) 76 sizep += sizeof(u64) - hdr_sz; 77 78 if (hdr_sz && pwrite(output_fd, sizep, hdr_sz, hdr_pos) < 0) { 79 pr_debug("writing file size failed\n"); 80 goto out; 81 } 82 83 err = 0; 84 out: 85 close(fd); 86 return err; 87 } 88 89 static int record_header_files(void) 90 { 91 char *path = get_events_file("header_page"); 92 struct stat st; 93 int err = -EIO; 94 95 if (!path) { 96 pr_debug("can't get tracing/events/header_page"); 97 return -ENOMEM; 98 } 99 100 if (stat(path, &st) < 0) { 101 pr_debug("can't read '%s'", path); 102 goto out; 103 } 104 105 if (write(output_fd, "header_page", 12) != 12) { 106 pr_debug("can't write header_page\n"); 107 goto out; 108 } 109 110 if (record_file(path, 8) < 0) { 111 pr_debug("can't record header_page file\n"); 112 goto out; 113 } 114 115 put_events_file(path); 116 117 path = get_events_file("header_event"); 118 if (!path) { 119 pr_debug("can't get tracing/events/header_event"); 120 err = -ENOMEM; 121 goto out; 122 } 123 124 if (stat(path, &st) < 0) { 125 pr_debug("can't read '%s'", path); 126 goto out; 127 } 128 129 if (write(output_fd, "header_event", 13) != 13) { 130 pr_debug("can't write header_event\n"); 131 goto out; 132 } 133 134 if (record_file(path, 8) < 0) { 135 pr_debug("can't record header_event file\n"); 136 goto out; 137 } 138 139 err = 0; 140 out: 141 put_events_file(path); 142 return err; 143 } 144 145 static bool name_in_tp_list(char *sys, struct tracepoint_path *tps) 146 { 147 while (tps) { 148 if (!strcmp(sys, tps->name)) 149 return true; 150 tps = tps->next; 151 } 152 153 return false; 154 } 155 156 #define for_each_event(dir, dent, tps) \ 157 while ((dent = readdir(dir))) \ 158 if (dent->d_type == DT_DIR && \ 159 (strcmp(dent->d_name, ".")) && \ 160 (strcmp(dent->d_name, ".."))) \ 161 162 static int copy_event_system(const char *sys, struct tracepoint_path *tps) 163 { 164 struct dirent *dent; 165 struct stat st; 166 char *format; 167 DIR *dir; 168 int count = 0; 169 int ret; 170 int err; 171 172 dir = opendir(sys); 173 if (!dir) { 174 pr_debug("can't read directory '%s'", sys); 175 return -errno; 176 } 177 178 for_each_event(dir, dent, tps) { 179 if (!name_in_tp_list(dent->d_name, tps)) 180 continue; 181 182 if (asprintf(&format, "%s/%s/format", sys, dent->d_name) < 0) { 183 err = -ENOMEM; 184 goto out; 185 } 186 ret = stat(format, &st); 187 free(format); 188 if (ret < 0) 189 continue; 190 count++; 191 } 192 193 if (write(output_fd, &count, 4) != 4) { 194 err = -EIO; 195 pr_debug("can't write count\n"); 196 goto out; 197 } 198 199 rewinddir(dir); 200 for_each_event(dir, dent, tps) { 201 if (!name_in_tp_list(dent->d_name, tps)) 202 continue; 203 204 if (asprintf(&format, "%s/%s/format", sys, dent->d_name) < 0) { 205 err = -ENOMEM; 206 goto out; 207 } 208 ret = stat(format, &st); 209 210 if (ret >= 0) { 211 err = record_file(format, 8); 212 if (err) { 213 free(format); 214 goto out; 215 } 216 } 217 free(format); 218 } 219 err = 0; 220 out: 221 closedir(dir); 222 return err; 223 } 224 225 static int record_ftrace_files(struct tracepoint_path *tps) 226 { 227 char *path; 228 int ret; 229 230 path = get_events_file("ftrace"); 231 if (!path) { 232 pr_debug("can't get tracing/events/ftrace"); 233 return -ENOMEM; 234 } 235 236 ret = copy_event_system(path, tps); 237 238 put_tracing_file(path); 239 240 return ret; 241 } 242 243 static bool system_in_tp_list(char *sys, struct tracepoint_path *tps) 244 { 245 while (tps) { 246 if (!strcmp(sys, tps->system)) 247 return true; 248 tps = tps->next; 249 } 250 251 return false; 252 } 253 254 static int record_event_files(struct tracepoint_path *tps) 255 { 256 struct dirent *dent; 257 struct stat st; 258 char *path; 259 char *sys; 260 DIR *dir; 261 int count = 0; 262 int ret; 263 int err; 264 265 path = get_tracing_file("events"); 266 if (!path) { 267 pr_debug("can't get tracing/events"); 268 return -ENOMEM; 269 } 270 271 dir = opendir(path); 272 if (!dir) { 273 err = -errno; 274 pr_debug("can't read directory '%s'", path); 275 goto out; 276 } 277 278 for_each_event(dir, dent, tps) { 279 if (strcmp(dent->d_name, "ftrace") == 0 || 280 !system_in_tp_list(dent->d_name, tps)) 281 continue; 282 283 count++; 284 } 285 286 if (write(output_fd, &count, 4) != 4) { 287 err = -EIO; 288 pr_debug("can't write count\n"); 289 goto out; 290 } 291 292 rewinddir(dir); 293 for_each_event(dir, dent, tps) { 294 if (strcmp(dent->d_name, "ftrace") == 0 || 295 !system_in_tp_list(dent->d_name, tps)) 296 continue; 297 298 if (asprintf(&sys, "%s/%s", path, dent->d_name) < 0) { 299 err = -ENOMEM; 300 goto out; 301 } 302 ret = stat(sys, &st); 303 if (ret >= 0) { 304 ssize_t size = strlen(dent->d_name) + 1; 305 306 if (write(output_fd, dent->d_name, size) != size || 307 copy_event_system(sys, tps) < 0) { 308 err = -EIO; 309 free(sys); 310 goto out; 311 } 312 } 313 free(sys); 314 } 315 err = 0; 316 out: 317 closedir(dir); 318 put_tracing_file(path); 319 320 return err; 321 } 322 323 static int record_proc_kallsyms(void) 324 { 325 unsigned long long size = 0; 326 /* 327 * Just to keep older perf.data file parsers happy, record a zero 328 * sized kallsyms file, i.e. do the same thing that was done when 329 * /proc/kallsyms (or something specified via --kallsyms, in a 330 * different path) couldn't be read. 331 */ 332 return write(output_fd, &size, 4) != 4 ? -EIO : 0; 333 } 334 335 static int record_ftrace_printk(void) 336 { 337 unsigned int size; 338 char *path; 339 struct stat st; 340 int ret, err = 0; 341 342 path = get_tracing_file("printk_formats"); 343 if (!path) { 344 pr_debug("can't get tracing/printk_formats"); 345 return -ENOMEM; 346 } 347 348 ret = stat(path, &st); 349 if (ret < 0) { 350 /* not found */ 351 size = 0; 352 if (write(output_fd, &size, 4) != 4) 353 err = -EIO; 354 goto out; 355 } 356 err = record_file(path, 4); 357 358 out: 359 put_tracing_file(path); 360 return err; 361 } 362 363 static int record_saved_cmdline(void) 364 { 365 unsigned long long size; 366 char *path; 367 struct stat st; 368 int ret, err = 0; 369 370 path = get_tracing_file("saved_cmdlines"); 371 if (!path) { 372 pr_debug("can't get tracing/saved_cmdline"); 373 return -ENOMEM; 374 } 375 376 ret = stat(path, &st); 377 if (ret < 0) { 378 /* not found */ 379 size = 0; 380 if (write(output_fd, &size, 8) != 8) 381 err = -EIO; 382 goto out; 383 } 384 err = record_file(path, 8); 385 386 out: 387 put_tracing_file(path); 388 return err; 389 } 390 391 static void 392 put_tracepoints_path(struct tracepoint_path *tps) 393 { 394 while (tps) { 395 struct tracepoint_path *t = tps; 396 397 tps = tps->next; 398 zfree(&t->name); 399 zfree(&t->system); 400 free(t); 401 } 402 } 403 404 static struct tracepoint_path * 405 get_tracepoints_path(struct list_head *pattrs) 406 { 407 struct tracepoint_path path, *ppath = &path; 408 struct perf_evsel *pos; 409 int nr_tracepoints = 0; 410 411 list_for_each_entry(pos, pattrs, node) { 412 if (pos->attr.type != PERF_TYPE_TRACEPOINT) 413 continue; 414 ++nr_tracepoints; 415 416 if (pos->name) { 417 ppath->next = tracepoint_name_to_path(pos->name); 418 if (ppath->next) 419 goto next; 420 421 if (strchr(pos->name, ':') == NULL) 422 goto try_id; 423 424 goto error; 425 } 426 427 try_id: 428 ppath->next = tracepoint_id_to_path(pos->attr.config); 429 if (!ppath->next) { 430 error: 431 pr_debug("No memory to alloc tracepoints list\n"); 432 put_tracepoints_path(&path); 433 return NULL; 434 } 435 next: 436 ppath = ppath->next; 437 } 438 439 return nr_tracepoints > 0 ? path.next : NULL; 440 } 441 442 bool have_tracepoints(struct list_head *pattrs) 443 { 444 struct perf_evsel *pos; 445 446 list_for_each_entry(pos, pattrs, node) 447 if (pos->attr.type == PERF_TYPE_TRACEPOINT) 448 return true; 449 450 return false; 451 } 452 453 static int tracing_data_header(void) 454 { 455 char buf[20]; 456 ssize_t size; 457 458 /* just guessing this is someone's birthday.. ;) */ 459 buf[0] = 23; 460 buf[1] = 8; 461 buf[2] = 68; 462 memcpy(buf + 3, "tracing", 7); 463 464 if (write(output_fd, buf, 10) != 10) 465 return -1; 466 467 size = strlen(VERSION) + 1; 468 if (write(output_fd, VERSION, size) != size) 469 return -1; 470 471 /* save endian */ 472 if (bigendian()) 473 buf[0] = 1; 474 else 475 buf[0] = 0; 476 477 if (write(output_fd, buf, 1) != 1) 478 return -1; 479 480 /* save size of long */ 481 buf[0] = sizeof(long); 482 if (write(output_fd, buf, 1) != 1) 483 return -1; 484 485 /* save page_size */ 486 if (write(output_fd, &page_size, 4) != 4) 487 return -1; 488 489 return 0; 490 } 491 492 struct tracing_data *tracing_data_get(struct list_head *pattrs, 493 int fd, bool temp) 494 { 495 struct tracepoint_path *tps; 496 struct tracing_data *tdata; 497 int err; 498 499 output_fd = fd; 500 501 tps = get_tracepoints_path(pattrs); 502 if (!tps) 503 return NULL; 504 505 tdata = malloc(sizeof(*tdata)); 506 if (!tdata) 507 return NULL; 508 509 tdata->temp = temp; 510 tdata->size = 0; 511 512 if (temp) { 513 int temp_fd; 514 515 snprintf(tdata->temp_file, sizeof(tdata->temp_file), 516 "/tmp/perf-XXXXXX"); 517 if (!mkstemp(tdata->temp_file)) { 518 pr_debug("Can't make temp file"); 519 free(tdata); 520 return NULL; 521 } 522 523 temp_fd = open(tdata->temp_file, O_RDWR); 524 if (temp_fd < 0) { 525 pr_debug("Can't read '%s'", tdata->temp_file); 526 free(tdata); 527 return NULL; 528 } 529 530 /* 531 * Set the temp file the default output, so all the 532 * tracing data are stored into it. 533 */ 534 output_fd = temp_fd; 535 } 536 537 err = tracing_data_header(); 538 if (err) 539 goto out; 540 err = record_header_files(); 541 if (err) 542 goto out; 543 err = record_ftrace_files(tps); 544 if (err) 545 goto out; 546 err = record_event_files(tps); 547 if (err) 548 goto out; 549 err = record_proc_kallsyms(); 550 if (err) 551 goto out; 552 err = record_ftrace_printk(); 553 if (err) 554 goto out; 555 err = record_saved_cmdline(); 556 557 out: 558 /* 559 * All tracing data are stored by now, we can restore 560 * the default output file in case we used temp file. 561 */ 562 if (temp) { 563 tdata->size = lseek(output_fd, 0, SEEK_CUR); 564 close(output_fd); 565 output_fd = fd; 566 } 567 568 if (err) 569 zfree(&tdata); 570 571 put_tracepoints_path(tps); 572 return tdata; 573 } 574 575 int tracing_data_put(struct tracing_data *tdata) 576 { 577 int err = 0; 578 579 if (tdata->temp) { 580 err = record_file(tdata->temp_file, 0); 581 unlink(tdata->temp_file); 582 } 583 584 free(tdata); 585 return err; 586 } 587 588 int read_tracing_data(int fd, struct list_head *pattrs) 589 { 590 int err; 591 struct tracing_data *tdata; 592 593 /* 594 * We work over the real file, so we can write data 595 * directly, no temp file is needed. 596 */ 597 tdata = tracing_data_get(pattrs, fd, false); 598 if (!tdata) 599 return -ENOMEM; 600 601 err = tracing_data_put(tdata); 602 return err; 603 } 604