1 // SPDX-License-Identifier: GPL-2.0 2 #include <linux/compiler.h> 3 #include <linux/kernel.h> 4 #include <linux/string.h> 5 #include <linux/zalloc.h> 6 #include <linux/err.h> 7 #include <sys/types.h> 8 #include <sys/stat.h> 9 #include <errno.h> 10 #include <fcntl.h> 11 #include <unistd.h> 12 #include <string.h> 13 #include <asm/bug.h> 14 #include <dirent.h> 15 16 #include "data.h" 17 #include "util.h" // rm_rf_perf_data() 18 #include "debug.h" 19 #include "header.h" 20 #include "rlimit.h" 21 #include <internal/lib.h> 22 23 static void perf_data_file__close(struct perf_data_file *file) 24 { 25 if (file->use_stdio) { 26 if (file->fptr) { 27 fclose(file->fptr); 28 file->fptr = NULL; 29 } 30 } else { 31 close(file->fd); 32 file->fd = -1; 33 } 34 zfree(&file->path); 35 } 36 37 static void close_dir(struct perf_data_file *files, int nr) 38 { 39 while (--nr >= 0) 40 perf_data_file__close(&files[nr]); 41 42 free(files); 43 } 44 45 void perf_data__close_dir(struct perf_data *data) 46 { 47 close_dir(data->dir.files, data->dir.nr); 48 data->dir.files = NULL; 49 data->dir.nr = 0; 50 } 51 52 int perf_data__create_dir(struct perf_data *data, int nr) 53 { 54 enum rlimit_action set_rlimit = NO_CHANGE; 55 struct perf_data_file *files = NULL; 56 int i, ret; 57 58 if (WARN_ON(!data->is_dir)) 59 return -EINVAL; 60 61 files = calloc(nr, sizeof(*files)); 62 if (!files) 63 return -ENOMEM; 64 65 for (i = 0; i < nr; i++) { 66 struct perf_data_file *file = &files[i]; 67 68 ret = asprintf(&file->path, "%s/data.%d", data->path, i); 69 if (ret < 0) { 70 ret = -ENOMEM; 71 goto out_err; 72 } 73 74 retry_open: 75 ret = open(file->path, O_RDWR|O_CREAT|O_TRUNC, S_IRUSR|S_IWUSR); 76 if (ret < 0) { 77 /* 78 * If using parallel threads to collect data, 79 * perf record needs at least 6 fds per CPU. 80 * When we run out of them try to increase the limits. 81 */ 82 if (errno == EMFILE && rlimit__increase_nofile(&set_rlimit)) 83 goto retry_open; 84 85 ret = -errno; 86 goto out_err; 87 } 88 set_rlimit = NO_CHANGE; 89 90 file->fd = ret; 91 } 92 93 data->dir.version = PERF_DIR_VERSION; 94 data->dir.files = files; 95 data->dir.nr = nr; 96 return 0; 97 98 out_err: 99 close_dir(files, i); 100 return ret; 101 } 102 103 int perf_data__open_dir(struct perf_data *data) 104 { 105 struct perf_data_file *files = NULL; 106 struct dirent *dent; 107 int ret = -1; 108 DIR *dir; 109 int nr = 0; 110 111 /* 112 * Directory containing a single regular perf data file which is already 113 * open, means there is nothing more to do here. 114 */ 115 if (perf_data__is_single_file(data)) 116 return 0; 117 118 if (WARN_ON(!data->is_dir)) 119 return -EINVAL; 120 121 /* The version is provided by DIR_FORMAT feature. */ 122 if (WARN_ON(data->dir.version != PERF_DIR_VERSION)) 123 return -1; 124 125 dir = opendir(data->path); 126 if (!dir) 127 return -EINVAL; 128 129 while ((dent = readdir(dir)) != NULL) { 130 struct perf_data_file *file; 131 char path[PATH_MAX]; 132 struct stat st; 133 134 snprintf(path, sizeof(path), "%s/%s", data->path, dent->d_name); 135 if (stat(path, &st)) 136 continue; 137 138 if (!S_ISREG(st.st_mode) || strncmp(dent->d_name, "data.", 5)) 139 continue; 140 141 ret = -ENOMEM; 142 143 file = realloc(files, (nr + 1) * sizeof(*files)); 144 if (!file) 145 goto out_err; 146 147 files = file; 148 file = &files[nr++]; 149 150 *file = (struct perf_data_file){ 151 .path = strdup(path), 152 .fd = -1, 153 .size = st.st_size, 154 .use_stdio = false, 155 }; 156 if (!file->path) 157 goto out_err; 158 159 ret = open(file->path, O_RDONLY); 160 if (ret < 0) { 161 ret = -errno; 162 goto out_err; 163 } 164 file->fd = ret; 165 } 166 167 closedir(dir); 168 if (!files) 169 return -EINVAL; 170 171 data->dir.files = files; 172 data->dir.nr = nr; 173 return 0; 174 175 out_err: 176 closedir(dir); 177 close_dir(files, nr); 178 return ret; 179 } 180 181 static bool check_pipe(struct perf_data *data) 182 { 183 struct stat st; 184 bool is_pipe = false; 185 int fd = perf_data__is_read(data) ? 186 STDIN_FILENO : STDOUT_FILENO; 187 188 if (!data->path) { 189 if (!fstat(fd, &st) && S_ISFIFO(st.st_mode)) 190 is_pipe = true; 191 } else { 192 if (!strcmp(data->path, "-")) 193 is_pipe = true; 194 } 195 196 if (is_pipe) { 197 if (data->file.use_stdio) { 198 const char *mode; 199 200 mode = perf_data__is_read(data) ? "r" : "w"; 201 data->file.fptr = fdopen(fd, mode); 202 203 if (data->file.fptr == NULL) { 204 data->file.fd = fd; 205 data->file.use_stdio = false; 206 } 207 208 /* 209 * When is_pipe and data->file.fd is given, use given fd 210 * instead of STDIN_FILENO or STDOUT_FILENO 211 */ 212 } else if (data->file.fd <= 0) { 213 data->file.fd = fd; 214 } 215 } 216 217 return data->is_pipe = is_pipe; 218 } 219 220 static int check_backup(struct perf_data *data) 221 { 222 struct stat st; 223 224 if (perf_data__is_read(data)) 225 return 0; 226 227 if (!stat(data->path, &st) && st.st_size) { 228 char oldname[PATH_MAX]; 229 int ret; 230 231 snprintf(oldname, sizeof(oldname), "%s.old", 232 data->path); 233 234 ret = rm_rf_perf_data(oldname); 235 if (ret) { 236 if (ret == -2) 237 pr_err("Can't remove old data: Unknown file found (%s)\n", oldname); 238 else 239 pr_err("Can't remove old data: %m (%s)\n", oldname); 240 return -1; 241 } 242 243 if (rename(data->path, oldname)) { 244 pr_err("Can't move data: %m (%s to %s)\n", data->path, oldname); 245 return -1; 246 } 247 } 248 249 return 0; 250 } 251 252 static bool is_dir(struct perf_data *data) 253 { 254 struct stat st; 255 256 if (stat(data->path, &st)) 257 return false; 258 259 return (st.st_mode & S_IFMT) == S_IFDIR; 260 } 261 262 static int open_file_read(struct perf_data *data) 263 { 264 int flags = data->in_place_update ? O_RDWR : O_RDONLY; 265 struct stat st; 266 int fd; 267 268 fd = open(data->file.path, flags); 269 if (fd < 0) { 270 int err = errno; 271 272 pr_err("failed to open %s: %m", data->file.path); 273 if (err == ENOENT && !strcmp(data->file.path, "perf.data")) 274 pr_err(" (try 'perf record' first)"); 275 pr_err("\n"); 276 return -err; 277 } 278 279 if (fstat(fd, &st) < 0) 280 goto out_close; 281 282 if (!data->force && st.st_uid && (st.st_uid != geteuid())) { 283 pr_err("File %s not owned by current user or root (use -f to override)\n", 284 data->file.path); 285 goto out_close; 286 } 287 288 if (!st.st_size) { 289 pr_info("zero-sized data (%s), nothing to do!\n", 290 data->file.path); 291 goto out_close; 292 } 293 294 data->file.size = st.st_size; 295 return fd; 296 297 out_close: 298 close(fd); 299 return -1; 300 } 301 302 static int open_file_write(struct perf_data *data) 303 { 304 int fd = open(data->file.path, O_CREAT|O_RDWR|O_TRUNC|O_CLOEXEC, S_IRUSR|S_IWUSR); 305 306 if (fd < 0) 307 pr_err("failed to open %s : %m\n", data->file.path); 308 309 return fd; 310 } 311 312 static int open_file(struct perf_data *data) 313 { 314 int fd; 315 316 fd = perf_data__is_read(data) ? 317 open_file_read(data) : open_file_write(data); 318 319 if (fd < 0) { 320 zfree(&data->file.path); 321 return -1; 322 } 323 324 data->file.fd = fd; 325 return 0; 326 } 327 328 static int open_file_dup(struct perf_data *data) 329 { 330 data->file.path = strdup(data->path); 331 if (!data->file.path) 332 return -ENOMEM; 333 334 return open_file(data); 335 } 336 337 static int open_dir(struct perf_data *data) 338 { 339 int ret; 340 341 /* 342 * So far we open only the header, so we can read the data version and 343 * layout. 344 */ 345 if (asprintf(&data->file.path, "%s/data", data->path) < 0) 346 return -1; 347 348 if (perf_data__is_write(data) && mkdir(data->path, 0700) < 0) { 349 zfree(&data->file.path); 350 return -1; 351 } 352 353 ret = open_file(data); 354 355 /* Cleanup whatever we managed to create so far. */ 356 if (ret && perf_data__is_write(data)) 357 rm_rf_perf_data(data->path); 358 359 return ret; 360 } 361 362 int perf_data__open(struct perf_data *data) 363 { 364 int ret; 365 366 if (data->open) 367 return 0; 368 369 if (check_pipe(data)) { 370 data->open = true; 371 return 0; 372 } 373 374 /* currently it allows stdio for pipe only */ 375 data->file.use_stdio = false; 376 377 if (!data->path) 378 data->path = "perf.data"; 379 380 if (check_backup(data)) 381 return -1; 382 383 if (perf_data__is_read(data)) 384 data->is_dir = is_dir(data); 385 386 ret = perf_data__is_dir(data) ? open_dir(data) : open_file_dup(data); 387 388 if (!ret) 389 data->open = true; 390 391 return ret; 392 } 393 394 void perf_data__close(struct perf_data *data) 395 { 396 if (!data->open) 397 return; 398 399 if (perf_data__is_dir(data)) 400 perf_data__close_dir(data); 401 402 perf_data_file__close(&data->file); 403 data->open = false; 404 } 405 406 static ssize_t perf_data_file__read(struct perf_data_file *file, void *buf, size_t size) 407 { 408 if (file->use_stdio) { 409 if (fread(buf, size, 1, file->fptr) == 1) 410 return size; 411 return feof(file->fptr) ? 0 : -1; 412 } 413 return readn(file->fd, buf, size); 414 } 415 416 ssize_t perf_data__read(struct perf_data *data, void *buf, size_t size) 417 { 418 return perf_data_file__read(&data->file, buf, size); 419 } 420 421 ssize_t perf_data_file__write(struct perf_data_file *file, 422 void *buf, size_t size) 423 { 424 if (file->use_stdio) { 425 if (fwrite(buf, size, /*nmemb=*/1, file->fptr) == 1) 426 return size; 427 return -1; 428 } 429 return writen(file->fd, buf, size); 430 } 431 432 ssize_t perf_data__write(struct perf_data *data, 433 void *buf, size_t size) 434 { 435 return perf_data_file__write(&data->file, buf, size); 436 } 437 438 off_t perf_data_file__seek(struct perf_data_file *file, off_t offset, int whence) 439 { 440 if (file->use_stdio) { 441 off_t res = fseeko(file->fptr, offset, whence); 442 443 return res < 0 ? -1 : ftello(file->fptr); 444 } 445 return lseek(file->fd, offset, whence); 446 } 447 448 off_t perf_data__seek(struct perf_data *data, off_t offset, int whence) 449 { 450 /* Note, a pipe fd will fail with -1 with errno of ESPIPE. */ 451 return perf_data_file__seek(&data->file, offset, whence); 452 } 453 454 int perf_data__switch(struct perf_data *data, 455 const char *postfix, 456 size_t pos, bool at_exit, 457 char **new_filepath) 458 { 459 int ret; 460 461 if (perf_data__is_read(data)) 462 return -EINVAL; 463 464 if (asprintf(new_filepath, "%s.%s", data->path, postfix) < 0) 465 return -ENOMEM; 466 467 /* 468 * Only fire a warning, don't return error, continue fill 469 * original file. 470 */ 471 if (rename(data->path, *new_filepath)) 472 pr_warning("Failed to rename %s to %s\n", data->path, *new_filepath); 473 474 if (!at_exit) { 475 perf_data_file__close(&data->file); 476 data->open = false; 477 ret = perf_data__open(data); 478 if (ret < 0) 479 goto out; 480 481 if (perf_data__seek(data, pos, SEEK_SET) == (off_t)-1) { 482 ret = -errno; 483 pr_debug("Failed to seek to %zu: %m", pos); 484 goto out; 485 } 486 } 487 ret = perf_data__fd(data); 488 out: 489 return ret; 490 } 491 492 unsigned long perf_data__size(struct perf_data *data) 493 { 494 u64 size = data->file.size; 495 int i; 496 497 if (perf_data__is_single_file(data)) 498 return size; 499 500 for (i = 0; i < data->dir.nr; i++) { 501 struct perf_data_file *file = &data->dir.files[i]; 502 503 size += file->size; 504 } 505 506 return size; 507 } 508 509 int perf_data__make_kcore_dir(struct perf_data *data, char *buf, size_t buf_sz) 510 { 511 int ret; 512 513 if (!data->is_dir) 514 return -1; 515 516 ret = snprintf(buf, buf_sz, "%s/kcore_dir", data->path); 517 if (ret < 0 || (size_t)ret >= buf_sz) 518 return -1; 519 520 return mkdir(buf, S_IRWXU); 521 } 522 523 bool has_kcore_dir(const char *path) 524 { 525 struct dirent *d = ERR_PTR(-EINVAL); 526 const char *name = "kcore_dir"; 527 DIR *dir = opendir(path); 528 size_t n = strlen(name); 529 bool result = false; 530 531 if (dir) { 532 while (d && !result) { 533 d = readdir(dir); 534 result = d ? strncmp(d->d_name, name, n) : false; 535 } 536 closedir(dir); 537 } 538 539 return result; 540 } 541 542 char *perf_data__kallsyms_name(struct perf_data *data) 543 { 544 char *kallsyms_name; 545 struct stat st; 546 547 if (!data->is_dir) 548 return NULL; 549 550 if (asprintf(&kallsyms_name, "%s/kcore_dir/kallsyms", data->path) < 0) 551 return NULL; 552 553 if (stat(kallsyms_name, &st)) { 554 free(kallsyms_name); 555 return NULL; 556 } 557 558 return kallsyms_name; 559 } 560 561 char *perf_data__guest_kallsyms_name(struct perf_data *data, pid_t machine_pid) 562 { 563 char *kallsyms_name; 564 struct stat st; 565 566 if (!data->is_dir) 567 return NULL; 568 569 if (asprintf(&kallsyms_name, "%s/kcore_dir__%d/kallsyms", data->path, machine_pid) < 0) 570 return NULL; 571 572 if (stat(kallsyms_name, &st)) { 573 free(kallsyms_name); 574 return NULL; 575 } 576 577 return kallsyms_name; 578 } 579 580 bool is_perf_data(const char *path) 581 { 582 bool ret = false; 583 FILE *file; 584 u64 magic; 585 586 file = fopen(path, "r"); 587 if (!file) 588 return false; 589 590 if (fread(&magic, 1, 8, file) < 8) 591 goto out; 592 593 ret = is_perf_magic(magic); 594 out: 595 fclose(file); 596 return ret; 597 } 598