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