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 } else { 208 data->file.fd = fd; 209 } 210 } 211 212 return data->is_pipe = is_pipe; 213 } 214 215 static int check_backup(struct perf_data *data) 216 { 217 struct stat st; 218 219 if (perf_data__is_read(data)) 220 return 0; 221 222 if (!stat(data->path, &st) && st.st_size) { 223 char oldname[PATH_MAX]; 224 int ret; 225 226 snprintf(oldname, sizeof(oldname), "%s.old", 227 data->path); 228 229 ret = rm_rf_perf_data(oldname); 230 if (ret) { 231 pr_err("Can't remove old data: %s (%s)\n", 232 ret == -2 ? 233 "Unknown file found" : strerror(errno), 234 oldname); 235 return -1; 236 } 237 238 if (rename(data->path, oldname)) { 239 pr_err("Can't move data: %s (%s to %s)\n", 240 strerror(errno), 241 data->path, oldname); 242 return -1; 243 } 244 } 245 246 return 0; 247 } 248 249 static bool is_dir(struct perf_data *data) 250 { 251 struct stat st; 252 253 if (stat(data->path, &st)) 254 return false; 255 256 return (st.st_mode & S_IFMT) == S_IFDIR; 257 } 258 259 static int open_file_read(struct perf_data *data) 260 { 261 int flags = data->in_place_update ? O_RDWR : O_RDONLY; 262 struct stat st; 263 int fd; 264 char sbuf[STRERR_BUFSIZE]; 265 266 fd = open(data->file.path, flags); 267 if (fd < 0) { 268 int err = errno; 269 270 pr_err("failed to open %s: %s", data->file.path, 271 str_error_r(err, sbuf, sizeof(sbuf))); 272 if (err == ENOENT && !strcmp(data->file.path, "perf.data")) 273 pr_err(" (try 'perf record' first)"); 274 pr_err("\n"); 275 return -err; 276 } 277 278 if (fstat(fd, &st) < 0) 279 goto out_close; 280 281 if (!data->force && st.st_uid && (st.st_uid != geteuid())) { 282 pr_err("File %s not owned by current user or root (use -f to override)\n", 283 data->file.path); 284 goto out_close; 285 } 286 287 if (!st.st_size) { 288 pr_info("zero-sized data (%s), nothing to do!\n", 289 data->file.path); 290 goto out_close; 291 } 292 293 data->file.size = st.st_size; 294 return fd; 295 296 out_close: 297 close(fd); 298 return -1; 299 } 300 301 static int open_file_write(struct perf_data *data) 302 { 303 int fd; 304 char sbuf[STRERR_BUFSIZE]; 305 306 fd = open(data->file.path, O_CREAT|O_RDWR|O_TRUNC|O_CLOEXEC, 307 S_IRUSR|S_IWUSR); 308 309 if (fd < 0) 310 pr_err("failed to open %s : %s\n", data->file.path, 311 str_error_r(errno, sbuf, sizeof(sbuf))); 312 313 return fd; 314 } 315 316 static int open_file(struct perf_data *data) 317 { 318 int fd; 319 320 fd = perf_data__is_read(data) ? 321 open_file_read(data) : open_file_write(data); 322 323 if (fd < 0) { 324 zfree(&data->file.path); 325 return -1; 326 } 327 328 data->file.fd = fd; 329 return 0; 330 } 331 332 static int open_file_dup(struct perf_data *data) 333 { 334 data->file.path = strdup(data->path); 335 if (!data->file.path) 336 return -ENOMEM; 337 338 return open_file(data); 339 } 340 341 static int open_dir(struct perf_data *data) 342 { 343 int ret; 344 345 /* 346 * So far we open only the header, so we can read the data version and 347 * layout. 348 */ 349 if (asprintf(&data->file.path, "%s/data", data->path) < 0) 350 return -1; 351 352 if (perf_data__is_write(data) && 353 mkdir(data->path, S_IRWXU) < 0) 354 return -1; 355 356 ret = open_file(data); 357 358 /* Cleanup whatever we managed to create so far. */ 359 if (ret && perf_data__is_write(data)) 360 rm_rf_perf_data(data->path); 361 362 return ret; 363 } 364 365 int perf_data__open(struct perf_data *data) 366 { 367 if (check_pipe(data)) 368 return 0; 369 370 /* currently it allows stdio for pipe only */ 371 data->use_stdio = false; 372 373 if (!data->path) 374 data->path = "perf.data"; 375 376 if (check_backup(data)) 377 return -1; 378 379 if (perf_data__is_read(data)) 380 data->is_dir = is_dir(data); 381 382 return perf_data__is_dir(data) ? 383 open_dir(data) : open_file_dup(data); 384 } 385 386 void perf_data__close(struct perf_data *data) 387 { 388 if (perf_data__is_dir(data)) 389 perf_data__close_dir(data); 390 391 zfree(&data->file.path); 392 393 if (data->use_stdio) 394 fclose(data->file.fptr); 395 else 396 close(data->file.fd); 397 } 398 399 ssize_t perf_data__read(struct perf_data *data, void *buf, size_t size) 400 { 401 if (data->use_stdio) { 402 if (fread(buf, size, 1, data->file.fptr) == 1) 403 return size; 404 return feof(data->file.fptr) ? 0 : -1; 405 } 406 return readn(data->file.fd, buf, size); 407 } 408 409 ssize_t perf_data_file__write(struct perf_data_file *file, 410 void *buf, size_t size) 411 { 412 return writen(file->fd, buf, size); 413 } 414 415 ssize_t perf_data__write(struct perf_data *data, 416 void *buf, size_t size) 417 { 418 if (data->use_stdio) { 419 if (fwrite(buf, size, 1, data->file.fptr) == 1) 420 return size; 421 return -1; 422 } 423 return perf_data_file__write(&data->file, buf, size); 424 } 425 426 int perf_data__switch(struct perf_data *data, 427 const char *postfix, 428 size_t pos, bool at_exit, 429 char **new_filepath) 430 { 431 int ret; 432 433 if (check_pipe(data)) 434 return -EINVAL; 435 if (perf_data__is_read(data)) 436 return -EINVAL; 437 438 if (asprintf(new_filepath, "%s.%s", data->path, postfix) < 0) 439 return -ENOMEM; 440 441 /* 442 * Only fire a warning, don't return error, continue fill 443 * original file. 444 */ 445 if (rename(data->path, *new_filepath)) 446 pr_warning("Failed to rename %s to %s\n", data->path, *new_filepath); 447 448 if (!at_exit) { 449 close(data->file.fd); 450 ret = perf_data__open(data); 451 if (ret < 0) 452 goto out; 453 454 if (lseek(data->file.fd, pos, SEEK_SET) == (off_t)-1) { 455 ret = -errno; 456 pr_debug("Failed to lseek to %zu: %s", 457 pos, strerror(errno)); 458 goto out; 459 } 460 } 461 ret = data->file.fd; 462 out: 463 return ret; 464 } 465 466 unsigned long perf_data__size(struct perf_data *data) 467 { 468 u64 size = data->file.size; 469 int i; 470 471 if (perf_data__is_single_file(data)) 472 return size; 473 474 for (i = 0; i < data->dir.nr; i++) { 475 struct perf_data_file *file = &data->dir.files[i]; 476 477 size += file->size; 478 } 479 480 return size; 481 } 482 483 int perf_data__make_kcore_dir(struct perf_data *data, char *buf, size_t buf_sz) 484 { 485 int ret; 486 487 if (!data->is_dir) 488 return -1; 489 490 ret = snprintf(buf, buf_sz, "%s/kcore_dir", data->path); 491 if (ret < 0 || (size_t)ret >= buf_sz) 492 return -1; 493 494 return mkdir(buf, S_IRWXU); 495 } 496 497 bool has_kcore_dir(const char *path) 498 { 499 struct dirent *d = ERR_PTR(-EINVAL); 500 const char *name = "kcore_dir"; 501 DIR *dir = opendir(path); 502 size_t n = strlen(name); 503 bool result = false; 504 505 if (dir) { 506 while (d && !result) { 507 d = readdir(dir); 508 result = d ? strncmp(d->d_name, name, n) : false; 509 } 510 closedir(dir); 511 } 512 513 return result; 514 } 515 516 char *perf_data__kallsyms_name(struct perf_data *data) 517 { 518 char *kallsyms_name; 519 struct stat st; 520 521 if (!data->is_dir) 522 return NULL; 523 524 if (asprintf(&kallsyms_name, "%s/kcore_dir/kallsyms", data->path) < 0) 525 return NULL; 526 527 if (stat(kallsyms_name, &st)) { 528 free(kallsyms_name); 529 return NULL; 530 } 531 532 return kallsyms_name; 533 } 534 535 char *perf_data__guest_kallsyms_name(struct perf_data *data, pid_t machine_pid) 536 { 537 char *kallsyms_name; 538 struct stat st; 539 540 if (!data->is_dir) 541 return NULL; 542 543 if (asprintf(&kallsyms_name, "%s/kcore_dir__%d/kallsyms", data->path, machine_pid) < 0) 544 return NULL; 545 546 if (stat(kallsyms_name, &st)) { 547 free(kallsyms_name); 548 return NULL; 549 } 550 551 return kallsyms_name; 552 } 553 554 bool is_perf_data(const char *path) 555 { 556 bool ret = false; 557 FILE *file; 558 u64 magic; 559 560 file = fopen(path, "r"); 561 if (!file) 562 return false; 563 564 if (fread(&magic, 1, 8, file) < 8) 565 goto out; 566 567 ret = is_perf_magic(magic); 568 out: 569 fclose(file); 570 return ret; 571 } 572