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