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