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