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