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