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 goto out_err; 53 54 ret = open(file->path, O_RDWR|O_CREAT|O_TRUNC, S_IRUSR|S_IWUSR); 55 if (ret < 0) 56 goto out_err; 57 58 file->fd = ret; 59 } 60 61 data->dir.version = PERF_DIR_VERSION; 62 data->dir.files = files; 63 data->dir.nr = nr; 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 int flags = data->in_place_update ? O_RDWR : O_RDONLY; 243 struct stat st; 244 int fd; 245 char sbuf[STRERR_BUFSIZE]; 246 247 fd = open(data->file.path, flags); 248 if (fd < 0) { 249 int err = errno; 250 251 pr_err("failed to open %s: %s", data->file.path, 252 str_error_r(err, sbuf, sizeof(sbuf))); 253 if (err == ENOENT && !strcmp(data->file.path, "perf.data")) 254 pr_err(" (try 'perf record' first)"); 255 pr_err("\n"); 256 return -err; 257 } 258 259 if (fstat(fd, &st) < 0) 260 goto out_close; 261 262 if (!data->force && st.st_uid && (st.st_uid != geteuid())) { 263 pr_err("File %s not owned by current user or root (use -f to override)\n", 264 data->file.path); 265 goto out_close; 266 } 267 268 if (!st.st_size) { 269 pr_info("zero-sized data (%s), nothing to do!\n", 270 data->file.path); 271 goto out_close; 272 } 273 274 data->file.size = st.st_size; 275 return fd; 276 277 out_close: 278 close(fd); 279 return -1; 280 } 281 282 static int open_file_write(struct perf_data *data) 283 { 284 int fd; 285 char sbuf[STRERR_BUFSIZE]; 286 287 fd = open(data->file.path, O_CREAT|O_RDWR|O_TRUNC|O_CLOEXEC, 288 S_IRUSR|S_IWUSR); 289 290 if (fd < 0) 291 pr_err("failed to open %s : %s\n", data->file.path, 292 str_error_r(errno, sbuf, sizeof(sbuf))); 293 294 return fd; 295 } 296 297 static int open_file(struct perf_data *data) 298 { 299 int fd; 300 301 fd = perf_data__is_read(data) ? 302 open_file_read(data) : open_file_write(data); 303 304 if (fd < 0) { 305 zfree(&data->file.path); 306 return -1; 307 } 308 309 data->file.fd = fd; 310 return 0; 311 } 312 313 static int open_file_dup(struct perf_data *data) 314 { 315 data->file.path = strdup(data->path); 316 if (!data->file.path) 317 return -ENOMEM; 318 319 return open_file(data); 320 } 321 322 static int open_dir(struct perf_data *data) 323 { 324 int ret; 325 326 /* 327 * So far we open only the header, so we can read the data version and 328 * layout. 329 */ 330 if (asprintf(&data->file.path, "%s/data", data->path) < 0) 331 return -1; 332 333 if (perf_data__is_write(data) && 334 mkdir(data->path, S_IRWXU) < 0) 335 return -1; 336 337 ret = open_file(data); 338 339 /* Cleanup whatever we managed to create so far. */ 340 if (ret && perf_data__is_write(data)) 341 rm_rf_perf_data(data->path); 342 343 return ret; 344 } 345 346 int perf_data__open(struct perf_data *data) 347 { 348 if (check_pipe(data)) 349 return 0; 350 351 /* currently it allows stdio for pipe only */ 352 data->use_stdio = false; 353 354 if (!data->path) 355 data->path = "perf.data"; 356 357 if (check_backup(data)) 358 return -1; 359 360 if (perf_data__is_read(data)) 361 data->is_dir = is_dir(data); 362 363 return perf_data__is_dir(data) ? 364 open_dir(data) : open_file_dup(data); 365 } 366 367 void perf_data__close(struct perf_data *data) 368 { 369 if (perf_data__is_dir(data)) 370 perf_data__close_dir(data); 371 372 zfree(&data->file.path); 373 374 if (data->use_stdio) 375 fclose(data->file.fptr); 376 else 377 close(data->file.fd); 378 } 379 380 ssize_t perf_data__read(struct perf_data *data, void *buf, size_t size) 381 { 382 if (data->use_stdio) { 383 if (fread(buf, size, 1, data->file.fptr) == 1) 384 return size; 385 return feof(data->file.fptr) ? 0 : -1; 386 } 387 return readn(data->file.fd, buf, size); 388 } 389 390 ssize_t perf_data_file__write(struct perf_data_file *file, 391 void *buf, size_t size) 392 { 393 return writen(file->fd, buf, size); 394 } 395 396 ssize_t perf_data__write(struct perf_data *data, 397 void *buf, size_t size) 398 { 399 if (data->use_stdio) { 400 if (fwrite(buf, size, 1, data->file.fptr) == 1) 401 return size; 402 return -1; 403 } 404 return perf_data_file__write(&data->file, buf, size); 405 } 406 407 int perf_data__switch(struct perf_data *data, 408 const char *postfix, 409 size_t pos, bool at_exit, 410 char **new_filepath) 411 { 412 int ret; 413 414 if (check_pipe(data)) 415 return -EINVAL; 416 if (perf_data__is_read(data)) 417 return -EINVAL; 418 419 if (asprintf(new_filepath, "%s.%s", data->path, postfix) < 0) 420 return -ENOMEM; 421 422 /* 423 * Only fire a warning, don't return error, continue fill 424 * original file. 425 */ 426 if (rename(data->path, *new_filepath)) 427 pr_warning("Failed to rename %s to %s\n", data->path, *new_filepath); 428 429 if (!at_exit) { 430 close(data->file.fd); 431 ret = perf_data__open(data); 432 if (ret < 0) 433 goto out; 434 435 if (lseek(data->file.fd, pos, SEEK_SET) == (off_t)-1) { 436 ret = -errno; 437 pr_debug("Failed to lseek to %zu: %s", 438 pos, strerror(errno)); 439 goto out; 440 } 441 } 442 ret = data->file.fd; 443 out: 444 return ret; 445 } 446 447 unsigned long perf_data__size(struct perf_data *data) 448 { 449 u64 size = data->file.size; 450 int i; 451 452 if (perf_data__is_single_file(data)) 453 return size; 454 455 for (i = 0; i < data->dir.nr; i++) { 456 struct perf_data_file *file = &data->dir.files[i]; 457 458 size += file->size; 459 } 460 461 return size; 462 } 463 464 int perf_data__make_kcore_dir(struct perf_data *data, char *buf, size_t buf_sz) 465 { 466 int ret; 467 468 if (!data->is_dir) 469 return -1; 470 471 ret = snprintf(buf, buf_sz, "%s/kcore_dir", data->path); 472 if (ret < 0 || (size_t)ret >= buf_sz) 473 return -1; 474 475 return mkdir(buf, S_IRWXU); 476 } 477 478 char *perf_data__kallsyms_name(struct perf_data *data) 479 { 480 char *kallsyms_name; 481 struct stat st; 482 483 if (!data->is_dir) 484 return NULL; 485 486 if (asprintf(&kallsyms_name, "%s/kcore_dir/kallsyms", data->path) < 0) 487 return NULL; 488 489 if (stat(kallsyms_name, &st)) { 490 free(kallsyms_name); 491 return NULL; 492 } 493 494 return kallsyms_name; 495 } 496 497 bool is_perf_data(const char *path) 498 { 499 bool ret = false; 500 FILE *file; 501 u64 magic; 502 503 file = fopen(path, "r"); 504 if (!file) 505 return false; 506 507 if (fread(&magic, 1, 8, file) < 8) 508 goto out; 509 510 ret = is_perf_magic(magic); 511 out: 512 fclose(file); 513 return ret; 514 } 515