| 1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | /* |
| 3 | * linux/fs/readdir.c |
| 4 | * |
| 5 | * Copyright (C) 1995 Linus Torvalds |
| 6 | */ |
| 7 | |
| 8 | #include <linux/stddef.h> |
| 9 | #include <linux/kernel.h> |
| 10 | #include <linux/export.h> |
| 11 | #include <linux/time.h> |
| 12 | #include <linux/mm.h> |
| 13 | #include <linux/errno.h> |
| 14 | #include <linux/stat.h> |
| 15 | #include <linux/file.h> |
| 16 | #include <linux/fs.h> |
| 17 | #include <linux/fsnotify.h> |
| 18 | #include <linux/dirent.h> |
| 19 | #include <linux/security.h> |
| 20 | #include <linux/syscalls.h> |
| 21 | #include <linux/unistd.h> |
| 22 | #include <linux/compat.h> |
| 23 | #include <linux/uaccess.h> |
| 24 | |
| 25 | #include <asm/unaligned.h> |
| 26 | |
| 27 | /* |
| 28 | * Some filesystems were never converted to '->iterate_shared()' |
| 29 | * and their directory iterators want the inode lock held for |
| 30 | * writing. This wrapper allows for converting from the shared |
| 31 | * semantics to the exclusive inode use. |
| 32 | */ |
| 33 | int wrap_directory_iterator(struct file *file, |
| 34 | struct dir_context *ctx, |
| 35 | int (*iter)(struct file *, struct dir_context *)) |
| 36 | { |
| 37 | struct inode *inode = file_inode(file); |
| 38 | int ret; |
| 39 | |
| 40 | /* |
| 41 | * We'd love to have an 'inode_upgrade_trylock()' operation, |
| 42 | * see the comment in mmap_upgrade_trylock() in mm/memory.c. |
| 43 | * |
| 44 | * But considering this is for "filesystems that never got |
| 45 | * converted", it really doesn't matter. |
| 46 | * |
| 47 | * Also note that since we have to return with the lock held |
| 48 | * for reading, we can't use the "killable()" locking here, |
| 49 | * since we do need to get the lock even if we're dying. |
| 50 | * |
| 51 | * We could do the write part killably and then get the read |
| 52 | * lock unconditionally if it mattered, but see above on why |
| 53 | * this does the very simplistic conversion. |
| 54 | */ |
| 55 | up_read(&inode->i_rwsem); |
| 56 | down_write(&inode->i_rwsem); |
| 57 | |
| 58 | /* |
| 59 | * Since we dropped the inode lock, we should do the |
| 60 | * DEADDIR test again. See 'iterate_dir()' below. |
| 61 | * |
| 62 | * Note that we don't need to re-do the f_pos games, |
| 63 | * since the file must be locked wrt f_pos anyway. |
| 64 | */ |
| 65 | ret = -ENOENT; |
| 66 | if (!IS_DEADDIR(inode)) |
| 67 | ret = iter(file, ctx); |
| 68 | |
| 69 | downgrade_write(&inode->i_rwsem); |
| 70 | return ret; |
| 71 | } |
| 72 | EXPORT_SYMBOL(wrap_directory_iterator); |
| 73 | |
| 74 | /* |
| 75 | * Note the "unsafe_put_user() semantics: we goto a |
| 76 | * label for errors. |
| 77 | */ |
| 78 | #define unsafe_copy_dirent_name(_dst, _src, _len, label) do { \ |
| 79 | char __user *dst = (_dst); \ |
| 80 | const char *src = (_src); \ |
| 81 | size_t len = (_len); \ |
| 82 | unsafe_put_user(0, dst+len, label); \ |
| 83 | unsafe_copy_to_user(dst, src, len, label); \ |
| 84 | } while (0) |
| 85 | |
| 86 | |
| 87 | int iterate_dir(struct file *file, struct dir_context *ctx) |
| 88 | { |
| 89 | struct inode *inode = file_inode(file); |
| 90 | int res = -ENOTDIR; |
| 91 | |
| 92 | if (!file->f_op->iterate_shared) |
| 93 | goto out; |
| 94 | |
| 95 | res = security_file_permission(file, MAY_READ); |
| 96 | if (res) |
| 97 | goto out; |
| 98 | |
| 99 | res = fsnotify_file_perm(file, MAY_READ); |
| 100 | if (res) |
| 101 | goto out; |
| 102 | |
| 103 | res = down_read_killable(&inode->i_rwsem); |
| 104 | if (res) |
| 105 | goto out; |
| 106 | |
| 107 | res = -ENOENT; |
| 108 | if (!IS_DEADDIR(inode)) { |
| 109 | ctx->pos = file->f_pos; |
| 110 | res = file->f_op->iterate_shared(file, ctx); |
| 111 | file->f_pos = ctx->pos; |
| 112 | fsnotify_access(file); |
| 113 | file_accessed(file); |
| 114 | } |
| 115 | inode_unlock_shared(inode); |
| 116 | out: |
| 117 | return res; |
| 118 | } |
| 119 | EXPORT_SYMBOL(iterate_dir); |
| 120 | |
| 121 | /* |
| 122 | * POSIX says that a dirent name cannot contain NULL or a '/'. |
| 123 | * |
| 124 | * It's not 100% clear what we should really do in this case. |
| 125 | * The filesystem is clearly corrupted, but returning a hard |
| 126 | * error means that you now don't see any of the other names |
| 127 | * either, so that isn't a perfect alternative. |
| 128 | * |
| 129 | * And if you return an error, what error do you use? Several |
| 130 | * filesystems seem to have decided on EUCLEAN being the error |
| 131 | * code for EFSCORRUPTED, and that may be the error to use. Or |
| 132 | * just EIO, which is perhaps more obvious to users. |
| 133 | * |
| 134 | * In order to see the other file names in the directory, the |
| 135 | * caller might want to make this a "soft" error: skip the |
| 136 | * entry, and return the error at the end instead. |
| 137 | * |
| 138 | * Note that this should likely do a "memchr(name, 0, len)" |
| 139 | * check too, since that would be filesystem corruption as |
| 140 | * well. However, that case can't actually confuse user space, |
| 141 | * which has to do a strlen() on the name anyway to find the |
| 142 | * filename length, and the above "soft error" worry means |
| 143 | * that it's probably better left alone until we have that |
| 144 | * issue clarified. |
| 145 | * |
| 146 | * Note the PATH_MAX check - it's arbitrary but the real |
| 147 | * kernel limit on a possible path component, not NAME_MAX, |
| 148 | * which is the technical standard limit. |
| 149 | */ |
| 150 | static int verify_dirent_name(const char *name, int len) |
| 151 | { |
| 152 | if (len <= 0 || len >= PATH_MAX) |
| 153 | return -EIO; |
| 154 | if (memchr(name, '/', len)) |
| 155 | return -EIO; |
| 156 | return 0; |
| 157 | } |
| 158 | |
| 159 | /* |
| 160 | * Traditional linux readdir() handling.. |
| 161 | * |
| 162 | * "count=1" is a special case, meaning that the buffer is one |
| 163 | * dirent-structure in size and that the code can't handle more |
| 164 | * anyway. Thus the special "fillonedir()" function for that |
| 165 | * case (the low-level handlers don't need to care about this). |
| 166 | */ |
| 167 | |
| 168 | #ifdef __ARCH_WANT_OLD_READDIR |
| 169 | |
| 170 | struct old_linux_dirent { |
| 171 | unsigned long d_ino; |
| 172 | unsigned long d_offset; |
| 173 | unsigned short d_namlen; |
| 174 | char d_name[]; |
| 175 | }; |
| 176 | |
| 177 | struct readdir_callback { |
| 178 | struct dir_context ctx; |
| 179 | struct old_linux_dirent __user * dirent; |
| 180 | int result; |
| 181 | }; |
| 182 | |
| 183 | static bool fillonedir(struct dir_context *ctx, const char *name, int namlen, |
| 184 | loff_t offset, u64 ino, unsigned int d_type) |
| 185 | { |
| 186 | struct readdir_callback *buf = |
| 187 | container_of(ctx, struct readdir_callback, ctx); |
| 188 | struct old_linux_dirent __user * dirent; |
| 189 | unsigned long d_ino; |
| 190 | |
| 191 | if (buf->result) |
| 192 | return false; |
| 193 | buf->result = verify_dirent_name(name, namlen); |
| 194 | if (buf->result) |
| 195 | return false; |
| 196 | d_ino = ino; |
| 197 | if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) { |
| 198 | buf->result = -EOVERFLOW; |
| 199 | return false; |
| 200 | } |
| 201 | buf->result++; |
| 202 | dirent = buf->dirent; |
| 203 | if (!user_write_access_begin(dirent, |
| 204 | (unsigned long)(dirent->d_name + namlen + 1) - |
| 205 | (unsigned long)dirent)) |
| 206 | goto efault; |
| 207 | unsafe_put_user(d_ino, &dirent->d_ino, efault_end); |
| 208 | unsafe_put_user(offset, &dirent->d_offset, efault_end); |
| 209 | unsafe_put_user(namlen, &dirent->d_namlen, efault_end); |
| 210 | unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault_end); |
| 211 | user_write_access_end(); |
| 212 | return true; |
| 213 | efault_end: |
| 214 | user_write_access_end(); |
| 215 | efault: |
| 216 | buf->result = -EFAULT; |
| 217 | return false; |
| 218 | } |
| 219 | |
| 220 | SYSCALL_DEFINE3(old_readdir, unsigned int, fd, |
| 221 | struct old_linux_dirent __user *, dirent, unsigned int, count) |
| 222 | { |
| 223 | int error; |
| 224 | struct fd f = fdget_pos(fd); |
| 225 | struct readdir_callback buf = { |
| 226 | .ctx.actor = fillonedir, |
| 227 | .dirent = dirent |
| 228 | }; |
| 229 | |
| 230 | if (!f.file) |
| 231 | return -EBADF; |
| 232 | |
| 233 | error = iterate_dir(f.file, &buf.ctx); |
| 234 | if (buf.result) |
| 235 | error = buf.result; |
| 236 | |
| 237 | fdput_pos(f); |
| 238 | return error; |
| 239 | } |
| 240 | |
| 241 | #endif /* __ARCH_WANT_OLD_READDIR */ |
| 242 | |
| 243 | /* |
| 244 | * New, all-improved, singing, dancing, iBCS2-compliant getdents() |
| 245 | * interface. |
| 246 | */ |
| 247 | struct linux_dirent { |
| 248 | unsigned long d_ino; |
| 249 | unsigned long d_off; |
| 250 | unsigned short d_reclen; |
| 251 | char d_name[]; |
| 252 | }; |
| 253 | |
| 254 | struct getdents_callback { |
| 255 | struct dir_context ctx; |
| 256 | struct linux_dirent __user * current_dir; |
| 257 | int prev_reclen; |
| 258 | int count; |
| 259 | int error; |
| 260 | }; |
| 261 | |
| 262 | static bool filldir(struct dir_context *ctx, const char *name, int namlen, |
| 263 | loff_t offset, u64 ino, unsigned int d_type) |
| 264 | { |
| 265 | struct linux_dirent __user *dirent, *prev; |
| 266 | struct getdents_callback *buf = |
| 267 | container_of(ctx, struct getdents_callback, ctx); |
| 268 | unsigned long d_ino; |
| 269 | int reclen = ALIGN(offsetof(struct linux_dirent, d_name) + namlen + 2, |
| 270 | sizeof(long)); |
| 271 | int prev_reclen; |
| 272 | |
| 273 | buf->error = verify_dirent_name(name, namlen); |
| 274 | if (unlikely(buf->error)) |
| 275 | return false; |
| 276 | buf->error = -EINVAL; /* only used if we fail.. */ |
| 277 | if (reclen > buf->count) |
| 278 | return false; |
| 279 | d_ino = ino; |
| 280 | if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) { |
| 281 | buf->error = -EOVERFLOW; |
| 282 | return false; |
| 283 | } |
| 284 | prev_reclen = buf->prev_reclen; |
| 285 | if (prev_reclen && signal_pending(current)) |
| 286 | return false; |
| 287 | dirent = buf->current_dir; |
| 288 | prev = (void __user *) dirent - prev_reclen; |
| 289 | if (!user_write_access_begin(prev, reclen + prev_reclen)) |
| 290 | goto efault; |
| 291 | |
| 292 | /* This might be 'dirent->d_off', but if so it will get overwritten */ |
| 293 | unsafe_put_user(offset, &prev->d_off, efault_end); |
| 294 | unsafe_put_user(d_ino, &dirent->d_ino, efault_end); |
| 295 | unsafe_put_user(reclen, &dirent->d_reclen, efault_end); |
| 296 | unsafe_put_user(d_type, (char __user *) dirent + reclen - 1, efault_end); |
| 297 | unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault_end); |
| 298 | user_write_access_end(); |
| 299 | |
| 300 | buf->current_dir = (void __user *)dirent + reclen; |
| 301 | buf->prev_reclen = reclen; |
| 302 | buf->count -= reclen; |
| 303 | return true; |
| 304 | efault_end: |
| 305 | user_write_access_end(); |
| 306 | efault: |
| 307 | buf->error = -EFAULT; |
| 308 | return false; |
| 309 | } |
| 310 | |
| 311 | SYSCALL_DEFINE3(getdents, unsigned int, fd, |
| 312 | struct linux_dirent __user *, dirent, unsigned int, count) |
| 313 | { |
| 314 | struct fd f; |
| 315 | struct getdents_callback buf = { |
| 316 | .ctx.actor = filldir, |
| 317 | .count = count, |
| 318 | .current_dir = dirent |
| 319 | }; |
| 320 | int error; |
| 321 | |
| 322 | f = fdget_pos(fd); |
| 323 | if (!f.file) |
| 324 | return -EBADF; |
| 325 | |
| 326 | error = iterate_dir(f.file, &buf.ctx); |
| 327 | if (error >= 0) |
| 328 | error = buf.error; |
| 329 | if (buf.prev_reclen) { |
| 330 | struct linux_dirent __user * lastdirent; |
| 331 | lastdirent = (void __user *)buf.current_dir - buf.prev_reclen; |
| 332 | |
| 333 | if (put_user(buf.ctx.pos, &lastdirent->d_off)) |
| 334 | error = -EFAULT; |
| 335 | else |
| 336 | error = count - buf.count; |
| 337 | } |
| 338 | fdput_pos(f); |
| 339 | return error; |
| 340 | } |
| 341 | |
| 342 | struct getdents_callback64 { |
| 343 | struct dir_context ctx; |
| 344 | struct linux_dirent64 __user * current_dir; |
| 345 | int prev_reclen; |
| 346 | int count; |
| 347 | int error; |
| 348 | }; |
| 349 | |
| 350 | static bool filldir64(struct dir_context *ctx, const char *name, int namlen, |
| 351 | loff_t offset, u64 ino, unsigned int d_type) |
| 352 | { |
| 353 | struct linux_dirent64 __user *dirent, *prev; |
| 354 | struct getdents_callback64 *buf = |
| 355 | container_of(ctx, struct getdents_callback64, ctx); |
| 356 | int reclen = ALIGN(offsetof(struct linux_dirent64, d_name) + namlen + 1, |
| 357 | sizeof(u64)); |
| 358 | int prev_reclen; |
| 359 | |
| 360 | buf->error = verify_dirent_name(name, namlen); |
| 361 | if (unlikely(buf->error)) |
| 362 | return false; |
| 363 | buf->error = -EINVAL; /* only used if we fail.. */ |
| 364 | if (reclen > buf->count) |
| 365 | return false; |
| 366 | prev_reclen = buf->prev_reclen; |
| 367 | if (prev_reclen && signal_pending(current)) |
| 368 | return false; |
| 369 | dirent = buf->current_dir; |
| 370 | prev = (void __user *)dirent - prev_reclen; |
| 371 | if (!user_write_access_begin(prev, reclen + prev_reclen)) |
| 372 | goto efault; |
| 373 | |
| 374 | /* This might be 'dirent->d_off', but if so it will get overwritten */ |
| 375 | unsafe_put_user(offset, &prev->d_off, efault_end); |
| 376 | unsafe_put_user(ino, &dirent->d_ino, efault_end); |
| 377 | unsafe_put_user(reclen, &dirent->d_reclen, efault_end); |
| 378 | unsafe_put_user(d_type, &dirent->d_type, efault_end); |
| 379 | unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault_end); |
| 380 | user_write_access_end(); |
| 381 | |
| 382 | buf->prev_reclen = reclen; |
| 383 | buf->current_dir = (void __user *)dirent + reclen; |
| 384 | buf->count -= reclen; |
| 385 | return true; |
| 386 | |
| 387 | efault_end: |
| 388 | user_write_access_end(); |
| 389 | efault: |
| 390 | buf->error = -EFAULT; |
| 391 | return false; |
| 392 | } |
| 393 | |
| 394 | SYSCALL_DEFINE3(getdents64, unsigned int, fd, |
| 395 | struct linux_dirent64 __user *, dirent, unsigned int, count) |
| 396 | { |
| 397 | struct fd f; |
| 398 | struct getdents_callback64 buf = { |
| 399 | .ctx.actor = filldir64, |
| 400 | .count = count, |
| 401 | .current_dir = dirent |
| 402 | }; |
| 403 | int error; |
| 404 | |
| 405 | f = fdget_pos(fd); |
| 406 | if (!f.file) |
| 407 | return -EBADF; |
| 408 | |
| 409 | error = iterate_dir(f.file, &buf.ctx); |
| 410 | if (error >= 0) |
| 411 | error = buf.error; |
| 412 | if (buf.prev_reclen) { |
| 413 | struct linux_dirent64 __user * lastdirent; |
| 414 | typeof(lastdirent->d_off) d_off = buf.ctx.pos; |
| 415 | |
| 416 | lastdirent = (void __user *) buf.current_dir - buf.prev_reclen; |
| 417 | if (put_user(d_off, &lastdirent->d_off)) |
| 418 | error = -EFAULT; |
| 419 | else |
| 420 | error = count - buf.count; |
| 421 | } |
| 422 | fdput_pos(f); |
| 423 | return error; |
| 424 | } |
| 425 | |
| 426 | #ifdef CONFIG_COMPAT |
| 427 | struct compat_old_linux_dirent { |
| 428 | compat_ulong_t d_ino; |
| 429 | compat_ulong_t d_offset; |
| 430 | unsigned short d_namlen; |
| 431 | char d_name[]; |
| 432 | }; |
| 433 | |
| 434 | struct compat_readdir_callback { |
| 435 | struct dir_context ctx; |
| 436 | struct compat_old_linux_dirent __user *dirent; |
| 437 | int result; |
| 438 | }; |
| 439 | |
| 440 | static bool compat_fillonedir(struct dir_context *ctx, const char *name, |
| 441 | int namlen, loff_t offset, u64 ino, |
| 442 | unsigned int d_type) |
| 443 | { |
| 444 | struct compat_readdir_callback *buf = |
| 445 | container_of(ctx, struct compat_readdir_callback, ctx); |
| 446 | struct compat_old_linux_dirent __user *dirent; |
| 447 | compat_ulong_t d_ino; |
| 448 | |
| 449 | if (buf->result) |
| 450 | return false; |
| 451 | buf->result = verify_dirent_name(name, namlen); |
| 452 | if (buf->result) |
| 453 | return false; |
| 454 | d_ino = ino; |
| 455 | if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) { |
| 456 | buf->result = -EOVERFLOW; |
| 457 | return false; |
| 458 | } |
| 459 | buf->result++; |
| 460 | dirent = buf->dirent; |
| 461 | if (!user_write_access_begin(dirent, |
| 462 | (unsigned long)(dirent->d_name + namlen + 1) - |
| 463 | (unsigned long)dirent)) |
| 464 | goto efault; |
| 465 | unsafe_put_user(d_ino, &dirent->d_ino, efault_end); |
| 466 | unsafe_put_user(offset, &dirent->d_offset, efault_end); |
| 467 | unsafe_put_user(namlen, &dirent->d_namlen, efault_end); |
| 468 | unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault_end); |
| 469 | user_write_access_end(); |
| 470 | return true; |
| 471 | efault_end: |
| 472 | user_write_access_end(); |
| 473 | efault: |
| 474 | buf->result = -EFAULT; |
| 475 | return false; |
| 476 | } |
| 477 | |
| 478 | COMPAT_SYSCALL_DEFINE3(old_readdir, unsigned int, fd, |
| 479 | struct compat_old_linux_dirent __user *, dirent, unsigned int, count) |
| 480 | { |
| 481 | int error; |
| 482 | struct fd f = fdget_pos(fd); |
| 483 | struct compat_readdir_callback buf = { |
| 484 | .ctx.actor = compat_fillonedir, |
| 485 | .dirent = dirent |
| 486 | }; |
| 487 | |
| 488 | if (!f.file) |
| 489 | return -EBADF; |
| 490 | |
| 491 | error = iterate_dir(f.file, &buf.ctx); |
| 492 | if (buf.result) |
| 493 | error = buf.result; |
| 494 | |
| 495 | fdput_pos(f); |
| 496 | return error; |
| 497 | } |
| 498 | |
| 499 | struct compat_linux_dirent { |
| 500 | compat_ulong_t d_ino; |
| 501 | compat_ulong_t d_off; |
| 502 | unsigned short d_reclen; |
| 503 | char d_name[]; |
| 504 | }; |
| 505 | |
| 506 | struct compat_getdents_callback { |
| 507 | struct dir_context ctx; |
| 508 | struct compat_linux_dirent __user *current_dir; |
| 509 | int prev_reclen; |
| 510 | int count; |
| 511 | int error; |
| 512 | }; |
| 513 | |
| 514 | static bool compat_filldir(struct dir_context *ctx, const char *name, int namlen, |
| 515 | loff_t offset, u64 ino, unsigned int d_type) |
| 516 | { |
| 517 | struct compat_linux_dirent __user *dirent, *prev; |
| 518 | struct compat_getdents_callback *buf = |
| 519 | container_of(ctx, struct compat_getdents_callback, ctx); |
| 520 | compat_ulong_t d_ino; |
| 521 | int reclen = ALIGN(offsetof(struct compat_linux_dirent, d_name) + |
| 522 | namlen + 2, sizeof(compat_long_t)); |
| 523 | int prev_reclen; |
| 524 | |
| 525 | buf->error = verify_dirent_name(name, namlen); |
| 526 | if (unlikely(buf->error)) |
| 527 | return false; |
| 528 | buf->error = -EINVAL; /* only used if we fail.. */ |
| 529 | if (reclen > buf->count) |
| 530 | return false; |
| 531 | d_ino = ino; |
| 532 | if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) { |
| 533 | buf->error = -EOVERFLOW; |
| 534 | return false; |
| 535 | } |
| 536 | prev_reclen = buf->prev_reclen; |
| 537 | if (prev_reclen && signal_pending(current)) |
| 538 | return false; |
| 539 | dirent = buf->current_dir; |
| 540 | prev = (void __user *) dirent - prev_reclen; |
| 541 | if (!user_write_access_begin(prev, reclen + prev_reclen)) |
| 542 | goto efault; |
| 543 | |
| 544 | unsafe_put_user(offset, &prev->d_off, efault_end); |
| 545 | unsafe_put_user(d_ino, &dirent->d_ino, efault_end); |
| 546 | unsafe_put_user(reclen, &dirent->d_reclen, efault_end); |
| 547 | unsafe_put_user(d_type, (char __user *) dirent + reclen - 1, efault_end); |
| 548 | unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault_end); |
| 549 | user_write_access_end(); |
| 550 | |
| 551 | buf->prev_reclen = reclen; |
| 552 | buf->current_dir = (void __user *)dirent + reclen; |
| 553 | buf->count -= reclen; |
| 554 | return true; |
| 555 | efault_end: |
| 556 | user_write_access_end(); |
| 557 | efault: |
| 558 | buf->error = -EFAULT; |
| 559 | return false; |
| 560 | } |
| 561 | |
| 562 | COMPAT_SYSCALL_DEFINE3(getdents, unsigned int, fd, |
| 563 | struct compat_linux_dirent __user *, dirent, unsigned int, count) |
| 564 | { |
| 565 | struct fd f; |
| 566 | struct compat_getdents_callback buf = { |
| 567 | .ctx.actor = compat_filldir, |
| 568 | .current_dir = dirent, |
| 569 | .count = count |
| 570 | }; |
| 571 | int error; |
| 572 | |
| 573 | f = fdget_pos(fd); |
| 574 | if (!f.file) |
| 575 | return -EBADF; |
| 576 | |
| 577 | error = iterate_dir(f.file, &buf.ctx); |
| 578 | if (error >= 0) |
| 579 | error = buf.error; |
| 580 | if (buf.prev_reclen) { |
| 581 | struct compat_linux_dirent __user * lastdirent; |
| 582 | lastdirent = (void __user *)buf.current_dir - buf.prev_reclen; |
| 583 | |
| 584 | if (put_user(buf.ctx.pos, &lastdirent->d_off)) |
| 585 | error = -EFAULT; |
| 586 | else |
| 587 | error = count - buf.count; |
| 588 | } |
| 589 | fdput_pos(f); |
| 590 | return error; |
| 591 | } |
| 592 | #endif |