Commit | Line | Data |
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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 LT |
2 | /* |
3 | * linux/fs/readdir.c | |
4 | * | |
5 | * Copyright (C) 1995 Linus Torvalds | |
6 | */ | |
7 | ||
85c9fe8f | 8 | #include <linux/stddef.h> |
022a1692 | 9 | #include <linux/kernel.h> |
630d9c47 | 10 | #include <linux/export.h> |
1da177e4 LT |
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> | |
1da177e4 | 16 | #include <linux/fs.h> |
d4c7cf6c | 17 | #include <linux/fsnotify.h> |
1da177e4 LT |
18 | #include <linux/dirent.h> |
19 | #include <linux/security.h> | |
20 | #include <linux/syscalls.h> | |
21 | #include <linux/unistd.h> | |
0460b2a2 | 22 | #include <linux/compat.h> |
7c0f6ba6 | 23 | #include <linux/uaccess.h> |
1da177e4 | 24 | |
9f79b78e LT |
25 | #include <asm/unaligned.h> |
26 | ||
27 | /* | |
28 | * Note the "unsafe_put_user() semantics: we goto a | |
29 | * label for errors. | |
30 | * | |
31 | * Also note how we use a "while()" loop here, even though | |
32 | * only the biggest size needs to loop. The compiler (well, | |
33 | * at least gcc) is smart enough to turn the smaller sizes | |
34 | * into just if-statements, and this way we don't need to | |
35 | * care whether 'u64' or 'u32' is the biggest size. | |
36 | */ | |
37 | #define unsafe_copy_loop(dst, src, len, type, label) \ | |
38 | while (len >= sizeof(type)) { \ | |
39 | unsafe_put_user(get_unaligned((type *)src), \ | |
40 | (type __user *)dst, label); \ | |
41 | dst += sizeof(type); \ | |
42 | src += sizeof(type); \ | |
43 | len -= sizeof(type); \ | |
44 | } | |
45 | ||
46 | /* | |
47 | * We avoid doing 64-bit copies on 32-bit architectures. They | |
48 | * might be better, but the component names are mostly small, | |
49 | * and the 64-bit cases can end up being much more complex and | |
50 | * put much more register pressure on the code, so it's likely | |
51 | * not worth the pain of unaligned accesses etc. | |
52 | * | |
53 | * So limit the copies to "unsigned long" size. I did verify | |
54 | * that at least the x86-32 case is ok without this limiting, | |
55 | * but I worry about random other legacy 32-bit cases that | |
56 | * might not do as well. | |
57 | */ | |
58 | #define unsafe_copy_type(dst, src, len, type, label) do { \ | |
59 | if (sizeof(type) <= sizeof(unsigned long)) \ | |
60 | unsafe_copy_loop(dst, src, len, type, label); \ | |
61 | } while (0) | |
62 | ||
63 | /* | |
64 | * Copy the dirent name to user space, and NUL-terminate | |
65 | * it. This should not be a function call, since we're doing | |
66 | * the copy inside a "user_access_begin/end()" section. | |
67 | */ | |
68 | #define unsafe_copy_dirent_name(_dst, _src, _len, label) do { \ | |
69 | char __user *dst = (_dst); \ | |
70 | const char *src = (_src); \ | |
71 | size_t len = (_len); \ | |
72 | unsafe_copy_type(dst, src, len, u64, label); \ | |
73 | unsafe_copy_type(dst, src, len, u32, label); \ | |
74 | unsafe_copy_type(dst, src, len, u16, label); \ | |
75 | unsafe_copy_type(dst, src, len, u8, label); \ | |
76 | unsafe_put_user(0, dst, label); \ | |
77 | } while (0) | |
78 | ||
79 | ||
5c0ba4e0 | 80 | int iterate_dir(struct file *file, struct dir_context *ctx) |
1da177e4 | 81 | { |
496ad9aa | 82 | struct inode *inode = file_inode(file); |
61922694 | 83 | bool shared = false; |
1da177e4 | 84 | int res = -ENOTDIR; |
61922694 AV |
85 | if (file->f_op->iterate_shared) |
86 | shared = true; | |
87 | else if (!file->f_op->iterate) | |
1da177e4 LT |
88 | goto out; |
89 | ||
90 | res = security_file_permission(file, MAY_READ); | |
91 | if (res) | |
92 | goto out; | |
93 | ||
0dc208b5 KT |
94 | if (shared) |
95 | res = down_read_killable(&inode->i_rwsem); | |
96 | else | |
00235411 | 97 | res = down_write_killable(&inode->i_rwsem); |
0dc208b5 KT |
98 | if (res) |
99 | goto out; | |
da784511 | 100 | |
1da177e4 LT |
101 | res = -ENOENT; |
102 | if (!IS_DEADDIR(inode)) { | |
2233f31a | 103 | ctx->pos = file->f_pos; |
61922694 AV |
104 | if (shared) |
105 | res = file->f_op->iterate_shared(file, ctx); | |
106 | else | |
107 | res = file->f_op->iterate(file, ctx); | |
2233f31a | 108 | file->f_pos = ctx->pos; |
d4c7cf6c | 109 | fsnotify_access(file); |
1da177e4 LT |
110 | file_accessed(file); |
111 | } | |
61922694 AV |
112 | if (shared) |
113 | inode_unlock_shared(inode); | |
114 | else | |
115 | inode_unlock(inode); | |
1da177e4 LT |
116 | out: |
117 | return res; | |
118 | } | |
5c0ba4e0 | 119 | EXPORT_SYMBOL(iterate_dir); |
1da177e4 LT |
120 | |
121 | /* | |
122 | * Traditional linux readdir() handling.. | |
123 | * | |
124 | * "count=1" is a special case, meaning that the buffer is one | |
125 | * dirent-structure in size and that the code can't handle more | |
126 | * anyway. Thus the special "fillonedir()" function for that | |
127 | * case (the low-level handlers don't need to care about this). | |
128 | */ | |
1da177e4 LT |
129 | |
130 | #ifdef __ARCH_WANT_OLD_READDIR | |
131 | ||
132 | struct old_linux_dirent { | |
133 | unsigned long d_ino; | |
134 | unsigned long d_offset; | |
135 | unsigned short d_namlen; | |
136 | char d_name[1]; | |
137 | }; | |
138 | ||
139 | struct readdir_callback { | |
5c0ba4e0 | 140 | struct dir_context ctx; |
1da177e4 LT |
141 | struct old_linux_dirent __user * dirent; |
142 | int result; | |
143 | }; | |
144 | ||
ac7576f4 MS |
145 | static int fillonedir(struct dir_context *ctx, const char *name, int namlen, |
146 | loff_t offset, u64 ino, unsigned int d_type) | |
1da177e4 | 147 | { |
ac7576f4 MS |
148 | struct readdir_callback *buf = |
149 | container_of(ctx, struct readdir_callback, ctx); | |
1da177e4 | 150 | struct old_linux_dirent __user * dirent; |
afefdbb2 | 151 | unsigned long d_ino; |
1da177e4 LT |
152 | |
153 | if (buf->result) | |
154 | return -EINVAL; | |
afefdbb2 | 155 | d_ino = ino; |
8f3f655d AV |
156 | if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) { |
157 | buf->result = -EOVERFLOW; | |
afefdbb2 | 158 | return -EOVERFLOW; |
8f3f655d | 159 | } |
1da177e4 LT |
160 | buf->result++; |
161 | dirent = buf->dirent; | |
96d4f267 | 162 | if (!access_ok(dirent, |
1da177e4 LT |
163 | (unsigned long)(dirent->d_name + namlen + 1) - |
164 | (unsigned long)dirent)) | |
165 | goto efault; | |
afefdbb2 | 166 | if ( __put_user(d_ino, &dirent->d_ino) || |
1da177e4 LT |
167 | __put_user(offset, &dirent->d_offset) || |
168 | __put_user(namlen, &dirent->d_namlen) || | |
169 | __copy_to_user(dirent->d_name, name, namlen) || | |
170 | __put_user(0, dirent->d_name + namlen)) | |
171 | goto efault; | |
172 | return 0; | |
173 | efault: | |
174 | buf->result = -EFAULT; | |
175 | return -EFAULT; | |
176 | } | |
177 | ||
d4e82042 HC |
178 | SYSCALL_DEFINE3(old_readdir, unsigned int, fd, |
179 | struct old_linux_dirent __user *, dirent, unsigned int, count) | |
1da177e4 LT |
180 | { |
181 | int error; | |
63b6df14 | 182 | struct fd f = fdget_pos(fd); |
ac6614b7 AV |
183 | struct readdir_callback buf = { |
184 | .ctx.actor = fillonedir, | |
185 | .dirent = dirent | |
186 | }; | |
1da177e4 | 187 | |
2903ff01 | 188 | if (!f.file) |
863ced7f | 189 | return -EBADF; |
1da177e4 | 190 | |
5c0ba4e0 | 191 | error = iterate_dir(f.file, &buf.ctx); |
53c9c5c0 | 192 | if (buf.result) |
1da177e4 LT |
193 | error = buf.result; |
194 | ||
63b6df14 | 195 | fdput_pos(f); |
1da177e4 LT |
196 | return error; |
197 | } | |
198 | ||
199 | #endif /* __ARCH_WANT_OLD_READDIR */ | |
200 | ||
201 | /* | |
202 | * New, all-improved, singing, dancing, iBCS2-compliant getdents() | |
203 | * interface. | |
204 | */ | |
205 | struct linux_dirent { | |
206 | unsigned long d_ino; | |
207 | unsigned long d_off; | |
208 | unsigned short d_reclen; | |
209 | char d_name[1]; | |
210 | }; | |
211 | ||
212 | struct getdents_callback { | |
5c0ba4e0 | 213 | struct dir_context ctx; |
1da177e4 LT |
214 | struct linux_dirent __user * current_dir; |
215 | struct linux_dirent __user * previous; | |
216 | int count; | |
217 | int error; | |
218 | }; | |
219 | ||
ac7576f4 MS |
220 | static int filldir(struct dir_context *ctx, const char *name, int namlen, |
221 | loff_t offset, u64 ino, unsigned int d_type) | |
1da177e4 LT |
222 | { |
223 | struct linux_dirent __user * dirent; | |
ac7576f4 MS |
224 | struct getdents_callback *buf = |
225 | container_of(ctx, struct getdents_callback, ctx); | |
afefdbb2 | 226 | unsigned long d_ino; |
85c9fe8f KW |
227 | int reclen = ALIGN(offsetof(struct linux_dirent, d_name) + namlen + 2, |
228 | sizeof(long)); | |
1da177e4 LT |
229 | |
230 | buf->error = -EINVAL; /* only used if we fail.. */ | |
231 | if (reclen > buf->count) | |
232 | return -EINVAL; | |
afefdbb2 | 233 | d_ino = ino; |
8f3f655d AV |
234 | if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) { |
235 | buf->error = -EOVERFLOW; | |
afefdbb2 | 236 | return -EOVERFLOW; |
8f3f655d | 237 | } |
1da177e4 | 238 | dirent = buf->previous; |
9f79b78e LT |
239 | if (dirent && signal_pending(current)) |
240 | return -EINTR; | |
241 | ||
242 | /* | |
243 | * Note! This range-checks 'previous' (which may be NULL). | |
244 | * The real range was checked in getdents | |
245 | */ | |
246 | if (!user_access_begin(dirent, sizeof(*dirent))) | |
1da177e4 | 247 | goto efault; |
9f79b78e LT |
248 | if (dirent) |
249 | unsafe_put_user(offset, &dirent->d_off, efault_end); | |
250 | dirent = buf->current_dir; | |
251 | unsafe_put_user(d_ino, &dirent->d_ino, efault_end); | |
252 | unsafe_put_user(reclen, &dirent->d_reclen, efault_end); | |
253 | unsafe_put_user(d_type, (char __user *) dirent + reclen - 1, efault_end); | |
254 | unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault_end); | |
255 | user_access_end(); | |
256 | ||
1da177e4 LT |
257 | buf->previous = dirent; |
258 | dirent = (void __user *)dirent + reclen; | |
259 | buf->current_dir = dirent; | |
260 | buf->count -= reclen; | |
261 | return 0; | |
9f79b78e LT |
262 | efault_end: |
263 | user_access_end(); | |
1da177e4 LT |
264 | efault: |
265 | buf->error = -EFAULT; | |
266 | return -EFAULT; | |
267 | } | |
268 | ||
20f37034 HC |
269 | SYSCALL_DEFINE3(getdents, unsigned int, fd, |
270 | struct linux_dirent __user *, dirent, unsigned int, count) | |
1da177e4 | 271 | { |
2903ff01 | 272 | struct fd f; |
1da177e4 | 273 | struct linux_dirent __user * lastdirent; |
ac6614b7 AV |
274 | struct getdents_callback buf = { |
275 | .ctx.actor = filldir, | |
276 | .count = count, | |
277 | .current_dir = dirent | |
278 | }; | |
1da177e4 LT |
279 | int error; |
280 | ||
96d4f267 | 281 | if (!access_ok(dirent, count)) |
863ced7f | 282 | return -EFAULT; |
1da177e4 | 283 | |
63b6df14 | 284 | f = fdget_pos(fd); |
2903ff01 | 285 | if (!f.file) |
863ced7f | 286 | return -EBADF; |
1da177e4 | 287 | |
5c0ba4e0 | 288 | error = iterate_dir(f.file, &buf.ctx); |
53c9c5c0 AV |
289 | if (error >= 0) |
290 | error = buf.error; | |
1da177e4 LT |
291 | lastdirent = buf.previous; |
292 | if (lastdirent) { | |
bb6f619b | 293 | if (put_user(buf.ctx.pos, &lastdirent->d_off)) |
1da177e4 LT |
294 | error = -EFAULT; |
295 | else | |
296 | error = count - buf.count; | |
297 | } | |
63b6df14 | 298 | fdput_pos(f); |
1da177e4 LT |
299 | return error; |
300 | } | |
301 | ||
1da177e4 | 302 | struct getdents_callback64 { |
5c0ba4e0 | 303 | struct dir_context ctx; |
1da177e4 LT |
304 | struct linux_dirent64 __user * current_dir; |
305 | struct linux_dirent64 __user * previous; | |
306 | int count; | |
307 | int error; | |
308 | }; | |
309 | ||
ac7576f4 MS |
310 | static int filldir64(struct dir_context *ctx, const char *name, int namlen, |
311 | loff_t offset, u64 ino, unsigned int d_type) | |
1da177e4 LT |
312 | { |
313 | struct linux_dirent64 __user *dirent; | |
ac7576f4 MS |
314 | struct getdents_callback64 *buf = |
315 | container_of(ctx, struct getdents_callback64, ctx); | |
85c9fe8f KW |
316 | int reclen = ALIGN(offsetof(struct linux_dirent64, d_name) + namlen + 1, |
317 | sizeof(u64)); | |
1da177e4 LT |
318 | |
319 | buf->error = -EINVAL; /* only used if we fail.. */ | |
320 | if (reclen > buf->count) | |
321 | return -EINVAL; | |
322 | dirent = buf->previous; | |
9f79b78e LT |
323 | if (dirent && signal_pending(current)) |
324 | return -EINTR; | |
325 | ||
326 | /* | |
327 | * Note! This range-checks 'previous' (which may be NULL). | |
328 | * The real range was checked in getdents | |
329 | */ | |
330 | if (!user_access_begin(dirent, sizeof(*dirent))) | |
1da177e4 | 331 | goto efault; |
9f79b78e LT |
332 | if (dirent) |
333 | unsafe_put_user(offset, &dirent->d_off, efault_end); | |
334 | dirent = buf->current_dir; | |
335 | unsafe_put_user(ino, &dirent->d_ino, efault_end); | |
336 | unsafe_put_user(reclen, &dirent->d_reclen, efault_end); | |
337 | unsafe_put_user(d_type, &dirent->d_type, efault_end); | |
338 | unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault_end); | |
339 | user_access_end(); | |
340 | ||
1da177e4 LT |
341 | buf->previous = dirent; |
342 | dirent = (void __user *)dirent + reclen; | |
343 | buf->current_dir = dirent; | |
344 | buf->count -= reclen; | |
345 | return 0; | |
9f79b78e LT |
346 | efault_end: |
347 | user_access_end(); | |
1da177e4 LT |
348 | efault: |
349 | buf->error = -EFAULT; | |
350 | return -EFAULT; | |
351 | } | |
352 | ||
454dab3f DB |
353 | int ksys_getdents64(unsigned int fd, struct linux_dirent64 __user *dirent, |
354 | unsigned int count) | |
1da177e4 | 355 | { |
2903ff01 | 356 | struct fd f; |
1da177e4 | 357 | struct linux_dirent64 __user * lastdirent; |
ac6614b7 AV |
358 | struct getdents_callback64 buf = { |
359 | .ctx.actor = filldir64, | |
360 | .count = count, | |
361 | .current_dir = dirent | |
362 | }; | |
1da177e4 LT |
363 | int error; |
364 | ||
96d4f267 | 365 | if (!access_ok(dirent, count)) |
863ced7f | 366 | return -EFAULT; |
1da177e4 | 367 | |
63b6df14 | 368 | f = fdget_pos(fd); |
2903ff01 | 369 | if (!f.file) |
863ced7f | 370 | return -EBADF; |
1da177e4 | 371 | |
5c0ba4e0 | 372 | error = iterate_dir(f.file, &buf.ctx); |
53c9c5c0 AV |
373 | if (error >= 0) |
374 | error = buf.error; | |
1da177e4 LT |
375 | lastdirent = buf.previous; |
376 | if (lastdirent) { | |
bb6f619b | 377 | typeof(lastdirent->d_off) d_off = buf.ctx.pos; |
1da177e4 | 378 | if (__put_user(d_off, &lastdirent->d_off)) |
53c9c5c0 AV |
379 | error = -EFAULT; |
380 | else | |
381 | error = count - buf.count; | |
1da177e4 | 382 | } |
63b6df14 | 383 | fdput_pos(f); |
1da177e4 LT |
384 | return error; |
385 | } | |
0460b2a2 | 386 | |
454dab3f DB |
387 | |
388 | SYSCALL_DEFINE3(getdents64, unsigned int, fd, | |
389 | struct linux_dirent64 __user *, dirent, unsigned int, count) | |
390 | { | |
391 | return ksys_getdents64(fd, dirent, count); | |
392 | } | |
393 | ||
0460b2a2 AV |
394 | #ifdef CONFIG_COMPAT |
395 | struct compat_old_linux_dirent { | |
396 | compat_ulong_t d_ino; | |
397 | compat_ulong_t d_offset; | |
398 | unsigned short d_namlen; | |
399 | char d_name[1]; | |
400 | }; | |
401 | ||
402 | struct compat_readdir_callback { | |
403 | struct dir_context ctx; | |
404 | struct compat_old_linux_dirent __user *dirent; | |
405 | int result; | |
406 | }; | |
407 | ||
408 | static int compat_fillonedir(struct dir_context *ctx, const char *name, | |
409 | int namlen, loff_t offset, u64 ino, | |
410 | unsigned int d_type) | |
411 | { | |
412 | struct compat_readdir_callback *buf = | |
413 | container_of(ctx, struct compat_readdir_callback, ctx); | |
414 | struct compat_old_linux_dirent __user *dirent; | |
415 | compat_ulong_t d_ino; | |
416 | ||
417 | if (buf->result) | |
418 | return -EINVAL; | |
419 | d_ino = ino; | |
420 | if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) { | |
421 | buf->result = -EOVERFLOW; | |
422 | return -EOVERFLOW; | |
423 | } | |
424 | buf->result++; | |
425 | dirent = buf->dirent; | |
96d4f267 | 426 | if (!access_ok(dirent, |
0460b2a2 AV |
427 | (unsigned long)(dirent->d_name + namlen + 1) - |
428 | (unsigned long)dirent)) | |
429 | goto efault; | |
430 | if ( __put_user(d_ino, &dirent->d_ino) || | |
431 | __put_user(offset, &dirent->d_offset) || | |
432 | __put_user(namlen, &dirent->d_namlen) || | |
433 | __copy_to_user(dirent->d_name, name, namlen) || | |
434 | __put_user(0, dirent->d_name + namlen)) | |
435 | goto efault; | |
436 | return 0; | |
437 | efault: | |
438 | buf->result = -EFAULT; | |
439 | return -EFAULT; | |
440 | } | |
441 | ||
442 | COMPAT_SYSCALL_DEFINE3(old_readdir, unsigned int, fd, | |
443 | struct compat_old_linux_dirent __user *, dirent, unsigned int, count) | |
444 | { | |
445 | int error; | |
446 | struct fd f = fdget_pos(fd); | |
447 | struct compat_readdir_callback buf = { | |
448 | .ctx.actor = compat_fillonedir, | |
449 | .dirent = dirent | |
450 | }; | |
451 | ||
452 | if (!f.file) | |
453 | return -EBADF; | |
454 | ||
455 | error = iterate_dir(f.file, &buf.ctx); | |
456 | if (buf.result) | |
457 | error = buf.result; | |
458 | ||
459 | fdput_pos(f); | |
460 | return error; | |
461 | } | |
462 | ||
463 | struct compat_linux_dirent { | |
464 | compat_ulong_t d_ino; | |
465 | compat_ulong_t d_off; | |
466 | unsigned short d_reclen; | |
467 | char d_name[1]; | |
468 | }; | |
469 | ||
470 | struct compat_getdents_callback { | |
471 | struct dir_context ctx; | |
472 | struct compat_linux_dirent __user *current_dir; | |
473 | struct compat_linux_dirent __user *previous; | |
474 | int count; | |
475 | int error; | |
476 | }; | |
477 | ||
478 | static int compat_filldir(struct dir_context *ctx, const char *name, int namlen, | |
479 | loff_t offset, u64 ino, unsigned int d_type) | |
480 | { | |
481 | struct compat_linux_dirent __user * dirent; | |
482 | struct compat_getdents_callback *buf = | |
483 | container_of(ctx, struct compat_getdents_callback, ctx); | |
484 | compat_ulong_t d_ino; | |
485 | int reclen = ALIGN(offsetof(struct compat_linux_dirent, d_name) + | |
486 | namlen + 2, sizeof(compat_long_t)); | |
487 | ||
488 | buf->error = -EINVAL; /* only used if we fail.. */ | |
489 | if (reclen > buf->count) | |
490 | return -EINVAL; | |
491 | d_ino = ino; | |
492 | if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) { | |
493 | buf->error = -EOVERFLOW; | |
494 | return -EOVERFLOW; | |
495 | } | |
496 | dirent = buf->previous; | |
497 | if (dirent) { | |
498 | if (signal_pending(current)) | |
499 | return -EINTR; | |
500 | if (__put_user(offset, &dirent->d_off)) | |
501 | goto efault; | |
502 | } | |
503 | dirent = buf->current_dir; | |
504 | if (__put_user(d_ino, &dirent->d_ino)) | |
505 | goto efault; | |
506 | if (__put_user(reclen, &dirent->d_reclen)) | |
507 | goto efault; | |
508 | if (copy_to_user(dirent->d_name, name, namlen)) | |
509 | goto efault; | |
510 | if (__put_user(0, dirent->d_name + namlen)) | |
511 | goto efault; | |
512 | if (__put_user(d_type, (char __user *) dirent + reclen - 1)) | |
513 | goto efault; | |
514 | buf->previous = dirent; | |
515 | dirent = (void __user *)dirent + reclen; | |
516 | buf->current_dir = dirent; | |
517 | buf->count -= reclen; | |
518 | return 0; | |
519 | efault: | |
520 | buf->error = -EFAULT; | |
521 | return -EFAULT; | |
522 | } | |
523 | ||
524 | COMPAT_SYSCALL_DEFINE3(getdents, unsigned int, fd, | |
525 | struct compat_linux_dirent __user *, dirent, unsigned int, count) | |
526 | { | |
527 | struct fd f; | |
528 | struct compat_linux_dirent __user * lastdirent; | |
529 | struct compat_getdents_callback buf = { | |
530 | .ctx.actor = compat_filldir, | |
531 | .current_dir = dirent, | |
532 | .count = count | |
533 | }; | |
534 | int error; | |
535 | ||
96d4f267 | 536 | if (!access_ok(dirent, count)) |
0460b2a2 AV |
537 | return -EFAULT; |
538 | ||
539 | f = fdget_pos(fd); | |
540 | if (!f.file) | |
541 | return -EBADF; | |
542 | ||
543 | error = iterate_dir(f.file, &buf.ctx); | |
544 | if (error >= 0) | |
545 | error = buf.error; | |
546 | lastdirent = buf.previous; | |
547 | if (lastdirent) { | |
548 | if (put_user(buf.ctx.pos, &lastdirent->d_off)) | |
549 | error = -EFAULT; | |
550 | else | |
551 | error = count - buf.count; | |
552 | } | |
553 | fdput_pos(f); | |
554 | return error; | |
555 | } | |
556 | #endif |