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1/*
2 * linux/fs/readdir.c
3 *
4 * Copyright (C) 1995 Linus Torvalds
5 */
6
7#include <linux/stddef.h>
8#include <linux/kernel.h>
9#include <linux/export.h>
10#include <linux/time.h>
11#include <linux/mm.h>
12#include <linux/errno.h>
13#include <linux/stat.h>
14#include <linux/file.h>
15#include <linux/fs.h>
16#include <linux/dirent.h>
17#include <linux/security.h>
18#include <linux/syscalls.h>
19#include <linux/unistd.h>
20
21#include <asm/uaccess.h>
22
23int iterate_dir(struct file *file, struct dir_context *ctx)
24{
25 struct inode *inode = file_inode(file);
26 int res = -ENOTDIR;
27 if (!file->f_op->iterate)
28 goto out;
29
30 res = security_file_permission(file, MAY_READ);
31 if (res)
32 goto out;
33
34 res = mutex_lock_killable(&inode->i_mutex);
35 if (res)
36 goto out;
37
38 res = -ENOENT;
39 if (!IS_DEADDIR(inode)) {
40 ctx->pos = file->f_pos;
41 res = file->f_op->iterate(file, ctx);
42 file->f_pos = ctx->pos;
43 file_accessed(file);
44 }
45 mutex_unlock(&inode->i_mutex);
46out:
47 return res;
48}
49EXPORT_SYMBOL(iterate_dir);
50
51/*
52 * Traditional linux readdir() handling..
53 *
54 * "count=1" is a special case, meaning that the buffer is one
55 * dirent-structure in size and that the code can't handle more
56 * anyway. Thus the special "fillonedir()" function for that
57 * case (the low-level handlers don't need to care about this).
58 */
59
60#ifdef __ARCH_WANT_OLD_READDIR
61
62struct old_linux_dirent {
63 unsigned long d_ino;
64 unsigned long d_offset;
65 unsigned short d_namlen;
66 char d_name[1];
67};
68
69struct readdir_callback {
70 struct dir_context ctx;
71 struct old_linux_dirent __user * dirent;
72 int result;
73};
74
75static int fillonedir(void * __buf, const char * name, int namlen, loff_t offset,
76 u64 ino, unsigned int d_type)
77{
78 struct readdir_callback *buf = (struct readdir_callback *) __buf;
79 struct old_linux_dirent __user * dirent;
80 unsigned long d_ino;
81
82 if (buf->result)
83 return -EINVAL;
84 d_ino = ino;
85 if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
86 buf->result = -EOVERFLOW;
87 return -EOVERFLOW;
88 }
89 buf->result++;
90 dirent = buf->dirent;
91 if (!access_ok(VERIFY_WRITE, dirent,
92 (unsigned long)(dirent->d_name + namlen + 1) -
93 (unsigned long)dirent))
94 goto efault;
95 if ( __put_user(d_ino, &dirent->d_ino) ||
96 __put_user(offset, &dirent->d_offset) ||
97 __put_user(namlen, &dirent->d_namlen) ||
98 __copy_to_user(dirent->d_name, name, namlen) ||
99 __put_user(0, dirent->d_name + namlen))
100 goto efault;
101 return 0;
102efault:
103 buf->result = -EFAULT;
104 return -EFAULT;
105}
106
107SYSCALL_DEFINE3(old_readdir, unsigned int, fd,
108 struct old_linux_dirent __user *, dirent, unsigned int, count)
109{
110 int error;
111 struct fd f = fdget(fd);
112 struct readdir_callback buf = {
113 .ctx.actor = fillonedir,
114 .dirent = dirent
115 };
116
117 if (!f.file)
118 return -EBADF;
119
120 error = iterate_dir(f.file, &buf.ctx);
121 if (buf.result)
122 error = buf.result;
123
124 fdput(f);
125 return error;
126}
127
128#endif /* __ARCH_WANT_OLD_READDIR */
129
130/*
131 * New, all-improved, singing, dancing, iBCS2-compliant getdents()
132 * interface.
133 */
134struct linux_dirent {
135 unsigned long d_ino;
136 unsigned long d_off;
137 unsigned short d_reclen;
138 char d_name[1];
139};
140
141struct getdents_callback {
142 struct dir_context ctx;
143 struct linux_dirent __user * current_dir;
144 struct linux_dirent __user * previous;
145 int count;
146 int error;
147};
148
149static int filldir(void * __buf, const char * name, int namlen, loff_t offset,
150 u64 ino, unsigned int d_type)
151{
152 struct linux_dirent __user * dirent;
153 struct getdents_callback * buf = (struct getdents_callback *) __buf;
154 unsigned long d_ino;
155 int reclen = ALIGN(offsetof(struct linux_dirent, d_name) + namlen + 2,
156 sizeof(long));
157
158 buf->error = -EINVAL; /* only used if we fail.. */
159 if (reclen > buf->count)
160 return -EINVAL;
161 d_ino = ino;
162 if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
163 buf->error = -EOVERFLOW;
164 return -EOVERFLOW;
165 }
166 dirent = buf->previous;
167 if (dirent) {
168 if (__put_user(offset, &dirent->d_off))
169 goto efault;
170 }
171 dirent = buf->current_dir;
172 if (__put_user(d_ino, &dirent->d_ino))
173 goto efault;
174 if (__put_user(reclen, &dirent->d_reclen))
175 goto efault;
176 if (copy_to_user(dirent->d_name, name, namlen))
177 goto efault;
178 if (__put_user(0, dirent->d_name + namlen))
179 goto efault;
180 if (__put_user(d_type, (char __user *) dirent + reclen - 1))
181 goto efault;
182 buf->previous = dirent;
183 dirent = (void __user *)dirent + reclen;
184 buf->current_dir = dirent;
185 buf->count -= reclen;
186 return 0;
187efault:
188 buf->error = -EFAULT;
189 return -EFAULT;
190}
191
192SYSCALL_DEFINE3(getdents, unsigned int, fd,
193 struct linux_dirent __user *, dirent, unsigned int, count)
194{
195 struct fd f;
196 struct linux_dirent __user * lastdirent;
197 struct getdents_callback buf = {
198 .ctx.actor = filldir,
199 .count = count,
200 .current_dir = dirent
201 };
202 int error;
203
204 if (!access_ok(VERIFY_WRITE, dirent, count))
205 return -EFAULT;
206
207 f = fdget(fd);
208 if (!f.file)
209 return -EBADF;
210
211 error = iterate_dir(f.file, &buf.ctx);
212 if (error >= 0)
213 error = buf.error;
214 lastdirent = buf.previous;
215 if (lastdirent) {
216 if (put_user(buf.ctx.pos, &lastdirent->d_off))
217 error = -EFAULT;
218 else
219 error = count - buf.count;
220 }
221 fdput(f);
222 return error;
223}
224
225struct getdents_callback64 {
226 struct dir_context ctx;
227 struct linux_dirent64 __user * current_dir;
228 struct linux_dirent64 __user * previous;
229 int count;
230 int error;
231};
232
233static int filldir64(void * __buf, const char * name, int namlen, loff_t offset,
234 u64 ino, unsigned int d_type)
235{
236 struct linux_dirent64 __user *dirent;
237 struct getdents_callback64 * buf = (struct getdents_callback64 *) __buf;
238 int reclen = ALIGN(offsetof(struct linux_dirent64, d_name) + namlen + 1,
239 sizeof(u64));
240
241 buf->error = -EINVAL; /* only used if we fail.. */
242 if (reclen > buf->count)
243 return -EINVAL;
244 dirent = buf->previous;
245 if (dirent) {
246 if (__put_user(offset, &dirent->d_off))
247 goto efault;
248 }
249 dirent = buf->current_dir;
250 if (__put_user(ino, &dirent->d_ino))
251 goto efault;
252 if (__put_user(0, &dirent->d_off))
253 goto efault;
254 if (__put_user(reclen, &dirent->d_reclen))
255 goto efault;
256 if (__put_user(d_type, &dirent->d_type))
257 goto efault;
258 if (copy_to_user(dirent->d_name, name, namlen))
259 goto efault;
260 if (__put_user(0, dirent->d_name + namlen))
261 goto efault;
262 buf->previous = dirent;
263 dirent = (void __user *)dirent + reclen;
264 buf->current_dir = dirent;
265 buf->count -= reclen;
266 return 0;
267efault:
268 buf->error = -EFAULT;
269 return -EFAULT;
270}
271
272SYSCALL_DEFINE3(getdents64, unsigned int, fd,
273 struct linux_dirent64 __user *, dirent, unsigned int, count)
274{
275 struct fd f;
276 struct linux_dirent64 __user * lastdirent;
277 struct getdents_callback64 buf = {
278 .ctx.actor = filldir64,
279 .count = count,
280 .current_dir = dirent
281 };
282 int error;
283
284 if (!access_ok(VERIFY_WRITE, dirent, count))
285 return -EFAULT;
286
287 f = fdget(fd);
288 if (!f.file)
289 return -EBADF;
290
291 error = iterate_dir(f.file, &buf.ctx);
292 if (error >= 0)
293 error = buf.error;
294 lastdirent = buf.previous;
295 if (lastdirent) {
296 typeof(lastdirent->d_off) d_off = buf.ctx.pos;
297 if (__put_user(d_off, &lastdirent->d_off))
298 error = -EFAULT;
299 else
300 error = count - buf.count;
301 }
302 fdput(f);
303 return error;
304}
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 * Note the "unsafe_put_user() semantics: we goto a
29 * label for errors.
30 */
31#define unsafe_copy_dirent_name(_dst, _src, _len, label) do { \
32 char __user *dst = (_dst); \
33 const char *src = (_src); \
34 size_t len = (_len); \
35 unsafe_put_user(0, dst+len, label); \
36 unsafe_copy_to_user(dst, src, len, label); \
37} while (0)
38
39
40int iterate_dir(struct file *file, struct dir_context *ctx)
41{
42 struct inode *inode = file_inode(file);
43 bool shared = false;
44 int res = -ENOTDIR;
45 if (file->f_op->iterate_shared)
46 shared = true;
47 else if (!file->f_op->iterate)
48 goto out;
49
50 res = security_file_permission(file, MAY_READ);
51 if (res)
52 goto out;
53
54 if (shared)
55 res = down_read_killable(&inode->i_rwsem);
56 else
57 res = down_write_killable(&inode->i_rwsem);
58 if (res)
59 goto out;
60
61 res = -ENOENT;
62 if (!IS_DEADDIR(inode)) {
63 ctx->pos = file->f_pos;
64 if (shared)
65 res = file->f_op->iterate_shared(file, ctx);
66 else
67 res = file->f_op->iterate(file, ctx);
68 file->f_pos = ctx->pos;
69 fsnotify_access(file);
70 file_accessed(file);
71 }
72 if (shared)
73 inode_unlock_shared(inode);
74 else
75 inode_unlock(inode);
76out:
77 return res;
78}
79EXPORT_SYMBOL(iterate_dir);
80
81/*
82 * POSIX says that a dirent name cannot contain NULL or a '/'.
83 *
84 * It's not 100% clear what we should really do in this case.
85 * The filesystem is clearly corrupted, but returning a hard
86 * error means that you now don't see any of the other names
87 * either, so that isn't a perfect alternative.
88 *
89 * And if you return an error, what error do you use? Several
90 * filesystems seem to have decided on EUCLEAN being the error
91 * code for EFSCORRUPTED, and that may be the error to use. Or
92 * just EIO, which is perhaps more obvious to users.
93 *
94 * In order to see the other file names in the directory, the
95 * caller might want to make this a "soft" error: skip the
96 * entry, and return the error at the end instead.
97 *
98 * Note that this should likely do a "memchr(name, 0, len)"
99 * check too, since that would be filesystem corruption as
100 * well. However, that case can't actually confuse user space,
101 * which has to do a strlen() on the name anyway to find the
102 * filename length, and the above "soft error" worry means
103 * that it's probably better left alone until we have that
104 * issue clarified.
105 */
106static int verify_dirent_name(const char *name, int len)
107{
108 if (!len)
109 return -EIO;
110 if (memchr(name, '/', len))
111 return -EIO;
112 return 0;
113}
114
115/*
116 * Traditional linux readdir() handling..
117 *
118 * "count=1" is a special case, meaning that the buffer is one
119 * dirent-structure in size and that the code can't handle more
120 * anyway. Thus the special "fillonedir()" function for that
121 * case (the low-level handlers don't need to care about this).
122 */
123
124#ifdef __ARCH_WANT_OLD_READDIR
125
126struct old_linux_dirent {
127 unsigned long d_ino;
128 unsigned long d_offset;
129 unsigned short d_namlen;
130 char d_name[1];
131};
132
133struct readdir_callback {
134 struct dir_context ctx;
135 struct old_linux_dirent __user * dirent;
136 int result;
137};
138
139static int fillonedir(struct dir_context *ctx, const char *name, int namlen,
140 loff_t offset, u64 ino, unsigned int d_type)
141{
142 struct readdir_callback *buf =
143 container_of(ctx, struct readdir_callback, ctx);
144 struct old_linux_dirent __user * dirent;
145 unsigned long d_ino;
146
147 if (buf->result)
148 return -EINVAL;
149 d_ino = ino;
150 if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
151 buf->result = -EOVERFLOW;
152 return -EOVERFLOW;
153 }
154 buf->result++;
155 dirent = buf->dirent;
156 if (!access_ok(dirent,
157 (unsigned long)(dirent->d_name + namlen + 1) -
158 (unsigned long)dirent))
159 goto efault;
160 if ( __put_user(d_ino, &dirent->d_ino) ||
161 __put_user(offset, &dirent->d_offset) ||
162 __put_user(namlen, &dirent->d_namlen) ||
163 __copy_to_user(dirent->d_name, name, namlen) ||
164 __put_user(0, dirent->d_name + namlen))
165 goto efault;
166 return 0;
167efault:
168 buf->result = -EFAULT;
169 return -EFAULT;
170}
171
172SYSCALL_DEFINE3(old_readdir, unsigned int, fd,
173 struct old_linux_dirent __user *, dirent, unsigned int, count)
174{
175 int error;
176 struct fd f = fdget_pos(fd);
177 struct readdir_callback buf = {
178 .ctx.actor = fillonedir,
179 .dirent = dirent
180 };
181
182 if (!f.file)
183 return -EBADF;
184
185 error = iterate_dir(f.file, &buf.ctx);
186 if (buf.result)
187 error = buf.result;
188
189 fdput_pos(f);
190 return error;
191}
192
193#endif /* __ARCH_WANT_OLD_READDIR */
194
195/*
196 * New, all-improved, singing, dancing, iBCS2-compliant getdents()
197 * interface.
198 */
199struct linux_dirent {
200 unsigned long d_ino;
201 unsigned long d_off;
202 unsigned short d_reclen;
203 char d_name[1];
204};
205
206struct getdents_callback {
207 struct dir_context ctx;
208 struct linux_dirent __user * current_dir;
209 struct linux_dirent __user * previous;
210 int count;
211 int error;
212};
213
214static int filldir(struct dir_context *ctx, const char *name, int namlen,
215 loff_t offset, u64 ino, unsigned int d_type)
216{
217 struct linux_dirent __user * dirent;
218 struct getdents_callback *buf =
219 container_of(ctx, struct getdents_callback, ctx);
220 unsigned long d_ino;
221 int reclen = ALIGN(offsetof(struct linux_dirent, d_name) + namlen + 2,
222 sizeof(long));
223
224 buf->error = verify_dirent_name(name, namlen);
225 if (unlikely(buf->error))
226 return buf->error;
227 buf->error = -EINVAL; /* only used if we fail.. */
228 if (reclen > buf->count)
229 return -EINVAL;
230 d_ino = ino;
231 if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
232 buf->error = -EOVERFLOW;
233 return -EOVERFLOW;
234 }
235 dirent = buf->previous;
236 if (dirent && signal_pending(current))
237 return -EINTR;
238
239 /*
240 * Note! This range-checks 'previous' (which may be NULL).
241 * The real range was checked in getdents
242 */
243 if (!user_access_begin(dirent, sizeof(*dirent)))
244 goto efault;
245 if (dirent)
246 unsafe_put_user(offset, &dirent->d_off, efault_end);
247 dirent = buf->current_dir;
248 unsafe_put_user(d_ino, &dirent->d_ino, efault_end);
249 unsafe_put_user(reclen, &dirent->d_reclen, efault_end);
250 unsafe_put_user(d_type, (char __user *) dirent + reclen - 1, efault_end);
251 unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault_end);
252 user_access_end();
253
254 buf->previous = dirent;
255 dirent = (void __user *)dirent + reclen;
256 buf->current_dir = dirent;
257 buf->count -= reclen;
258 return 0;
259efault_end:
260 user_access_end();
261efault:
262 buf->error = -EFAULT;
263 return -EFAULT;
264}
265
266SYSCALL_DEFINE3(getdents, unsigned int, fd,
267 struct linux_dirent __user *, dirent, unsigned int, count)
268{
269 struct fd f;
270 struct linux_dirent __user * lastdirent;
271 struct getdents_callback buf = {
272 .ctx.actor = filldir,
273 .count = count,
274 .current_dir = dirent
275 };
276 int error;
277
278 if (!access_ok(dirent, count))
279 return -EFAULT;
280
281 f = fdget_pos(fd);
282 if (!f.file)
283 return -EBADF;
284
285 error = iterate_dir(f.file, &buf.ctx);
286 if (error >= 0)
287 error = buf.error;
288 lastdirent = buf.previous;
289 if (lastdirent) {
290 if (put_user(buf.ctx.pos, &lastdirent->d_off))
291 error = -EFAULT;
292 else
293 error = count - buf.count;
294 }
295 fdput_pos(f);
296 return error;
297}
298
299struct getdents_callback64 {
300 struct dir_context ctx;
301 struct linux_dirent64 __user * current_dir;
302 struct linux_dirent64 __user * previous;
303 int count;
304 int error;
305};
306
307static int filldir64(struct dir_context *ctx, const char *name, int namlen,
308 loff_t offset, u64 ino, unsigned int d_type)
309{
310 struct linux_dirent64 __user *dirent;
311 struct getdents_callback64 *buf =
312 container_of(ctx, struct getdents_callback64, ctx);
313 int reclen = ALIGN(offsetof(struct linux_dirent64, d_name) + namlen + 1,
314 sizeof(u64));
315
316 buf->error = verify_dirent_name(name, namlen);
317 if (unlikely(buf->error))
318 return buf->error;
319 buf->error = -EINVAL; /* only used if we fail.. */
320 if (reclen > buf->count)
321 return -EINVAL;
322 dirent = buf->previous;
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)))
331 goto efault;
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
341 buf->previous = dirent;
342 dirent = (void __user *)dirent + reclen;
343 buf->current_dir = dirent;
344 buf->count -= reclen;
345 return 0;
346efault_end:
347 user_access_end();
348efault:
349 buf->error = -EFAULT;
350 return -EFAULT;
351}
352
353int ksys_getdents64(unsigned int fd, struct linux_dirent64 __user *dirent,
354 unsigned int count)
355{
356 struct fd f;
357 struct linux_dirent64 __user * lastdirent;
358 struct getdents_callback64 buf = {
359 .ctx.actor = filldir64,
360 .count = count,
361 .current_dir = dirent
362 };
363 int error;
364
365 if (!access_ok(dirent, count))
366 return -EFAULT;
367
368 f = fdget_pos(fd);
369 if (!f.file)
370 return -EBADF;
371
372 error = iterate_dir(f.file, &buf.ctx);
373 if (error >= 0)
374 error = buf.error;
375 lastdirent = buf.previous;
376 if (lastdirent) {
377 typeof(lastdirent->d_off) d_off = buf.ctx.pos;
378 if (__put_user(d_off, &lastdirent->d_off))
379 error = -EFAULT;
380 else
381 error = count - buf.count;
382 }
383 fdput_pos(f);
384 return error;
385}
386
387
388SYSCALL_DEFINE3(getdents64, unsigned int, fd,
389 struct linux_dirent64 __user *, dirent, unsigned int, count)
390{
391 return ksys_getdents64(fd, dirent, count);
392}
393
394#ifdef CONFIG_COMPAT
395struct 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
402struct compat_readdir_callback {
403 struct dir_context ctx;
404 struct compat_old_linux_dirent __user *dirent;
405 int result;
406};
407
408static 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;
426 if (!access_ok(dirent,
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;
437efault:
438 buf->result = -EFAULT;
439 return -EFAULT;
440}
441
442COMPAT_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
463struct 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
470struct 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
478static 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;
519efault:
520 buf->error = -EFAULT;
521 return -EFAULT;
522}
523
524COMPAT_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
536 if (!access_ok(dirent, count))
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