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v3.15
 
  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}
v4.17
  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
 24#include <linux/uaccess.h>
 25
 26int iterate_dir(struct file *file, struct dir_context *ctx)
 27{
 28	struct inode *inode = file_inode(file);
 29	bool shared = false;
 30	int res = -ENOTDIR;
 31	if (file->f_op->iterate_shared)
 32		shared = true;
 33	else if (!file->f_op->iterate)
 34		goto out;
 35
 36	res = security_file_permission(file, MAY_READ);
 37	if (res)
 38		goto out;
 39
 40	if (shared)
 41		res = down_read_killable(&inode->i_rwsem);
 42	else
 43		res = down_write_killable(&inode->i_rwsem);
 44	if (res)
 45		goto out;
 46
 47	res = -ENOENT;
 48	if (!IS_DEADDIR(inode)) {
 49		ctx->pos = file->f_pos;
 50		if (shared)
 51			res = file->f_op->iterate_shared(file, ctx);
 52		else
 53			res = file->f_op->iterate(file, ctx);
 54		file->f_pos = ctx->pos;
 55		fsnotify_access(file);
 56		file_accessed(file);
 57	}
 58	if (shared)
 59		inode_unlock_shared(inode);
 60	else
 61		inode_unlock(inode);
 62out:
 63	return res;
 64}
 65EXPORT_SYMBOL(iterate_dir);
 66
 67/*
 68 * Traditional linux readdir() handling..
 69 *
 70 * "count=1" is a special case, meaning that the buffer is one
 71 * dirent-structure in size and that the code can't handle more
 72 * anyway. Thus the special "fillonedir()" function for that
 73 * case (the low-level handlers don't need to care about this).
 74 */
 75
 76#ifdef __ARCH_WANT_OLD_READDIR
 77
 78struct old_linux_dirent {
 79	unsigned long	d_ino;
 80	unsigned long	d_offset;
 81	unsigned short	d_namlen;
 82	char		d_name[1];
 83};
 84
 85struct readdir_callback {
 86	struct dir_context ctx;
 87	struct old_linux_dirent __user * dirent;
 88	int result;
 89};
 90
 91static int fillonedir(struct dir_context *ctx, const char *name, int namlen,
 92		      loff_t offset, u64 ino, unsigned int d_type)
 93{
 94	struct readdir_callback *buf =
 95		container_of(ctx, struct readdir_callback, ctx);
 96	struct old_linux_dirent __user * dirent;
 97	unsigned long d_ino;
 98
 99	if (buf->result)
100		return -EINVAL;
101	d_ino = ino;
102	if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
103		buf->result = -EOVERFLOW;
104		return -EOVERFLOW;
105	}
106	buf->result++;
107	dirent = buf->dirent;
108	if (!access_ok(VERIFY_WRITE, dirent,
109			(unsigned long)(dirent->d_name + namlen + 1) -
110				(unsigned long)dirent))
111		goto efault;
112	if (	__put_user(d_ino, &dirent->d_ino) ||
113		__put_user(offset, &dirent->d_offset) ||
114		__put_user(namlen, &dirent->d_namlen) ||
115		__copy_to_user(dirent->d_name, name, namlen) ||
116		__put_user(0, dirent->d_name + namlen))
117		goto efault;
118	return 0;
119efault:
120	buf->result = -EFAULT;
121	return -EFAULT;
122}
123
124SYSCALL_DEFINE3(old_readdir, unsigned int, fd,
125		struct old_linux_dirent __user *, dirent, unsigned int, count)
126{
127	int error;
128	struct fd f = fdget_pos(fd);
129	struct readdir_callback buf = {
130		.ctx.actor = fillonedir,
131		.dirent = dirent
132	};
133
134	if (!f.file)
135		return -EBADF;
136
137	error = iterate_dir(f.file, &buf.ctx);
138	if (buf.result)
139		error = buf.result;
140
141	fdput_pos(f);
142	return error;
143}
144
145#endif /* __ARCH_WANT_OLD_READDIR */
146
147/*
148 * New, all-improved, singing, dancing, iBCS2-compliant getdents()
149 * interface. 
150 */
151struct linux_dirent {
152	unsigned long	d_ino;
153	unsigned long	d_off;
154	unsigned short	d_reclen;
155	char		d_name[1];
156};
157
158struct getdents_callback {
159	struct dir_context ctx;
160	struct linux_dirent __user * current_dir;
161	struct linux_dirent __user * previous;
162	int count;
163	int error;
164};
165
166static int filldir(struct dir_context *ctx, const char *name, int namlen,
167		   loff_t offset, u64 ino, unsigned int d_type)
168{
169	struct linux_dirent __user * dirent;
170	struct getdents_callback *buf =
171		container_of(ctx, struct getdents_callback, ctx);
172	unsigned long d_ino;
173	int reclen = ALIGN(offsetof(struct linux_dirent, d_name) + namlen + 2,
174		sizeof(long));
175
176	buf->error = -EINVAL;	/* only used if we fail.. */
177	if (reclen > buf->count)
178		return -EINVAL;
179	d_ino = ino;
180	if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
181		buf->error = -EOVERFLOW;
182		return -EOVERFLOW;
183	}
184	dirent = buf->previous;
185	if (dirent) {
186		if (signal_pending(current))
187			return -EINTR;
188		if (__put_user(offset, &dirent->d_off))
189			goto efault;
190	}
191	dirent = buf->current_dir;
192	if (__put_user(d_ino, &dirent->d_ino))
193		goto efault;
194	if (__put_user(reclen, &dirent->d_reclen))
195		goto efault;
196	if (copy_to_user(dirent->d_name, name, namlen))
197		goto efault;
198	if (__put_user(0, dirent->d_name + namlen))
199		goto efault;
200	if (__put_user(d_type, (char __user *) dirent + reclen - 1))
201		goto efault;
202	buf->previous = dirent;
203	dirent = (void __user *)dirent + reclen;
204	buf->current_dir = dirent;
205	buf->count -= reclen;
206	return 0;
207efault:
208	buf->error = -EFAULT;
209	return -EFAULT;
210}
211
212SYSCALL_DEFINE3(getdents, unsigned int, fd,
213		struct linux_dirent __user *, dirent, unsigned int, count)
214{
215	struct fd f;
216	struct linux_dirent __user * lastdirent;
217	struct getdents_callback buf = {
218		.ctx.actor = filldir,
219		.count = count,
220		.current_dir = dirent
221	};
222	int error;
223
224	if (!access_ok(VERIFY_WRITE, dirent, count))
225		return -EFAULT;
226
227	f = fdget_pos(fd);
228	if (!f.file)
229		return -EBADF;
230
231	error = iterate_dir(f.file, &buf.ctx);
232	if (error >= 0)
233		error = buf.error;
234	lastdirent = buf.previous;
235	if (lastdirent) {
236		if (put_user(buf.ctx.pos, &lastdirent->d_off))
237			error = -EFAULT;
238		else
239			error = count - buf.count;
240	}
241	fdput_pos(f);
242	return error;
243}
244
245struct getdents_callback64 {
246	struct dir_context ctx;
247	struct linux_dirent64 __user * current_dir;
248	struct linux_dirent64 __user * previous;
249	int count;
250	int error;
251};
252
253static int filldir64(struct dir_context *ctx, const char *name, int namlen,
254		     loff_t offset, u64 ino, unsigned int d_type)
255{
256	struct linux_dirent64 __user *dirent;
257	struct getdents_callback64 *buf =
258		container_of(ctx, struct getdents_callback64, ctx);
259	int reclen = ALIGN(offsetof(struct linux_dirent64, d_name) + namlen + 1,
260		sizeof(u64));
261
262	buf->error = -EINVAL;	/* only used if we fail.. */
263	if (reclen > buf->count)
264		return -EINVAL;
265	dirent = buf->previous;
266	if (dirent) {
267		if (signal_pending(current))
268			return -EINTR;
269		if (__put_user(offset, &dirent->d_off))
270			goto efault;
271	}
272	dirent = buf->current_dir;
273	if (__put_user(ino, &dirent->d_ino))
274		goto efault;
275	if (__put_user(0, &dirent->d_off))
276		goto efault;
277	if (__put_user(reclen, &dirent->d_reclen))
278		goto efault;
279	if (__put_user(d_type, &dirent->d_type))
280		goto efault;
281	if (copy_to_user(dirent->d_name, name, namlen))
282		goto efault;
283	if (__put_user(0, dirent->d_name + namlen))
284		goto efault;
285	buf->previous = dirent;
286	dirent = (void __user *)dirent + reclen;
287	buf->current_dir = dirent;
288	buf->count -= reclen;
289	return 0;
290efault:
291	buf->error = -EFAULT;
292	return -EFAULT;
293}
294
295int ksys_getdents64(unsigned int fd, struct linux_dirent64 __user *dirent,
296		    unsigned int count)
297{
298	struct fd f;
299	struct linux_dirent64 __user * lastdirent;
300	struct getdents_callback64 buf = {
301		.ctx.actor = filldir64,
302		.count = count,
303		.current_dir = dirent
304	};
305	int error;
306
307	if (!access_ok(VERIFY_WRITE, dirent, count))
308		return -EFAULT;
309
310	f = fdget_pos(fd);
311	if (!f.file)
312		return -EBADF;
313
314	error = iterate_dir(f.file, &buf.ctx);
315	if (error >= 0)
316		error = buf.error;
317	lastdirent = buf.previous;
318	if (lastdirent) {
319		typeof(lastdirent->d_off) d_off = buf.ctx.pos;
320		if (__put_user(d_off, &lastdirent->d_off))
321			error = -EFAULT;
322		else
323			error = count - buf.count;
324	}
325	fdput_pos(f);
326	return error;
327}
328
329
330SYSCALL_DEFINE3(getdents64, unsigned int, fd,
331		struct linux_dirent64 __user *, dirent, unsigned int, count)
332{
333	return ksys_getdents64(fd, dirent, count);
334}
335
336#ifdef CONFIG_COMPAT
337struct compat_old_linux_dirent {
338	compat_ulong_t	d_ino;
339	compat_ulong_t	d_offset;
340	unsigned short	d_namlen;
341	char		d_name[1];
342};
343
344struct compat_readdir_callback {
345	struct dir_context ctx;
346	struct compat_old_linux_dirent __user *dirent;
347	int result;
348};
349
350static int compat_fillonedir(struct dir_context *ctx, const char *name,
351			     int namlen, loff_t offset, u64 ino,
352			     unsigned int d_type)
353{
354	struct compat_readdir_callback *buf =
355		container_of(ctx, struct compat_readdir_callback, ctx);
356	struct compat_old_linux_dirent __user *dirent;
357	compat_ulong_t d_ino;
358
359	if (buf->result)
360		return -EINVAL;
361	d_ino = ino;
362	if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
363		buf->result = -EOVERFLOW;
364		return -EOVERFLOW;
365	}
366	buf->result++;
367	dirent = buf->dirent;
368	if (!access_ok(VERIFY_WRITE, dirent,
369			(unsigned long)(dirent->d_name + namlen + 1) -
370				(unsigned long)dirent))
371		goto efault;
372	if (	__put_user(d_ino, &dirent->d_ino) ||
373		__put_user(offset, &dirent->d_offset) ||
374		__put_user(namlen, &dirent->d_namlen) ||
375		__copy_to_user(dirent->d_name, name, namlen) ||
376		__put_user(0, dirent->d_name + namlen))
377		goto efault;
378	return 0;
379efault:
380	buf->result = -EFAULT;
381	return -EFAULT;
382}
383
384COMPAT_SYSCALL_DEFINE3(old_readdir, unsigned int, fd,
385		struct compat_old_linux_dirent __user *, dirent, unsigned int, count)
386{
387	int error;
388	struct fd f = fdget_pos(fd);
389	struct compat_readdir_callback buf = {
390		.ctx.actor = compat_fillonedir,
391		.dirent = dirent
392	};
393
394	if (!f.file)
395		return -EBADF;
396
397	error = iterate_dir(f.file, &buf.ctx);
398	if (buf.result)
399		error = buf.result;
400
401	fdput_pos(f);
402	return error;
403}
404
405struct compat_linux_dirent {
406	compat_ulong_t	d_ino;
407	compat_ulong_t	d_off;
408	unsigned short	d_reclen;
409	char		d_name[1];
410};
411
412struct compat_getdents_callback {
413	struct dir_context ctx;
414	struct compat_linux_dirent __user *current_dir;
415	struct compat_linux_dirent __user *previous;
416	int count;
417	int error;
418};
419
420static int compat_filldir(struct dir_context *ctx, const char *name, int namlen,
421		loff_t offset, u64 ino, unsigned int d_type)
422{
423	struct compat_linux_dirent __user * dirent;
424	struct compat_getdents_callback *buf =
425		container_of(ctx, struct compat_getdents_callback, ctx);
426	compat_ulong_t d_ino;
427	int reclen = ALIGN(offsetof(struct compat_linux_dirent, d_name) +
428		namlen + 2, sizeof(compat_long_t));
429
430	buf->error = -EINVAL;	/* only used if we fail.. */
431	if (reclen > buf->count)
432		return -EINVAL;
433	d_ino = ino;
434	if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
435		buf->error = -EOVERFLOW;
436		return -EOVERFLOW;
437	}
438	dirent = buf->previous;
439	if (dirent) {
440		if (signal_pending(current))
441			return -EINTR;
442		if (__put_user(offset, &dirent->d_off))
443			goto efault;
444	}
445	dirent = buf->current_dir;
446	if (__put_user(d_ino, &dirent->d_ino))
447		goto efault;
448	if (__put_user(reclen, &dirent->d_reclen))
449		goto efault;
450	if (copy_to_user(dirent->d_name, name, namlen))
451		goto efault;
452	if (__put_user(0, dirent->d_name + namlen))
453		goto efault;
454	if (__put_user(d_type, (char  __user *) dirent + reclen - 1))
455		goto efault;
456	buf->previous = dirent;
457	dirent = (void __user *)dirent + reclen;
458	buf->current_dir = dirent;
459	buf->count -= reclen;
460	return 0;
461efault:
462	buf->error = -EFAULT;
463	return -EFAULT;
464}
465
466COMPAT_SYSCALL_DEFINE3(getdents, unsigned int, fd,
467		struct compat_linux_dirent __user *, dirent, unsigned int, count)
468{
469	struct fd f;
470	struct compat_linux_dirent __user * lastdirent;
471	struct compat_getdents_callback buf = {
472		.ctx.actor = compat_filldir,
473		.current_dir = dirent,
474		.count = count
475	};
476	int error;
477
478	if (!access_ok(VERIFY_WRITE, dirent, count))
479		return -EFAULT;
480
481	f = fdget_pos(fd);
482	if (!f.file)
483		return -EBADF;
484
485	error = iterate_dir(f.file, &buf.ctx);
486	if (error >= 0)
487		error = buf.error;
488	lastdirent = buf.previous;
489	if (lastdirent) {
490		if (put_user(buf.ctx.pos, &lastdirent->d_off))
491			error = -EFAULT;
492		else
493			error = count - buf.count;
494	}
495	fdput_pos(f);
496	return error;
497}
498#endif