Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/fs/read_write.c | |
3 | * | |
4 | * Copyright (C) 1991, 1992 Linus Torvalds | |
5 | */ | |
6 | ||
7 | #include <linux/slab.h> | |
8 | #include <linux/stat.h> | |
9 | #include <linux/fcntl.h> | |
10 | #include <linux/file.h> | |
11 | #include <linux/uio.h> | |
0eeca283 | 12 | #include <linux/fsnotify.h> |
1da177e4 | 13 | #include <linux/security.h> |
630d9c47 | 14 | #include <linux/export.h> |
1da177e4 | 15 | #include <linux/syscalls.h> |
e28cc715 | 16 | #include <linux/pagemap.h> |
d6b29d7c | 17 | #include <linux/splice.h> |
561c6731 | 18 | #include <linux/compat.h> |
06ae43f3 | 19 | #include "internal.h" |
1da177e4 LT |
20 | |
21 | #include <asm/uaccess.h> | |
22 | #include <asm/unistd.h> | |
23 | ||
c0bd14af | 24 | typedef ssize_t (*io_fn_t)(struct file *, char __user *, size_t, loff_t *); |
293bc982 | 25 | typedef ssize_t (*iter_fn_t)(struct kiocb *, struct iov_iter *); |
c0bd14af | 26 | |
4b6f5d20 | 27 | const struct file_operations generic_ro_fops = { |
1da177e4 | 28 | .llseek = generic_file_llseek, |
aad4f8bb | 29 | .read_iter = generic_file_read_iter, |
1da177e4 | 30 | .mmap = generic_file_readonly_mmap, |
534f2aaa | 31 | .splice_read = generic_file_splice_read, |
1da177e4 LT |
32 | }; |
33 | ||
34 | EXPORT_SYMBOL(generic_ro_fops); | |
35 | ||
cccb5a1e | 36 | static inline int unsigned_offsets(struct file *file) |
4a3956c7 | 37 | { |
cccb5a1e | 38 | return file->f_mode & FMODE_UNSIGNED_OFFSET; |
4a3956c7 KH |
39 | } |
40 | ||
46a1c2c7 JL |
41 | /** |
42 | * vfs_setpos - update the file offset for lseek | |
43 | * @file: file structure in question | |
44 | * @offset: file offset to seek to | |
45 | * @maxsize: maximum file size | |
46 | * | |
47 | * This is a low-level filesystem helper for updating the file offset to | |
48 | * the value specified by @offset if the given offset is valid and it is | |
49 | * not equal to the current file offset. | |
50 | * | |
51 | * Return the specified offset on success and -EINVAL on invalid offset. | |
52 | */ | |
53 | loff_t vfs_setpos(struct file *file, loff_t offset, loff_t maxsize) | |
ef3d0fd2 AK |
54 | { |
55 | if (offset < 0 && !unsigned_offsets(file)) | |
56 | return -EINVAL; | |
57 | if (offset > maxsize) | |
58 | return -EINVAL; | |
59 | ||
60 | if (offset != file->f_pos) { | |
61 | file->f_pos = offset; | |
62 | file->f_version = 0; | |
63 | } | |
64 | return offset; | |
65 | } | |
46a1c2c7 | 66 | EXPORT_SYMBOL(vfs_setpos); |
ef3d0fd2 | 67 | |
3a8cff4f | 68 | /** |
5760495a | 69 | * generic_file_llseek_size - generic llseek implementation for regular files |
3a8cff4f CH |
70 | * @file: file structure to seek on |
71 | * @offset: file offset to seek to | |
965c8e59 | 72 | * @whence: type of seek |
e8b96eb5 ES |
73 | * @size: max size of this file in file system |
74 | * @eof: offset used for SEEK_END position | |
3a8cff4f | 75 | * |
5760495a | 76 | * This is a variant of generic_file_llseek that allows passing in a custom |
e8b96eb5 | 77 | * maximum file size and a custom EOF position, for e.g. hashed directories |
ef3d0fd2 AK |
78 | * |
79 | * Synchronization: | |
5760495a | 80 | * SEEK_SET and SEEK_END are unsynchronized (but atomic on 64bit platforms) |
ef3d0fd2 AK |
81 | * SEEK_CUR is synchronized against other SEEK_CURs, but not read/writes. |
82 | * read/writes behave like SEEK_SET against seeks. | |
3a8cff4f | 83 | */ |
9465efc9 | 84 | loff_t |
965c8e59 | 85 | generic_file_llseek_size(struct file *file, loff_t offset, int whence, |
e8b96eb5 | 86 | loff_t maxsize, loff_t eof) |
1da177e4 | 87 | { |
965c8e59 | 88 | switch (whence) { |
3a8cff4f | 89 | case SEEK_END: |
e8b96eb5 | 90 | offset += eof; |
3a8cff4f CH |
91 | break; |
92 | case SEEK_CUR: | |
5b6f1eb9 AK |
93 | /* |
94 | * Here we special-case the lseek(fd, 0, SEEK_CUR) | |
95 | * position-querying operation. Avoid rewriting the "same" | |
96 | * f_pos value back to the file because a concurrent read(), | |
97 | * write() or lseek() might have altered it | |
98 | */ | |
99 | if (offset == 0) | |
100 | return file->f_pos; | |
ef3d0fd2 AK |
101 | /* |
102 | * f_lock protects against read/modify/write race with other | |
103 | * SEEK_CURs. Note that parallel writes and reads behave | |
104 | * like SEEK_SET. | |
105 | */ | |
106 | spin_lock(&file->f_lock); | |
46a1c2c7 | 107 | offset = vfs_setpos(file, file->f_pos + offset, maxsize); |
ef3d0fd2 AK |
108 | spin_unlock(&file->f_lock); |
109 | return offset; | |
982d8165 JB |
110 | case SEEK_DATA: |
111 | /* | |
112 | * In the generic case the entire file is data, so as long as | |
113 | * offset isn't at the end of the file then the offset is data. | |
114 | */ | |
e8b96eb5 | 115 | if (offset >= eof) |
982d8165 JB |
116 | return -ENXIO; |
117 | break; | |
118 | case SEEK_HOLE: | |
119 | /* | |
120 | * There is a virtual hole at the end of the file, so as long as | |
121 | * offset isn't i_size or larger, return i_size. | |
122 | */ | |
e8b96eb5 | 123 | if (offset >= eof) |
982d8165 | 124 | return -ENXIO; |
e8b96eb5 | 125 | offset = eof; |
982d8165 | 126 | break; |
1da177e4 | 127 | } |
3a8cff4f | 128 | |
46a1c2c7 | 129 | return vfs_setpos(file, offset, maxsize); |
5760495a AK |
130 | } |
131 | EXPORT_SYMBOL(generic_file_llseek_size); | |
132 | ||
133 | /** | |
134 | * generic_file_llseek - generic llseek implementation for regular files | |
135 | * @file: file structure to seek on | |
136 | * @offset: file offset to seek to | |
965c8e59 | 137 | * @whence: type of seek |
5760495a AK |
138 | * |
139 | * This is a generic implemenation of ->llseek useable for all normal local | |
140 | * filesystems. It just updates the file offset to the value specified by | |
546ae2d2 | 141 | * @offset and @whence. |
5760495a | 142 | */ |
965c8e59 | 143 | loff_t generic_file_llseek(struct file *file, loff_t offset, int whence) |
5760495a AK |
144 | { |
145 | struct inode *inode = file->f_mapping->host; | |
146 | ||
965c8e59 | 147 | return generic_file_llseek_size(file, offset, whence, |
e8b96eb5 ES |
148 | inode->i_sb->s_maxbytes, |
149 | i_size_read(inode)); | |
1da177e4 | 150 | } |
9465efc9 | 151 | EXPORT_SYMBOL(generic_file_llseek); |
1da177e4 | 152 | |
1bf9d14d AV |
153 | /** |
154 | * fixed_size_llseek - llseek implementation for fixed-sized devices | |
155 | * @file: file structure to seek on | |
156 | * @offset: file offset to seek to | |
157 | * @whence: type of seek | |
158 | * @size: size of the file | |
159 | * | |
160 | */ | |
161 | loff_t fixed_size_llseek(struct file *file, loff_t offset, int whence, loff_t size) | |
162 | { | |
163 | switch (whence) { | |
164 | case SEEK_SET: case SEEK_CUR: case SEEK_END: | |
165 | return generic_file_llseek_size(file, offset, whence, | |
166 | size, size); | |
167 | default: | |
168 | return -EINVAL; | |
169 | } | |
170 | } | |
171 | EXPORT_SYMBOL(fixed_size_llseek); | |
172 | ||
b25472f9 AV |
173 | /** |
174 | * no_seek_end_llseek - llseek implementation for fixed-sized devices | |
175 | * @file: file structure to seek on | |
176 | * @offset: file offset to seek to | |
177 | * @whence: type of seek | |
178 | * | |
179 | */ | |
180 | loff_t no_seek_end_llseek(struct file *file, loff_t offset, int whence) | |
181 | { | |
182 | switch (whence) { | |
183 | case SEEK_SET: case SEEK_CUR: | |
184 | return generic_file_llseek_size(file, offset, whence, | |
185 | ~0ULL, 0); | |
186 | default: | |
187 | return -EINVAL; | |
188 | } | |
189 | } | |
190 | EXPORT_SYMBOL(no_seek_end_llseek); | |
191 | ||
192 | /** | |
193 | * no_seek_end_llseek_size - llseek implementation for fixed-sized devices | |
194 | * @file: file structure to seek on | |
195 | * @offset: file offset to seek to | |
196 | * @whence: type of seek | |
197 | * @size: maximal offset allowed | |
198 | * | |
199 | */ | |
200 | loff_t no_seek_end_llseek_size(struct file *file, loff_t offset, int whence, loff_t size) | |
201 | { | |
202 | switch (whence) { | |
203 | case SEEK_SET: case SEEK_CUR: | |
204 | return generic_file_llseek_size(file, offset, whence, | |
205 | size, 0); | |
206 | default: | |
207 | return -EINVAL; | |
208 | } | |
209 | } | |
210 | EXPORT_SYMBOL(no_seek_end_llseek_size); | |
211 | ||
ae6afc3f B |
212 | /** |
213 | * noop_llseek - No Operation Performed llseek implementation | |
214 | * @file: file structure to seek on | |
215 | * @offset: file offset to seek to | |
965c8e59 | 216 | * @whence: type of seek |
ae6afc3f B |
217 | * |
218 | * This is an implementation of ->llseek useable for the rare special case when | |
219 | * userspace expects the seek to succeed but the (device) file is actually not | |
220 | * able to perform the seek. In this case you use noop_llseek() instead of | |
221 | * falling back to the default implementation of ->llseek. | |
222 | */ | |
965c8e59 | 223 | loff_t noop_llseek(struct file *file, loff_t offset, int whence) |
ae6afc3f B |
224 | { |
225 | return file->f_pos; | |
226 | } | |
227 | EXPORT_SYMBOL(noop_llseek); | |
228 | ||
965c8e59 | 229 | loff_t no_llseek(struct file *file, loff_t offset, int whence) |
1da177e4 LT |
230 | { |
231 | return -ESPIPE; | |
232 | } | |
233 | EXPORT_SYMBOL(no_llseek); | |
234 | ||
965c8e59 | 235 | loff_t default_llseek(struct file *file, loff_t offset, int whence) |
1da177e4 | 236 | { |
496ad9aa | 237 | struct inode *inode = file_inode(file); |
16abef0e | 238 | loff_t retval; |
1da177e4 | 239 | |
982d8165 | 240 | mutex_lock(&inode->i_mutex); |
965c8e59 | 241 | switch (whence) { |
7b8e8924 | 242 | case SEEK_END: |
982d8165 | 243 | offset += i_size_read(inode); |
1da177e4 | 244 | break; |
7b8e8924 | 245 | case SEEK_CUR: |
5b6f1eb9 AK |
246 | if (offset == 0) { |
247 | retval = file->f_pos; | |
248 | goto out; | |
249 | } | |
1da177e4 | 250 | offset += file->f_pos; |
982d8165 JB |
251 | break; |
252 | case SEEK_DATA: | |
253 | /* | |
254 | * In the generic case the entire file is data, so as | |
255 | * long as offset isn't at the end of the file then the | |
256 | * offset is data. | |
257 | */ | |
bacb2d81 DC |
258 | if (offset >= inode->i_size) { |
259 | retval = -ENXIO; | |
260 | goto out; | |
261 | } | |
982d8165 JB |
262 | break; |
263 | case SEEK_HOLE: | |
264 | /* | |
265 | * There is a virtual hole at the end of the file, so | |
266 | * as long as offset isn't i_size or larger, return | |
267 | * i_size. | |
268 | */ | |
bacb2d81 DC |
269 | if (offset >= inode->i_size) { |
270 | retval = -ENXIO; | |
271 | goto out; | |
272 | } | |
982d8165 JB |
273 | offset = inode->i_size; |
274 | break; | |
1da177e4 LT |
275 | } |
276 | retval = -EINVAL; | |
cccb5a1e | 277 | if (offset >= 0 || unsigned_offsets(file)) { |
1da177e4 LT |
278 | if (offset != file->f_pos) { |
279 | file->f_pos = offset; | |
280 | file->f_version = 0; | |
281 | } | |
282 | retval = offset; | |
283 | } | |
5b6f1eb9 | 284 | out: |
982d8165 | 285 | mutex_unlock(&inode->i_mutex); |
1da177e4 LT |
286 | return retval; |
287 | } | |
288 | EXPORT_SYMBOL(default_llseek); | |
289 | ||
965c8e59 | 290 | loff_t vfs_llseek(struct file *file, loff_t offset, int whence) |
1da177e4 LT |
291 | { |
292 | loff_t (*fn)(struct file *, loff_t, int); | |
293 | ||
294 | fn = no_llseek; | |
295 | if (file->f_mode & FMODE_LSEEK) { | |
72c2d531 | 296 | if (file->f_op->llseek) |
1da177e4 LT |
297 | fn = file->f_op->llseek; |
298 | } | |
965c8e59 | 299 | return fn(file, offset, whence); |
1da177e4 LT |
300 | } |
301 | EXPORT_SYMBOL(vfs_llseek); | |
302 | ||
9c225f26 LT |
303 | static inline struct fd fdget_pos(int fd) |
304 | { | |
bd2a31d5 | 305 | return __to_fd(__fdget_pos(fd)); |
9c225f26 LT |
306 | } |
307 | ||
308 | static inline void fdput_pos(struct fd f) | |
309 | { | |
310 | if (f.flags & FDPUT_POS_UNLOCK) | |
311 | mutex_unlock(&f.file->f_pos_lock); | |
312 | fdput(f); | |
313 | } | |
314 | ||
965c8e59 | 315 | SYSCALL_DEFINE3(lseek, unsigned int, fd, off_t, offset, unsigned int, whence) |
1da177e4 LT |
316 | { |
317 | off_t retval; | |
9c225f26 | 318 | struct fd f = fdget_pos(fd); |
2903ff01 AV |
319 | if (!f.file) |
320 | return -EBADF; | |
1da177e4 LT |
321 | |
322 | retval = -EINVAL; | |
965c8e59 AM |
323 | if (whence <= SEEK_MAX) { |
324 | loff_t res = vfs_llseek(f.file, offset, whence); | |
1da177e4 LT |
325 | retval = res; |
326 | if (res != (loff_t)retval) | |
327 | retval = -EOVERFLOW; /* LFS: should only happen on 32 bit platforms */ | |
328 | } | |
9c225f26 | 329 | fdput_pos(f); |
1da177e4 LT |
330 | return retval; |
331 | } | |
332 | ||
561c6731 AV |
333 | #ifdef CONFIG_COMPAT |
334 | COMPAT_SYSCALL_DEFINE3(lseek, unsigned int, fd, compat_off_t, offset, unsigned int, whence) | |
335 | { | |
336 | return sys_lseek(fd, offset, whence); | |
337 | } | |
338 | #endif | |
339 | ||
1da177e4 | 340 | #ifdef __ARCH_WANT_SYS_LLSEEK |
003d7ab4 HC |
341 | SYSCALL_DEFINE5(llseek, unsigned int, fd, unsigned long, offset_high, |
342 | unsigned long, offset_low, loff_t __user *, result, | |
965c8e59 | 343 | unsigned int, whence) |
1da177e4 LT |
344 | { |
345 | int retval; | |
d7a15f8d | 346 | struct fd f = fdget_pos(fd); |
1da177e4 | 347 | loff_t offset; |
1da177e4 | 348 | |
2903ff01 AV |
349 | if (!f.file) |
350 | return -EBADF; | |
1da177e4 LT |
351 | |
352 | retval = -EINVAL; | |
965c8e59 | 353 | if (whence > SEEK_MAX) |
1da177e4 LT |
354 | goto out_putf; |
355 | ||
2903ff01 | 356 | offset = vfs_llseek(f.file, ((loff_t) offset_high << 32) | offset_low, |
965c8e59 | 357 | whence); |
1da177e4 LT |
358 | |
359 | retval = (int)offset; | |
360 | if (offset >= 0) { | |
361 | retval = -EFAULT; | |
362 | if (!copy_to_user(result, &offset, sizeof(offset))) | |
363 | retval = 0; | |
364 | } | |
365 | out_putf: | |
d7a15f8d | 366 | fdput_pos(f); |
1da177e4 LT |
367 | return retval; |
368 | } | |
369 | #endif | |
370 | ||
dbe4e192 CH |
371 | ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos) |
372 | { | |
373 | struct kiocb kiocb; | |
374 | ssize_t ret; | |
375 | ||
376 | if (!file->f_op->read_iter) | |
377 | return -EINVAL; | |
378 | ||
379 | init_sync_kiocb(&kiocb, file); | |
380 | kiocb.ki_pos = *ppos; | |
dbe4e192 CH |
381 | |
382 | iter->type |= READ; | |
383 | ret = file->f_op->read_iter(&kiocb, iter); | |
599bd19b | 384 | BUG_ON(ret == -EIOCBQUEUED); |
dbe4e192 CH |
385 | if (ret > 0) |
386 | *ppos = kiocb.ki_pos; | |
387 | return ret; | |
388 | } | |
389 | EXPORT_SYMBOL(vfs_iter_read); | |
390 | ||
391 | ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos) | |
392 | { | |
393 | struct kiocb kiocb; | |
394 | ssize_t ret; | |
395 | ||
396 | if (!file->f_op->write_iter) | |
397 | return -EINVAL; | |
398 | ||
399 | init_sync_kiocb(&kiocb, file); | |
400 | kiocb.ki_pos = *ppos; | |
dbe4e192 CH |
401 | |
402 | iter->type |= WRITE; | |
403 | ret = file->f_op->write_iter(&kiocb, iter); | |
599bd19b | 404 | BUG_ON(ret == -EIOCBQUEUED); |
dbe4e192 CH |
405 | if (ret > 0) |
406 | *ppos = kiocb.ki_pos; | |
407 | return ret; | |
408 | } | |
409 | EXPORT_SYMBOL(vfs_iter_write); | |
410 | ||
e28cc715 LT |
411 | /* |
412 | * rw_verify_area doesn't like huge counts. We limit | |
413 | * them to something that fits in "int" so that others | |
414 | * won't have to do range checks all the time. | |
415 | */ | |
68d70d03 | 416 | int rw_verify_area(int read_write, struct file *file, const loff_t *ppos, size_t count) |
1da177e4 LT |
417 | { |
418 | struct inode *inode; | |
419 | loff_t pos; | |
c43e259c | 420 | int retval = -EINVAL; |
1da177e4 | 421 | |
496ad9aa | 422 | inode = file_inode(file); |
e28cc715 | 423 | if (unlikely((ssize_t) count < 0)) |
c43e259c | 424 | return retval; |
1da177e4 | 425 | pos = *ppos; |
cccb5a1e AV |
426 | if (unlikely(pos < 0)) { |
427 | if (!unsigned_offsets(file)) | |
428 | return retval; | |
429 | if (count >= -pos) /* both values are in 0..LLONG_MAX */ | |
430 | return -EOVERFLOW; | |
431 | } else if (unlikely((loff_t) (pos + count) < 0)) { | |
432 | if (!unsigned_offsets(file)) | |
4a3956c7 KH |
433 | return retval; |
434 | } | |
1da177e4 | 435 | |
bd61e0a9 | 436 | if (unlikely(inode->i_flctx && mandatory_lock(inode))) { |
c43e259c | 437 | retval = locks_mandatory_area( |
e28cc715 LT |
438 | read_write == READ ? FLOCK_VERIFY_READ : FLOCK_VERIFY_WRITE, |
439 | inode, file, pos, count); | |
440 | if (retval < 0) | |
441 | return retval; | |
442 | } | |
c43e259c JM |
443 | retval = security_file_permission(file, |
444 | read_write == READ ? MAY_READ : MAY_WRITE); | |
445 | if (retval) | |
446 | return retval; | |
e28cc715 | 447 | return count > MAX_RW_COUNT ? MAX_RW_COUNT : count; |
1da177e4 LT |
448 | } |
449 | ||
5d5d5689 | 450 | static ssize_t new_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos) |
293bc982 AV |
451 | { |
452 | struct iovec iov = { .iov_base = buf, .iov_len = len }; | |
453 | struct kiocb kiocb; | |
454 | struct iov_iter iter; | |
455 | ssize_t ret; | |
456 | ||
457 | init_sync_kiocb(&kiocb, filp); | |
458 | kiocb.ki_pos = *ppos; | |
293bc982 AV |
459 | iov_iter_init(&iter, READ, &iov, 1, len); |
460 | ||
461 | ret = filp->f_op->read_iter(&kiocb, &iter); | |
599bd19b | 462 | BUG_ON(ret == -EIOCBQUEUED); |
293bc982 AV |
463 | *ppos = kiocb.ki_pos; |
464 | return ret; | |
465 | } | |
466 | ||
6fb5032e DK |
467 | ssize_t __vfs_read(struct file *file, char __user *buf, size_t count, |
468 | loff_t *pos) | |
469 | { | |
6fb5032e | 470 | if (file->f_op->read) |
3d04c8a1 | 471 | return file->f_op->read(file, buf, count, pos); |
6fb5032e | 472 | else if (file->f_op->read_iter) |
3d04c8a1 | 473 | return new_sync_read(file, buf, count, pos); |
6fb5032e | 474 | else |
3d04c8a1 | 475 | return -EINVAL; |
6fb5032e | 476 | } |
3d04c8a1 | 477 | EXPORT_SYMBOL(__vfs_read); |
6fb5032e | 478 | |
1da177e4 LT |
479 | ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos) |
480 | { | |
481 | ssize_t ret; | |
482 | ||
483 | if (!(file->f_mode & FMODE_READ)) | |
484 | return -EBADF; | |
7f7f25e8 | 485 | if (!(file->f_mode & FMODE_CAN_READ)) |
1da177e4 LT |
486 | return -EINVAL; |
487 | if (unlikely(!access_ok(VERIFY_WRITE, buf, count))) | |
488 | return -EFAULT; | |
489 | ||
490 | ret = rw_verify_area(READ, file, pos, count); | |
e28cc715 LT |
491 | if (ret >= 0) { |
492 | count = ret; | |
6fb5032e | 493 | ret = __vfs_read(file, buf, count, pos); |
c43e259c | 494 | if (ret > 0) { |
2a12a9d7 | 495 | fsnotify_access(file); |
c43e259c | 496 | add_rchar(current, ret); |
1da177e4 | 497 | } |
c43e259c | 498 | inc_syscr(current); |
1da177e4 LT |
499 | } |
500 | ||
501 | return ret; | |
502 | } | |
503 | ||
504 | EXPORT_SYMBOL(vfs_read); | |
505 | ||
5d5d5689 | 506 | static ssize_t new_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos) |
293bc982 AV |
507 | { |
508 | struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = len }; | |
509 | struct kiocb kiocb; | |
510 | struct iov_iter iter; | |
511 | ssize_t ret; | |
512 | ||
513 | init_sync_kiocb(&kiocb, filp); | |
514 | kiocb.ki_pos = *ppos; | |
293bc982 AV |
515 | iov_iter_init(&iter, WRITE, &iov, 1, len); |
516 | ||
517 | ret = filp->f_op->write_iter(&kiocb, &iter); | |
599bd19b | 518 | BUG_ON(ret == -EIOCBQUEUED); |
f765b134 AV |
519 | if (ret > 0) |
520 | *ppos = kiocb.ki_pos; | |
293bc982 AV |
521 | return ret; |
522 | } | |
523 | ||
493c84c0 AV |
524 | ssize_t __vfs_write(struct file *file, const char __user *p, size_t count, |
525 | loff_t *pos) | |
526 | { | |
527 | if (file->f_op->write) | |
528 | return file->f_op->write(file, p, count, pos); | |
493c84c0 AV |
529 | else if (file->f_op->write_iter) |
530 | return new_sync_write(file, p, count, pos); | |
531 | else | |
532 | return -EINVAL; | |
533 | } | |
534 | EXPORT_SYMBOL(__vfs_write); | |
535 | ||
06ae43f3 AV |
536 | ssize_t __kernel_write(struct file *file, const char *buf, size_t count, loff_t *pos) |
537 | { | |
538 | mm_segment_t old_fs; | |
539 | const char __user *p; | |
540 | ssize_t ret; | |
541 | ||
7f7f25e8 | 542 | if (!(file->f_mode & FMODE_CAN_WRITE)) |
3e84f48e AV |
543 | return -EINVAL; |
544 | ||
06ae43f3 AV |
545 | old_fs = get_fs(); |
546 | set_fs(get_ds()); | |
547 | p = (__force const char __user *)buf; | |
548 | if (count > MAX_RW_COUNT) | |
549 | count = MAX_RW_COUNT; | |
493c84c0 | 550 | ret = __vfs_write(file, p, count, pos); |
06ae43f3 AV |
551 | set_fs(old_fs); |
552 | if (ret > 0) { | |
553 | fsnotify_modify(file); | |
554 | add_wchar(current, ret); | |
555 | } | |
556 | inc_syscw(current); | |
557 | return ret; | |
558 | } | |
559 | ||
2ec3a12a AV |
560 | EXPORT_SYMBOL(__kernel_write); |
561 | ||
1da177e4 LT |
562 | ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_t *pos) |
563 | { | |
564 | ssize_t ret; | |
565 | ||
566 | if (!(file->f_mode & FMODE_WRITE)) | |
567 | return -EBADF; | |
7f7f25e8 | 568 | if (!(file->f_mode & FMODE_CAN_WRITE)) |
1da177e4 LT |
569 | return -EINVAL; |
570 | if (unlikely(!access_ok(VERIFY_READ, buf, count))) | |
571 | return -EFAULT; | |
572 | ||
573 | ret = rw_verify_area(WRITE, file, pos, count); | |
e28cc715 LT |
574 | if (ret >= 0) { |
575 | count = ret; | |
03d95eb2 | 576 | file_start_write(file); |
493c84c0 | 577 | ret = __vfs_write(file, buf, count, pos); |
c43e259c | 578 | if (ret > 0) { |
2a12a9d7 | 579 | fsnotify_modify(file); |
c43e259c | 580 | add_wchar(current, ret); |
1da177e4 | 581 | } |
c43e259c | 582 | inc_syscw(current); |
03d95eb2 | 583 | file_end_write(file); |
1da177e4 LT |
584 | } |
585 | ||
586 | return ret; | |
587 | } | |
588 | ||
589 | EXPORT_SYMBOL(vfs_write); | |
590 | ||
591 | static inline loff_t file_pos_read(struct file *file) | |
592 | { | |
593 | return file->f_pos; | |
594 | } | |
595 | ||
596 | static inline void file_pos_write(struct file *file, loff_t pos) | |
597 | { | |
598 | file->f_pos = pos; | |
599 | } | |
600 | ||
3cdad428 | 601 | SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count) |
1da177e4 | 602 | { |
9c225f26 | 603 | struct fd f = fdget_pos(fd); |
1da177e4 | 604 | ssize_t ret = -EBADF; |
1da177e4 | 605 | |
2903ff01 AV |
606 | if (f.file) { |
607 | loff_t pos = file_pos_read(f.file); | |
608 | ret = vfs_read(f.file, buf, count, &pos); | |
5faf153e AV |
609 | if (ret >= 0) |
610 | file_pos_write(f.file, pos); | |
9c225f26 | 611 | fdput_pos(f); |
1da177e4 | 612 | } |
1da177e4 LT |
613 | return ret; |
614 | } | |
1da177e4 | 615 | |
3cdad428 HC |
616 | SYSCALL_DEFINE3(write, unsigned int, fd, const char __user *, buf, |
617 | size_t, count) | |
1da177e4 | 618 | { |
9c225f26 | 619 | struct fd f = fdget_pos(fd); |
1da177e4 | 620 | ssize_t ret = -EBADF; |
1da177e4 | 621 | |
2903ff01 AV |
622 | if (f.file) { |
623 | loff_t pos = file_pos_read(f.file); | |
624 | ret = vfs_write(f.file, buf, count, &pos); | |
5faf153e AV |
625 | if (ret >= 0) |
626 | file_pos_write(f.file, pos); | |
9c225f26 | 627 | fdput_pos(f); |
1da177e4 LT |
628 | } |
629 | ||
630 | return ret; | |
631 | } | |
632 | ||
4a0fd5bf AV |
633 | SYSCALL_DEFINE4(pread64, unsigned int, fd, char __user *, buf, |
634 | size_t, count, loff_t, pos) | |
1da177e4 | 635 | { |
2903ff01 | 636 | struct fd f; |
1da177e4 | 637 | ssize_t ret = -EBADF; |
1da177e4 LT |
638 | |
639 | if (pos < 0) | |
640 | return -EINVAL; | |
641 | ||
2903ff01 AV |
642 | f = fdget(fd); |
643 | if (f.file) { | |
1da177e4 | 644 | ret = -ESPIPE; |
2903ff01 AV |
645 | if (f.file->f_mode & FMODE_PREAD) |
646 | ret = vfs_read(f.file, buf, count, &pos); | |
647 | fdput(f); | |
1da177e4 LT |
648 | } |
649 | ||
650 | return ret; | |
651 | } | |
652 | ||
4a0fd5bf AV |
653 | SYSCALL_DEFINE4(pwrite64, unsigned int, fd, const char __user *, buf, |
654 | size_t, count, loff_t, pos) | |
1da177e4 | 655 | { |
2903ff01 | 656 | struct fd f; |
1da177e4 | 657 | ssize_t ret = -EBADF; |
1da177e4 LT |
658 | |
659 | if (pos < 0) | |
660 | return -EINVAL; | |
661 | ||
2903ff01 AV |
662 | f = fdget(fd); |
663 | if (f.file) { | |
1da177e4 | 664 | ret = -ESPIPE; |
2903ff01 AV |
665 | if (f.file->f_mode & FMODE_PWRITE) |
666 | ret = vfs_write(f.file, buf, count, &pos); | |
667 | fdput(f); | |
1da177e4 LT |
668 | } |
669 | ||
670 | return ret; | |
671 | } | |
672 | ||
673 | /* | |
674 | * Reduce an iovec's length in-place. Return the resulting number of segments | |
675 | */ | |
676 | unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to) | |
677 | { | |
678 | unsigned long seg = 0; | |
679 | size_t len = 0; | |
680 | ||
681 | while (seg < nr_segs) { | |
682 | seg++; | |
683 | if (len + iov->iov_len >= to) { | |
684 | iov->iov_len = to - len; | |
685 | break; | |
686 | } | |
687 | len += iov->iov_len; | |
688 | iov++; | |
689 | } | |
690 | return seg; | |
691 | } | |
19295529 | 692 | EXPORT_SYMBOL(iov_shorten); |
1da177e4 | 693 | |
ac15ac06 AV |
694 | static ssize_t do_iter_readv_writev(struct file *filp, struct iov_iter *iter, |
695 | loff_t *ppos, iter_fn_t fn) | |
293bc982 AV |
696 | { |
697 | struct kiocb kiocb; | |
293bc982 AV |
698 | ssize_t ret; |
699 | ||
700 | init_sync_kiocb(&kiocb, filp); | |
701 | kiocb.ki_pos = *ppos; | |
293bc982 | 702 | |
ac15ac06 | 703 | ret = fn(&kiocb, iter); |
599bd19b | 704 | BUG_ON(ret == -EIOCBQUEUED); |
293bc982 AV |
705 | *ppos = kiocb.ki_pos; |
706 | return ret; | |
707 | } | |
708 | ||
ee0b3e67 | 709 | /* Do it by hand, with file-ops */ |
ac15ac06 AV |
710 | static ssize_t do_loop_readv_writev(struct file *filp, struct iov_iter *iter, |
711 | loff_t *ppos, io_fn_t fn) | |
ee0b3e67 | 712 | { |
ee0b3e67 BP |
713 | ssize_t ret = 0; |
714 | ||
ac15ac06 AV |
715 | while (iov_iter_count(iter)) { |
716 | struct iovec iovec = iov_iter_iovec(iter); | |
ee0b3e67 BP |
717 | ssize_t nr; |
718 | ||
ac15ac06 | 719 | nr = fn(filp, iovec.iov_base, iovec.iov_len, ppos); |
ee0b3e67 BP |
720 | |
721 | if (nr < 0) { | |
722 | if (!ret) | |
723 | ret = nr; | |
724 | break; | |
725 | } | |
726 | ret += nr; | |
ac15ac06 | 727 | if (nr != iovec.iov_len) |
ee0b3e67 | 728 | break; |
ac15ac06 | 729 | iov_iter_advance(iter, nr); |
ee0b3e67 BP |
730 | } |
731 | ||
732 | return ret; | |
733 | } | |
734 | ||
1da177e4 LT |
735 | /* A write operation does a read from user space and vice versa */ |
736 | #define vrfy_dir(type) ((type) == READ ? VERIFY_WRITE : VERIFY_READ) | |
737 | ||
eed4e51f BP |
738 | ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector, |
739 | unsigned long nr_segs, unsigned long fast_segs, | |
740 | struct iovec *fast_pointer, | |
ac34ebb3 | 741 | struct iovec **ret_pointer) |
435f49a5 | 742 | { |
eed4e51f | 743 | unsigned long seg; |
435f49a5 | 744 | ssize_t ret; |
eed4e51f BP |
745 | struct iovec *iov = fast_pointer; |
746 | ||
435f49a5 LT |
747 | /* |
748 | * SuS says "The readv() function *may* fail if the iovcnt argument | |
749 | * was less than or equal to 0, or greater than {IOV_MAX}. Linux has | |
750 | * traditionally returned zero for zero segments, so... | |
751 | */ | |
eed4e51f BP |
752 | if (nr_segs == 0) { |
753 | ret = 0; | |
435f49a5 | 754 | goto out; |
eed4e51f BP |
755 | } |
756 | ||
435f49a5 LT |
757 | /* |
758 | * First get the "struct iovec" from user memory and | |
759 | * verify all the pointers | |
760 | */ | |
eed4e51f BP |
761 | if (nr_segs > UIO_MAXIOV) { |
762 | ret = -EINVAL; | |
435f49a5 | 763 | goto out; |
eed4e51f BP |
764 | } |
765 | if (nr_segs > fast_segs) { | |
435f49a5 | 766 | iov = kmalloc(nr_segs*sizeof(struct iovec), GFP_KERNEL); |
eed4e51f BP |
767 | if (iov == NULL) { |
768 | ret = -ENOMEM; | |
435f49a5 | 769 | goto out; |
eed4e51f | 770 | } |
435f49a5 | 771 | } |
eed4e51f BP |
772 | if (copy_from_user(iov, uvector, nr_segs*sizeof(*uvector))) { |
773 | ret = -EFAULT; | |
435f49a5 | 774 | goto out; |
eed4e51f BP |
775 | } |
776 | ||
435f49a5 | 777 | /* |
eed4e51f BP |
778 | * According to the Single Unix Specification we should return EINVAL |
779 | * if an element length is < 0 when cast to ssize_t or if the | |
780 | * total length would overflow the ssize_t return value of the | |
781 | * system call. | |
435f49a5 LT |
782 | * |
783 | * Linux caps all read/write calls to MAX_RW_COUNT, and avoids the | |
784 | * overflow case. | |
785 | */ | |
eed4e51f | 786 | ret = 0; |
435f49a5 LT |
787 | for (seg = 0; seg < nr_segs; seg++) { |
788 | void __user *buf = iov[seg].iov_base; | |
789 | ssize_t len = (ssize_t)iov[seg].iov_len; | |
eed4e51f BP |
790 | |
791 | /* see if we we're about to use an invalid len or if | |
792 | * it's about to overflow ssize_t */ | |
435f49a5 | 793 | if (len < 0) { |
eed4e51f | 794 | ret = -EINVAL; |
435f49a5 | 795 | goto out; |
eed4e51f | 796 | } |
ac34ebb3 | 797 | if (type >= 0 |
fcf63409 | 798 | && unlikely(!access_ok(vrfy_dir(type), buf, len))) { |
eed4e51f | 799 | ret = -EFAULT; |
435f49a5 LT |
800 | goto out; |
801 | } | |
802 | if (len > MAX_RW_COUNT - ret) { | |
803 | len = MAX_RW_COUNT - ret; | |
804 | iov[seg].iov_len = len; | |
eed4e51f | 805 | } |
eed4e51f | 806 | ret += len; |
435f49a5 | 807 | } |
eed4e51f BP |
808 | out: |
809 | *ret_pointer = iov; | |
810 | return ret; | |
811 | } | |
812 | ||
1da177e4 LT |
813 | static ssize_t do_readv_writev(int type, struct file *file, |
814 | const struct iovec __user * uvector, | |
815 | unsigned long nr_segs, loff_t *pos) | |
816 | { | |
1da177e4 LT |
817 | size_t tot_len; |
818 | struct iovec iovstack[UIO_FASTIOV]; | |
ee0b3e67 | 819 | struct iovec *iov = iovstack; |
ac15ac06 | 820 | struct iov_iter iter; |
1da177e4 | 821 | ssize_t ret; |
1da177e4 | 822 | io_fn_t fn; |
293bc982 | 823 | iter_fn_t iter_fn; |
1da177e4 | 824 | |
0504c074 AV |
825 | ret = import_iovec(type, uvector, nr_segs, |
826 | ARRAY_SIZE(iovstack), &iov, &iter); | |
827 | if (ret < 0) | |
828 | return ret; | |
1da177e4 | 829 | |
0504c074 AV |
830 | tot_len = iov_iter_count(&iter); |
831 | if (!tot_len) | |
832 | goto out; | |
1da177e4 | 833 | ret = rw_verify_area(type, file, pos, tot_len); |
e28cc715 | 834 | if (ret < 0) |
411b67b4 | 835 | goto out; |
1da177e4 | 836 | |
1da177e4 LT |
837 | if (type == READ) { |
838 | fn = file->f_op->read; | |
293bc982 | 839 | iter_fn = file->f_op->read_iter; |
1da177e4 LT |
840 | } else { |
841 | fn = (io_fn_t)file->f_op->write; | |
293bc982 | 842 | iter_fn = file->f_op->write_iter; |
03d95eb2 | 843 | file_start_write(file); |
1da177e4 LT |
844 | } |
845 | ||
293bc982 | 846 | if (iter_fn) |
ac15ac06 | 847 | ret = do_iter_readv_writev(file, &iter, pos, iter_fn); |
ee0b3e67 | 848 | else |
ac15ac06 | 849 | ret = do_loop_readv_writev(file, &iter, pos, fn); |
1da177e4 | 850 | |
03d95eb2 AV |
851 | if (type != READ) |
852 | file_end_write(file); | |
853 | ||
1da177e4 | 854 | out: |
0504c074 | 855 | kfree(iov); |
0eeca283 RL |
856 | if ((ret + (type == READ)) > 0) { |
857 | if (type == READ) | |
2a12a9d7 | 858 | fsnotify_access(file); |
0eeca283 | 859 | else |
2a12a9d7 | 860 | fsnotify_modify(file); |
0eeca283 | 861 | } |
1da177e4 | 862 | return ret; |
1da177e4 LT |
863 | } |
864 | ||
865 | ssize_t vfs_readv(struct file *file, const struct iovec __user *vec, | |
866 | unsigned long vlen, loff_t *pos) | |
867 | { | |
868 | if (!(file->f_mode & FMODE_READ)) | |
869 | return -EBADF; | |
7f7f25e8 | 870 | if (!(file->f_mode & FMODE_CAN_READ)) |
1da177e4 LT |
871 | return -EINVAL; |
872 | ||
873 | return do_readv_writev(READ, file, vec, vlen, pos); | |
874 | } | |
875 | ||
876 | EXPORT_SYMBOL(vfs_readv); | |
877 | ||
878 | ssize_t vfs_writev(struct file *file, const struct iovec __user *vec, | |
879 | unsigned long vlen, loff_t *pos) | |
880 | { | |
881 | if (!(file->f_mode & FMODE_WRITE)) | |
882 | return -EBADF; | |
7f7f25e8 | 883 | if (!(file->f_mode & FMODE_CAN_WRITE)) |
1da177e4 LT |
884 | return -EINVAL; |
885 | ||
886 | return do_readv_writev(WRITE, file, vec, vlen, pos); | |
887 | } | |
888 | ||
889 | EXPORT_SYMBOL(vfs_writev); | |
890 | ||
3cdad428 HC |
891 | SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec, |
892 | unsigned long, vlen) | |
1da177e4 | 893 | { |
9c225f26 | 894 | struct fd f = fdget_pos(fd); |
1da177e4 | 895 | ssize_t ret = -EBADF; |
1da177e4 | 896 | |
2903ff01 AV |
897 | if (f.file) { |
898 | loff_t pos = file_pos_read(f.file); | |
899 | ret = vfs_readv(f.file, vec, vlen, &pos); | |
5faf153e AV |
900 | if (ret >= 0) |
901 | file_pos_write(f.file, pos); | |
9c225f26 | 902 | fdput_pos(f); |
1da177e4 LT |
903 | } |
904 | ||
905 | if (ret > 0) | |
4b98d11b AD |
906 | add_rchar(current, ret); |
907 | inc_syscr(current); | |
1da177e4 LT |
908 | return ret; |
909 | } | |
910 | ||
3cdad428 HC |
911 | SYSCALL_DEFINE3(writev, unsigned long, fd, const struct iovec __user *, vec, |
912 | unsigned long, vlen) | |
1da177e4 | 913 | { |
9c225f26 | 914 | struct fd f = fdget_pos(fd); |
1da177e4 | 915 | ssize_t ret = -EBADF; |
1da177e4 | 916 | |
2903ff01 AV |
917 | if (f.file) { |
918 | loff_t pos = file_pos_read(f.file); | |
919 | ret = vfs_writev(f.file, vec, vlen, &pos); | |
5faf153e AV |
920 | if (ret >= 0) |
921 | file_pos_write(f.file, pos); | |
9c225f26 | 922 | fdput_pos(f); |
1da177e4 LT |
923 | } |
924 | ||
925 | if (ret > 0) | |
4b98d11b AD |
926 | add_wchar(current, ret); |
927 | inc_syscw(current); | |
1da177e4 LT |
928 | return ret; |
929 | } | |
930 | ||
601cc11d LT |
931 | static inline loff_t pos_from_hilo(unsigned long high, unsigned long low) |
932 | { | |
933 | #define HALF_LONG_BITS (BITS_PER_LONG / 2) | |
934 | return (((loff_t)high << HALF_LONG_BITS) << HALF_LONG_BITS) | low; | |
935 | } | |
936 | ||
f3554f4b | 937 | SYSCALL_DEFINE5(preadv, unsigned long, fd, const struct iovec __user *, vec, |
601cc11d | 938 | unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h) |
f3554f4b | 939 | { |
601cc11d | 940 | loff_t pos = pos_from_hilo(pos_h, pos_l); |
2903ff01 | 941 | struct fd f; |
f3554f4b | 942 | ssize_t ret = -EBADF; |
f3554f4b GH |
943 | |
944 | if (pos < 0) | |
945 | return -EINVAL; | |
946 | ||
2903ff01 AV |
947 | f = fdget(fd); |
948 | if (f.file) { | |
f3554f4b | 949 | ret = -ESPIPE; |
2903ff01 AV |
950 | if (f.file->f_mode & FMODE_PREAD) |
951 | ret = vfs_readv(f.file, vec, vlen, &pos); | |
952 | fdput(f); | |
f3554f4b GH |
953 | } |
954 | ||
955 | if (ret > 0) | |
956 | add_rchar(current, ret); | |
957 | inc_syscr(current); | |
958 | return ret; | |
959 | } | |
960 | ||
961 | SYSCALL_DEFINE5(pwritev, unsigned long, fd, const struct iovec __user *, vec, | |
601cc11d | 962 | unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h) |
f3554f4b | 963 | { |
601cc11d | 964 | loff_t pos = pos_from_hilo(pos_h, pos_l); |
2903ff01 | 965 | struct fd f; |
f3554f4b | 966 | ssize_t ret = -EBADF; |
f3554f4b GH |
967 | |
968 | if (pos < 0) | |
969 | return -EINVAL; | |
970 | ||
2903ff01 AV |
971 | f = fdget(fd); |
972 | if (f.file) { | |
f3554f4b | 973 | ret = -ESPIPE; |
2903ff01 AV |
974 | if (f.file->f_mode & FMODE_PWRITE) |
975 | ret = vfs_writev(f.file, vec, vlen, &pos); | |
976 | fdput(f); | |
f3554f4b GH |
977 | } |
978 | ||
979 | if (ret > 0) | |
980 | add_wchar(current, ret); | |
981 | inc_syscw(current); | |
982 | return ret; | |
983 | } | |
984 | ||
72ec3516 AV |
985 | #ifdef CONFIG_COMPAT |
986 | ||
987 | static ssize_t compat_do_readv_writev(int type, struct file *file, | |
988 | const struct compat_iovec __user *uvector, | |
989 | unsigned long nr_segs, loff_t *pos) | |
990 | { | |
991 | compat_ssize_t tot_len; | |
992 | struct iovec iovstack[UIO_FASTIOV]; | |
993 | struct iovec *iov = iovstack; | |
ac15ac06 | 994 | struct iov_iter iter; |
72ec3516 AV |
995 | ssize_t ret; |
996 | io_fn_t fn; | |
293bc982 | 997 | iter_fn_t iter_fn; |
72ec3516 | 998 | |
0504c074 AV |
999 | ret = compat_import_iovec(type, uvector, nr_segs, |
1000 | UIO_FASTIOV, &iov, &iter); | |
1001 | if (ret < 0) | |
1002 | return ret; | |
72ec3516 | 1003 | |
0504c074 AV |
1004 | tot_len = iov_iter_count(&iter); |
1005 | if (!tot_len) | |
1006 | goto out; | |
72ec3516 AV |
1007 | ret = rw_verify_area(type, file, pos, tot_len); |
1008 | if (ret < 0) | |
1009 | goto out; | |
1010 | ||
72ec3516 AV |
1011 | if (type == READ) { |
1012 | fn = file->f_op->read; | |
293bc982 | 1013 | iter_fn = file->f_op->read_iter; |
72ec3516 AV |
1014 | } else { |
1015 | fn = (io_fn_t)file->f_op->write; | |
293bc982 | 1016 | iter_fn = file->f_op->write_iter; |
03d95eb2 | 1017 | file_start_write(file); |
72ec3516 AV |
1018 | } |
1019 | ||
293bc982 | 1020 | if (iter_fn) |
ac15ac06 | 1021 | ret = do_iter_readv_writev(file, &iter, pos, iter_fn); |
03d95eb2 | 1022 | else |
ac15ac06 | 1023 | ret = do_loop_readv_writev(file, &iter, pos, fn); |
72ec3516 | 1024 | |
03d95eb2 AV |
1025 | if (type != READ) |
1026 | file_end_write(file); | |
1027 | ||
72ec3516 | 1028 | out: |
0504c074 | 1029 | kfree(iov); |
72ec3516 AV |
1030 | if ((ret + (type == READ)) > 0) { |
1031 | if (type == READ) | |
1032 | fsnotify_access(file); | |
1033 | else | |
1034 | fsnotify_modify(file); | |
1035 | } | |
1036 | return ret; | |
1037 | } | |
1038 | ||
1039 | static size_t compat_readv(struct file *file, | |
1040 | const struct compat_iovec __user *vec, | |
1041 | unsigned long vlen, loff_t *pos) | |
1042 | { | |
1043 | ssize_t ret = -EBADF; | |
1044 | ||
1045 | if (!(file->f_mode & FMODE_READ)) | |
1046 | goto out; | |
1047 | ||
1048 | ret = -EINVAL; | |
7f7f25e8 | 1049 | if (!(file->f_mode & FMODE_CAN_READ)) |
72ec3516 AV |
1050 | goto out; |
1051 | ||
1052 | ret = compat_do_readv_writev(READ, file, vec, vlen, pos); | |
1053 | ||
1054 | out: | |
1055 | if (ret > 0) | |
1056 | add_rchar(current, ret); | |
1057 | inc_syscr(current); | |
1058 | return ret; | |
1059 | } | |
1060 | ||
dfd948e3 | 1061 | COMPAT_SYSCALL_DEFINE3(readv, compat_ulong_t, fd, |
72ec3516 | 1062 | const struct compat_iovec __user *,vec, |
dfd948e3 | 1063 | compat_ulong_t, vlen) |
72ec3516 | 1064 | { |
9c225f26 | 1065 | struct fd f = fdget_pos(fd); |
72ec3516 AV |
1066 | ssize_t ret; |
1067 | loff_t pos; | |
1068 | ||
1069 | if (!f.file) | |
1070 | return -EBADF; | |
1071 | pos = f.file->f_pos; | |
1072 | ret = compat_readv(f.file, vec, vlen, &pos); | |
5faf153e AV |
1073 | if (ret >= 0) |
1074 | f.file->f_pos = pos; | |
9c225f26 | 1075 | fdput_pos(f); |
72ec3516 AV |
1076 | return ret; |
1077 | } | |
1078 | ||
378a10f3 HC |
1079 | static long __compat_sys_preadv64(unsigned long fd, |
1080 | const struct compat_iovec __user *vec, | |
1081 | unsigned long vlen, loff_t pos) | |
72ec3516 AV |
1082 | { |
1083 | struct fd f; | |
1084 | ssize_t ret; | |
1085 | ||
1086 | if (pos < 0) | |
1087 | return -EINVAL; | |
1088 | f = fdget(fd); | |
1089 | if (!f.file) | |
1090 | return -EBADF; | |
1091 | ret = -ESPIPE; | |
1092 | if (f.file->f_mode & FMODE_PREAD) | |
1093 | ret = compat_readv(f.file, vec, vlen, &pos); | |
1094 | fdput(f); | |
1095 | return ret; | |
1096 | } | |
1097 | ||
378a10f3 HC |
1098 | #ifdef __ARCH_WANT_COMPAT_SYS_PREADV64 |
1099 | COMPAT_SYSCALL_DEFINE4(preadv64, unsigned long, fd, | |
1100 | const struct compat_iovec __user *,vec, | |
1101 | unsigned long, vlen, loff_t, pos) | |
1102 | { | |
1103 | return __compat_sys_preadv64(fd, vec, vlen, pos); | |
1104 | } | |
1105 | #endif | |
1106 | ||
dfd948e3 | 1107 | COMPAT_SYSCALL_DEFINE5(preadv, compat_ulong_t, fd, |
72ec3516 | 1108 | const struct compat_iovec __user *,vec, |
dfd948e3 | 1109 | compat_ulong_t, vlen, u32, pos_low, u32, pos_high) |
72ec3516 AV |
1110 | { |
1111 | loff_t pos = ((loff_t)pos_high << 32) | pos_low; | |
378a10f3 HC |
1112 | |
1113 | return __compat_sys_preadv64(fd, vec, vlen, pos); | |
72ec3516 AV |
1114 | } |
1115 | ||
1116 | static size_t compat_writev(struct file *file, | |
1117 | const struct compat_iovec __user *vec, | |
1118 | unsigned long vlen, loff_t *pos) | |
1119 | { | |
1120 | ssize_t ret = -EBADF; | |
1121 | ||
1122 | if (!(file->f_mode & FMODE_WRITE)) | |
1123 | goto out; | |
1124 | ||
1125 | ret = -EINVAL; | |
7f7f25e8 | 1126 | if (!(file->f_mode & FMODE_CAN_WRITE)) |
72ec3516 AV |
1127 | goto out; |
1128 | ||
1129 | ret = compat_do_readv_writev(WRITE, file, vec, vlen, pos); | |
1130 | ||
1131 | out: | |
1132 | if (ret > 0) | |
1133 | add_wchar(current, ret); | |
1134 | inc_syscw(current); | |
1135 | return ret; | |
1136 | } | |
1137 | ||
dfd948e3 | 1138 | COMPAT_SYSCALL_DEFINE3(writev, compat_ulong_t, fd, |
72ec3516 | 1139 | const struct compat_iovec __user *, vec, |
dfd948e3 | 1140 | compat_ulong_t, vlen) |
72ec3516 | 1141 | { |
9c225f26 | 1142 | struct fd f = fdget_pos(fd); |
72ec3516 AV |
1143 | ssize_t ret; |
1144 | loff_t pos; | |
1145 | ||
1146 | if (!f.file) | |
1147 | return -EBADF; | |
1148 | pos = f.file->f_pos; | |
1149 | ret = compat_writev(f.file, vec, vlen, &pos); | |
5faf153e AV |
1150 | if (ret >= 0) |
1151 | f.file->f_pos = pos; | |
9c225f26 | 1152 | fdput_pos(f); |
72ec3516 AV |
1153 | return ret; |
1154 | } | |
1155 | ||
378a10f3 HC |
1156 | static long __compat_sys_pwritev64(unsigned long fd, |
1157 | const struct compat_iovec __user *vec, | |
1158 | unsigned long vlen, loff_t pos) | |
72ec3516 AV |
1159 | { |
1160 | struct fd f; | |
1161 | ssize_t ret; | |
1162 | ||
1163 | if (pos < 0) | |
1164 | return -EINVAL; | |
1165 | f = fdget(fd); | |
1166 | if (!f.file) | |
1167 | return -EBADF; | |
1168 | ret = -ESPIPE; | |
1169 | if (f.file->f_mode & FMODE_PWRITE) | |
1170 | ret = compat_writev(f.file, vec, vlen, &pos); | |
1171 | fdput(f); | |
1172 | return ret; | |
1173 | } | |
1174 | ||
378a10f3 HC |
1175 | #ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64 |
1176 | COMPAT_SYSCALL_DEFINE4(pwritev64, unsigned long, fd, | |
1177 | const struct compat_iovec __user *,vec, | |
1178 | unsigned long, vlen, loff_t, pos) | |
1179 | { | |
1180 | return __compat_sys_pwritev64(fd, vec, vlen, pos); | |
1181 | } | |
1182 | #endif | |
1183 | ||
dfd948e3 | 1184 | COMPAT_SYSCALL_DEFINE5(pwritev, compat_ulong_t, fd, |
72ec3516 | 1185 | const struct compat_iovec __user *,vec, |
dfd948e3 | 1186 | compat_ulong_t, vlen, u32, pos_low, u32, pos_high) |
72ec3516 AV |
1187 | { |
1188 | loff_t pos = ((loff_t)pos_high << 32) | pos_low; | |
378a10f3 HC |
1189 | |
1190 | return __compat_sys_pwritev64(fd, vec, vlen, pos); | |
72ec3516 AV |
1191 | } |
1192 | #endif | |
1193 | ||
19f4fc3a AV |
1194 | static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, |
1195 | size_t count, loff_t max) | |
1da177e4 | 1196 | { |
2903ff01 AV |
1197 | struct fd in, out; |
1198 | struct inode *in_inode, *out_inode; | |
1da177e4 | 1199 | loff_t pos; |
7995bd28 | 1200 | loff_t out_pos; |
1da177e4 | 1201 | ssize_t retval; |
2903ff01 | 1202 | int fl; |
1da177e4 LT |
1203 | |
1204 | /* | |
1205 | * Get input file, and verify that it is ok.. | |
1206 | */ | |
1207 | retval = -EBADF; | |
2903ff01 AV |
1208 | in = fdget(in_fd); |
1209 | if (!in.file) | |
1da177e4 | 1210 | goto out; |
2903ff01 | 1211 | if (!(in.file->f_mode & FMODE_READ)) |
1da177e4 | 1212 | goto fput_in; |
1da177e4 | 1213 | retval = -ESPIPE; |
7995bd28 AV |
1214 | if (!ppos) { |
1215 | pos = in.file->f_pos; | |
1216 | } else { | |
1217 | pos = *ppos; | |
2903ff01 | 1218 | if (!(in.file->f_mode & FMODE_PREAD)) |
1da177e4 | 1219 | goto fput_in; |
7995bd28 AV |
1220 | } |
1221 | retval = rw_verify_area(READ, in.file, &pos, count); | |
e28cc715 | 1222 | if (retval < 0) |
1da177e4 | 1223 | goto fput_in; |
e28cc715 | 1224 | count = retval; |
1da177e4 | 1225 | |
1da177e4 LT |
1226 | /* |
1227 | * Get output file, and verify that it is ok.. | |
1228 | */ | |
1229 | retval = -EBADF; | |
2903ff01 AV |
1230 | out = fdget(out_fd); |
1231 | if (!out.file) | |
1da177e4 | 1232 | goto fput_in; |
2903ff01 | 1233 | if (!(out.file->f_mode & FMODE_WRITE)) |
1da177e4 LT |
1234 | goto fput_out; |
1235 | retval = -EINVAL; | |
496ad9aa AV |
1236 | in_inode = file_inode(in.file); |
1237 | out_inode = file_inode(out.file); | |
7995bd28 AV |
1238 | out_pos = out.file->f_pos; |
1239 | retval = rw_verify_area(WRITE, out.file, &out_pos, count); | |
e28cc715 | 1240 | if (retval < 0) |
1da177e4 | 1241 | goto fput_out; |
e28cc715 | 1242 | count = retval; |
1da177e4 | 1243 | |
1da177e4 LT |
1244 | if (!max) |
1245 | max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes); | |
1246 | ||
1da177e4 LT |
1247 | if (unlikely(pos + count > max)) { |
1248 | retval = -EOVERFLOW; | |
1249 | if (pos >= max) | |
1250 | goto fput_out; | |
1251 | count = max - pos; | |
1252 | } | |
1253 | ||
d96e6e71 | 1254 | fl = 0; |
534f2aaa | 1255 | #if 0 |
d96e6e71 JA |
1256 | /* |
1257 | * We need to debate whether we can enable this or not. The | |
1258 | * man page documents EAGAIN return for the output at least, | |
1259 | * and the application is arguably buggy if it doesn't expect | |
1260 | * EAGAIN on a non-blocking file descriptor. | |
1261 | */ | |
2903ff01 | 1262 | if (in.file->f_flags & O_NONBLOCK) |
d96e6e71 | 1263 | fl = SPLICE_F_NONBLOCK; |
534f2aaa | 1264 | #endif |
50cd2c57 | 1265 | file_start_write(out.file); |
7995bd28 | 1266 | retval = do_splice_direct(in.file, &pos, out.file, &out_pos, count, fl); |
50cd2c57 | 1267 | file_end_write(out.file); |
1da177e4 LT |
1268 | |
1269 | if (retval > 0) { | |
4b98d11b AD |
1270 | add_rchar(current, retval); |
1271 | add_wchar(current, retval); | |
a68c2f12 SW |
1272 | fsnotify_access(in.file); |
1273 | fsnotify_modify(out.file); | |
7995bd28 AV |
1274 | out.file->f_pos = out_pos; |
1275 | if (ppos) | |
1276 | *ppos = pos; | |
1277 | else | |
1278 | in.file->f_pos = pos; | |
1da177e4 | 1279 | } |
1da177e4 | 1280 | |
4b98d11b AD |
1281 | inc_syscr(current); |
1282 | inc_syscw(current); | |
7995bd28 | 1283 | if (pos > max) |
1da177e4 LT |
1284 | retval = -EOVERFLOW; |
1285 | ||
1286 | fput_out: | |
2903ff01 | 1287 | fdput(out); |
1da177e4 | 1288 | fput_in: |
2903ff01 | 1289 | fdput(in); |
1da177e4 LT |
1290 | out: |
1291 | return retval; | |
1292 | } | |
1293 | ||
002c8976 | 1294 | SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, off_t __user *, offset, size_t, count) |
1da177e4 LT |
1295 | { |
1296 | loff_t pos; | |
1297 | off_t off; | |
1298 | ssize_t ret; | |
1299 | ||
1300 | if (offset) { | |
1301 | if (unlikely(get_user(off, offset))) | |
1302 | return -EFAULT; | |
1303 | pos = off; | |
1304 | ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS); | |
1305 | if (unlikely(put_user(pos, offset))) | |
1306 | return -EFAULT; | |
1307 | return ret; | |
1308 | } | |
1309 | ||
1310 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1311 | } | |
1312 | ||
002c8976 | 1313 | SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, loff_t __user *, offset, size_t, count) |
1da177e4 LT |
1314 | { |
1315 | loff_t pos; | |
1316 | ssize_t ret; | |
1317 | ||
1318 | if (offset) { | |
1319 | if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t)))) | |
1320 | return -EFAULT; | |
1321 | ret = do_sendfile(out_fd, in_fd, &pos, count, 0); | |
1322 | if (unlikely(put_user(pos, offset))) | |
1323 | return -EFAULT; | |
1324 | return ret; | |
1325 | } | |
1326 | ||
1327 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1328 | } | |
19f4fc3a AV |
1329 | |
1330 | #ifdef CONFIG_COMPAT | |
1331 | COMPAT_SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, | |
1332 | compat_off_t __user *, offset, compat_size_t, count) | |
1333 | { | |
1334 | loff_t pos; | |
1335 | off_t off; | |
1336 | ssize_t ret; | |
1337 | ||
1338 | if (offset) { | |
1339 | if (unlikely(get_user(off, offset))) | |
1340 | return -EFAULT; | |
1341 | pos = off; | |
1342 | ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS); | |
1343 | if (unlikely(put_user(pos, offset))) | |
1344 | return -EFAULT; | |
1345 | return ret; | |
1346 | } | |
1347 | ||
1348 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1349 | } | |
1350 | ||
1351 | COMPAT_SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, | |
1352 | compat_loff_t __user *, offset, compat_size_t, count) | |
1353 | { | |
1354 | loff_t pos; | |
1355 | ssize_t ret; | |
1356 | ||
1357 | if (offset) { | |
1358 | if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t)))) | |
1359 | return -EFAULT; | |
1360 | ret = do_sendfile(out_fd, in_fd, &pos, count, 0); | |
1361 | if (unlikely(put_user(pos, offset))) | |
1362 | return -EFAULT; | |
1363 | return ret; | |
1364 | } | |
1365 | ||
1366 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1367 | } | |
1368 | #endif |