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Commit | Line | Data |
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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 | */ | |
10e98800 | 115 | if ((unsigned long long)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 | */ | |
10e98800 | 123 | if ((unsigned long long)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 | ||
ae6afc3f B |
173 | /** |
174 | * noop_llseek - No Operation Performed llseek implementation | |
175 | * @file: file structure to seek on | |
176 | * @offset: file offset to seek to | |
965c8e59 | 177 | * @whence: type of seek |
ae6afc3f B |
178 | * |
179 | * This is an implementation of ->llseek useable for the rare special case when | |
180 | * userspace expects the seek to succeed but the (device) file is actually not | |
181 | * able to perform the seek. In this case you use noop_llseek() instead of | |
182 | * falling back to the default implementation of ->llseek. | |
183 | */ | |
965c8e59 | 184 | loff_t noop_llseek(struct file *file, loff_t offset, int whence) |
ae6afc3f B |
185 | { |
186 | return file->f_pos; | |
187 | } | |
188 | EXPORT_SYMBOL(noop_llseek); | |
189 | ||
965c8e59 | 190 | loff_t no_llseek(struct file *file, loff_t offset, int whence) |
1da177e4 LT |
191 | { |
192 | return -ESPIPE; | |
193 | } | |
194 | EXPORT_SYMBOL(no_llseek); | |
195 | ||
965c8e59 | 196 | loff_t default_llseek(struct file *file, loff_t offset, int whence) |
1da177e4 | 197 | { |
496ad9aa | 198 | struct inode *inode = file_inode(file); |
16abef0e | 199 | loff_t retval; |
1da177e4 | 200 | |
982d8165 | 201 | mutex_lock(&inode->i_mutex); |
965c8e59 | 202 | switch (whence) { |
7b8e8924 | 203 | case SEEK_END: |
982d8165 | 204 | offset += i_size_read(inode); |
1da177e4 | 205 | break; |
7b8e8924 | 206 | case SEEK_CUR: |
5b6f1eb9 AK |
207 | if (offset == 0) { |
208 | retval = file->f_pos; | |
209 | goto out; | |
210 | } | |
1da177e4 | 211 | offset += file->f_pos; |
982d8165 JB |
212 | break; |
213 | case SEEK_DATA: | |
214 | /* | |
215 | * In the generic case the entire file is data, so as | |
216 | * long as offset isn't at the end of the file then the | |
217 | * offset is data. | |
218 | */ | |
bacb2d81 DC |
219 | if (offset >= inode->i_size) { |
220 | retval = -ENXIO; | |
221 | goto out; | |
222 | } | |
982d8165 JB |
223 | break; |
224 | case SEEK_HOLE: | |
225 | /* | |
226 | * There is a virtual hole at the end of the file, so | |
227 | * as long as offset isn't i_size or larger, return | |
228 | * i_size. | |
229 | */ | |
bacb2d81 DC |
230 | if (offset >= inode->i_size) { |
231 | retval = -ENXIO; | |
232 | goto out; | |
233 | } | |
982d8165 JB |
234 | offset = inode->i_size; |
235 | break; | |
1da177e4 LT |
236 | } |
237 | retval = -EINVAL; | |
cccb5a1e | 238 | if (offset >= 0 || unsigned_offsets(file)) { |
1da177e4 LT |
239 | if (offset != file->f_pos) { |
240 | file->f_pos = offset; | |
241 | file->f_version = 0; | |
242 | } | |
243 | retval = offset; | |
244 | } | |
5b6f1eb9 | 245 | out: |
982d8165 | 246 | mutex_unlock(&inode->i_mutex); |
1da177e4 LT |
247 | return retval; |
248 | } | |
249 | EXPORT_SYMBOL(default_llseek); | |
250 | ||
965c8e59 | 251 | loff_t vfs_llseek(struct file *file, loff_t offset, int whence) |
1da177e4 LT |
252 | { |
253 | loff_t (*fn)(struct file *, loff_t, int); | |
254 | ||
255 | fn = no_llseek; | |
256 | if (file->f_mode & FMODE_LSEEK) { | |
72c2d531 | 257 | if (file->f_op->llseek) |
1da177e4 LT |
258 | fn = file->f_op->llseek; |
259 | } | |
965c8e59 | 260 | return fn(file, offset, whence); |
1da177e4 LT |
261 | } |
262 | EXPORT_SYMBOL(vfs_llseek); | |
263 | ||
9c225f26 LT |
264 | static inline struct fd fdget_pos(int fd) |
265 | { | |
bd2a31d5 | 266 | return __to_fd(__fdget_pos(fd)); |
9c225f26 LT |
267 | } |
268 | ||
269 | static inline void fdput_pos(struct fd f) | |
270 | { | |
271 | if (f.flags & FDPUT_POS_UNLOCK) | |
272 | mutex_unlock(&f.file->f_pos_lock); | |
273 | fdput(f); | |
274 | } | |
275 | ||
965c8e59 | 276 | SYSCALL_DEFINE3(lseek, unsigned int, fd, off_t, offset, unsigned int, whence) |
1da177e4 LT |
277 | { |
278 | off_t retval; | |
9c225f26 | 279 | struct fd f = fdget_pos(fd); |
2903ff01 AV |
280 | if (!f.file) |
281 | return -EBADF; | |
1da177e4 LT |
282 | |
283 | retval = -EINVAL; | |
965c8e59 AM |
284 | if (whence <= SEEK_MAX) { |
285 | loff_t res = vfs_llseek(f.file, offset, whence); | |
1da177e4 LT |
286 | retval = res; |
287 | if (res != (loff_t)retval) | |
288 | retval = -EOVERFLOW; /* LFS: should only happen on 32 bit platforms */ | |
289 | } | |
9c225f26 | 290 | fdput_pos(f); |
1da177e4 LT |
291 | return retval; |
292 | } | |
293 | ||
561c6731 AV |
294 | #ifdef CONFIG_COMPAT |
295 | COMPAT_SYSCALL_DEFINE3(lseek, unsigned int, fd, compat_off_t, offset, unsigned int, whence) | |
296 | { | |
297 | return sys_lseek(fd, offset, whence); | |
298 | } | |
299 | #endif | |
300 | ||
1da177e4 | 301 | #ifdef __ARCH_WANT_SYS_LLSEEK |
003d7ab4 HC |
302 | SYSCALL_DEFINE5(llseek, unsigned int, fd, unsigned long, offset_high, |
303 | unsigned long, offset_low, loff_t __user *, result, | |
965c8e59 | 304 | unsigned int, whence) |
1da177e4 LT |
305 | { |
306 | int retval; | |
d7a15f8d | 307 | struct fd f = fdget_pos(fd); |
1da177e4 | 308 | loff_t offset; |
1da177e4 | 309 | |
2903ff01 AV |
310 | if (!f.file) |
311 | return -EBADF; | |
1da177e4 LT |
312 | |
313 | retval = -EINVAL; | |
965c8e59 | 314 | if (whence > SEEK_MAX) |
1da177e4 LT |
315 | goto out_putf; |
316 | ||
2903ff01 | 317 | offset = vfs_llseek(f.file, ((loff_t) offset_high << 32) | offset_low, |
965c8e59 | 318 | whence); |
1da177e4 LT |
319 | |
320 | retval = (int)offset; | |
321 | if (offset >= 0) { | |
322 | retval = -EFAULT; | |
323 | if (!copy_to_user(result, &offset, sizeof(offset))) | |
324 | retval = 0; | |
325 | } | |
326 | out_putf: | |
d7a15f8d | 327 | fdput_pos(f); |
1da177e4 LT |
328 | return retval; |
329 | } | |
330 | #endif | |
331 | ||
dbe4e192 CH |
332 | ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos) |
333 | { | |
334 | struct kiocb kiocb; | |
335 | ssize_t ret; | |
336 | ||
337 | if (!file->f_op->read_iter) | |
338 | return -EINVAL; | |
339 | ||
340 | init_sync_kiocb(&kiocb, file); | |
341 | kiocb.ki_pos = *ppos; | |
dbe4e192 CH |
342 | |
343 | iter->type |= READ; | |
344 | ret = file->f_op->read_iter(&kiocb, iter); | |
599bd19b | 345 | BUG_ON(ret == -EIOCBQUEUED); |
dbe4e192 CH |
346 | if (ret > 0) |
347 | *ppos = kiocb.ki_pos; | |
348 | return ret; | |
349 | } | |
350 | EXPORT_SYMBOL(vfs_iter_read); | |
351 | ||
352 | ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos) | |
353 | { | |
354 | struct kiocb kiocb; | |
355 | ssize_t ret; | |
356 | ||
357 | if (!file->f_op->write_iter) | |
358 | return -EINVAL; | |
359 | ||
360 | init_sync_kiocb(&kiocb, file); | |
361 | kiocb.ki_pos = *ppos; | |
dbe4e192 CH |
362 | |
363 | iter->type |= WRITE; | |
364 | ret = file->f_op->write_iter(&kiocb, iter); | |
599bd19b | 365 | BUG_ON(ret == -EIOCBQUEUED); |
dbe4e192 CH |
366 | if (ret > 0) |
367 | *ppos = kiocb.ki_pos; | |
368 | return ret; | |
369 | } | |
370 | EXPORT_SYMBOL(vfs_iter_write); | |
371 | ||
e28cc715 LT |
372 | /* |
373 | * rw_verify_area doesn't like huge counts. We limit | |
374 | * them to something that fits in "int" so that others | |
375 | * won't have to do range checks all the time. | |
376 | */ | |
68d70d03 | 377 | int rw_verify_area(int read_write, struct file *file, const loff_t *ppos, size_t count) |
1da177e4 LT |
378 | { |
379 | struct inode *inode; | |
380 | loff_t pos; | |
c43e259c | 381 | int retval = -EINVAL; |
1da177e4 | 382 | |
496ad9aa | 383 | inode = file_inode(file); |
e28cc715 | 384 | if (unlikely((ssize_t) count < 0)) |
c43e259c | 385 | return retval; |
1da177e4 | 386 | pos = *ppos; |
cccb5a1e AV |
387 | if (unlikely(pos < 0)) { |
388 | if (!unsigned_offsets(file)) | |
389 | return retval; | |
390 | if (count >= -pos) /* both values are in 0..LLONG_MAX */ | |
391 | return -EOVERFLOW; | |
392 | } else if (unlikely((loff_t) (pos + count) < 0)) { | |
393 | if (!unsigned_offsets(file)) | |
4a3956c7 KH |
394 | return retval; |
395 | } | |
1da177e4 | 396 | |
bd61e0a9 | 397 | if (unlikely(inode->i_flctx && mandatory_lock(inode))) { |
c43e259c | 398 | retval = locks_mandatory_area( |
e28cc715 LT |
399 | read_write == READ ? FLOCK_VERIFY_READ : FLOCK_VERIFY_WRITE, |
400 | inode, file, pos, count); | |
401 | if (retval < 0) | |
402 | return retval; | |
403 | } | |
c43e259c JM |
404 | retval = security_file_permission(file, |
405 | read_write == READ ? MAY_READ : MAY_WRITE); | |
406 | if (retval) | |
407 | return retval; | |
e28cc715 | 408 | return count > MAX_RW_COUNT ? MAX_RW_COUNT : count; |
1da177e4 LT |
409 | } |
410 | ||
5d5d5689 | 411 | static ssize_t new_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos) |
293bc982 AV |
412 | { |
413 | struct iovec iov = { .iov_base = buf, .iov_len = len }; | |
414 | struct kiocb kiocb; | |
415 | struct iov_iter iter; | |
416 | ssize_t ret; | |
417 | ||
418 | init_sync_kiocb(&kiocb, filp); | |
419 | kiocb.ki_pos = *ppos; | |
293bc982 AV |
420 | iov_iter_init(&iter, READ, &iov, 1, len); |
421 | ||
422 | ret = filp->f_op->read_iter(&kiocb, &iter); | |
599bd19b | 423 | BUG_ON(ret == -EIOCBQUEUED); |
293bc982 AV |
424 | *ppos = kiocb.ki_pos; |
425 | return ret; | |
426 | } | |
427 | ||
6fb5032e DK |
428 | ssize_t __vfs_read(struct file *file, char __user *buf, size_t count, |
429 | loff_t *pos) | |
430 | { | |
6fb5032e | 431 | if (file->f_op->read) |
3d04c8a1 | 432 | return file->f_op->read(file, buf, count, pos); |
6fb5032e | 433 | else if (file->f_op->read_iter) |
3d04c8a1 | 434 | return new_sync_read(file, buf, count, pos); |
6fb5032e | 435 | else |
3d04c8a1 | 436 | return -EINVAL; |
6fb5032e | 437 | } |
3d04c8a1 | 438 | EXPORT_SYMBOL(__vfs_read); |
6fb5032e | 439 | |
1da177e4 LT |
440 | ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos) |
441 | { | |
442 | ssize_t ret; | |
443 | ||
444 | if (!(file->f_mode & FMODE_READ)) | |
445 | return -EBADF; | |
7f7f25e8 | 446 | if (!(file->f_mode & FMODE_CAN_READ)) |
1da177e4 LT |
447 | return -EINVAL; |
448 | if (unlikely(!access_ok(VERIFY_WRITE, buf, count))) | |
449 | return -EFAULT; | |
450 | ||
451 | ret = rw_verify_area(READ, file, pos, count); | |
e28cc715 LT |
452 | if (ret >= 0) { |
453 | count = ret; | |
6fb5032e | 454 | ret = __vfs_read(file, buf, count, pos); |
c43e259c | 455 | if (ret > 0) { |
2a12a9d7 | 456 | fsnotify_access(file); |
c43e259c | 457 | add_rchar(current, ret); |
1da177e4 | 458 | } |
c43e259c | 459 | inc_syscr(current); |
1da177e4 LT |
460 | } |
461 | ||
462 | return ret; | |
463 | } | |
464 | ||
465 | EXPORT_SYMBOL(vfs_read); | |
466 | ||
5d5d5689 | 467 | static ssize_t new_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos) |
293bc982 AV |
468 | { |
469 | struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = len }; | |
470 | struct kiocb kiocb; | |
471 | struct iov_iter iter; | |
472 | ssize_t ret; | |
473 | ||
474 | init_sync_kiocb(&kiocb, filp); | |
475 | kiocb.ki_pos = *ppos; | |
293bc982 AV |
476 | iov_iter_init(&iter, WRITE, &iov, 1, len); |
477 | ||
478 | ret = filp->f_op->write_iter(&kiocb, &iter); | |
599bd19b | 479 | BUG_ON(ret == -EIOCBQUEUED); |
f765b134 AV |
480 | if (ret > 0) |
481 | *ppos = kiocb.ki_pos; | |
293bc982 AV |
482 | return ret; |
483 | } | |
484 | ||
493c84c0 AV |
485 | ssize_t __vfs_write(struct file *file, const char __user *p, size_t count, |
486 | loff_t *pos) | |
487 | { | |
488 | if (file->f_op->write) | |
489 | return file->f_op->write(file, p, count, pos); | |
493c84c0 AV |
490 | else if (file->f_op->write_iter) |
491 | return new_sync_write(file, p, count, pos); | |
492 | else | |
493 | return -EINVAL; | |
494 | } | |
495 | EXPORT_SYMBOL(__vfs_write); | |
496 | ||
dee5220c TG |
497 | vfs_readf_t vfs_readf(struct file *file) |
498 | { | |
499 | const struct file_operations *fop = file->f_op; | |
500 | ||
501 | if (fop->read) | |
502 | return fop->read; | |
503 | if (fop->read_iter) | |
504 | return new_sync_read; | |
505 | return ERR_PTR(-ENOSYS); | |
506 | } | |
507 | EXPORT_SYMBOL(vfs_readf); | |
508 | ||
509 | vfs_writef_t vfs_writef(struct file *file) | |
510 | { | |
511 | const struct file_operations *fop = file->f_op; | |
512 | ||
513 | if (fop->write) | |
514 | return fop->write; | |
515 | if (fop->write_iter) | |
516 | return new_sync_write; | |
517 | return ERR_PTR(-ENOSYS); | |
518 | } | |
519 | EXPORT_SYMBOL(vfs_writef); | |
520 | ||
06ae43f3 AV |
521 | ssize_t __kernel_write(struct file *file, const char *buf, size_t count, loff_t *pos) |
522 | { | |
523 | mm_segment_t old_fs; | |
524 | const char __user *p; | |
525 | ssize_t ret; | |
526 | ||
7f7f25e8 | 527 | if (!(file->f_mode & FMODE_CAN_WRITE)) |
3e84f48e AV |
528 | return -EINVAL; |
529 | ||
06ae43f3 AV |
530 | old_fs = get_fs(); |
531 | set_fs(get_ds()); | |
532 | p = (__force const char __user *)buf; | |
533 | if (count > MAX_RW_COUNT) | |
534 | count = MAX_RW_COUNT; | |
493c84c0 | 535 | ret = __vfs_write(file, p, count, pos); |
06ae43f3 AV |
536 | set_fs(old_fs); |
537 | if (ret > 0) { | |
538 | fsnotify_modify(file); | |
539 | add_wchar(current, ret); | |
540 | } | |
541 | inc_syscw(current); | |
542 | return ret; | |
543 | } | |
544 | ||
2ec3a12a AV |
545 | EXPORT_SYMBOL(__kernel_write); |
546 | ||
1da177e4 LT |
547 | ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_t *pos) |
548 | { | |
549 | ssize_t ret; | |
550 | ||
551 | if (!(file->f_mode & FMODE_WRITE)) | |
552 | return -EBADF; | |
7f7f25e8 | 553 | if (!(file->f_mode & FMODE_CAN_WRITE)) |
1da177e4 LT |
554 | return -EINVAL; |
555 | if (unlikely(!access_ok(VERIFY_READ, buf, count))) | |
556 | return -EFAULT; | |
557 | ||
558 | ret = rw_verify_area(WRITE, file, pos, count); | |
e28cc715 LT |
559 | if (ret >= 0) { |
560 | count = ret; | |
03d95eb2 | 561 | file_start_write(file); |
493c84c0 | 562 | ret = __vfs_write(file, buf, count, pos); |
c43e259c | 563 | if (ret > 0) { |
2a12a9d7 | 564 | fsnotify_modify(file); |
c43e259c | 565 | add_wchar(current, ret); |
1da177e4 | 566 | } |
c43e259c | 567 | inc_syscw(current); |
03d95eb2 | 568 | file_end_write(file); |
1da177e4 LT |
569 | } |
570 | ||
571 | return ret; | |
572 | } | |
573 | ||
574 | EXPORT_SYMBOL(vfs_write); | |
575 | ||
576 | static inline loff_t file_pos_read(struct file *file) | |
577 | { | |
578 | return file->f_pos; | |
579 | } | |
580 | ||
581 | static inline void file_pos_write(struct file *file, loff_t pos) | |
582 | { | |
583 | file->f_pos = pos; | |
584 | } | |
585 | ||
3cdad428 | 586 | SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count) |
1da177e4 | 587 | { |
9c225f26 | 588 | struct fd f = fdget_pos(fd); |
1da177e4 | 589 | ssize_t ret = -EBADF; |
1da177e4 | 590 | |
2903ff01 AV |
591 | if (f.file) { |
592 | loff_t pos = file_pos_read(f.file); | |
593 | ret = vfs_read(f.file, buf, count, &pos); | |
5faf153e AV |
594 | if (ret >= 0) |
595 | file_pos_write(f.file, pos); | |
9c225f26 | 596 | fdput_pos(f); |
1da177e4 | 597 | } |
1da177e4 LT |
598 | return ret; |
599 | } | |
1da177e4 | 600 | |
3cdad428 HC |
601 | SYSCALL_DEFINE3(write, unsigned int, fd, const char __user *, buf, |
602 | size_t, count) | |
1da177e4 | 603 | { |
9c225f26 | 604 | struct fd f = fdget_pos(fd); |
1da177e4 | 605 | ssize_t ret = -EBADF; |
1da177e4 | 606 | |
2903ff01 AV |
607 | if (f.file) { |
608 | loff_t pos = file_pos_read(f.file); | |
609 | ret = vfs_write(f.file, buf, count, &pos); | |
5faf153e AV |
610 | if (ret >= 0) |
611 | file_pos_write(f.file, pos); | |
9c225f26 | 612 | fdput_pos(f); |
1da177e4 LT |
613 | } |
614 | ||
615 | return ret; | |
616 | } | |
617 | ||
4a0fd5bf AV |
618 | SYSCALL_DEFINE4(pread64, unsigned int, fd, char __user *, buf, |
619 | size_t, count, loff_t, pos) | |
1da177e4 | 620 | { |
2903ff01 | 621 | struct fd f; |
1da177e4 | 622 | ssize_t ret = -EBADF; |
1da177e4 LT |
623 | |
624 | if (pos < 0) | |
625 | return -EINVAL; | |
626 | ||
2903ff01 AV |
627 | f = fdget(fd); |
628 | if (f.file) { | |
1da177e4 | 629 | ret = -ESPIPE; |
2903ff01 AV |
630 | if (f.file->f_mode & FMODE_PREAD) |
631 | ret = vfs_read(f.file, buf, count, &pos); | |
632 | fdput(f); | |
1da177e4 LT |
633 | } |
634 | ||
635 | return ret; | |
636 | } | |
637 | ||
4a0fd5bf AV |
638 | SYSCALL_DEFINE4(pwrite64, unsigned int, fd, const char __user *, buf, |
639 | size_t, count, loff_t, pos) | |
1da177e4 | 640 | { |
2903ff01 | 641 | struct fd f; |
1da177e4 | 642 | ssize_t ret = -EBADF; |
1da177e4 LT |
643 | |
644 | if (pos < 0) | |
645 | return -EINVAL; | |
646 | ||
2903ff01 AV |
647 | f = fdget(fd); |
648 | if (f.file) { | |
1da177e4 | 649 | ret = -ESPIPE; |
2903ff01 AV |
650 | if (f.file->f_mode & FMODE_PWRITE) |
651 | ret = vfs_write(f.file, buf, count, &pos); | |
652 | fdput(f); | |
1da177e4 LT |
653 | } |
654 | ||
655 | return ret; | |
656 | } | |
657 | ||
658 | /* | |
659 | * Reduce an iovec's length in-place. Return the resulting number of segments | |
660 | */ | |
661 | unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to) | |
662 | { | |
663 | unsigned long seg = 0; | |
664 | size_t len = 0; | |
665 | ||
666 | while (seg < nr_segs) { | |
667 | seg++; | |
668 | if (len + iov->iov_len >= to) { | |
669 | iov->iov_len = to - len; | |
670 | break; | |
671 | } | |
672 | len += iov->iov_len; | |
673 | iov++; | |
674 | } | |
675 | return seg; | |
676 | } | |
19295529 | 677 | EXPORT_SYMBOL(iov_shorten); |
1da177e4 | 678 | |
ac15ac06 AV |
679 | static ssize_t do_iter_readv_writev(struct file *filp, struct iov_iter *iter, |
680 | loff_t *ppos, iter_fn_t fn) | |
293bc982 AV |
681 | { |
682 | struct kiocb kiocb; | |
293bc982 AV |
683 | ssize_t ret; |
684 | ||
685 | init_sync_kiocb(&kiocb, filp); | |
686 | kiocb.ki_pos = *ppos; | |
293bc982 | 687 | |
ac15ac06 | 688 | ret = fn(&kiocb, iter); |
599bd19b | 689 | BUG_ON(ret == -EIOCBQUEUED); |
293bc982 AV |
690 | *ppos = kiocb.ki_pos; |
691 | return ret; | |
692 | } | |
693 | ||
ee0b3e67 | 694 | /* Do it by hand, with file-ops */ |
ac15ac06 AV |
695 | static ssize_t do_loop_readv_writev(struct file *filp, struct iov_iter *iter, |
696 | loff_t *ppos, io_fn_t fn) | |
ee0b3e67 | 697 | { |
ee0b3e67 BP |
698 | ssize_t ret = 0; |
699 | ||
ac15ac06 AV |
700 | while (iov_iter_count(iter)) { |
701 | struct iovec iovec = iov_iter_iovec(iter); | |
ee0b3e67 BP |
702 | ssize_t nr; |
703 | ||
ac15ac06 | 704 | nr = fn(filp, iovec.iov_base, iovec.iov_len, ppos); |
ee0b3e67 BP |
705 | |
706 | if (nr < 0) { | |
707 | if (!ret) | |
708 | ret = nr; | |
709 | break; | |
710 | } | |
711 | ret += nr; | |
ac15ac06 | 712 | if (nr != iovec.iov_len) |
ee0b3e67 | 713 | break; |
ac15ac06 | 714 | iov_iter_advance(iter, nr); |
ee0b3e67 BP |
715 | } |
716 | ||
717 | return ret; | |
718 | } | |
719 | ||
1da177e4 LT |
720 | /* A write operation does a read from user space and vice versa */ |
721 | #define vrfy_dir(type) ((type) == READ ? VERIFY_WRITE : VERIFY_READ) | |
722 | ||
eed4e51f BP |
723 | ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector, |
724 | unsigned long nr_segs, unsigned long fast_segs, | |
725 | struct iovec *fast_pointer, | |
ac34ebb3 | 726 | struct iovec **ret_pointer) |
435f49a5 | 727 | { |
eed4e51f | 728 | unsigned long seg; |
435f49a5 | 729 | ssize_t ret; |
eed4e51f BP |
730 | struct iovec *iov = fast_pointer; |
731 | ||
435f49a5 LT |
732 | /* |
733 | * SuS says "The readv() function *may* fail if the iovcnt argument | |
734 | * was less than or equal to 0, or greater than {IOV_MAX}. Linux has | |
735 | * traditionally returned zero for zero segments, so... | |
736 | */ | |
eed4e51f BP |
737 | if (nr_segs == 0) { |
738 | ret = 0; | |
435f49a5 | 739 | goto out; |
eed4e51f BP |
740 | } |
741 | ||
435f49a5 LT |
742 | /* |
743 | * First get the "struct iovec" from user memory and | |
744 | * verify all the pointers | |
745 | */ | |
eed4e51f BP |
746 | if (nr_segs > UIO_MAXIOV) { |
747 | ret = -EINVAL; | |
435f49a5 | 748 | goto out; |
eed4e51f BP |
749 | } |
750 | if (nr_segs > fast_segs) { | |
435f49a5 | 751 | iov = kmalloc(nr_segs*sizeof(struct iovec), GFP_KERNEL); |
eed4e51f BP |
752 | if (iov == NULL) { |
753 | ret = -ENOMEM; | |
435f49a5 | 754 | goto out; |
eed4e51f | 755 | } |
435f49a5 | 756 | } |
eed4e51f BP |
757 | if (copy_from_user(iov, uvector, nr_segs*sizeof(*uvector))) { |
758 | ret = -EFAULT; | |
435f49a5 | 759 | goto out; |
eed4e51f BP |
760 | } |
761 | ||
435f49a5 | 762 | /* |
eed4e51f BP |
763 | * According to the Single Unix Specification we should return EINVAL |
764 | * if an element length is < 0 when cast to ssize_t or if the | |
765 | * total length would overflow the ssize_t return value of the | |
766 | * system call. | |
435f49a5 LT |
767 | * |
768 | * Linux caps all read/write calls to MAX_RW_COUNT, and avoids the | |
769 | * overflow case. | |
770 | */ | |
eed4e51f | 771 | ret = 0; |
435f49a5 LT |
772 | for (seg = 0; seg < nr_segs; seg++) { |
773 | void __user *buf = iov[seg].iov_base; | |
774 | ssize_t len = (ssize_t)iov[seg].iov_len; | |
eed4e51f BP |
775 | |
776 | /* see if we we're about to use an invalid len or if | |
777 | * it's about to overflow ssize_t */ | |
435f49a5 | 778 | if (len < 0) { |
eed4e51f | 779 | ret = -EINVAL; |
435f49a5 | 780 | goto out; |
eed4e51f | 781 | } |
ac34ebb3 | 782 | if (type >= 0 |
fcf63409 | 783 | && unlikely(!access_ok(vrfy_dir(type), buf, len))) { |
eed4e51f | 784 | ret = -EFAULT; |
435f49a5 LT |
785 | goto out; |
786 | } | |
787 | if (len > MAX_RW_COUNT - ret) { | |
788 | len = MAX_RW_COUNT - ret; | |
789 | iov[seg].iov_len = len; | |
eed4e51f | 790 | } |
eed4e51f | 791 | ret += len; |
435f49a5 | 792 | } |
eed4e51f BP |
793 | out: |
794 | *ret_pointer = iov; | |
795 | return ret; | |
796 | } | |
797 | ||
1da177e4 LT |
798 | static ssize_t do_readv_writev(int type, struct file *file, |
799 | const struct iovec __user * uvector, | |
800 | unsigned long nr_segs, loff_t *pos) | |
801 | { | |
1da177e4 LT |
802 | size_t tot_len; |
803 | struct iovec iovstack[UIO_FASTIOV]; | |
ee0b3e67 | 804 | struct iovec *iov = iovstack; |
ac15ac06 | 805 | struct iov_iter iter; |
1da177e4 | 806 | ssize_t ret; |
1da177e4 | 807 | io_fn_t fn; |
293bc982 | 808 | iter_fn_t iter_fn; |
1da177e4 | 809 | |
0504c074 AV |
810 | ret = import_iovec(type, uvector, nr_segs, |
811 | ARRAY_SIZE(iovstack), &iov, &iter); | |
812 | if (ret < 0) | |
813 | return ret; | |
1da177e4 | 814 | |
0504c074 AV |
815 | tot_len = iov_iter_count(&iter); |
816 | if (!tot_len) | |
817 | goto out; | |
1da177e4 | 818 | ret = rw_verify_area(type, file, pos, tot_len); |
e28cc715 | 819 | if (ret < 0) |
411b67b4 | 820 | goto out; |
1da177e4 | 821 | |
1da177e4 LT |
822 | if (type == READ) { |
823 | fn = file->f_op->read; | |
293bc982 | 824 | iter_fn = file->f_op->read_iter; |
1da177e4 LT |
825 | } else { |
826 | fn = (io_fn_t)file->f_op->write; | |
293bc982 | 827 | iter_fn = file->f_op->write_iter; |
03d95eb2 | 828 | file_start_write(file); |
1da177e4 LT |
829 | } |
830 | ||
293bc982 | 831 | if (iter_fn) |
ac15ac06 | 832 | ret = do_iter_readv_writev(file, &iter, pos, iter_fn); |
ee0b3e67 | 833 | else |
ac15ac06 | 834 | ret = do_loop_readv_writev(file, &iter, pos, fn); |
1da177e4 | 835 | |
03d95eb2 AV |
836 | if (type != READ) |
837 | file_end_write(file); | |
838 | ||
1da177e4 | 839 | out: |
0504c074 | 840 | kfree(iov); |
0eeca283 RL |
841 | if ((ret + (type == READ)) > 0) { |
842 | if (type == READ) | |
2a12a9d7 | 843 | fsnotify_access(file); |
0eeca283 | 844 | else |
2a12a9d7 | 845 | fsnotify_modify(file); |
0eeca283 | 846 | } |
1da177e4 | 847 | return ret; |
1da177e4 LT |
848 | } |
849 | ||
850 | ssize_t vfs_readv(struct file *file, const struct iovec __user *vec, | |
851 | unsigned long vlen, loff_t *pos) | |
852 | { | |
853 | if (!(file->f_mode & FMODE_READ)) | |
854 | return -EBADF; | |
7f7f25e8 | 855 | if (!(file->f_mode & FMODE_CAN_READ)) |
1da177e4 LT |
856 | return -EINVAL; |
857 | ||
858 | return do_readv_writev(READ, file, vec, vlen, pos); | |
859 | } | |
860 | ||
861 | EXPORT_SYMBOL(vfs_readv); | |
862 | ||
863 | ssize_t vfs_writev(struct file *file, const struct iovec __user *vec, | |
864 | unsigned long vlen, loff_t *pos) | |
865 | { | |
866 | if (!(file->f_mode & FMODE_WRITE)) | |
867 | return -EBADF; | |
7f7f25e8 | 868 | if (!(file->f_mode & FMODE_CAN_WRITE)) |
1da177e4 LT |
869 | return -EINVAL; |
870 | ||
871 | return do_readv_writev(WRITE, file, vec, vlen, pos); | |
872 | } | |
873 | ||
874 | EXPORT_SYMBOL(vfs_writev); | |
875 | ||
3cdad428 HC |
876 | SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec, |
877 | unsigned long, vlen) | |
1da177e4 | 878 | { |
9c225f26 | 879 | struct fd f = fdget_pos(fd); |
1da177e4 | 880 | ssize_t ret = -EBADF; |
1da177e4 | 881 | |
2903ff01 AV |
882 | if (f.file) { |
883 | loff_t pos = file_pos_read(f.file); | |
884 | ret = vfs_readv(f.file, vec, vlen, &pos); | |
5faf153e AV |
885 | if (ret >= 0) |
886 | file_pos_write(f.file, pos); | |
9c225f26 | 887 | fdput_pos(f); |
1da177e4 LT |
888 | } |
889 | ||
890 | if (ret > 0) | |
4b98d11b AD |
891 | add_rchar(current, ret); |
892 | inc_syscr(current); | |
1da177e4 LT |
893 | return ret; |
894 | } | |
895 | ||
3cdad428 HC |
896 | SYSCALL_DEFINE3(writev, unsigned long, fd, const struct iovec __user *, vec, |
897 | unsigned long, vlen) | |
1da177e4 | 898 | { |
9c225f26 | 899 | struct fd f = fdget_pos(fd); |
1da177e4 | 900 | ssize_t ret = -EBADF; |
1da177e4 | 901 | |
2903ff01 AV |
902 | if (f.file) { |
903 | loff_t pos = file_pos_read(f.file); | |
904 | ret = vfs_writev(f.file, vec, vlen, &pos); | |
5faf153e AV |
905 | if (ret >= 0) |
906 | file_pos_write(f.file, pos); | |
9c225f26 | 907 | fdput_pos(f); |
1da177e4 LT |
908 | } |
909 | ||
910 | if (ret > 0) | |
4b98d11b AD |
911 | add_wchar(current, ret); |
912 | inc_syscw(current); | |
1da177e4 LT |
913 | return ret; |
914 | } | |
915 | ||
601cc11d LT |
916 | static inline loff_t pos_from_hilo(unsigned long high, unsigned long low) |
917 | { | |
918 | #define HALF_LONG_BITS (BITS_PER_LONG / 2) | |
919 | return (((loff_t)high << HALF_LONG_BITS) << HALF_LONG_BITS) | low; | |
920 | } | |
921 | ||
f3554f4b | 922 | SYSCALL_DEFINE5(preadv, unsigned long, fd, const struct iovec __user *, vec, |
601cc11d | 923 | unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h) |
f3554f4b | 924 | { |
601cc11d | 925 | loff_t pos = pos_from_hilo(pos_h, pos_l); |
2903ff01 | 926 | struct fd f; |
f3554f4b | 927 | ssize_t ret = -EBADF; |
f3554f4b GH |
928 | |
929 | if (pos < 0) | |
930 | return -EINVAL; | |
931 | ||
2903ff01 AV |
932 | f = fdget(fd); |
933 | if (f.file) { | |
f3554f4b | 934 | ret = -ESPIPE; |
2903ff01 AV |
935 | if (f.file->f_mode & FMODE_PREAD) |
936 | ret = vfs_readv(f.file, vec, vlen, &pos); | |
937 | fdput(f); | |
f3554f4b GH |
938 | } |
939 | ||
940 | if (ret > 0) | |
941 | add_rchar(current, ret); | |
942 | inc_syscr(current); | |
943 | return ret; | |
944 | } | |
945 | ||
946 | SYSCALL_DEFINE5(pwritev, unsigned long, fd, const struct iovec __user *, vec, | |
601cc11d | 947 | unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h) |
f3554f4b | 948 | { |
601cc11d | 949 | loff_t pos = pos_from_hilo(pos_h, pos_l); |
2903ff01 | 950 | struct fd f; |
f3554f4b | 951 | ssize_t ret = -EBADF; |
f3554f4b GH |
952 | |
953 | if (pos < 0) | |
954 | return -EINVAL; | |
955 | ||
2903ff01 AV |
956 | f = fdget(fd); |
957 | if (f.file) { | |
f3554f4b | 958 | ret = -ESPIPE; |
2903ff01 AV |
959 | if (f.file->f_mode & FMODE_PWRITE) |
960 | ret = vfs_writev(f.file, vec, vlen, &pos); | |
961 | fdput(f); | |
f3554f4b GH |
962 | } |
963 | ||
964 | if (ret > 0) | |
965 | add_wchar(current, ret); | |
966 | inc_syscw(current); | |
967 | return ret; | |
968 | } | |
969 | ||
72ec3516 AV |
970 | #ifdef CONFIG_COMPAT |
971 | ||
972 | static ssize_t compat_do_readv_writev(int type, struct file *file, | |
973 | const struct compat_iovec __user *uvector, | |
974 | unsigned long nr_segs, loff_t *pos) | |
975 | { | |
976 | compat_ssize_t tot_len; | |
977 | struct iovec iovstack[UIO_FASTIOV]; | |
978 | struct iovec *iov = iovstack; | |
ac15ac06 | 979 | struct iov_iter iter; |
72ec3516 AV |
980 | ssize_t ret; |
981 | io_fn_t fn; | |
293bc982 | 982 | iter_fn_t iter_fn; |
72ec3516 | 983 | |
0504c074 AV |
984 | ret = compat_import_iovec(type, uvector, nr_segs, |
985 | UIO_FASTIOV, &iov, &iter); | |
986 | if (ret < 0) | |
987 | return ret; | |
72ec3516 | 988 | |
0504c074 AV |
989 | tot_len = iov_iter_count(&iter); |
990 | if (!tot_len) | |
991 | goto out; | |
72ec3516 AV |
992 | ret = rw_verify_area(type, file, pos, tot_len); |
993 | if (ret < 0) | |
994 | goto out; | |
995 | ||
72ec3516 AV |
996 | if (type == READ) { |
997 | fn = file->f_op->read; | |
293bc982 | 998 | iter_fn = file->f_op->read_iter; |
72ec3516 AV |
999 | } else { |
1000 | fn = (io_fn_t)file->f_op->write; | |
293bc982 | 1001 | iter_fn = file->f_op->write_iter; |
03d95eb2 | 1002 | file_start_write(file); |
72ec3516 AV |
1003 | } |
1004 | ||
293bc982 | 1005 | if (iter_fn) |
ac15ac06 | 1006 | ret = do_iter_readv_writev(file, &iter, pos, iter_fn); |
03d95eb2 | 1007 | else |
ac15ac06 | 1008 | ret = do_loop_readv_writev(file, &iter, pos, fn); |
72ec3516 | 1009 | |
03d95eb2 AV |
1010 | if (type != READ) |
1011 | file_end_write(file); | |
1012 | ||
72ec3516 | 1013 | out: |
0504c074 | 1014 | kfree(iov); |
72ec3516 AV |
1015 | if ((ret + (type == READ)) > 0) { |
1016 | if (type == READ) | |
1017 | fsnotify_access(file); | |
1018 | else | |
1019 | fsnotify_modify(file); | |
1020 | } | |
1021 | return ret; | |
1022 | } | |
1023 | ||
1024 | static size_t compat_readv(struct file *file, | |
1025 | const struct compat_iovec __user *vec, | |
1026 | unsigned long vlen, loff_t *pos) | |
1027 | { | |
1028 | ssize_t ret = -EBADF; | |
1029 | ||
1030 | if (!(file->f_mode & FMODE_READ)) | |
1031 | goto out; | |
1032 | ||
1033 | ret = -EINVAL; | |
7f7f25e8 | 1034 | if (!(file->f_mode & FMODE_CAN_READ)) |
72ec3516 AV |
1035 | goto out; |
1036 | ||
1037 | ret = compat_do_readv_writev(READ, file, vec, vlen, pos); | |
1038 | ||
1039 | out: | |
1040 | if (ret > 0) | |
1041 | add_rchar(current, ret); | |
1042 | inc_syscr(current); | |
1043 | return ret; | |
1044 | } | |
1045 | ||
dfd948e3 | 1046 | COMPAT_SYSCALL_DEFINE3(readv, compat_ulong_t, fd, |
72ec3516 | 1047 | const struct compat_iovec __user *,vec, |
dfd948e3 | 1048 | compat_ulong_t, vlen) |
72ec3516 | 1049 | { |
9c225f26 | 1050 | struct fd f = fdget_pos(fd); |
72ec3516 AV |
1051 | ssize_t ret; |
1052 | loff_t pos; | |
1053 | ||
1054 | if (!f.file) | |
1055 | return -EBADF; | |
1056 | pos = f.file->f_pos; | |
1057 | ret = compat_readv(f.file, vec, vlen, &pos); | |
5faf153e AV |
1058 | if (ret >= 0) |
1059 | f.file->f_pos = pos; | |
9c225f26 | 1060 | fdput_pos(f); |
72ec3516 AV |
1061 | return ret; |
1062 | } | |
1063 | ||
378a10f3 HC |
1064 | static long __compat_sys_preadv64(unsigned long fd, |
1065 | const struct compat_iovec __user *vec, | |
1066 | unsigned long vlen, loff_t pos) | |
72ec3516 AV |
1067 | { |
1068 | struct fd f; | |
1069 | ssize_t ret; | |
1070 | ||
1071 | if (pos < 0) | |
1072 | return -EINVAL; | |
1073 | f = fdget(fd); | |
1074 | if (!f.file) | |
1075 | return -EBADF; | |
1076 | ret = -ESPIPE; | |
1077 | if (f.file->f_mode & FMODE_PREAD) | |
1078 | ret = compat_readv(f.file, vec, vlen, &pos); | |
1079 | fdput(f); | |
1080 | return ret; | |
1081 | } | |
1082 | ||
378a10f3 HC |
1083 | #ifdef __ARCH_WANT_COMPAT_SYS_PREADV64 |
1084 | COMPAT_SYSCALL_DEFINE4(preadv64, unsigned long, fd, | |
1085 | const struct compat_iovec __user *,vec, | |
1086 | unsigned long, vlen, loff_t, pos) | |
1087 | { | |
1088 | return __compat_sys_preadv64(fd, vec, vlen, pos); | |
1089 | } | |
1090 | #endif | |
1091 | ||
dfd948e3 | 1092 | COMPAT_SYSCALL_DEFINE5(preadv, compat_ulong_t, fd, |
72ec3516 | 1093 | const struct compat_iovec __user *,vec, |
dfd948e3 | 1094 | compat_ulong_t, vlen, u32, pos_low, u32, pos_high) |
72ec3516 AV |
1095 | { |
1096 | loff_t pos = ((loff_t)pos_high << 32) | pos_low; | |
378a10f3 HC |
1097 | |
1098 | return __compat_sys_preadv64(fd, vec, vlen, pos); | |
72ec3516 AV |
1099 | } |
1100 | ||
1101 | static size_t compat_writev(struct file *file, | |
1102 | const struct compat_iovec __user *vec, | |
1103 | unsigned long vlen, loff_t *pos) | |
1104 | { | |
1105 | ssize_t ret = -EBADF; | |
1106 | ||
1107 | if (!(file->f_mode & FMODE_WRITE)) | |
1108 | goto out; | |
1109 | ||
1110 | ret = -EINVAL; | |
7f7f25e8 | 1111 | if (!(file->f_mode & FMODE_CAN_WRITE)) |
72ec3516 AV |
1112 | goto out; |
1113 | ||
1114 | ret = compat_do_readv_writev(WRITE, file, vec, vlen, pos); | |
1115 | ||
1116 | out: | |
1117 | if (ret > 0) | |
1118 | add_wchar(current, ret); | |
1119 | inc_syscw(current); | |
1120 | return ret; | |
1121 | } | |
1122 | ||
dfd948e3 | 1123 | COMPAT_SYSCALL_DEFINE3(writev, compat_ulong_t, fd, |
72ec3516 | 1124 | const struct compat_iovec __user *, vec, |
dfd948e3 | 1125 | compat_ulong_t, vlen) |
72ec3516 | 1126 | { |
9c225f26 | 1127 | struct fd f = fdget_pos(fd); |
72ec3516 AV |
1128 | ssize_t ret; |
1129 | loff_t pos; | |
1130 | ||
1131 | if (!f.file) | |
1132 | return -EBADF; | |
1133 | pos = f.file->f_pos; | |
1134 | ret = compat_writev(f.file, vec, vlen, &pos); | |
5faf153e AV |
1135 | if (ret >= 0) |
1136 | f.file->f_pos = pos; | |
9c225f26 | 1137 | fdput_pos(f); |
72ec3516 AV |
1138 | return ret; |
1139 | } | |
1140 | ||
378a10f3 HC |
1141 | static long __compat_sys_pwritev64(unsigned long fd, |
1142 | const struct compat_iovec __user *vec, | |
1143 | unsigned long vlen, loff_t pos) | |
72ec3516 AV |
1144 | { |
1145 | struct fd f; | |
1146 | ssize_t ret; | |
1147 | ||
1148 | if (pos < 0) | |
1149 | return -EINVAL; | |
1150 | f = fdget(fd); | |
1151 | if (!f.file) | |
1152 | return -EBADF; | |
1153 | ret = -ESPIPE; | |
1154 | if (f.file->f_mode & FMODE_PWRITE) | |
1155 | ret = compat_writev(f.file, vec, vlen, &pos); | |
1156 | fdput(f); | |
1157 | return ret; | |
1158 | } | |
1159 | ||
378a10f3 HC |
1160 | #ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64 |
1161 | COMPAT_SYSCALL_DEFINE4(pwritev64, unsigned long, fd, | |
1162 | const struct compat_iovec __user *,vec, | |
1163 | unsigned long, vlen, loff_t, pos) | |
1164 | { | |
1165 | return __compat_sys_pwritev64(fd, vec, vlen, pos); | |
1166 | } | |
1167 | #endif | |
1168 | ||
dfd948e3 | 1169 | COMPAT_SYSCALL_DEFINE5(pwritev, compat_ulong_t, fd, |
72ec3516 | 1170 | const struct compat_iovec __user *,vec, |
dfd948e3 | 1171 | compat_ulong_t, vlen, u32, pos_low, u32, pos_high) |
72ec3516 AV |
1172 | { |
1173 | loff_t pos = ((loff_t)pos_high << 32) | pos_low; | |
378a10f3 HC |
1174 | |
1175 | return __compat_sys_pwritev64(fd, vec, vlen, pos); | |
72ec3516 AV |
1176 | } |
1177 | #endif | |
1178 | ||
19f4fc3a AV |
1179 | static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, |
1180 | size_t count, loff_t max) | |
1da177e4 | 1181 | { |
2903ff01 AV |
1182 | struct fd in, out; |
1183 | struct inode *in_inode, *out_inode; | |
1da177e4 | 1184 | loff_t pos; |
7995bd28 | 1185 | loff_t out_pos; |
1da177e4 | 1186 | ssize_t retval; |
2903ff01 | 1187 | int fl; |
1da177e4 LT |
1188 | |
1189 | /* | |
1190 | * Get input file, and verify that it is ok.. | |
1191 | */ | |
1192 | retval = -EBADF; | |
2903ff01 AV |
1193 | in = fdget(in_fd); |
1194 | if (!in.file) | |
1da177e4 | 1195 | goto out; |
2903ff01 | 1196 | if (!(in.file->f_mode & FMODE_READ)) |
1da177e4 | 1197 | goto fput_in; |
1da177e4 | 1198 | retval = -ESPIPE; |
7995bd28 AV |
1199 | if (!ppos) { |
1200 | pos = in.file->f_pos; | |
1201 | } else { | |
1202 | pos = *ppos; | |
2903ff01 | 1203 | if (!(in.file->f_mode & FMODE_PREAD)) |
1da177e4 | 1204 | goto fput_in; |
7995bd28 AV |
1205 | } |
1206 | retval = rw_verify_area(READ, in.file, &pos, count); | |
e28cc715 | 1207 | if (retval < 0) |
1da177e4 | 1208 | goto fput_in; |
e28cc715 | 1209 | count = retval; |
1da177e4 | 1210 | |
1da177e4 LT |
1211 | /* |
1212 | * Get output file, and verify that it is ok.. | |
1213 | */ | |
1214 | retval = -EBADF; | |
2903ff01 AV |
1215 | out = fdget(out_fd); |
1216 | if (!out.file) | |
1da177e4 | 1217 | goto fput_in; |
2903ff01 | 1218 | if (!(out.file->f_mode & FMODE_WRITE)) |
1da177e4 LT |
1219 | goto fput_out; |
1220 | retval = -EINVAL; | |
496ad9aa AV |
1221 | in_inode = file_inode(in.file); |
1222 | out_inode = file_inode(out.file); | |
7995bd28 AV |
1223 | out_pos = out.file->f_pos; |
1224 | retval = rw_verify_area(WRITE, out.file, &out_pos, count); | |
e28cc715 | 1225 | if (retval < 0) |
1da177e4 | 1226 | goto fput_out; |
e28cc715 | 1227 | count = retval; |
1da177e4 | 1228 | |
1da177e4 LT |
1229 | if (!max) |
1230 | max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes); | |
1231 | ||
1da177e4 LT |
1232 | if (unlikely(pos + count > max)) { |
1233 | retval = -EOVERFLOW; | |
1234 | if (pos >= max) | |
1235 | goto fput_out; | |
1236 | count = max - pos; | |
1237 | } | |
1238 | ||
d96e6e71 | 1239 | fl = 0; |
534f2aaa | 1240 | #if 0 |
d96e6e71 JA |
1241 | /* |
1242 | * We need to debate whether we can enable this or not. The | |
1243 | * man page documents EAGAIN return for the output at least, | |
1244 | * and the application is arguably buggy if it doesn't expect | |
1245 | * EAGAIN on a non-blocking file descriptor. | |
1246 | */ | |
2903ff01 | 1247 | if (in.file->f_flags & O_NONBLOCK) |
d96e6e71 | 1248 | fl = SPLICE_F_NONBLOCK; |
534f2aaa | 1249 | #endif |
50cd2c57 | 1250 | file_start_write(out.file); |
7995bd28 | 1251 | retval = do_splice_direct(in.file, &pos, out.file, &out_pos, count, fl); |
50cd2c57 | 1252 | file_end_write(out.file); |
1da177e4 LT |
1253 | |
1254 | if (retval > 0) { | |
4b98d11b AD |
1255 | add_rchar(current, retval); |
1256 | add_wchar(current, retval); | |
a68c2f12 SW |
1257 | fsnotify_access(in.file); |
1258 | fsnotify_modify(out.file); | |
7995bd28 AV |
1259 | out.file->f_pos = out_pos; |
1260 | if (ppos) | |
1261 | *ppos = pos; | |
1262 | else | |
1263 | in.file->f_pos = pos; | |
1da177e4 | 1264 | } |
1da177e4 | 1265 | |
4b98d11b AD |
1266 | inc_syscr(current); |
1267 | inc_syscw(current); | |
7995bd28 | 1268 | if (pos > max) |
1da177e4 LT |
1269 | retval = -EOVERFLOW; |
1270 | ||
1271 | fput_out: | |
2903ff01 | 1272 | fdput(out); |
1da177e4 | 1273 | fput_in: |
2903ff01 | 1274 | fdput(in); |
1da177e4 LT |
1275 | out: |
1276 | return retval; | |
1277 | } | |
1278 | ||
002c8976 | 1279 | SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, off_t __user *, offset, size_t, count) |
1da177e4 LT |
1280 | { |
1281 | loff_t pos; | |
1282 | off_t off; | |
1283 | ssize_t ret; | |
1284 | ||
1285 | if (offset) { | |
1286 | if (unlikely(get_user(off, offset))) | |
1287 | return -EFAULT; | |
1288 | pos = off; | |
1289 | ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS); | |
1290 | if (unlikely(put_user(pos, offset))) | |
1291 | return -EFAULT; | |
1292 | return ret; | |
1293 | } | |
1294 | ||
1295 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1296 | } | |
1297 | ||
002c8976 | 1298 | SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, loff_t __user *, offset, size_t, count) |
1da177e4 LT |
1299 | { |
1300 | loff_t pos; | |
1301 | ssize_t ret; | |
1302 | ||
1303 | if (offset) { | |
1304 | if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t)))) | |
1305 | return -EFAULT; | |
1306 | ret = do_sendfile(out_fd, in_fd, &pos, count, 0); | |
1307 | if (unlikely(put_user(pos, offset))) | |
1308 | return -EFAULT; | |
1309 | return ret; | |
1310 | } | |
1311 | ||
1312 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1313 | } | |
19f4fc3a AV |
1314 | |
1315 | #ifdef CONFIG_COMPAT | |
1316 | COMPAT_SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, | |
1317 | compat_off_t __user *, offset, compat_size_t, count) | |
1318 | { | |
1319 | loff_t pos; | |
1320 | off_t off; | |
1321 | ssize_t ret; | |
1322 | ||
1323 | if (offset) { | |
1324 | if (unlikely(get_user(off, offset))) | |
1325 | return -EFAULT; | |
1326 | pos = off; | |
1327 | ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS); | |
1328 | if (unlikely(put_user(pos, offset))) | |
1329 | return -EFAULT; | |
1330 | return ret; | |
1331 | } | |
1332 | ||
1333 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1334 | } | |
1335 | ||
1336 | COMPAT_SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, | |
1337 | compat_loff_t __user *, offset, compat_size_t, count) | |
1338 | { | |
1339 | loff_t pos; | |
1340 | ssize_t ret; | |
1341 | ||
1342 | if (offset) { | |
1343 | if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t)))) | |
1344 | return -EFAULT; | |
1345 | ret = do_sendfile(out_fd, in_fd, &pos, count, 0); | |
1346 | if (unlikely(put_user(pos, offset))) | |
1347 | return -EFAULT; | |
1348 | return ret; | |
1349 | } | |
1350 | ||
1351 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1352 | } | |
1353 | #endif |