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 | ||
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); |
293bc982 AV |
480 | *ppos = kiocb.ki_pos; |
481 | return ret; | |
482 | } | |
483 | ||
493c84c0 AV |
484 | ssize_t __vfs_write(struct file *file, const char __user *p, size_t count, |
485 | loff_t *pos) | |
486 | { | |
487 | if (file->f_op->write) | |
488 | return file->f_op->write(file, p, count, pos); | |
493c84c0 AV |
489 | else if (file->f_op->write_iter) |
490 | return new_sync_write(file, p, count, pos); | |
491 | else | |
492 | return -EINVAL; | |
493 | } | |
494 | EXPORT_SYMBOL(__vfs_write); | |
495 | ||
06ae43f3 AV |
496 | ssize_t __kernel_write(struct file *file, const char *buf, size_t count, loff_t *pos) |
497 | { | |
498 | mm_segment_t old_fs; | |
499 | const char __user *p; | |
500 | ssize_t ret; | |
501 | ||
7f7f25e8 | 502 | if (!(file->f_mode & FMODE_CAN_WRITE)) |
3e84f48e AV |
503 | return -EINVAL; |
504 | ||
06ae43f3 AV |
505 | old_fs = get_fs(); |
506 | set_fs(get_ds()); | |
507 | p = (__force const char __user *)buf; | |
508 | if (count > MAX_RW_COUNT) | |
509 | count = MAX_RW_COUNT; | |
493c84c0 | 510 | ret = __vfs_write(file, p, count, pos); |
06ae43f3 AV |
511 | set_fs(old_fs); |
512 | if (ret > 0) { | |
513 | fsnotify_modify(file); | |
514 | add_wchar(current, ret); | |
515 | } | |
516 | inc_syscw(current); | |
517 | return ret; | |
518 | } | |
519 | ||
2ec3a12a AV |
520 | EXPORT_SYMBOL(__kernel_write); |
521 | ||
1da177e4 LT |
522 | ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_t *pos) |
523 | { | |
524 | ssize_t ret; | |
525 | ||
526 | if (!(file->f_mode & FMODE_WRITE)) | |
527 | return -EBADF; | |
7f7f25e8 | 528 | if (!(file->f_mode & FMODE_CAN_WRITE)) |
1da177e4 LT |
529 | return -EINVAL; |
530 | if (unlikely(!access_ok(VERIFY_READ, buf, count))) | |
531 | return -EFAULT; | |
532 | ||
533 | ret = rw_verify_area(WRITE, file, pos, count); | |
e28cc715 LT |
534 | if (ret >= 0) { |
535 | count = ret; | |
03d95eb2 | 536 | file_start_write(file); |
493c84c0 | 537 | ret = __vfs_write(file, buf, count, pos); |
c43e259c | 538 | if (ret > 0) { |
2a12a9d7 | 539 | fsnotify_modify(file); |
c43e259c | 540 | add_wchar(current, ret); |
1da177e4 | 541 | } |
c43e259c | 542 | inc_syscw(current); |
03d95eb2 | 543 | file_end_write(file); |
1da177e4 LT |
544 | } |
545 | ||
546 | return ret; | |
547 | } | |
548 | ||
549 | EXPORT_SYMBOL(vfs_write); | |
550 | ||
551 | static inline loff_t file_pos_read(struct file *file) | |
552 | { | |
553 | return file->f_pos; | |
554 | } | |
555 | ||
556 | static inline void file_pos_write(struct file *file, loff_t pos) | |
557 | { | |
558 | file->f_pos = pos; | |
559 | } | |
560 | ||
3cdad428 | 561 | SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count) |
1da177e4 | 562 | { |
9c225f26 | 563 | struct fd f = fdget_pos(fd); |
1da177e4 | 564 | ssize_t ret = -EBADF; |
1da177e4 | 565 | |
2903ff01 AV |
566 | if (f.file) { |
567 | loff_t pos = file_pos_read(f.file); | |
568 | ret = vfs_read(f.file, buf, count, &pos); | |
5faf153e AV |
569 | if (ret >= 0) |
570 | file_pos_write(f.file, pos); | |
9c225f26 | 571 | fdput_pos(f); |
1da177e4 | 572 | } |
1da177e4 LT |
573 | return ret; |
574 | } | |
1da177e4 | 575 | |
3cdad428 HC |
576 | SYSCALL_DEFINE3(write, unsigned int, fd, const char __user *, buf, |
577 | size_t, count) | |
1da177e4 | 578 | { |
9c225f26 | 579 | struct fd f = fdget_pos(fd); |
1da177e4 | 580 | ssize_t ret = -EBADF; |
1da177e4 | 581 | |
2903ff01 AV |
582 | if (f.file) { |
583 | loff_t pos = file_pos_read(f.file); | |
584 | ret = vfs_write(f.file, buf, count, &pos); | |
5faf153e AV |
585 | if (ret >= 0) |
586 | file_pos_write(f.file, pos); | |
9c225f26 | 587 | fdput_pos(f); |
1da177e4 LT |
588 | } |
589 | ||
590 | return ret; | |
591 | } | |
592 | ||
4a0fd5bf AV |
593 | SYSCALL_DEFINE4(pread64, unsigned int, fd, char __user *, buf, |
594 | size_t, count, loff_t, pos) | |
1da177e4 | 595 | { |
2903ff01 | 596 | struct fd f; |
1da177e4 | 597 | ssize_t ret = -EBADF; |
1da177e4 LT |
598 | |
599 | if (pos < 0) | |
600 | return -EINVAL; | |
601 | ||
2903ff01 AV |
602 | f = fdget(fd); |
603 | if (f.file) { | |
1da177e4 | 604 | ret = -ESPIPE; |
2903ff01 AV |
605 | if (f.file->f_mode & FMODE_PREAD) |
606 | ret = vfs_read(f.file, buf, count, &pos); | |
607 | fdput(f); | |
1da177e4 LT |
608 | } |
609 | ||
610 | return ret; | |
611 | } | |
612 | ||
4a0fd5bf AV |
613 | SYSCALL_DEFINE4(pwrite64, unsigned int, fd, const char __user *, buf, |
614 | size_t, count, loff_t, pos) | |
1da177e4 | 615 | { |
2903ff01 | 616 | struct fd f; |
1da177e4 | 617 | ssize_t ret = -EBADF; |
1da177e4 LT |
618 | |
619 | if (pos < 0) | |
620 | return -EINVAL; | |
621 | ||
2903ff01 AV |
622 | f = fdget(fd); |
623 | if (f.file) { | |
1da177e4 | 624 | ret = -ESPIPE; |
2903ff01 AV |
625 | if (f.file->f_mode & FMODE_PWRITE) |
626 | ret = vfs_write(f.file, buf, count, &pos); | |
627 | fdput(f); | |
1da177e4 LT |
628 | } |
629 | ||
630 | return ret; | |
631 | } | |
632 | ||
633 | /* | |
634 | * Reduce an iovec's length in-place. Return the resulting number of segments | |
635 | */ | |
636 | unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to) | |
637 | { | |
638 | unsigned long seg = 0; | |
639 | size_t len = 0; | |
640 | ||
641 | while (seg < nr_segs) { | |
642 | seg++; | |
643 | if (len + iov->iov_len >= to) { | |
644 | iov->iov_len = to - len; | |
645 | break; | |
646 | } | |
647 | len += iov->iov_len; | |
648 | iov++; | |
649 | } | |
650 | return seg; | |
651 | } | |
19295529 | 652 | EXPORT_SYMBOL(iov_shorten); |
1da177e4 | 653 | |
ac15ac06 AV |
654 | static ssize_t do_iter_readv_writev(struct file *filp, struct iov_iter *iter, |
655 | loff_t *ppos, iter_fn_t fn) | |
293bc982 AV |
656 | { |
657 | struct kiocb kiocb; | |
293bc982 AV |
658 | ssize_t ret; |
659 | ||
660 | init_sync_kiocb(&kiocb, filp); | |
661 | kiocb.ki_pos = *ppos; | |
293bc982 | 662 | |
ac15ac06 | 663 | ret = fn(&kiocb, iter); |
599bd19b | 664 | BUG_ON(ret == -EIOCBQUEUED); |
293bc982 AV |
665 | *ppos = kiocb.ki_pos; |
666 | return ret; | |
667 | } | |
668 | ||
ee0b3e67 | 669 | /* Do it by hand, with file-ops */ |
ac15ac06 AV |
670 | static ssize_t do_loop_readv_writev(struct file *filp, struct iov_iter *iter, |
671 | loff_t *ppos, io_fn_t fn) | |
ee0b3e67 | 672 | { |
ee0b3e67 BP |
673 | ssize_t ret = 0; |
674 | ||
ac15ac06 AV |
675 | while (iov_iter_count(iter)) { |
676 | struct iovec iovec = iov_iter_iovec(iter); | |
ee0b3e67 BP |
677 | ssize_t nr; |
678 | ||
ac15ac06 | 679 | nr = fn(filp, iovec.iov_base, iovec.iov_len, ppos); |
ee0b3e67 BP |
680 | |
681 | if (nr < 0) { | |
682 | if (!ret) | |
683 | ret = nr; | |
684 | break; | |
685 | } | |
686 | ret += nr; | |
ac15ac06 | 687 | if (nr != iovec.iov_len) |
ee0b3e67 | 688 | break; |
ac15ac06 | 689 | iov_iter_advance(iter, nr); |
ee0b3e67 BP |
690 | } |
691 | ||
692 | return ret; | |
693 | } | |
694 | ||
1da177e4 LT |
695 | /* A write operation does a read from user space and vice versa */ |
696 | #define vrfy_dir(type) ((type) == READ ? VERIFY_WRITE : VERIFY_READ) | |
697 | ||
eed4e51f BP |
698 | ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector, |
699 | unsigned long nr_segs, unsigned long fast_segs, | |
700 | struct iovec *fast_pointer, | |
ac34ebb3 | 701 | struct iovec **ret_pointer) |
435f49a5 | 702 | { |
eed4e51f | 703 | unsigned long seg; |
435f49a5 | 704 | ssize_t ret; |
eed4e51f BP |
705 | struct iovec *iov = fast_pointer; |
706 | ||
435f49a5 LT |
707 | /* |
708 | * SuS says "The readv() function *may* fail if the iovcnt argument | |
709 | * was less than or equal to 0, or greater than {IOV_MAX}. Linux has | |
710 | * traditionally returned zero for zero segments, so... | |
711 | */ | |
eed4e51f BP |
712 | if (nr_segs == 0) { |
713 | ret = 0; | |
435f49a5 | 714 | goto out; |
eed4e51f BP |
715 | } |
716 | ||
435f49a5 LT |
717 | /* |
718 | * First get the "struct iovec" from user memory and | |
719 | * verify all the pointers | |
720 | */ | |
eed4e51f BP |
721 | if (nr_segs > UIO_MAXIOV) { |
722 | ret = -EINVAL; | |
435f49a5 | 723 | goto out; |
eed4e51f BP |
724 | } |
725 | if (nr_segs > fast_segs) { | |
435f49a5 | 726 | iov = kmalloc(nr_segs*sizeof(struct iovec), GFP_KERNEL); |
eed4e51f BP |
727 | if (iov == NULL) { |
728 | ret = -ENOMEM; | |
435f49a5 | 729 | goto out; |
eed4e51f | 730 | } |
435f49a5 | 731 | } |
eed4e51f BP |
732 | if (copy_from_user(iov, uvector, nr_segs*sizeof(*uvector))) { |
733 | ret = -EFAULT; | |
435f49a5 | 734 | goto out; |
eed4e51f BP |
735 | } |
736 | ||
435f49a5 | 737 | /* |
eed4e51f BP |
738 | * According to the Single Unix Specification we should return EINVAL |
739 | * if an element length is < 0 when cast to ssize_t or if the | |
740 | * total length would overflow the ssize_t return value of the | |
741 | * system call. | |
435f49a5 LT |
742 | * |
743 | * Linux caps all read/write calls to MAX_RW_COUNT, and avoids the | |
744 | * overflow case. | |
745 | */ | |
eed4e51f | 746 | ret = 0; |
435f49a5 LT |
747 | for (seg = 0; seg < nr_segs; seg++) { |
748 | void __user *buf = iov[seg].iov_base; | |
749 | ssize_t len = (ssize_t)iov[seg].iov_len; | |
eed4e51f BP |
750 | |
751 | /* see if we we're about to use an invalid len or if | |
752 | * it's about to overflow ssize_t */ | |
435f49a5 | 753 | if (len < 0) { |
eed4e51f | 754 | ret = -EINVAL; |
435f49a5 | 755 | goto out; |
eed4e51f | 756 | } |
ac34ebb3 | 757 | if (type >= 0 |
fcf63409 | 758 | && unlikely(!access_ok(vrfy_dir(type), buf, len))) { |
eed4e51f | 759 | ret = -EFAULT; |
435f49a5 LT |
760 | goto out; |
761 | } | |
762 | if (len > MAX_RW_COUNT - ret) { | |
763 | len = MAX_RW_COUNT - ret; | |
764 | iov[seg].iov_len = len; | |
eed4e51f | 765 | } |
eed4e51f | 766 | ret += len; |
435f49a5 | 767 | } |
eed4e51f BP |
768 | out: |
769 | *ret_pointer = iov; | |
770 | return ret; | |
771 | } | |
772 | ||
1da177e4 LT |
773 | static ssize_t do_readv_writev(int type, struct file *file, |
774 | const struct iovec __user * uvector, | |
775 | unsigned long nr_segs, loff_t *pos) | |
776 | { | |
1da177e4 LT |
777 | size_t tot_len; |
778 | struct iovec iovstack[UIO_FASTIOV]; | |
ee0b3e67 | 779 | struct iovec *iov = iovstack; |
ac15ac06 | 780 | struct iov_iter iter; |
1da177e4 | 781 | ssize_t ret; |
1da177e4 | 782 | io_fn_t fn; |
293bc982 | 783 | iter_fn_t iter_fn; |
1da177e4 | 784 | |
0504c074 AV |
785 | ret = import_iovec(type, uvector, nr_segs, |
786 | ARRAY_SIZE(iovstack), &iov, &iter); | |
787 | if (ret < 0) | |
788 | return ret; | |
1da177e4 | 789 | |
0504c074 AV |
790 | tot_len = iov_iter_count(&iter); |
791 | if (!tot_len) | |
792 | goto out; | |
1da177e4 | 793 | ret = rw_verify_area(type, file, pos, tot_len); |
e28cc715 | 794 | if (ret < 0) |
411b67b4 | 795 | goto out; |
1da177e4 | 796 | |
1da177e4 LT |
797 | if (type == READ) { |
798 | fn = file->f_op->read; | |
293bc982 | 799 | iter_fn = file->f_op->read_iter; |
1da177e4 LT |
800 | } else { |
801 | fn = (io_fn_t)file->f_op->write; | |
293bc982 | 802 | iter_fn = file->f_op->write_iter; |
03d95eb2 | 803 | file_start_write(file); |
1da177e4 LT |
804 | } |
805 | ||
293bc982 | 806 | if (iter_fn) |
ac15ac06 | 807 | ret = do_iter_readv_writev(file, &iter, pos, iter_fn); |
ee0b3e67 | 808 | else |
ac15ac06 | 809 | ret = do_loop_readv_writev(file, &iter, pos, fn); |
1da177e4 | 810 | |
03d95eb2 AV |
811 | if (type != READ) |
812 | file_end_write(file); | |
813 | ||
1da177e4 | 814 | out: |
0504c074 | 815 | kfree(iov); |
0eeca283 RL |
816 | if ((ret + (type == READ)) > 0) { |
817 | if (type == READ) | |
2a12a9d7 | 818 | fsnotify_access(file); |
0eeca283 | 819 | else |
2a12a9d7 | 820 | fsnotify_modify(file); |
0eeca283 | 821 | } |
1da177e4 | 822 | return ret; |
1da177e4 LT |
823 | } |
824 | ||
825 | ssize_t vfs_readv(struct file *file, const struct iovec __user *vec, | |
826 | unsigned long vlen, loff_t *pos) | |
827 | { | |
828 | if (!(file->f_mode & FMODE_READ)) | |
829 | return -EBADF; | |
7f7f25e8 | 830 | if (!(file->f_mode & FMODE_CAN_READ)) |
1da177e4 LT |
831 | return -EINVAL; |
832 | ||
833 | return do_readv_writev(READ, file, vec, vlen, pos); | |
834 | } | |
835 | ||
836 | EXPORT_SYMBOL(vfs_readv); | |
837 | ||
838 | ssize_t vfs_writev(struct file *file, const struct iovec __user *vec, | |
839 | unsigned long vlen, loff_t *pos) | |
840 | { | |
841 | if (!(file->f_mode & FMODE_WRITE)) | |
842 | return -EBADF; | |
7f7f25e8 | 843 | if (!(file->f_mode & FMODE_CAN_WRITE)) |
1da177e4 LT |
844 | return -EINVAL; |
845 | ||
846 | return do_readv_writev(WRITE, file, vec, vlen, pos); | |
847 | } | |
848 | ||
849 | EXPORT_SYMBOL(vfs_writev); | |
850 | ||
3cdad428 HC |
851 | SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec, |
852 | unsigned long, vlen) | |
1da177e4 | 853 | { |
9c225f26 | 854 | struct fd f = fdget_pos(fd); |
1da177e4 | 855 | ssize_t ret = -EBADF; |
1da177e4 | 856 | |
2903ff01 AV |
857 | if (f.file) { |
858 | loff_t pos = file_pos_read(f.file); | |
859 | ret = vfs_readv(f.file, vec, vlen, &pos); | |
5faf153e AV |
860 | if (ret >= 0) |
861 | file_pos_write(f.file, pos); | |
9c225f26 | 862 | fdput_pos(f); |
1da177e4 LT |
863 | } |
864 | ||
865 | if (ret > 0) | |
4b98d11b AD |
866 | add_rchar(current, ret); |
867 | inc_syscr(current); | |
1da177e4 LT |
868 | return ret; |
869 | } | |
870 | ||
3cdad428 HC |
871 | SYSCALL_DEFINE3(writev, unsigned long, fd, const struct iovec __user *, vec, |
872 | unsigned long, vlen) | |
1da177e4 | 873 | { |
9c225f26 | 874 | struct fd f = fdget_pos(fd); |
1da177e4 | 875 | ssize_t ret = -EBADF; |
1da177e4 | 876 | |
2903ff01 AV |
877 | if (f.file) { |
878 | loff_t pos = file_pos_read(f.file); | |
879 | ret = vfs_writev(f.file, vec, vlen, &pos); | |
5faf153e AV |
880 | if (ret >= 0) |
881 | file_pos_write(f.file, pos); | |
9c225f26 | 882 | fdput_pos(f); |
1da177e4 LT |
883 | } |
884 | ||
885 | if (ret > 0) | |
4b98d11b AD |
886 | add_wchar(current, ret); |
887 | inc_syscw(current); | |
1da177e4 LT |
888 | return ret; |
889 | } | |
890 | ||
601cc11d LT |
891 | static inline loff_t pos_from_hilo(unsigned long high, unsigned long low) |
892 | { | |
893 | #define HALF_LONG_BITS (BITS_PER_LONG / 2) | |
894 | return (((loff_t)high << HALF_LONG_BITS) << HALF_LONG_BITS) | low; | |
895 | } | |
896 | ||
f3554f4b | 897 | SYSCALL_DEFINE5(preadv, unsigned long, fd, const struct iovec __user *, vec, |
601cc11d | 898 | unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h) |
f3554f4b | 899 | { |
601cc11d | 900 | loff_t pos = pos_from_hilo(pos_h, pos_l); |
2903ff01 | 901 | struct fd f; |
f3554f4b | 902 | ssize_t ret = -EBADF; |
f3554f4b GH |
903 | |
904 | if (pos < 0) | |
905 | return -EINVAL; | |
906 | ||
2903ff01 AV |
907 | f = fdget(fd); |
908 | if (f.file) { | |
f3554f4b | 909 | ret = -ESPIPE; |
2903ff01 AV |
910 | if (f.file->f_mode & FMODE_PREAD) |
911 | ret = vfs_readv(f.file, vec, vlen, &pos); | |
912 | fdput(f); | |
f3554f4b GH |
913 | } |
914 | ||
915 | if (ret > 0) | |
916 | add_rchar(current, ret); | |
917 | inc_syscr(current); | |
918 | return ret; | |
919 | } | |
920 | ||
921 | SYSCALL_DEFINE5(pwritev, unsigned long, fd, const struct iovec __user *, vec, | |
601cc11d | 922 | unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h) |
f3554f4b | 923 | { |
601cc11d | 924 | loff_t pos = pos_from_hilo(pos_h, pos_l); |
2903ff01 | 925 | struct fd f; |
f3554f4b | 926 | ssize_t ret = -EBADF; |
f3554f4b GH |
927 | |
928 | if (pos < 0) | |
929 | return -EINVAL; | |
930 | ||
2903ff01 AV |
931 | f = fdget(fd); |
932 | if (f.file) { | |
f3554f4b | 933 | ret = -ESPIPE; |
2903ff01 AV |
934 | if (f.file->f_mode & FMODE_PWRITE) |
935 | ret = vfs_writev(f.file, vec, vlen, &pos); | |
936 | fdput(f); | |
f3554f4b GH |
937 | } |
938 | ||
939 | if (ret > 0) | |
940 | add_wchar(current, ret); | |
941 | inc_syscw(current); | |
942 | return ret; | |
943 | } | |
944 | ||
72ec3516 AV |
945 | #ifdef CONFIG_COMPAT |
946 | ||
947 | static ssize_t compat_do_readv_writev(int type, struct file *file, | |
948 | const struct compat_iovec __user *uvector, | |
949 | unsigned long nr_segs, loff_t *pos) | |
950 | { | |
951 | compat_ssize_t tot_len; | |
952 | struct iovec iovstack[UIO_FASTIOV]; | |
953 | struct iovec *iov = iovstack; | |
ac15ac06 | 954 | struct iov_iter iter; |
72ec3516 AV |
955 | ssize_t ret; |
956 | io_fn_t fn; | |
293bc982 | 957 | iter_fn_t iter_fn; |
72ec3516 | 958 | |
0504c074 AV |
959 | ret = compat_import_iovec(type, uvector, nr_segs, |
960 | UIO_FASTIOV, &iov, &iter); | |
961 | if (ret < 0) | |
962 | return ret; | |
72ec3516 | 963 | |
0504c074 AV |
964 | tot_len = iov_iter_count(&iter); |
965 | if (!tot_len) | |
966 | goto out; | |
72ec3516 AV |
967 | ret = rw_verify_area(type, file, pos, tot_len); |
968 | if (ret < 0) | |
969 | goto out; | |
970 | ||
72ec3516 AV |
971 | if (type == READ) { |
972 | fn = file->f_op->read; | |
293bc982 | 973 | iter_fn = file->f_op->read_iter; |
72ec3516 AV |
974 | } else { |
975 | fn = (io_fn_t)file->f_op->write; | |
293bc982 | 976 | iter_fn = file->f_op->write_iter; |
03d95eb2 | 977 | file_start_write(file); |
72ec3516 AV |
978 | } |
979 | ||
293bc982 | 980 | if (iter_fn) |
ac15ac06 | 981 | ret = do_iter_readv_writev(file, &iter, pos, iter_fn); |
03d95eb2 | 982 | else |
ac15ac06 | 983 | ret = do_loop_readv_writev(file, &iter, pos, fn); |
72ec3516 | 984 | |
03d95eb2 AV |
985 | if (type != READ) |
986 | file_end_write(file); | |
987 | ||
72ec3516 | 988 | out: |
0504c074 | 989 | kfree(iov); |
72ec3516 AV |
990 | if ((ret + (type == READ)) > 0) { |
991 | if (type == READ) | |
992 | fsnotify_access(file); | |
993 | else | |
994 | fsnotify_modify(file); | |
995 | } | |
996 | return ret; | |
997 | } | |
998 | ||
999 | static size_t compat_readv(struct file *file, | |
1000 | const struct compat_iovec __user *vec, | |
1001 | unsigned long vlen, loff_t *pos) | |
1002 | { | |
1003 | ssize_t ret = -EBADF; | |
1004 | ||
1005 | if (!(file->f_mode & FMODE_READ)) | |
1006 | goto out; | |
1007 | ||
1008 | ret = -EINVAL; | |
7f7f25e8 | 1009 | if (!(file->f_mode & FMODE_CAN_READ)) |
72ec3516 AV |
1010 | goto out; |
1011 | ||
1012 | ret = compat_do_readv_writev(READ, file, vec, vlen, pos); | |
1013 | ||
1014 | out: | |
1015 | if (ret > 0) | |
1016 | add_rchar(current, ret); | |
1017 | inc_syscr(current); | |
1018 | return ret; | |
1019 | } | |
1020 | ||
dfd948e3 | 1021 | COMPAT_SYSCALL_DEFINE3(readv, compat_ulong_t, fd, |
72ec3516 | 1022 | const struct compat_iovec __user *,vec, |
dfd948e3 | 1023 | compat_ulong_t, vlen) |
72ec3516 | 1024 | { |
9c225f26 | 1025 | struct fd f = fdget_pos(fd); |
72ec3516 AV |
1026 | ssize_t ret; |
1027 | loff_t pos; | |
1028 | ||
1029 | if (!f.file) | |
1030 | return -EBADF; | |
1031 | pos = f.file->f_pos; | |
1032 | ret = compat_readv(f.file, vec, vlen, &pos); | |
5faf153e AV |
1033 | if (ret >= 0) |
1034 | f.file->f_pos = pos; | |
9c225f26 | 1035 | fdput_pos(f); |
72ec3516 AV |
1036 | return ret; |
1037 | } | |
1038 | ||
378a10f3 HC |
1039 | static long __compat_sys_preadv64(unsigned long fd, |
1040 | const struct compat_iovec __user *vec, | |
1041 | unsigned long vlen, loff_t pos) | |
72ec3516 AV |
1042 | { |
1043 | struct fd f; | |
1044 | ssize_t ret; | |
1045 | ||
1046 | if (pos < 0) | |
1047 | return -EINVAL; | |
1048 | f = fdget(fd); | |
1049 | if (!f.file) | |
1050 | return -EBADF; | |
1051 | ret = -ESPIPE; | |
1052 | if (f.file->f_mode & FMODE_PREAD) | |
1053 | ret = compat_readv(f.file, vec, vlen, &pos); | |
1054 | fdput(f); | |
1055 | return ret; | |
1056 | } | |
1057 | ||
378a10f3 HC |
1058 | #ifdef __ARCH_WANT_COMPAT_SYS_PREADV64 |
1059 | COMPAT_SYSCALL_DEFINE4(preadv64, unsigned long, fd, | |
1060 | const struct compat_iovec __user *,vec, | |
1061 | unsigned long, vlen, loff_t, pos) | |
1062 | { | |
1063 | return __compat_sys_preadv64(fd, vec, vlen, pos); | |
1064 | } | |
1065 | #endif | |
1066 | ||
dfd948e3 | 1067 | COMPAT_SYSCALL_DEFINE5(preadv, compat_ulong_t, fd, |
72ec3516 | 1068 | const struct compat_iovec __user *,vec, |
dfd948e3 | 1069 | compat_ulong_t, vlen, u32, pos_low, u32, pos_high) |
72ec3516 AV |
1070 | { |
1071 | loff_t pos = ((loff_t)pos_high << 32) | pos_low; | |
378a10f3 HC |
1072 | |
1073 | return __compat_sys_preadv64(fd, vec, vlen, pos); | |
72ec3516 AV |
1074 | } |
1075 | ||
1076 | static size_t compat_writev(struct file *file, | |
1077 | const struct compat_iovec __user *vec, | |
1078 | unsigned long vlen, loff_t *pos) | |
1079 | { | |
1080 | ssize_t ret = -EBADF; | |
1081 | ||
1082 | if (!(file->f_mode & FMODE_WRITE)) | |
1083 | goto out; | |
1084 | ||
1085 | ret = -EINVAL; | |
7f7f25e8 | 1086 | if (!(file->f_mode & FMODE_CAN_WRITE)) |
72ec3516 AV |
1087 | goto out; |
1088 | ||
1089 | ret = compat_do_readv_writev(WRITE, file, vec, vlen, pos); | |
1090 | ||
1091 | out: | |
1092 | if (ret > 0) | |
1093 | add_wchar(current, ret); | |
1094 | inc_syscw(current); | |
1095 | return ret; | |
1096 | } | |
1097 | ||
dfd948e3 | 1098 | COMPAT_SYSCALL_DEFINE3(writev, compat_ulong_t, fd, |
72ec3516 | 1099 | const struct compat_iovec __user *, vec, |
dfd948e3 | 1100 | compat_ulong_t, vlen) |
72ec3516 | 1101 | { |
9c225f26 | 1102 | struct fd f = fdget_pos(fd); |
72ec3516 AV |
1103 | ssize_t ret; |
1104 | loff_t pos; | |
1105 | ||
1106 | if (!f.file) | |
1107 | return -EBADF; | |
1108 | pos = f.file->f_pos; | |
1109 | ret = compat_writev(f.file, vec, vlen, &pos); | |
5faf153e AV |
1110 | if (ret >= 0) |
1111 | f.file->f_pos = pos; | |
9c225f26 | 1112 | fdput_pos(f); |
72ec3516 AV |
1113 | return ret; |
1114 | } | |
1115 | ||
378a10f3 HC |
1116 | static long __compat_sys_pwritev64(unsigned long fd, |
1117 | const struct compat_iovec __user *vec, | |
1118 | unsigned long vlen, loff_t pos) | |
72ec3516 AV |
1119 | { |
1120 | struct fd f; | |
1121 | ssize_t ret; | |
1122 | ||
1123 | if (pos < 0) | |
1124 | return -EINVAL; | |
1125 | f = fdget(fd); | |
1126 | if (!f.file) | |
1127 | return -EBADF; | |
1128 | ret = -ESPIPE; | |
1129 | if (f.file->f_mode & FMODE_PWRITE) | |
1130 | ret = compat_writev(f.file, vec, vlen, &pos); | |
1131 | fdput(f); | |
1132 | return ret; | |
1133 | } | |
1134 | ||
378a10f3 HC |
1135 | #ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64 |
1136 | COMPAT_SYSCALL_DEFINE4(pwritev64, unsigned long, fd, | |
1137 | const struct compat_iovec __user *,vec, | |
1138 | unsigned long, vlen, loff_t, pos) | |
1139 | { | |
1140 | return __compat_sys_pwritev64(fd, vec, vlen, pos); | |
1141 | } | |
1142 | #endif | |
1143 | ||
dfd948e3 | 1144 | COMPAT_SYSCALL_DEFINE5(pwritev, compat_ulong_t, fd, |
72ec3516 | 1145 | const struct compat_iovec __user *,vec, |
dfd948e3 | 1146 | compat_ulong_t, vlen, u32, pos_low, u32, pos_high) |
72ec3516 AV |
1147 | { |
1148 | loff_t pos = ((loff_t)pos_high << 32) | pos_low; | |
378a10f3 HC |
1149 | |
1150 | return __compat_sys_pwritev64(fd, vec, vlen, pos); | |
72ec3516 AV |
1151 | } |
1152 | #endif | |
1153 | ||
19f4fc3a AV |
1154 | static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, |
1155 | size_t count, loff_t max) | |
1da177e4 | 1156 | { |
2903ff01 AV |
1157 | struct fd in, out; |
1158 | struct inode *in_inode, *out_inode; | |
1da177e4 | 1159 | loff_t pos; |
7995bd28 | 1160 | loff_t out_pos; |
1da177e4 | 1161 | ssize_t retval; |
2903ff01 | 1162 | int fl; |
1da177e4 LT |
1163 | |
1164 | /* | |
1165 | * Get input file, and verify that it is ok.. | |
1166 | */ | |
1167 | retval = -EBADF; | |
2903ff01 AV |
1168 | in = fdget(in_fd); |
1169 | if (!in.file) | |
1da177e4 | 1170 | goto out; |
2903ff01 | 1171 | if (!(in.file->f_mode & FMODE_READ)) |
1da177e4 | 1172 | goto fput_in; |
1da177e4 | 1173 | retval = -ESPIPE; |
7995bd28 AV |
1174 | if (!ppos) { |
1175 | pos = in.file->f_pos; | |
1176 | } else { | |
1177 | pos = *ppos; | |
2903ff01 | 1178 | if (!(in.file->f_mode & FMODE_PREAD)) |
1da177e4 | 1179 | goto fput_in; |
7995bd28 AV |
1180 | } |
1181 | retval = rw_verify_area(READ, in.file, &pos, count); | |
e28cc715 | 1182 | if (retval < 0) |
1da177e4 | 1183 | goto fput_in; |
e28cc715 | 1184 | count = retval; |
1da177e4 | 1185 | |
1da177e4 LT |
1186 | /* |
1187 | * Get output file, and verify that it is ok.. | |
1188 | */ | |
1189 | retval = -EBADF; | |
2903ff01 AV |
1190 | out = fdget(out_fd); |
1191 | if (!out.file) | |
1da177e4 | 1192 | goto fput_in; |
2903ff01 | 1193 | if (!(out.file->f_mode & FMODE_WRITE)) |
1da177e4 LT |
1194 | goto fput_out; |
1195 | retval = -EINVAL; | |
496ad9aa AV |
1196 | in_inode = file_inode(in.file); |
1197 | out_inode = file_inode(out.file); | |
7995bd28 AV |
1198 | out_pos = out.file->f_pos; |
1199 | retval = rw_verify_area(WRITE, out.file, &out_pos, count); | |
e28cc715 | 1200 | if (retval < 0) |
1da177e4 | 1201 | goto fput_out; |
e28cc715 | 1202 | count = retval; |
1da177e4 | 1203 | |
1da177e4 LT |
1204 | if (!max) |
1205 | max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes); | |
1206 | ||
1da177e4 LT |
1207 | if (unlikely(pos + count > max)) { |
1208 | retval = -EOVERFLOW; | |
1209 | if (pos >= max) | |
1210 | goto fput_out; | |
1211 | count = max - pos; | |
1212 | } | |
1213 | ||
d96e6e71 | 1214 | fl = 0; |
534f2aaa | 1215 | #if 0 |
d96e6e71 JA |
1216 | /* |
1217 | * We need to debate whether we can enable this or not. The | |
1218 | * man page documents EAGAIN return for the output at least, | |
1219 | * and the application is arguably buggy if it doesn't expect | |
1220 | * EAGAIN on a non-blocking file descriptor. | |
1221 | */ | |
2903ff01 | 1222 | if (in.file->f_flags & O_NONBLOCK) |
d96e6e71 | 1223 | fl = SPLICE_F_NONBLOCK; |
534f2aaa | 1224 | #endif |
50cd2c57 | 1225 | file_start_write(out.file); |
7995bd28 | 1226 | retval = do_splice_direct(in.file, &pos, out.file, &out_pos, count, fl); |
50cd2c57 | 1227 | file_end_write(out.file); |
1da177e4 LT |
1228 | |
1229 | if (retval > 0) { | |
4b98d11b AD |
1230 | add_rchar(current, retval); |
1231 | add_wchar(current, retval); | |
a68c2f12 SW |
1232 | fsnotify_access(in.file); |
1233 | fsnotify_modify(out.file); | |
7995bd28 AV |
1234 | out.file->f_pos = out_pos; |
1235 | if (ppos) | |
1236 | *ppos = pos; | |
1237 | else | |
1238 | in.file->f_pos = pos; | |
1da177e4 | 1239 | } |
1da177e4 | 1240 | |
4b98d11b AD |
1241 | inc_syscr(current); |
1242 | inc_syscw(current); | |
7995bd28 | 1243 | if (pos > max) |
1da177e4 LT |
1244 | retval = -EOVERFLOW; |
1245 | ||
1246 | fput_out: | |
2903ff01 | 1247 | fdput(out); |
1da177e4 | 1248 | fput_in: |
2903ff01 | 1249 | fdput(in); |
1da177e4 LT |
1250 | out: |
1251 | return retval; | |
1252 | } | |
1253 | ||
002c8976 | 1254 | SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, off_t __user *, offset, size_t, count) |
1da177e4 LT |
1255 | { |
1256 | loff_t pos; | |
1257 | off_t off; | |
1258 | ssize_t ret; | |
1259 | ||
1260 | if (offset) { | |
1261 | if (unlikely(get_user(off, offset))) | |
1262 | return -EFAULT; | |
1263 | pos = off; | |
1264 | ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS); | |
1265 | if (unlikely(put_user(pos, offset))) | |
1266 | return -EFAULT; | |
1267 | return ret; | |
1268 | } | |
1269 | ||
1270 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1271 | } | |
1272 | ||
002c8976 | 1273 | SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, loff_t __user *, offset, size_t, count) |
1da177e4 LT |
1274 | { |
1275 | loff_t pos; | |
1276 | ssize_t ret; | |
1277 | ||
1278 | if (offset) { | |
1279 | if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t)))) | |
1280 | return -EFAULT; | |
1281 | ret = do_sendfile(out_fd, in_fd, &pos, count, 0); | |
1282 | if (unlikely(put_user(pos, offset))) | |
1283 | return -EFAULT; | |
1284 | return ret; | |
1285 | } | |
1286 | ||
1287 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1288 | } | |
19f4fc3a AV |
1289 | |
1290 | #ifdef CONFIG_COMPAT | |
1291 | COMPAT_SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, | |
1292 | compat_off_t __user *, offset, compat_size_t, count) | |
1293 | { | |
1294 | loff_t pos; | |
1295 | off_t off; | |
1296 | ssize_t ret; | |
1297 | ||
1298 | if (offset) { | |
1299 | if (unlikely(get_user(off, offset))) | |
1300 | return -EFAULT; | |
1301 | pos = off; | |
1302 | ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS); | |
1303 | if (unlikely(put_user(pos, offset))) | |
1304 | return -EFAULT; | |
1305 | return ret; | |
1306 | } | |
1307 | ||
1308 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1309 | } | |
1310 | ||
1311 | COMPAT_SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, | |
1312 | compat_loff_t __user *, offset, compat_size_t, count) | |
1313 | { | |
1314 | loff_t pos; | |
1315 | ssize_t ret; | |
1316 | ||
1317 | if (offset) { | |
1318 | if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t)))) | |
1319 | return -EFAULT; | |
1320 | ret = do_sendfile(out_fd, in_fd, &pos, count, 0); | |
1321 | if (unlikely(put_user(pos, offset))) | |
1322 | return -EFAULT; | |
1323 | return ret; | |
1324 | } | |
1325 | ||
1326 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1327 | } | |
1328 | #endif |