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> | |
a27bb332 | 12 | #include <linux/aio.h> |
0eeca283 | 13 | #include <linux/fsnotify.h> |
1da177e4 | 14 | #include <linux/security.h> |
630d9c47 | 15 | #include <linux/export.h> |
1da177e4 | 16 | #include <linux/syscalls.h> |
e28cc715 | 17 | #include <linux/pagemap.h> |
d6b29d7c | 18 | #include <linux/splice.h> |
561c6731 | 19 | #include <linux/compat.h> |
06ae43f3 | 20 | #include "internal.h" |
1da177e4 LT |
21 | |
22 | #include <asm/uaccess.h> | |
23 | #include <asm/unistd.h> | |
24 | ||
c0bd14af AV |
25 | typedef ssize_t (*io_fn_t)(struct file *, char __user *, size_t, loff_t *); |
26 | typedef ssize_t (*iov_fn_t)(struct kiocb *, const struct iovec *, | |
27 | unsigned long, loff_t); | |
293bc982 | 28 | typedef ssize_t (*iter_fn_t)(struct kiocb *, struct iov_iter *); |
c0bd14af | 29 | |
4b6f5d20 | 30 | const struct file_operations generic_ro_fops = { |
1da177e4 | 31 | .llseek = generic_file_llseek, |
aad4f8bb AV |
32 | .read = new_sync_read, |
33 | .read_iter = generic_file_read_iter, | |
1da177e4 | 34 | .mmap = generic_file_readonly_mmap, |
534f2aaa | 35 | .splice_read = generic_file_splice_read, |
1da177e4 LT |
36 | }; |
37 | ||
38 | EXPORT_SYMBOL(generic_ro_fops); | |
39 | ||
cccb5a1e | 40 | static inline int unsigned_offsets(struct file *file) |
4a3956c7 | 41 | { |
cccb5a1e | 42 | return file->f_mode & FMODE_UNSIGNED_OFFSET; |
4a3956c7 KH |
43 | } |
44 | ||
46a1c2c7 JL |
45 | /** |
46 | * vfs_setpos - update the file offset for lseek | |
47 | * @file: file structure in question | |
48 | * @offset: file offset to seek to | |
49 | * @maxsize: maximum file size | |
50 | * | |
51 | * This is a low-level filesystem helper for updating the file offset to | |
52 | * the value specified by @offset if the given offset is valid and it is | |
53 | * not equal to the current file offset. | |
54 | * | |
55 | * Return the specified offset on success and -EINVAL on invalid offset. | |
56 | */ | |
57 | loff_t vfs_setpos(struct file *file, loff_t offset, loff_t maxsize) | |
ef3d0fd2 AK |
58 | { |
59 | if (offset < 0 && !unsigned_offsets(file)) | |
60 | return -EINVAL; | |
61 | if (offset > maxsize) | |
62 | return -EINVAL; | |
63 | ||
64 | if (offset != file->f_pos) { | |
65 | file->f_pos = offset; | |
66 | file->f_version = 0; | |
67 | } | |
68 | return offset; | |
69 | } | |
46a1c2c7 | 70 | EXPORT_SYMBOL(vfs_setpos); |
ef3d0fd2 | 71 | |
3a8cff4f | 72 | /** |
5760495a | 73 | * generic_file_llseek_size - generic llseek implementation for regular files |
3a8cff4f CH |
74 | * @file: file structure to seek on |
75 | * @offset: file offset to seek to | |
965c8e59 | 76 | * @whence: type of seek |
e8b96eb5 ES |
77 | * @size: max size of this file in file system |
78 | * @eof: offset used for SEEK_END position | |
3a8cff4f | 79 | * |
5760495a | 80 | * This is a variant of generic_file_llseek that allows passing in a custom |
e8b96eb5 | 81 | * maximum file size and a custom EOF position, for e.g. hashed directories |
ef3d0fd2 AK |
82 | * |
83 | * Synchronization: | |
5760495a | 84 | * SEEK_SET and SEEK_END are unsynchronized (but atomic on 64bit platforms) |
ef3d0fd2 AK |
85 | * SEEK_CUR is synchronized against other SEEK_CURs, but not read/writes. |
86 | * read/writes behave like SEEK_SET against seeks. | |
3a8cff4f | 87 | */ |
9465efc9 | 88 | loff_t |
965c8e59 | 89 | generic_file_llseek_size(struct file *file, loff_t offset, int whence, |
e8b96eb5 | 90 | loff_t maxsize, loff_t eof) |
1da177e4 | 91 | { |
965c8e59 | 92 | switch (whence) { |
3a8cff4f | 93 | case SEEK_END: |
e8b96eb5 | 94 | offset += eof; |
3a8cff4f CH |
95 | break; |
96 | case SEEK_CUR: | |
5b6f1eb9 AK |
97 | /* |
98 | * Here we special-case the lseek(fd, 0, SEEK_CUR) | |
99 | * position-querying operation. Avoid rewriting the "same" | |
100 | * f_pos value back to the file because a concurrent read(), | |
101 | * write() or lseek() might have altered it | |
102 | */ | |
103 | if (offset == 0) | |
104 | return file->f_pos; | |
ef3d0fd2 AK |
105 | /* |
106 | * f_lock protects against read/modify/write race with other | |
107 | * SEEK_CURs. Note that parallel writes and reads behave | |
108 | * like SEEK_SET. | |
109 | */ | |
110 | spin_lock(&file->f_lock); | |
46a1c2c7 | 111 | offset = vfs_setpos(file, file->f_pos + offset, maxsize); |
ef3d0fd2 AK |
112 | spin_unlock(&file->f_lock); |
113 | return offset; | |
982d8165 JB |
114 | case SEEK_DATA: |
115 | /* | |
116 | * In the generic case the entire file is data, so as long as | |
117 | * offset isn't at the end of the file then the offset is data. | |
118 | */ | |
e8b96eb5 | 119 | if (offset >= eof) |
982d8165 JB |
120 | return -ENXIO; |
121 | break; | |
122 | case SEEK_HOLE: | |
123 | /* | |
124 | * There is a virtual hole at the end of the file, so as long as | |
125 | * offset isn't i_size or larger, return i_size. | |
126 | */ | |
e8b96eb5 | 127 | if (offset >= eof) |
982d8165 | 128 | return -ENXIO; |
e8b96eb5 | 129 | offset = eof; |
982d8165 | 130 | break; |
1da177e4 | 131 | } |
3a8cff4f | 132 | |
46a1c2c7 | 133 | return vfs_setpos(file, offset, maxsize); |
5760495a AK |
134 | } |
135 | EXPORT_SYMBOL(generic_file_llseek_size); | |
136 | ||
137 | /** | |
138 | * generic_file_llseek - generic llseek implementation for regular files | |
139 | * @file: file structure to seek on | |
140 | * @offset: file offset to seek to | |
965c8e59 | 141 | * @whence: type of seek |
5760495a AK |
142 | * |
143 | * This is a generic implemenation of ->llseek useable for all normal local | |
144 | * filesystems. It just updates the file offset to the value specified by | |
546ae2d2 | 145 | * @offset and @whence. |
5760495a | 146 | */ |
965c8e59 | 147 | loff_t generic_file_llseek(struct file *file, loff_t offset, int whence) |
5760495a AK |
148 | { |
149 | struct inode *inode = file->f_mapping->host; | |
150 | ||
965c8e59 | 151 | return generic_file_llseek_size(file, offset, whence, |
e8b96eb5 ES |
152 | inode->i_sb->s_maxbytes, |
153 | i_size_read(inode)); | |
1da177e4 | 154 | } |
9465efc9 | 155 | EXPORT_SYMBOL(generic_file_llseek); |
1da177e4 | 156 | |
1bf9d14d AV |
157 | /** |
158 | * fixed_size_llseek - llseek implementation for fixed-sized devices | |
159 | * @file: file structure to seek on | |
160 | * @offset: file offset to seek to | |
161 | * @whence: type of seek | |
162 | * @size: size of the file | |
163 | * | |
164 | */ | |
165 | loff_t fixed_size_llseek(struct file *file, loff_t offset, int whence, loff_t size) | |
166 | { | |
167 | switch (whence) { | |
168 | case SEEK_SET: case SEEK_CUR: case SEEK_END: | |
169 | return generic_file_llseek_size(file, offset, whence, | |
170 | size, size); | |
171 | default: | |
172 | return -EINVAL; | |
173 | } | |
174 | } | |
175 | EXPORT_SYMBOL(fixed_size_llseek); | |
176 | ||
ae6afc3f B |
177 | /** |
178 | * noop_llseek - No Operation Performed llseek implementation | |
179 | * @file: file structure to seek on | |
180 | * @offset: file offset to seek to | |
965c8e59 | 181 | * @whence: type of seek |
ae6afc3f B |
182 | * |
183 | * This is an implementation of ->llseek useable for the rare special case when | |
184 | * userspace expects the seek to succeed but the (device) file is actually not | |
185 | * able to perform the seek. In this case you use noop_llseek() instead of | |
186 | * falling back to the default implementation of ->llseek. | |
187 | */ | |
965c8e59 | 188 | loff_t noop_llseek(struct file *file, loff_t offset, int whence) |
ae6afc3f B |
189 | { |
190 | return file->f_pos; | |
191 | } | |
192 | EXPORT_SYMBOL(noop_llseek); | |
193 | ||
965c8e59 | 194 | loff_t no_llseek(struct file *file, loff_t offset, int whence) |
1da177e4 LT |
195 | { |
196 | return -ESPIPE; | |
197 | } | |
198 | EXPORT_SYMBOL(no_llseek); | |
199 | ||
965c8e59 | 200 | loff_t default_llseek(struct file *file, loff_t offset, int whence) |
1da177e4 | 201 | { |
496ad9aa | 202 | struct inode *inode = file_inode(file); |
16abef0e | 203 | loff_t retval; |
1da177e4 | 204 | |
982d8165 | 205 | mutex_lock(&inode->i_mutex); |
965c8e59 | 206 | switch (whence) { |
7b8e8924 | 207 | case SEEK_END: |
982d8165 | 208 | offset += i_size_read(inode); |
1da177e4 | 209 | break; |
7b8e8924 | 210 | case SEEK_CUR: |
5b6f1eb9 AK |
211 | if (offset == 0) { |
212 | retval = file->f_pos; | |
213 | goto out; | |
214 | } | |
1da177e4 | 215 | offset += file->f_pos; |
982d8165 JB |
216 | break; |
217 | case SEEK_DATA: | |
218 | /* | |
219 | * In the generic case the entire file is data, so as | |
220 | * long as offset isn't at the end of the file then the | |
221 | * offset is data. | |
222 | */ | |
bacb2d81 DC |
223 | if (offset >= inode->i_size) { |
224 | retval = -ENXIO; | |
225 | goto out; | |
226 | } | |
982d8165 JB |
227 | break; |
228 | case SEEK_HOLE: | |
229 | /* | |
230 | * There is a virtual hole at the end of the file, so | |
231 | * as long as offset isn't i_size or larger, return | |
232 | * i_size. | |
233 | */ | |
bacb2d81 DC |
234 | if (offset >= inode->i_size) { |
235 | retval = -ENXIO; | |
236 | goto out; | |
237 | } | |
982d8165 JB |
238 | offset = inode->i_size; |
239 | break; | |
1da177e4 LT |
240 | } |
241 | retval = -EINVAL; | |
cccb5a1e | 242 | if (offset >= 0 || unsigned_offsets(file)) { |
1da177e4 LT |
243 | if (offset != file->f_pos) { |
244 | file->f_pos = offset; | |
245 | file->f_version = 0; | |
246 | } | |
247 | retval = offset; | |
248 | } | |
5b6f1eb9 | 249 | out: |
982d8165 | 250 | mutex_unlock(&inode->i_mutex); |
1da177e4 LT |
251 | return retval; |
252 | } | |
253 | EXPORT_SYMBOL(default_llseek); | |
254 | ||
965c8e59 | 255 | loff_t vfs_llseek(struct file *file, loff_t offset, int whence) |
1da177e4 LT |
256 | { |
257 | loff_t (*fn)(struct file *, loff_t, int); | |
258 | ||
259 | fn = no_llseek; | |
260 | if (file->f_mode & FMODE_LSEEK) { | |
72c2d531 | 261 | if (file->f_op->llseek) |
1da177e4 LT |
262 | fn = file->f_op->llseek; |
263 | } | |
965c8e59 | 264 | return fn(file, offset, whence); |
1da177e4 LT |
265 | } |
266 | EXPORT_SYMBOL(vfs_llseek); | |
267 | ||
9c225f26 LT |
268 | static inline struct fd fdget_pos(int fd) |
269 | { | |
bd2a31d5 | 270 | return __to_fd(__fdget_pos(fd)); |
9c225f26 LT |
271 | } |
272 | ||
273 | static inline void fdput_pos(struct fd f) | |
274 | { | |
275 | if (f.flags & FDPUT_POS_UNLOCK) | |
276 | mutex_unlock(&f.file->f_pos_lock); | |
277 | fdput(f); | |
278 | } | |
279 | ||
965c8e59 | 280 | SYSCALL_DEFINE3(lseek, unsigned int, fd, off_t, offset, unsigned int, whence) |
1da177e4 LT |
281 | { |
282 | off_t retval; | |
9c225f26 | 283 | struct fd f = fdget_pos(fd); |
2903ff01 AV |
284 | if (!f.file) |
285 | return -EBADF; | |
1da177e4 LT |
286 | |
287 | retval = -EINVAL; | |
965c8e59 AM |
288 | if (whence <= SEEK_MAX) { |
289 | loff_t res = vfs_llseek(f.file, offset, whence); | |
1da177e4 LT |
290 | retval = res; |
291 | if (res != (loff_t)retval) | |
292 | retval = -EOVERFLOW; /* LFS: should only happen on 32 bit platforms */ | |
293 | } | |
9c225f26 | 294 | fdput_pos(f); |
1da177e4 LT |
295 | return retval; |
296 | } | |
297 | ||
561c6731 AV |
298 | #ifdef CONFIG_COMPAT |
299 | COMPAT_SYSCALL_DEFINE3(lseek, unsigned int, fd, compat_off_t, offset, unsigned int, whence) | |
300 | { | |
301 | return sys_lseek(fd, offset, whence); | |
302 | } | |
303 | #endif | |
304 | ||
1da177e4 | 305 | #ifdef __ARCH_WANT_SYS_LLSEEK |
003d7ab4 HC |
306 | SYSCALL_DEFINE5(llseek, unsigned int, fd, unsigned long, offset_high, |
307 | unsigned long, offset_low, loff_t __user *, result, | |
965c8e59 | 308 | unsigned int, whence) |
1da177e4 LT |
309 | { |
310 | int retval; | |
d7a15f8d | 311 | struct fd f = fdget_pos(fd); |
1da177e4 | 312 | loff_t offset; |
1da177e4 | 313 | |
2903ff01 AV |
314 | if (!f.file) |
315 | return -EBADF; | |
1da177e4 LT |
316 | |
317 | retval = -EINVAL; | |
965c8e59 | 318 | if (whence > SEEK_MAX) |
1da177e4 LT |
319 | goto out_putf; |
320 | ||
2903ff01 | 321 | offset = vfs_llseek(f.file, ((loff_t) offset_high << 32) | offset_low, |
965c8e59 | 322 | whence); |
1da177e4 LT |
323 | |
324 | retval = (int)offset; | |
325 | if (offset >= 0) { | |
326 | retval = -EFAULT; | |
327 | if (!copy_to_user(result, &offset, sizeof(offset))) | |
328 | retval = 0; | |
329 | } | |
330 | out_putf: | |
d7a15f8d | 331 | fdput_pos(f); |
1da177e4 LT |
332 | return retval; |
333 | } | |
334 | #endif | |
335 | ||
dbe4e192 CH |
336 | ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos) |
337 | { | |
338 | struct kiocb kiocb; | |
339 | ssize_t ret; | |
340 | ||
341 | if (!file->f_op->read_iter) | |
342 | return -EINVAL; | |
343 | ||
344 | init_sync_kiocb(&kiocb, file); | |
345 | kiocb.ki_pos = *ppos; | |
346 | kiocb.ki_nbytes = iov_iter_count(iter); | |
347 | ||
348 | iter->type |= READ; | |
349 | ret = file->f_op->read_iter(&kiocb, iter); | |
350 | if (ret == -EIOCBQUEUED) | |
351 | ret = wait_on_sync_kiocb(&kiocb); | |
352 | ||
353 | if (ret > 0) | |
354 | *ppos = kiocb.ki_pos; | |
355 | return ret; | |
356 | } | |
357 | EXPORT_SYMBOL(vfs_iter_read); | |
358 | ||
359 | ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos) | |
360 | { | |
361 | struct kiocb kiocb; | |
362 | ssize_t ret; | |
363 | ||
364 | if (!file->f_op->write_iter) | |
365 | return -EINVAL; | |
366 | ||
367 | init_sync_kiocb(&kiocb, file); | |
368 | kiocb.ki_pos = *ppos; | |
369 | kiocb.ki_nbytes = iov_iter_count(iter); | |
370 | ||
371 | iter->type |= WRITE; | |
372 | ret = file->f_op->write_iter(&kiocb, iter); | |
373 | if (ret == -EIOCBQUEUED) | |
374 | ret = wait_on_sync_kiocb(&kiocb); | |
375 | ||
376 | if (ret > 0) | |
377 | *ppos = kiocb.ki_pos; | |
378 | return ret; | |
379 | } | |
380 | EXPORT_SYMBOL(vfs_iter_write); | |
381 | ||
e28cc715 LT |
382 | /* |
383 | * rw_verify_area doesn't like huge counts. We limit | |
384 | * them to something that fits in "int" so that others | |
385 | * won't have to do range checks all the time. | |
386 | */ | |
68d70d03 | 387 | int rw_verify_area(int read_write, struct file *file, const loff_t *ppos, size_t count) |
1da177e4 LT |
388 | { |
389 | struct inode *inode; | |
390 | loff_t pos; | |
c43e259c | 391 | int retval = -EINVAL; |
1da177e4 | 392 | |
496ad9aa | 393 | inode = file_inode(file); |
e28cc715 | 394 | if (unlikely((ssize_t) count < 0)) |
c43e259c | 395 | return retval; |
1da177e4 | 396 | pos = *ppos; |
cccb5a1e AV |
397 | if (unlikely(pos < 0)) { |
398 | if (!unsigned_offsets(file)) | |
399 | return retval; | |
400 | if (count >= -pos) /* both values are in 0..LLONG_MAX */ | |
401 | return -EOVERFLOW; | |
402 | } else if (unlikely((loff_t) (pos + count) < 0)) { | |
403 | if (!unsigned_offsets(file)) | |
4a3956c7 KH |
404 | return retval; |
405 | } | |
1da177e4 | 406 | |
bd61e0a9 | 407 | if (unlikely(inode->i_flctx && mandatory_lock(inode))) { |
c43e259c | 408 | retval = locks_mandatory_area( |
e28cc715 LT |
409 | read_write == READ ? FLOCK_VERIFY_READ : FLOCK_VERIFY_WRITE, |
410 | inode, file, pos, count); | |
411 | if (retval < 0) | |
412 | return retval; | |
413 | } | |
c43e259c JM |
414 | retval = security_file_permission(file, |
415 | read_write == READ ? MAY_READ : MAY_WRITE); | |
416 | if (retval) | |
417 | return retval; | |
e28cc715 | 418 | return count > MAX_RW_COUNT ? MAX_RW_COUNT : count; |
1da177e4 LT |
419 | } |
420 | ||
421 | ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos) | |
422 | { | |
027445c3 | 423 | struct iovec iov = { .iov_base = buf, .iov_len = len }; |
1da177e4 LT |
424 | struct kiocb kiocb; |
425 | ssize_t ret; | |
426 | ||
427 | init_sync_kiocb(&kiocb, filp); | |
428 | kiocb.ki_pos = *ppos; | |
61964eba | 429 | kiocb.ki_nbytes = len; |
027445c3 | 430 | |
41003a7b | 431 | ret = filp->f_op->aio_read(&kiocb, &iov, 1, kiocb.ki_pos); |
1da177e4 LT |
432 | if (-EIOCBQUEUED == ret) |
433 | ret = wait_on_sync_kiocb(&kiocb); | |
434 | *ppos = kiocb.ki_pos; | |
435 | return ret; | |
436 | } | |
437 | ||
438 | EXPORT_SYMBOL(do_sync_read); | |
439 | ||
293bc982 AV |
440 | ssize_t new_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos) |
441 | { | |
442 | struct iovec iov = { .iov_base = buf, .iov_len = len }; | |
443 | struct kiocb kiocb; | |
444 | struct iov_iter iter; | |
445 | ssize_t ret; | |
446 | ||
447 | init_sync_kiocb(&kiocb, filp); | |
448 | kiocb.ki_pos = *ppos; | |
449 | kiocb.ki_nbytes = len; | |
450 | iov_iter_init(&iter, READ, &iov, 1, len); | |
451 | ||
452 | ret = filp->f_op->read_iter(&kiocb, &iter); | |
453 | if (-EIOCBQUEUED == ret) | |
454 | ret = wait_on_sync_kiocb(&kiocb); | |
455 | *ppos = kiocb.ki_pos; | |
456 | return ret; | |
457 | } | |
458 | ||
459 | EXPORT_SYMBOL(new_sync_read); | |
460 | ||
6fb5032e DK |
461 | ssize_t __vfs_read(struct file *file, char __user *buf, size_t count, |
462 | loff_t *pos) | |
463 | { | |
464 | ssize_t ret; | |
465 | ||
466 | if (file->f_op->read) | |
467 | ret = file->f_op->read(file, buf, count, pos); | |
468 | else if (file->f_op->aio_read) | |
469 | ret = do_sync_read(file, buf, count, pos); | |
470 | else if (file->f_op->read_iter) | |
471 | ret = new_sync_read(file, buf, count, pos); | |
472 | else | |
473 | ret = -EINVAL; | |
474 | ||
475 | return ret; | |
476 | } | |
477 | ||
1da177e4 LT |
478 | ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos) |
479 | { | |
480 | ssize_t ret; | |
481 | ||
482 | if (!(file->f_mode & FMODE_READ)) | |
483 | return -EBADF; | |
7f7f25e8 | 484 | if (!(file->f_mode & FMODE_CAN_READ)) |
1da177e4 LT |
485 | return -EINVAL; |
486 | if (unlikely(!access_ok(VERIFY_WRITE, buf, count))) | |
487 | return -EFAULT; | |
488 | ||
489 | ret = rw_verify_area(READ, file, pos, count); | |
e28cc715 LT |
490 | if (ret >= 0) { |
491 | count = ret; | |
6fb5032e | 492 | ret = __vfs_read(file, buf, count, pos); |
c43e259c | 493 | if (ret > 0) { |
2a12a9d7 | 494 | fsnotify_access(file); |
c43e259c | 495 | add_rchar(current, ret); |
1da177e4 | 496 | } |
c43e259c | 497 | inc_syscr(current); |
1da177e4 LT |
498 | } |
499 | ||
500 | return ret; | |
501 | } | |
502 | ||
503 | EXPORT_SYMBOL(vfs_read); | |
504 | ||
505 | ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos) | |
506 | { | |
027445c3 | 507 | struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = len }; |
1da177e4 LT |
508 | struct kiocb kiocb; |
509 | ssize_t ret; | |
510 | ||
511 | init_sync_kiocb(&kiocb, filp); | |
512 | kiocb.ki_pos = *ppos; | |
61964eba | 513 | kiocb.ki_nbytes = len; |
027445c3 | 514 | |
41003a7b | 515 | ret = filp->f_op->aio_write(&kiocb, &iov, 1, kiocb.ki_pos); |
1da177e4 LT |
516 | if (-EIOCBQUEUED == ret) |
517 | ret = wait_on_sync_kiocb(&kiocb); | |
518 | *ppos = kiocb.ki_pos; | |
519 | return ret; | |
520 | } | |
521 | ||
522 | EXPORT_SYMBOL(do_sync_write); | |
523 | ||
293bc982 AV |
524 | ssize_t new_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos) |
525 | { | |
526 | struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = len }; | |
527 | struct kiocb kiocb; | |
528 | struct iov_iter iter; | |
529 | ssize_t ret; | |
530 | ||
531 | init_sync_kiocb(&kiocb, filp); | |
532 | kiocb.ki_pos = *ppos; | |
533 | kiocb.ki_nbytes = len; | |
534 | iov_iter_init(&iter, WRITE, &iov, 1, len); | |
535 | ||
536 | ret = filp->f_op->write_iter(&kiocb, &iter); | |
537 | if (-EIOCBQUEUED == ret) | |
538 | ret = wait_on_sync_kiocb(&kiocb); | |
539 | *ppos = kiocb.ki_pos; | |
540 | return ret; | |
541 | } | |
542 | ||
543 | EXPORT_SYMBOL(new_sync_write); | |
544 | ||
06ae43f3 AV |
545 | ssize_t __kernel_write(struct file *file, const char *buf, size_t count, loff_t *pos) |
546 | { | |
547 | mm_segment_t old_fs; | |
548 | const char __user *p; | |
549 | ssize_t ret; | |
550 | ||
7f7f25e8 | 551 | if (!(file->f_mode & FMODE_CAN_WRITE)) |
3e84f48e AV |
552 | return -EINVAL; |
553 | ||
06ae43f3 AV |
554 | old_fs = get_fs(); |
555 | set_fs(get_ds()); | |
556 | p = (__force const char __user *)buf; | |
557 | if (count > MAX_RW_COUNT) | |
558 | count = MAX_RW_COUNT; | |
559 | if (file->f_op->write) | |
560 | ret = file->f_op->write(file, p, count, pos); | |
293bc982 | 561 | else if (file->f_op->aio_write) |
06ae43f3 | 562 | ret = do_sync_write(file, p, count, pos); |
293bc982 AV |
563 | else |
564 | ret = new_sync_write(file, p, count, pos); | |
06ae43f3 AV |
565 | set_fs(old_fs); |
566 | if (ret > 0) { | |
567 | fsnotify_modify(file); | |
568 | add_wchar(current, ret); | |
569 | } | |
570 | inc_syscw(current); | |
571 | return ret; | |
572 | } | |
573 | ||
2ec3a12a AV |
574 | EXPORT_SYMBOL(__kernel_write); |
575 | ||
1da177e4 LT |
576 | ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_t *pos) |
577 | { | |
578 | ssize_t ret; | |
579 | ||
580 | if (!(file->f_mode & FMODE_WRITE)) | |
581 | return -EBADF; | |
7f7f25e8 | 582 | if (!(file->f_mode & FMODE_CAN_WRITE)) |
1da177e4 LT |
583 | return -EINVAL; |
584 | if (unlikely(!access_ok(VERIFY_READ, buf, count))) | |
585 | return -EFAULT; | |
586 | ||
587 | ret = rw_verify_area(WRITE, file, pos, count); | |
e28cc715 LT |
588 | if (ret >= 0) { |
589 | count = ret; | |
03d95eb2 | 590 | file_start_write(file); |
c43e259c JM |
591 | if (file->f_op->write) |
592 | ret = file->f_op->write(file, buf, count, pos); | |
293bc982 | 593 | else if (file->f_op->aio_write) |
c43e259c | 594 | ret = do_sync_write(file, buf, count, pos); |
293bc982 AV |
595 | else |
596 | ret = new_sync_write(file, buf, count, pos); | |
c43e259c | 597 | if (ret > 0) { |
2a12a9d7 | 598 | fsnotify_modify(file); |
c43e259c | 599 | add_wchar(current, ret); |
1da177e4 | 600 | } |
c43e259c | 601 | inc_syscw(current); |
03d95eb2 | 602 | file_end_write(file); |
1da177e4 LT |
603 | } |
604 | ||
605 | return ret; | |
606 | } | |
607 | ||
608 | EXPORT_SYMBOL(vfs_write); | |
609 | ||
610 | static inline loff_t file_pos_read(struct file *file) | |
611 | { | |
612 | return file->f_pos; | |
613 | } | |
614 | ||
615 | static inline void file_pos_write(struct file *file, loff_t pos) | |
616 | { | |
617 | file->f_pos = pos; | |
618 | } | |
619 | ||
3cdad428 | 620 | SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count) |
1da177e4 | 621 | { |
9c225f26 | 622 | struct fd f = fdget_pos(fd); |
1da177e4 | 623 | ssize_t ret = -EBADF; |
1da177e4 | 624 | |
2903ff01 AV |
625 | if (f.file) { |
626 | loff_t pos = file_pos_read(f.file); | |
627 | ret = vfs_read(f.file, buf, count, &pos); | |
5faf153e AV |
628 | if (ret >= 0) |
629 | file_pos_write(f.file, pos); | |
9c225f26 | 630 | fdput_pos(f); |
1da177e4 | 631 | } |
1da177e4 LT |
632 | return ret; |
633 | } | |
1da177e4 | 634 | |
3cdad428 HC |
635 | SYSCALL_DEFINE3(write, unsigned int, fd, const char __user *, buf, |
636 | size_t, count) | |
1da177e4 | 637 | { |
9c225f26 | 638 | struct fd f = fdget_pos(fd); |
1da177e4 | 639 | ssize_t ret = -EBADF; |
1da177e4 | 640 | |
2903ff01 AV |
641 | if (f.file) { |
642 | loff_t pos = file_pos_read(f.file); | |
643 | ret = vfs_write(f.file, buf, count, &pos); | |
5faf153e AV |
644 | if (ret >= 0) |
645 | file_pos_write(f.file, pos); | |
9c225f26 | 646 | fdput_pos(f); |
1da177e4 LT |
647 | } |
648 | ||
649 | return ret; | |
650 | } | |
651 | ||
4a0fd5bf AV |
652 | SYSCALL_DEFINE4(pread64, unsigned int, fd, char __user *, buf, |
653 | size_t, count, loff_t, pos) | |
1da177e4 | 654 | { |
2903ff01 | 655 | struct fd f; |
1da177e4 | 656 | ssize_t ret = -EBADF; |
1da177e4 LT |
657 | |
658 | if (pos < 0) | |
659 | return -EINVAL; | |
660 | ||
2903ff01 AV |
661 | f = fdget(fd); |
662 | if (f.file) { | |
1da177e4 | 663 | ret = -ESPIPE; |
2903ff01 AV |
664 | if (f.file->f_mode & FMODE_PREAD) |
665 | ret = vfs_read(f.file, buf, count, &pos); | |
666 | fdput(f); | |
1da177e4 LT |
667 | } |
668 | ||
669 | return ret; | |
670 | } | |
671 | ||
4a0fd5bf AV |
672 | SYSCALL_DEFINE4(pwrite64, unsigned int, fd, const char __user *, buf, |
673 | size_t, count, loff_t, pos) | |
1da177e4 | 674 | { |
2903ff01 | 675 | struct fd f; |
1da177e4 | 676 | ssize_t ret = -EBADF; |
1da177e4 LT |
677 | |
678 | if (pos < 0) | |
679 | return -EINVAL; | |
680 | ||
2903ff01 AV |
681 | f = fdget(fd); |
682 | if (f.file) { | |
1da177e4 | 683 | ret = -ESPIPE; |
2903ff01 AV |
684 | if (f.file->f_mode & FMODE_PWRITE) |
685 | ret = vfs_write(f.file, buf, count, &pos); | |
686 | fdput(f); | |
1da177e4 LT |
687 | } |
688 | ||
689 | return ret; | |
690 | } | |
691 | ||
692 | /* | |
693 | * Reduce an iovec's length in-place. Return the resulting number of segments | |
694 | */ | |
695 | unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to) | |
696 | { | |
697 | unsigned long seg = 0; | |
698 | size_t len = 0; | |
699 | ||
700 | while (seg < nr_segs) { | |
701 | seg++; | |
702 | if (len + iov->iov_len >= to) { | |
703 | iov->iov_len = to - len; | |
704 | break; | |
705 | } | |
706 | len += iov->iov_len; | |
707 | iov++; | |
708 | } | |
709 | return seg; | |
710 | } | |
19295529 | 711 | EXPORT_SYMBOL(iov_shorten); |
1da177e4 | 712 | |
293bc982 AV |
713 | static ssize_t do_iter_readv_writev(struct file *filp, int rw, const struct iovec *iov, |
714 | unsigned long nr_segs, size_t len, loff_t *ppos, iter_fn_t fn) | |
715 | { | |
716 | struct kiocb kiocb; | |
717 | struct iov_iter iter; | |
718 | ssize_t ret; | |
719 | ||
720 | init_sync_kiocb(&kiocb, filp); | |
721 | kiocb.ki_pos = *ppos; | |
722 | kiocb.ki_nbytes = len; | |
723 | ||
724 | iov_iter_init(&iter, rw, iov, nr_segs, len); | |
725 | ret = fn(&kiocb, &iter); | |
726 | if (ret == -EIOCBQUEUED) | |
727 | ret = wait_on_sync_kiocb(&kiocb); | |
728 | *ppos = kiocb.ki_pos; | |
729 | return ret; | |
730 | } | |
731 | ||
72ec3516 | 732 | static ssize_t do_sync_readv_writev(struct file *filp, const struct iovec *iov, |
ee0b3e67 BP |
733 | unsigned long nr_segs, size_t len, loff_t *ppos, iov_fn_t fn) |
734 | { | |
735 | struct kiocb kiocb; | |
736 | ssize_t ret; | |
737 | ||
738 | init_sync_kiocb(&kiocb, filp); | |
739 | kiocb.ki_pos = *ppos; | |
ee0b3e67 BP |
740 | kiocb.ki_nbytes = len; |
741 | ||
41003a7b | 742 | ret = fn(&kiocb, iov, nr_segs, kiocb.ki_pos); |
ee0b3e67 BP |
743 | if (ret == -EIOCBQUEUED) |
744 | ret = wait_on_sync_kiocb(&kiocb); | |
745 | *ppos = kiocb.ki_pos; | |
746 | return ret; | |
747 | } | |
748 | ||
749 | /* Do it by hand, with file-ops */ | |
72ec3516 | 750 | static ssize_t do_loop_readv_writev(struct file *filp, struct iovec *iov, |
ee0b3e67 BP |
751 | unsigned long nr_segs, loff_t *ppos, io_fn_t fn) |
752 | { | |
753 | struct iovec *vector = iov; | |
754 | ssize_t ret = 0; | |
755 | ||
756 | while (nr_segs > 0) { | |
757 | void __user *base; | |
758 | size_t len; | |
759 | ssize_t nr; | |
760 | ||
761 | base = vector->iov_base; | |
762 | len = vector->iov_len; | |
763 | vector++; | |
764 | nr_segs--; | |
765 | ||
766 | nr = fn(filp, base, len, ppos); | |
767 | ||
768 | if (nr < 0) { | |
769 | if (!ret) | |
770 | ret = nr; | |
771 | break; | |
772 | } | |
773 | ret += nr; | |
774 | if (nr != len) | |
775 | break; | |
776 | } | |
777 | ||
778 | return ret; | |
779 | } | |
780 | ||
1da177e4 LT |
781 | /* A write operation does a read from user space and vice versa */ |
782 | #define vrfy_dir(type) ((type) == READ ? VERIFY_WRITE : VERIFY_READ) | |
783 | ||
eed4e51f BP |
784 | ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector, |
785 | unsigned long nr_segs, unsigned long fast_segs, | |
786 | struct iovec *fast_pointer, | |
ac34ebb3 | 787 | struct iovec **ret_pointer) |
435f49a5 | 788 | { |
eed4e51f | 789 | unsigned long seg; |
435f49a5 | 790 | ssize_t ret; |
eed4e51f BP |
791 | struct iovec *iov = fast_pointer; |
792 | ||
435f49a5 LT |
793 | /* |
794 | * SuS says "The readv() function *may* fail if the iovcnt argument | |
795 | * was less than or equal to 0, or greater than {IOV_MAX}. Linux has | |
796 | * traditionally returned zero for zero segments, so... | |
797 | */ | |
eed4e51f BP |
798 | if (nr_segs == 0) { |
799 | ret = 0; | |
435f49a5 | 800 | goto out; |
eed4e51f BP |
801 | } |
802 | ||
435f49a5 LT |
803 | /* |
804 | * First get the "struct iovec" from user memory and | |
805 | * verify all the pointers | |
806 | */ | |
eed4e51f BP |
807 | if (nr_segs > UIO_MAXIOV) { |
808 | ret = -EINVAL; | |
435f49a5 | 809 | goto out; |
eed4e51f BP |
810 | } |
811 | if (nr_segs > fast_segs) { | |
435f49a5 | 812 | iov = kmalloc(nr_segs*sizeof(struct iovec), GFP_KERNEL); |
eed4e51f BP |
813 | if (iov == NULL) { |
814 | ret = -ENOMEM; | |
435f49a5 | 815 | goto out; |
eed4e51f | 816 | } |
435f49a5 | 817 | } |
eed4e51f BP |
818 | if (copy_from_user(iov, uvector, nr_segs*sizeof(*uvector))) { |
819 | ret = -EFAULT; | |
435f49a5 | 820 | goto out; |
eed4e51f BP |
821 | } |
822 | ||
435f49a5 | 823 | /* |
eed4e51f BP |
824 | * According to the Single Unix Specification we should return EINVAL |
825 | * if an element length is < 0 when cast to ssize_t or if the | |
826 | * total length would overflow the ssize_t return value of the | |
827 | * system call. | |
435f49a5 LT |
828 | * |
829 | * Linux caps all read/write calls to MAX_RW_COUNT, and avoids the | |
830 | * overflow case. | |
831 | */ | |
eed4e51f | 832 | ret = 0; |
435f49a5 LT |
833 | for (seg = 0; seg < nr_segs; seg++) { |
834 | void __user *buf = iov[seg].iov_base; | |
835 | ssize_t len = (ssize_t)iov[seg].iov_len; | |
eed4e51f BP |
836 | |
837 | /* see if we we're about to use an invalid len or if | |
838 | * it's about to overflow ssize_t */ | |
435f49a5 | 839 | if (len < 0) { |
eed4e51f | 840 | ret = -EINVAL; |
435f49a5 | 841 | goto out; |
eed4e51f | 842 | } |
ac34ebb3 | 843 | if (type >= 0 |
fcf63409 | 844 | && unlikely(!access_ok(vrfy_dir(type), buf, len))) { |
eed4e51f | 845 | ret = -EFAULT; |
435f49a5 LT |
846 | goto out; |
847 | } | |
848 | if (len > MAX_RW_COUNT - ret) { | |
849 | len = MAX_RW_COUNT - ret; | |
850 | iov[seg].iov_len = len; | |
eed4e51f | 851 | } |
eed4e51f | 852 | ret += len; |
435f49a5 | 853 | } |
eed4e51f BP |
854 | out: |
855 | *ret_pointer = iov; | |
856 | return ret; | |
857 | } | |
858 | ||
1da177e4 LT |
859 | static ssize_t do_readv_writev(int type, struct file *file, |
860 | const struct iovec __user * uvector, | |
861 | unsigned long nr_segs, loff_t *pos) | |
862 | { | |
1da177e4 LT |
863 | size_t tot_len; |
864 | struct iovec iovstack[UIO_FASTIOV]; | |
ee0b3e67 | 865 | struct iovec *iov = iovstack; |
1da177e4 | 866 | ssize_t ret; |
1da177e4 LT |
867 | io_fn_t fn; |
868 | iov_fn_t fnv; | |
293bc982 | 869 | iter_fn_t iter_fn; |
1da177e4 | 870 | |
eed4e51f | 871 | ret = rw_copy_check_uvector(type, uvector, nr_segs, |
ac34ebb3 | 872 | ARRAY_SIZE(iovstack), iovstack, &iov); |
eed4e51f | 873 | if (ret <= 0) |
1da177e4 | 874 | goto out; |
1da177e4 | 875 | |
eed4e51f | 876 | tot_len = ret; |
1da177e4 | 877 | ret = rw_verify_area(type, file, pos, tot_len); |
e28cc715 | 878 | if (ret < 0) |
411b67b4 | 879 | goto out; |
1da177e4 LT |
880 | |
881 | fnv = NULL; | |
882 | if (type == READ) { | |
883 | fn = file->f_op->read; | |
ee0b3e67 | 884 | fnv = file->f_op->aio_read; |
293bc982 | 885 | iter_fn = file->f_op->read_iter; |
1da177e4 LT |
886 | } else { |
887 | fn = (io_fn_t)file->f_op->write; | |
ee0b3e67 | 888 | fnv = file->f_op->aio_write; |
293bc982 | 889 | iter_fn = file->f_op->write_iter; |
03d95eb2 | 890 | file_start_write(file); |
1da177e4 LT |
891 | } |
892 | ||
293bc982 AV |
893 | if (iter_fn) |
894 | ret = do_iter_readv_writev(file, type, iov, nr_segs, tot_len, | |
895 | pos, iter_fn); | |
896 | else if (fnv) | |
ee0b3e67 BP |
897 | ret = do_sync_readv_writev(file, iov, nr_segs, tot_len, |
898 | pos, fnv); | |
899 | else | |
900 | ret = do_loop_readv_writev(file, iov, nr_segs, pos, fn); | |
1da177e4 | 901 | |
03d95eb2 AV |
902 | if (type != READ) |
903 | file_end_write(file); | |
904 | ||
1da177e4 LT |
905 | out: |
906 | if (iov != iovstack) | |
907 | kfree(iov); | |
0eeca283 RL |
908 | if ((ret + (type == READ)) > 0) { |
909 | if (type == READ) | |
2a12a9d7 | 910 | fsnotify_access(file); |
0eeca283 | 911 | else |
2a12a9d7 | 912 | fsnotify_modify(file); |
0eeca283 | 913 | } |
1da177e4 | 914 | return ret; |
1da177e4 LT |
915 | } |
916 | ||
917 | ssize_t vfs_readv(struct file *file, const struct iovec __user *vec, | |
918 | unsigned long vlen, loff_t *pos) | |
919 | { | |
920 | if (!(file->f_mode & FMODE_READ)) | |
921 | return -EBADF; | |
7f7f25e8 | 922 | if (!(file->f_mode & FMODE_CAN_READ)) |
1da177e4 LT |
923 | return -EINVAL; |
924 | ||
925 | return do_readv_writev(READ, file, vec, vlen, pos); | |
926 | } | |
927 | ||
928 | EXPORT_SYMBOL(vfs_readv); | |
929 | ||
930 | ssize_t vfs_writev(struct file *file, const struct iovec __user *vec, | |
931 | unsigned long vlen, loff_t *pos) | |
932 | { | |
933 | if (!(file->f_mode & FMODE_WRITE)) | |
934 | return -EBADF; | |
7f7f25e8 | 935 | if (!(file->f_mode & FMODE_CAN_WRITE)) |
1da177e4 LT |
936 | return -EINVAL; |
937 | ||
938 | return do_readv_writev(WRITE, file, vec, vlen, pos); | |
939 | } | |
940 | ||
941 | EXPORT_SYMBOL(vfs_writev); | |
942 | ||
3cdad428 HC |
943 | SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec, |
944 | unsigned long, vlen) | |
1da177e4 | 945 | { |
9c225f26 | 946 | struct fd f = fdget_pos(fd); |
1da177e4 | 947 | ssize_t ret = -EBADF; |
1da177e4 | 948 | |
2903ff01 AV |
949 | if (f.file) { |
950 | loff_t pos = file_pos_read(f.file); | |
951 | ret = vfs_readv(f.file, vec, vlen, &pos); | |
5faf153e AV |
952 | if (ret >= 0) |
953 | file_pos_write(f.file, pos); | |
9c225f26 | 954 | fdput_pos(f); |
1da177e4 LT |
955 | } |
956 | ||
957 | if (ret > 0) | |
4b98d11b AD |
958 | add_rchar(current, ret); |
959 | inc_syscr(current); | |
1da177e4 LT |
960 | return ret; |
961 | } | |
962 | ||
3cdad428 HC |
963 | SYSCALL_DEFINE3(writev, unsigned long, fd, const struct iovec __user *, vec, |
964 | unsigned long, vlen) | |
1da177e4 | 965 | { |
9c225f26 | 966 | struct fd f = fdget_pos(fd); |
1da177e4 | 967 | ssize_t ret = -EBADF; |
1da177e4 | 968 | |
2903ff01 AV |
969 | if (f.file) { |
970 | loff_t pos = file_pos_read(f.file); | |
971 | ret = vfs_writev(f.file, vec, vlen, &pos); | |
5faf153e AV |
972 | if (ret >= 0) |
973 | file_pos_write(f.file, pos); | |
9c225f26 | 974 | fdput_pos(f); |
1da177e4 LT |
975 | } |
976 | ||
977 | if (ret > 0) | |
4b98d11b AD |
978 | add_wchar(current, ret); |
979 | inc_syscw(current); | |
1da177e4 LT |
980 | return ret; |
981 | } | |
982 | ||
601cc11d LT |
983 | static inline loff_t pos_from_hilo(unsigned long high, unsigned long low) |
984 | { | |
985 | #define HALF_LONG_BITS (BITS_PER_LONG / 2) | |
986 | return (((loff_t)high << HALF_LONG_BITS) << HALF_LONG_BITS) | low; | |
987 | } | |
988 | ||
f3554f4b | 989 | SYSCALL_DEFINE5(preadv, unsigned long, fd, const struct iovec __user *, vec, |
601cc11d | 990 | unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h) |
f3554f4b | 991 | { |
601cc11d | 992 | loff_t pos = pos_from_hilo(pos_h, pos_l); |
2903ff01 | 993 | struct fd f; |
f3554f4b | 994 | ssize_t ret = -EBADF; |
f3554f4b GH |
995 | |
996 | if (pos < 0) | |
997 | return -EINVAL; | |
998 | ||
2903ff01 AV |
999 | f = fdget(fd); |
1000 | if (f.file) { | |
f3554f4b | 1001 | ret = -ESPIPE; |
2903ff01 AV |
1002 | if (f.file->f_mode & FMODE_PREAD) |
1003 | ret = vfs_readv(f.file, vec, vlen, &pos); | |
1004 | fdput(f); | |
f3554f4b GH |
1005 | } |
1006 | ||
1007 | if (ret > 0) | |
1008 | add_rchar(current, ret); | |
1009 | inc_syscr(current); | |
1010 | return ret; | |
1011 | } | |
1012 | ||
1013 | SYSCALL_DEFINE5(pwritev, unsigned long, fd, const struct iovec __user *, vec, | |
601cc11d | 1014 | unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h) |
f3554f4b | 1015 | { |
601cc11d | 1016 | loff_t pos = pos_from_hilo(pos_h, pos_l); |
2903ff01 | 1017 | struct fd f; |
f3554f4b | 1018 | ssize_t ret = -EBADF; |
f3554f4b GH |
1019 | |
1020 | if (pos < 0) | |
1021 | return -EINVAL; | |
1022 | ||
2903ff01 AV |
1023 | f = fdget(fd); |
1024 | if (f.file) { | |
f3554f4b | 1025 | ret = -ESPIPE; |
2903ff01 AV |
1026 | if (f.file->f_mode & FMODE_PWRITE) |
1027 | ret = vfs_writev(f.file, vec, vlen, &pos); | |
1028 | fdput(f); | |
f3554f4b GH |
1029 | } |
1030 | ||
1031 | if (ret > 0) | |
1032 | add_wchar(current, ret); | |
1033 | inc_syscw(current); | |
1034 | return ret; | |
1035 | } | |
1036 | ||
72ec3516 AV |
1037 | #ifdef CONFIG_COMPAT |
1038 | ||
1039 | static ssize_t compat_do_readv_writev(int type, struct file *file, | |
1040 | const struct compat_iovec __user *uvector, | |
1041 | unsigned long nr_segs, loff_t *pos) | |
1042 | { | |
1043 | compat_ssize_t tot_len; | |
1044 | struct iovec iovstack[UIO_FASTIOV]; | |
1045 | struct iovec *iov = iovstack; | |
1046 | ssize_t ret; | |
1047 | io_fn_t fn; | |
1048 | iov_fn_t fnv; | |
293bc982 | 1049 | iter_fn_t iter_fn; |
72ec3516 | 1050 | |
72ec3516 AV |
1051 | ret = compat_rw_copy_check_uvector(type, uvector, nr_segs, |
1052 | UIO_FASTIOV, iovstack, &iov); | |
1053 | if (ret <= 0) | |
1054 | goto out; | |
1055 | ||
1056 | tot_len = ret; | |
1057 | ret = rw_verify_area(type, file, pos, tot_len); | |
1058 | if (ret < 0) | |
1059 | goto out; | |
1060 | ||
1061 | fnv = NULL; | |
1062 | if (type == READ) { | |
1063 | fn = file->f_op->read; | |
1064 | fnv = file->f_op->aio_read; | |
293bc982 | 1065 | iter_fn = file->f_op->read_iter; |
72ec3516 AV |
1066 | } else { |
1067 | fn = (io_fn_t)file->f_op->write; | |
1068 | fnv = file->f_op->aio_write; | |
293bc982 | 1069 | iter_fn = file->f_op->write_iter; |
03d95eb2 | 1070 | file_start_write(file); |
72ec3516 AV |
1071 | } |
1072 | ||
293bc982 AV |
1073 | if (iter_fn) |
1074 | ret = do_iter_readv_writev(file, type, iov, nr_segs, tot_len, | |
1075 | pos, iter_fn); | |
1076 | else if (fnv) | |
72ec3516 AV |
1077 | ret = do_sync_readv_writev(file, iov, nr_segs, tot_len, |
1078 | pos, fnv); | |
03d95eb2 | 1079 | else |
72ec3516 AV |
1080 | ret = do_loop_readv_writev(file, iov, nr_segs, pos, fn); |
1081 | ||
03d95eb2 AV |
1082 | if (type != READ) |
1083 | file_end_write(file); | |
1084 | ||
72ec3516 AV |
1085 | out: |
1086 | if (iov != iovstack) | |
1087 | kfree(iov); | |
1088 | if ((ret + (type == READ)) > 0) { | |
1089 | if (type == READ) | |
1090 | fsnotify_access(file); | |
1091 | else | |
1092 | fsnotify_modify(file); | |
1093 | } | |
1094 | return ret; | |
1095 | } | |
1096 | ||
1097 | static size_t compat_readv(struct file *file, | |
1098 | const struct compat_iovec __user *vec, | |
1099 | unsigned long vlen, loff_t *pos) | |
1100 | { | |
1101 | ssize_t ret = -EBADF; | |
1102 | ||
1103 | if (!(file->f_mode & FMODE_READ)) | |
1104 | goto out; | |
1105 | ||
1106 | ret = -EINVAL; | |
7f7f25e8 | 1107 | if (!(file->f_mode & FMODE_CAN_READ)) |
72ec3516 AV |
1108 | goto out; |
1109 | ||
1110 | ret = compat_do_readv_writev(READ, file, vec, vlen, pos); | |
1111 | ||
1112 | out: | |
1113 | if (ret > 0) | |
1114 | add_rchar(current, ret); | |
1115 | inc_syscr(current); | |
1116 | return ret; | |
1117 | } | |
1118 | ||
dfd948e3 | 1119 | COMPAT_SYSCALL_DEFINE3(readv, compat_ulong_t, fd, |
72ec3516 | 1120 | const struct compat_iovec __user *,vec, |
dfd948e3 | 1121 | compat_ulong_t, vlen) |
72ec3516 | 1122 | { |
9c225f26 | 1123 | struct fd f = fdget_pos(fd); |
72ec3516 AV |
1124 | ssize_t ret; |
1125 | loff_t pos; | |
1126 | ||
1127 | if (!f.file) | |
1128 | return -EBADF; | |
1129 | pos = f.file->f_pos; | |
1130 | ret = compat_readv(f.file, vec, vlen, &pos); | |
5faf153e AV |
1131 | if (ret >= 0) |
1132 | f.file->f_pos = pos; | |
9c225f26 | 1133 | fdput_pos(f); |
72ec3516 AV |
1134 | return ret; |
1135 | } | |
1136 | ||
378a10f3 HC |
1137 | static long __compat_sys_preadv64(unsigned long fd, |
1138 | const struct compat_iovec __user *vec, | |
1139 | unsigned long vlen, loff_t pos) | |
72ec3516 AV |
1140 | { |
1141 | struct fd f; | |
1142 | ssize_t ret; | |
1143 | ||
1144 | if (pos < 0) | |
1145 | return -EINVAL; | |
1146 | f = fdget(fd); | |
1147 | if (!f.file) | |
1148 | return -EBADF; | |
1149 | ret = -ESPIPE; | |
1150 | if (f.file->f_mode & FMODE_PREAD) | |
1151 | ret = compat_readv(f.file, vec, vlen, &pos); | |
1152 | fdput(f); | |
1153 | return ret; | |
1154 | } | |
1155 | ||
378a10f3 HC |
1156 | #ifdef __ARCH_WANT_COMPAT_SYS_PREADV64 |
1157 | COMPAT_SYSCALL_DEFINE4(preadv64, unsigned long, fd, | |
1158 | const struct compat_iovec __user *,vec, | |
1159 | unsigned long, vlen, loff_t, pos) | |
1160 | { | |
1161 | return __compat_sys_preadv64(fd, vec, vlen, pos); | |
1162 | } | |
1163 | #endif | |
1164 | ||
dfd948e3 | 1165 | COMPAT_SYSCALL_DEFINE5(preadv, compat_ulong_t, fd, |
72ec3516 | 1166 | const struct compat_iovec __user *,vec, |
dfd948e3 | 1167 | compat_ulong_t, vlen, u32, pos_low, u32, pos_high) |
72ec3516 AV |
1168 | { |
1169 | loff_t pos = ((loff_t)pos_high << 32) | pos_low; | |
378a10f3 HC |
1170 | |
1171 | return __compat_sys_preadv64(fd, vec, vlen, pos); | |
72ec3516 AV |
1172 | } |
1173 | ||
1174 | static size_t compat_writev(struct file *file, | |
1175 | const struct compat_iovec __user *vec, | |
1176 | unsigned long vlen, loff_t *pos) | |
1177 | { | |
1178 | ssize_t ret = -EBADF; | |
1179 | ||
1180 | if (!(file->f_mode & FMODE_WRITE)) | |
1181 | goto out; | |
1182 | ||
1183 | ret = -EINVAL; | |
7f7f25e8 | 1184 | if (!(file->f_mode & FMODE_CAN_WRITE)) |
72ec3516 AV |
1185 | goto out; |
1186 | ||
1187 | ret = compat_do_readv_writev(WRITE, file, vec, vlen, pos); | |
1188 | ||
1189 | out: | |
1190 | if (ret > 0) | |
1191 | add_wchar(current, ret); | |
1192 | inc_syscw(current); | |
1193 | return ret; | |
1194 | } | |
1195 | ||
dfd948e3 | 1196 | COMPAT_SYSCALL_DEFINE3(writev, compat_ulong_t, fd, |
72ec3516 | 1197 | const struct compat_iovec __user *, vec, |
dfd948e3 | 1198 | compat_ulong_t, vlen) |
72ec3516 | 1199 | { |
9c225f26 | 1200 | struct fd f = fdget_pos(fd); |
72ec3516 AV |
1201 | ssize_t ret; |
1202 | loff_t pos; | |
1203 | ||
1204 | if (!f.file) | |
1205 | return -EBADF; | |
1206 | pos = f.file->f_pos; | |
1207 | ret = compat_writev(f.file, vec, vlen, &pos); | |
5faf153e AV |
1208 | if (ret >= 0) |
1209 | f.file->f_pos = pos; | |
9c225f26 | 1210 | fdput_pos(f); |
72ec3516 AV |
1211 | return ret; |
1212 | } | |
1213 | ||
378a10f3 HC |
1214 | static long __compat_sys_pwritev64(unsigned long fd, |
1215 | const struct compat_iovec __user *vec, | |
1216 | unsigned long vlen, loff_t pos) | |
72ec3516 AV |
1217 | { |
1218 | struct fd f; | |
1219 | ssize_t ret; | |
1220 | ||
1221 | if (pos < 0) | |
1222 | return -EINVAL; | |
1223 | f = fdget(fd); | |
1224 | if (!f.file) | |
1225 | return -EBADF; | |
1226 | ret = -ESPIPE; | |
1227 | if (f.file->f_mode & FMODE_PWRITE) | |
1228 | ret = compat_writev(f.file, vec, vlen, &pos); | |
1229 | fdput(f); | |
1230 | return ret; | |
1231 | } | |
1232 | ||
378a10f3 HC |
1233 | #ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64 |
1234 | COMPAT_SYSCALL_DEFINE4(pwritev64, unsigned long, fd, | |
1235 | const struct compat_iovec __user *,vec, | |
1236 | unsigned long, vlen, loff_t, pos) | |
1237 | { | |
1238 | return __compat_sys_pwritev64(fd, vec, vlen, pos); | |
1239 | } | |
1240 | #endif | |
1241 | ||
dfd948e3 | 1242 | COMPAT_SYSCALL_DEFINE5(pwritev, compat_ulong_t, fd, |
72ec3516 | 1243 | const struct compat_iovec __user *,vec, |
dfd948e3 | 1244 | compat_ulong_t, vlen, u32, pos_low, u32, pos_high) |
72ec3516 AV |
1245 | { |
1246 | loff_t pos = ((loff_t)pos_high << 32) | pos_low; | |
378a10f3 HC |
1247 | |
1248 | return __compat_sys_pwritev64(fd, vec, vlen, pos); | |
72ec3516 AV |
1249 | } |
1250 | #endif | |
1251 | ||
19f4fc3a AV |
1252 | static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, |
1253 | size_t count, loff_t max) | |
1da177e4 | 1254 | { |
2903ff01 AV |
1255 | struct fd in, out; |
1256 | struct inode *in_inode, *out_inode; | |
1da177e4 | 1257 | loff_t pos; |
7995bd28 | 1258 | loff_t out_pos; |
1da177e4 | 1259 | ssize_t retval; |
2903ff01 | 1260 | int fl; |
1da177e4 LT |
1261 | |
1262 | /* | |
1263 | * Get input file, and verify that it is ok.. | |
1264 | */ | |
1265 | retval = -EBADF; | |
2903ff01 AV |
1266 | in = fdget(in_fd); |
1267 | if (!in.file) | |
1da177e4 | 1268 | goto out; |
2903ff01 | 1269 | if (!(in.file->f_mode & FMODE_READ)) |
1da177e4 | 1270 | goto fput_in; |
1da177e4 | 1271 | retval = -ESPIPE; |
7995bd28 AV |
1272 | if (!ppos) { |
1273 | pos = in.file->f_pos; | |
1274 | } else { | |
1275 | pos = *ppos; | |
2903ff01 | 1276 | if (!(in.file->f_mode & FMODE_PREAD)) |
1da177e4 | 1277 | goto fput_in; |
7995bd28 AV |
1278 | } |
1279 | retval = rw_verify_area(READ, in.file, &pos, count); | |
e28cc715 | 1280 | if (retval < 0) |
1da177e4 | 1281 | goto fput_in; |
e28cc715 | 1282 | count = retval; |
1da177e4 | 1283 | |
1da177e4 LT |
1284 | /* |
1285 | * Get output file, and verify that it is ok.. | |
1286 | */ | |
1287 | retval = -EBADF; | |
2903ff01 AV |
1288 | out = fdget(out_fd); |
1289 | if (!out.file) | |
1da177e4 | 1290 | goto fput_in; |
2903ff01 | 1291 | if (!(out.file->f_mode & FMODE_WRITE)) |
1da177e4 LT |
1292 | goto fput_out; |
1293 | retval = -EINVAL; | |
496ad9aa AV |
1294 | in_inode = file_inode(in.file); |
1295 | out_inode = file_inode(out.file); | |
7995bd28 AV |
1296 | out_pos = out.file->f_pos; |
1297 | retval = rw_verify_area(WRITE, out.file, &out_pos, count); | |
e28cc715 | 1298 | if (retval < 0) |
1da177e4 | 1299 | goto fput_out; |
e28cc715 | 1300 | count = retval; |
1da177e4 | 1301 | |
1da177e4 LT |
1302 | if (!max) |
1303 | max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes); | |
1304 | ||
1da177e4 LT |
1305 | if (unlikely(pos + count > max)) { |
1306 | retval = -EOVERFLOW; | |
1307 | if (pos >= max) | |
1308 | goto fput_out; | |
1309 | count = max - pos; | |
1310 | } | |
1311 | ||
d96e6e71 | 1312 | fl = 0; |
534f2aaa | 1313 | #if 0 |
d96e6e71 JA |
1314 | /* |
1315 | * We need to debate whether we can enable this or not. The | |
1316 | * man page documents EAGAIN return for the output at least, | |
1317 | * and the application is arguably buggy if it doesn't expect | |
1318 | * EAGAIN on a non-blocking file descriptor. | |
1319 | */ | |
2903ff01 | 1320 | if (in.file->f_flags & O_NONBLOCK) |
d96e6e71 | 1321 | fl = SPLICE_F_NONBLOCK; |
534f2aaa | 1322 | #endif |
50cd2c57 | 1323 | file_start_write(out.file); |
7995bd28 | 1324 | retval = do_splice_direct(in.file, &pos, out.file, &out_pos, count, fl); |
50cd2c57 | 1325 | file_end_write(out.file); |
1da177e4 LT |
1326 | |
1327 | if (retval > 0) { | |
4b98d11b AD |
1328 | add_rchar(current, retval); |
1329 | add_wchar(current, retval); | |
a68c2f12 SW |
1330 | fsnotify_access(in.file); |
1331 | fsnotify_modify(out.file); | |
7995bd28 AV |
1332 | out.file->f_pos = out_pos; |
1333 | if (ppos) | |
1334 | *ppos = pos; | |
1335 | else | |
1336 | in.file->f_pos = pos; | |
1da177e4 | 1337 | } |
1da177e4 | 1338 | |
4b98d11b AD |
1339 | inc_syscr(current); |
1340 | inc_syscw(current); | |
7995bd28 | 1341 | if (pos > max) |
1da177e4 LT |
1342 | retval = -EOVERFLOW; |
1343 | ||
1344 | fput_out: | |
2903ff01 | 1345 | fdput(out); |
1da177e4 | 1346 | fput_in: |
2903ff01 | 1347 | fdput(in); |
1da177e4 LT |
1348 | out: |
1349 | return retval; | |
1350 | } | |
1351 | ||
002c8976 | 1352 | SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, off_t __user *, offset, size_t, count) |
1da177e4 LT |
1353 | { |
1354 | loff_t pos; | |
1355 | off_t off; | |
1356 | ssize_t ret; | |
1357 | ||
1358 | if (offset) { | |
1359 | if (unlikely(get_user(off, offset))) | |
1360 | return -EFAULT; | |
1361 | pos = off; | |
1362 | ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS); | |
1363 | if (unlikely(put_user(pos, offset))) | |
1364 | return -EFAULT; | |
1365 | return ret; | |
1366 | } | |
1367 | ||
1368 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1369 | } | |
1370 | ||
002c8976 | 1371 | SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, loff_t __user *, offset, size_t, count) |
1da177e4 LT |
1372 | { |
1373 | loff_t pos; | |
1374 | ssize_t ret; | |
1375 | ||
1376 | if (offset) { | |
1377 | if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t)))) | |
1378 | return -EFAULT; | |
1379 | ret = do_sendfile(out_fd, in_fd, &pos, count, 0); | |
1380 | if (unlikely(put_user(pos, offset))) | |
1381 | return -EFAULT; | |
1382 | return ret; | |
1383 | } | |
1384 | ||
1385 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1386 | } | |
19f4fc3a AV |
1387 | |
1388 | #ifdef CONFIG_COMPAT | |
1389 | COMPAT_SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, | |
1390 | compat_off_t __user *, offset, compat_size_t, count) | |
1391 | { | |
1392 | loff_t pos; | |
1393 | off_t off; | |
1394 | ssize_t ret; | |
1395 | ||
1396 | if (offset) { | |
1397 | if (unlikely(get_user(off, offset))) | |
1398 | return -EFAULT; | |
1399 | pos = off; | |
1400 | ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS); | |
1401 | if (unlikely(put_user(pos, offset))) | |
1402 | return -EFAULT; | |
1403 | return ret; | |
1404 | } | |
1405 | ||
1406 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1407 | } | |
1408 | ||
1409 | COMPAT_SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, | |
1410 | compat_loff_t __user *, offset, compat_size_t, count) | |
1411 | { | |
1412 | loff_t pos; | |
1413 | ssize_t ret; | |
1414 | ||
1415 | if (offset) { | |
1416 | if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t)))) | |
1417 | return -EFAULT; | |
1418 | ret = do_sendfile(out_fd, in_fd, &pos, count, 0); | |
1419 | if (unlikely(put_user(pos, offset))) | |
1420 | return -EFAULT; | |
1421 | return ret; | |
1422 | } | |
1423 | ||
1424 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1425 | } | |
1426 | #endif |