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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/fs/read_write.c | |
3 | * | |
4 | * Copyright (C) 1991, 1992 Linus Torvalds | |
5 | */ | |
6 | ||
7 | #include <linux/slab.h> | |
8 | #include <linux/stat.h> | |
9 | #include <linux/fcntl.h> | |
10 | #include <linux/file.h> | |
11 | #include <linux/uio.h> | |
0eeca283 | 12 | #include <linux/fsnotify.h> |
1da177e4 | 13 | #include <linux/security.h> |
630d9c47 | 14 | #include <linux/export.h> |
1da177e4 | 15 | #include <linux/syscalls.h> |
e28cc715 | 16 | #include <linux/pagemap.h> |
d6b29d7c | 17 | #include <linux/splice.h> |
561c6731 | 18 | #include <linux/compat.h> |
06ae43f3 | 19 | #include "internal.h" |
1da177e4 LT |
20 | |
21 | #include <asm/uaccess.h> | |
22 | #include <asm/unistd.h> | |
23 | ||
c0bd14af AV |
24 | typedef ssize_t (*io_fn_t)(struct file *, char __user *, size_t, loff_t *); |
25 | typedef ssize_t (*iov_fn_t)(struct kiocb *, const struct iovec *, | |
26 | unsigned long, loff_t); | |
293bc982 | 27 | typedef ssize_t (*iter_fn_t)(struct kiocb *, struct iov_iter *); |
c0bd14af | 28 | |
4b6f5d20 | 29 | const struct file_operations generic_ro_fops = { |
1da177e4 | 30 | .llseek = generic_file_llseek, |
aad4f8bb AV |
31 | .read = new_sync_read, |
32 | .read_iter = generic_file_read_iter, | |
1da177e4 | 33 | .mmap = generic_file_readonly_mmap, |
534f2aaa | 34 | .splice_read = generic_file_splice_read, |
1da177e4 LT |
35 | }; |
36 | ||
37 | EXPORT_SYMBOL(generic_ro_fops); | |
38 | ||
cccb5a1e | 39 | static inline int unsigned_offsets(struct file *file) |
4a3956c7 | 40 | { |
cccb5a1e | 41 | return file->f_mode & FMODE_UNSIGNED_OFFSET; |
4a3956c7 KH |
42 | } |
43 | ||
46a1c2c7 JL |
44 | /** |
45 | * vfs_setpos - update the file offset for lseek | |
46 | * @file: file structure in question | |
47 | * @offset: file offset to seek to | |
48 | * @maxsize: maximum file size | |
49 | * | |
50 | * This is a low-level filesystem helper for updating the file offset to | |
51 | * the value specified by @offset if the given offset is valid and it is | |
52 | * not equal to the current file offset. | |
53 | * | |
54 | * Return the specified offset on success and -EINVAL on invalid offset. | |
55 | */ | |
56 | loff_t vfs_setpos(struct file *file, loff_t offset, loff_t maxsize) | |
ef3d0fd2 AK |
57 | { |
58 | if (offset < 0 && !unsigned_offsets(file)) | |
59 | return -EINVAL; | |
60 | if (offset > maxsize) | |
61 | return -EINVAL; | |
62 | ||
63 | if (offset != file->f_pos) { | |
64 | file->f_pos = offset; | |
65 | file->f_version = 0; | |
66 | } | |
67 | return offset; | |
68 | } | |
46a1c2c7 | 69 | EXPORT_SYMBOL(vfs_setpos); |
ef3d0fd2 | 70 | |
3a8cff4f | 71 | /** |
5760495a | 72 | * generic_file_llseek_size - generic llseek implementation for regular files |
3a8cff4f CH |
73 | * @file: file structure to seek on |
74 | * @offset: file offset to seek to | |
965c8e59 | 75 | * @whence: type of seek |
e8b96eb5 ES |
76 | * @size: max size of this file in file system |
77 | * @eof: offset used for SEEK_END position | |
3a8cff4f | 78 | * |
5760495a | 79 | * This is a variant of generic_file_llseek that allows passing in a custom |
e8b96eb5 | 80 | * maximum file size and a custom EOF position, for e.g. hashed directories |
ef3d0fd2 AK |
81 | * |
82 | * Synchronization: | |
5760495a | 83 | * SEEK_SET and SEEK_END are unsynchronized (but atomic on 64bit platforms) |
ef3d0fd2 AK |
84 | * SEEK_CUR is synchronized against other SEEK_CURs, but not read/writes. |
85 | * read/writes behave like SEEK_SET against seeks. | |
3a8cff4f | 86 | */ |
9465efc9 | 87 | loff_t |
965c8e59 | 88 | generic_file_llseek_size(struct file *file, loff_t offset, int whence, |
e8b96eb5 | 89 | loff_t maxsize, loff_t eof) |
1da177e4 | 90 | { |
965c8e59 | 91 | switch (whence) { |
3a8cff4f | 92 | case SEEK_END: |
e8b96eb5 | 93 | offset += eof; |
3a8cff4f CH |
94 | break; |
95 | case SEEK_CUR: | |
5b6f1eb9 AK |
96 | /* |
97 | * Here we special-case the lseek(fd, 0, SEEK_CUR) | |
98 | * position-querying operation. Avoid rewriting the "same" | |
99 | * f_pos value back to the file because a concurrent read(), | |
100 | * write() or lseek() might have altered it | |
101 | */ | |
102 | if (offset == 0) | |
103 | return file->f_pos; | |
ef3d0fd2 AK |
104 | /* |
105 | * f_lock protects against read/modify/write race with other | |
106 | * SEEK_CURs. Note that parallel writes and reads behave | |
107 | * like SEEK_SET. | |
108 | */ | |
109 | spin_lock(&file->f_lock); | |
46a1c2c7 | 110 | offset = vfs_setpos(file, file->f_pos + offset, maxsize); |
ef3d0fd2 AK |
111 | spin_unlock(&file->f_lock); |
112 | return offset; | |
982d8165 JB |
113 | case SEEK_DATA: |
114 | /* | |
115 | * In the generic case the entire file is data, so as long as | |
116 | * offset isn't at the end of the file then the offset is data. | |
117 | */ | |
e8b96eb5 | 118 | if (offset >= eof) |
982d8165 JB |
119 | return -ENXIO; |
120 | break; | |
121 | case SEEK_HOLE: | |
122 | /* | |
123 | * There is a virtual hole at the end of the file, so as long as | |
124 | * offset isn't i_size or larger, return i_size. | |
125 | */ | |
e8b96eb5 | 126 | if (offset >= eof) |
982d8165 | 127 | return -ENXIO; |
e8b96eb5 | 128 | offset = eof; |
982d8165 | 129 | break; |
1da177e4 | 130 | } |
3a8cff4f | 131 | |
46a1c2c7 | 132 | return vfs_setpos(file, offset, maxsize); |
5760495a AK |
133 | } |
134 | EXPORT_SYMBOL(generic_file_llseek_size); | |
135 | ||
136 | /** | |
137 | * generic_file_llseek - generic llseek implementation for regular files | |
138 | * @file: file structure to seek on | |
139 | * @offset: file offset to seek to | |
965c8e59 | 140 | * @whence: type of seek |
5760495a AK |
141 | * |
142 | * This is a generic implemenation of ->llseek useable for all normal local | |
143 | * filesystems. It just updates the file offset to the value specified by | |
546ae2d2 | 144 | * @offset and @whence. |
5760495a | 145 | */ |
965c8e59 | 146 | loff_t generic_file_llseek(struct file *file, loff_t offset, int whence) |
5760495a AK |
147 | { |
148 | struct inode *inode = file->f_mapping->host; | |
149 | ||
965c8e59 | 150 | return generic_file_llseek_size(file, offset, whence, |
e8b96eb5 ES |
151 | inode->i_sb->s_maxbytes, |
152 | i_size_read(inode)); | |
1da177e4 | 153 | } |
9465efc9 | 154 | EXPORT_SYMBOL(generic_file_llseek); |
1da177e4 | 155 | |
1bf9d14d AV |
156 | /** |
157 | * fixed_size_llseek - llseek implementation for fixed-sized devices | |
158 | * @file: file structure to seek on | |
159 | * @offset: file offset to seek to | |
160 | * @whence: type of seek | |
161 | * @size: size of the file | |
162 | * | |
163 | */ | |
164 | loff_t fixed_size_llseek(struct file *file, loff_t offset, int whence, loff_t size) | |
165 | { | |
166 | switch (whence) { | |
167 | case SEEK_SET: case SEEK_CUR: case SEEK_END: | |
168 | return generic_file_llseek_size(file, offset, whence, | |
169 | size, size); | |
170 | default: | |
171 | return -EINVAL; | |
172 | } | |
173 | } | |
174 | EXPORT_SYMBOL(fixed_size_llseek); | |
175 | ||
ae6afc3f B |
176 | /** |
177 | * noop_llseek - No Operation Performed llseek implementation | |
178 | * @file: file structure to seek on | |
179 | * @offset: file offset to seek to | |
965c8e59 | 180 | * @whence: type of seek |
ae6afc3f B |
181 | * |
182 | * This is an implementation of ->llseek useable for the rare special case when | |
183 | * userspace expects the seek to succeed but the (device) file is actually not | |
184 | * able to perform the seek. In this case you use noop_llseek() instead of | |
185 | * falling back to the default implementation of ->llseek. | |
186 | */ | |
965c8e59 | 187 | loff_t noop_llseek(struct file *file, loff_t offset, int whence) |
ae6afc3f B |
188 | { |
189 | return file->f_pos; | |
190 | } | |
191 | EXPORT_SYMBOL(noop_llseek); | |
192 | ||
965c8e59 | 193 | loff_t no_llseek(struct file *file, loff_t offset, int whence) |
1da177e4 LT |
194 | { |
195 | return -ESPIPE; | |
196 | } | |
197 | EXPORT_SYMBOL(no_llseek); | |
198 | ||
965c8e59 | 199 | loff_t default_llseek(struct file *file, loff_t offset, int whence) |
1da177e4 | 200 | { |
496ad9aa | 201 | struct inode *inode = file_inode(file); |
16abef0e | 202 | loff_t retval; |
1da177e4 | 203 | |
982d8165 | 204 | mutex_lock(&inode->i_mutex); |
965c8e59 | 205 | switch (whence) { |
7b8e8924 | 206 | case SEEK_END: |
982d8165 | 207 | offset += i_size_read(inode); |
1da177e4 | 208 | break; |
7b8e8924 | 209 | case SEEK_CUR: |
5b6f1eb9 AK |
210 | if (offset == 0) { |
211 | retval = file->f_pos; | |
212 | goto out; | |
213 | } | |
1da177e4 | 214 | offset += file->f_pos; |
982d8165 JB |
215 | break; |
216 | case SEEK_DATA: | |
217 | /* | |
218 | * In the generic case the entire file is data, so as | |
219 | * long as offset isn't at the end of the file then the | |
220 | * offset is data. | |
221 | */ | |
bacb2d81 DC |
222 | if (offset >= inode->i_size) { |
223 | retval = -ENXIO; | |
224 | goto out; | |
225 | } | |
982d8165 JB |
226 | break; |
227 | case SEEK_HOLE: | |
228 | /* | |
229 | * There is a virtual hole at the end of the file, so | |
230 | * as long as offset isn't i_size or larger, return | |
231 | * i_size. | |
232 | */ | |
bacb2d81 DC |
233 | if (offset >= inode->i_size) { |
234 | retval = -ENXIO; | |
235 | goto out; | |
236 | } | |
982d8165 JB |
237 | offset = inode->i_size; |
238 | break; | |
1da177e4 LT |
239 | } |
240 | retval = -EINVAL; | |
cccb5a1e | 241 | if (offset >= 0 || unsigned_offsets(file)) { |
1da177e4 LT |
242 | if (offset != file->f_pos) { |
243 | file->f_pos = offset; | |
244 | file->f_version = 0; | |
245 | } | |
246 | retval = offset; | |
247 | } | |
5b6f1eb9 | 248 | out: |
982d8165 | 249 | mutex_unlock(&inode->i_mutex); |
1da177e4 LT |
250 | return retval; |
251 | } | |
252 | EXPORT_SYMBOL(default_llseek); | |
253 | ||
965c8e59 | 254 | loff_t vfs_llseek(struct file *file, loff_t offset, int whence) |
1da177e4 LT |
255 | { |
256 | loff_t (*fn)(struct file *, loff_t, int); | |
257 | ||
258 | fn = no_llseek; | |
259 | if (file->f_mode & FMODE_LSEEK) { | |
72c2d531 | 260 | if (file->f_op->llseek) |
1da177e4 LT |
261 | fn = file->f_op->llseek; |
262 | } | |
965c8e59 | 263 | return fn(file, offset, whence); |
1da177e4 LT |
264 | } |
265 | EXPORT_SYMBOL(vfs_llseek); | |
266 | ||
9c225f26 LT |
267 | static inline struct fd fdget_pos(int fd) |
268 | { | |
bd2a31d5 | 269 | return __to_fd(__fdget_pos(fd)); |
9c225f26 LT |
270 | } |
271 | ||
272 | static inline void fdput_pos(struct fd f) | |
273 | { | |
274 | if (f.flags & FDPUT_POS_UNLOCK) | |
275 | mutex_unlock(&f.file->f_pos_lock); | |
276 | fdput(f); | |
277 | } | |
278 | ||
965c8e59 | 279 | SYSCALL_DEFINE3(lseek, unsigned int, fd, off_t, offset, unsigned int, whence) |
1da177e4 LT |
280 | { |
281 | off_t retval; | |
9c225f26 | 282 | struct fd f = fdget_pos(fd); |
2903ff01 AV |
283 | if (!f.file) |
284 | return -EBADF; | |
1da177e4 LT |
285 | |
286 | retval = -EINVAL; | |
965c8e59 AM |
287 | if (whence <= SEEK_MAX) { |
288 | loff_t res = vfs_llseek(f.file, offset, whence); | |
1da177e4 LT |
289 | retval = res; |
290 | if (res != (loff_t)retval) | |
291 | retval = -EOVERFLOW; /* LFS: should only happen on 32 bit platforms */ | |
292 | } | |
9c225f26 | 293 | fdput_pos(f); |
1da177e4 LT |
294 | return retval; |
295 | } | |
296 | ||
561c6731 AV |
297 | #ifdef CONFIG_COMPAT |
298 | COMPAT_SYSCALL_DEFINE3(lseek, unsigned int, fd, compat_off_t, offset, unsigned int, whence) | |
299 | { | |
300 | return sys_lseek(fd, offset, whence); | |
301 | } | |
302 | #endif | |
303 | ||
1da177e4 | 304 | #ifdef __ARCH_WANT_SYS_LLSEEK |
003d7ab4 HC |
305 | SYSCALL_DEFINE5(llseek, unsigned int, fd, unsigned long, offset_high, |
306 | unsigned long, offset_low, loff_t __user *, result, | |
965c8e59 | 307 | unsigned int, whence) |
1da177e4 LT |
308 | { |
309 | int retval; | |
d7a15f8d | 310 | struct fd f = fdget_pos(fd); |
1da177e4 | 311 | loff_t offset; |
1da177e4 | 312 | |
2903ff01 AV |
313 | if (!f.file) |
314 | return -EBADF; | |
1da177e4 LT |
315 | |
316 | retval = -EINVAL; | |
965c8e59 | 317 | if (whence > SEEK_MAX) |
1da177e4 LT |
318 | goto out_putf; |
319 | ||
2903ff01 | 320 | offset = vfs_llseek(f.file, ((loff_t) offset_high << 32) | offset_low, |
965c8e59 | 321 | whence); |
1da177e4 LT |
322 | |
323 | retval = (int)offset; | |
324 | if (offset >= 0) { | |
325 | retval = -EFAULT; | |
326 | if (!copy_to_user(result, &offset, sizeof(offset))) | |
327 | retval = 0; | |
328 | } | |
329 | out_putf: | |
d7a15f8d | 330 | fdput_pos(f); |
1da177e4 LT |
331 | return retval; |
332 | } | |
333 | #endif | |
334 | ||
dbe4e192 CH |
335 | ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos) |
336 | { | |
337 | struct kiocb kiocb; | |
338 | ssize_t ret; | |
339 | ||
340 | if (!file->f_op->read_iter) | |
341 | return -EINVAL; | |
342 | ||
343 | init_sync_kiocb(&kiocb, file); | |
344 | kiocb.ki_pos = *ppos; | |
dbe4e192 CH |
345 | |
346 | iter->type |= READ; | |
347 | ret = file->f_op->read_iter(&kiocb, iter); | |
599bd19b | 348 | BUG_ON(ret == -EIOCBQUEUED); |
dbe4e192 CH |
349 | if (ret > 0) |
350 | *ppos = kiocb.ki_pos; | |
351 | return ret; | |
352 | } | |
353 | EXPORT_SYMBOL(vfs_iter_read); | |
354 | ||
355 | ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos) | |
356 | { | |
357 | struct kiocb kiocb; | |
358 | ssize_t ret; | |
359 | ||
360 | if (!file->f_op->write_iter) | |
361 | return -EINVAL; | |
362 | ||
363 | init_sync_kiocb(&kiocb, file); | |
364 | kiocb.ki_pos = *ppos; | |
dbe4e192 CH |
365 | |
366 | iter->type |= WRITE; | |
367 | ret = file->f_op->write_iter(&kiocb, iter); | |
599bd19b | 368 | BUG_ON(ret == -EIOCBQUEUED); |
dbe4e192 CH |
369 | if (ret > 0) |
370 | *ppos = kiocb.ki_pos; | |
371 | return ret; | |
372 | } | |
373 | EXPORT_SYMBOL(vfs_iter_write); | |
374 | ||
e28cc715 LT |
375 | /* |
376 | * rw_verify_area doesn't like huge counts. We limit | |
377 | * them to something that fits in "int" so that others | |
378 | * won't have to do range checks all the time. | |
379 | */ | |
68d70d03 | 380 | int rw_verify_area(int read_write, struct file *file, const loff_t *ppos, size_t count) |
1da177e4 LT |
381 | { |
382 | struct inode *inode; | |
383 | loff_t pos; | |
c43e259c | 384 | int retval = -EINVAL; |
1da177e4 | 385 | |
496ad9aa | 386 | inode = file_inode(file); |
e28cc715 | 387 | if (unlikely((ssize_t) count < 0)) |
c43e259c | 388 | return retval; |
1da177e4 | 389 | pos = *ppos; |
cccb5a1e AV |
390 | if (unlikely(pos < 0)) { |
391 | if (!unsigned_offsets(file)) | |
392 | return retval; | |
393 | if (count >= -pos) /* both values are in 0..LLONG_MAX */ | |
394 | return -EOVERFLOW; | |
395 | } else if (unlikely((loff_t) (pos + count) < 0)) { | |
396 | if (!unsigned_offsets(file)) | |
4a3956c7 KH |
397 | return retval; |
398 | } | |
1da177e4 | 399 | |
bd61e0a9 | 400 | if (unlikely(inode->i_flctx && mandatory_lock(inode))) { |
c43e259c | 401 | retval = locks_mandatory_area( |
e28cc715 LT |
402 | read_write == READ ? FLOCK_VERIFY_READ : FLOCK_VERIFY_WRITE, |
403 | inode, file, pos, count); | |
404 | if (retval < 0) | |
405 | return retval; | |
406 | } | |
c43e259c JM |
407 | retval = security_file_permission(file, |
408 | read_write == READ ? MAY_READ : MAY_WRITE); | |
409 | if (retval) | |
410 | return retval; | |
e28cc715 | 411 | return count > MAX_RW_COUNT ? MAX_RW_COUNT : count; |
1da177e4 LT |
412 | } |
413 | ||
414 | ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos) | |
415 | { | |
027445c3 | 416 | struct iovec iov = { .iov_base = buf, .iov_len = len }; |
1da177e4 LT |
417 | struct kiocb kiocb; |
418 | ssize_t ret; | |
419 | ||
420 | init_sync_kiocb(&kiocb, filp); | |
421 | kiocb.ki_pos = *ppos; | |
027445c3 | 422 | |
41003a7b | 423 | ret = filp->f_op->aio_read(&kiocb, &iov, 1, kiocb.ki_pos); |
599bd19b | 424 | BUG_ON(ret == -EIOCBQUEUED); |
1da177e4 LT |
425 | *ppos = kiocb.ki_pos; |
426 | return ret; | |
427 | } | |
428 | ||
429 | EXPORT_SYMBOL(do_sync_read); | |
430 | ||
293bc982 AV |
431 | ssize_t new_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos) |
432 | { | |
433 | struct iovec iov = { .iov_base = buf, .iov_len = len }; | |
434 | struct kiocb kiocb; | |
435 | struct iov_iter iter; | |
436 | ssize_t ret; | |
437 | ||
438 | init_sync_kiocb(&kiocb, filp); | |
439 | kiocb.ki_pos = *ppos; | |
293bc982 AV |
440 | iov_iter_init(&iter, READ, &iov, 1, len); |
441 | ||
442 | ret = filp->f_op->read_iter(&kiocb, &iter); | |
599bd19b | 443 | BUG_ON(ret == -EIOCBQUEUED); |
293bc982 AV |
444 | *ppos = kiocb.ki_pos; |
445 | return ret; | |
446 | } | |
447 | ||
448 | EXPORT_SYMBOL(new_sync_read); | |
449 | ||
6fb5032e DK |
450 | ssize_t __vfs_read(struct file *file, char __user *buf, size_t count, |
451 | loff_t *pos) | |
452 | { | |
453 | ssize_t ret; | |
454 | ||
455 | if (file->f_op->read) | |
456 | ret = file->f_op->read(file, buf, count, pos); | |
457 | else if (file->f_op->aio_read) | |
458 | ret = do_sync_read(file, buf, count, pos); | |
459 | else if (file->f_op->read_iter) | |
460 | ret = new_sync_read(file, buf, count, pos); | |
461 | else | |
462 | ret = -EINVAL; | |
463 | ||
464 | return ret; | |
465 | } | |
466 | ||
1da177e4 LT |
467 | ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos) |
468 | { | |
469 | ssize_t ret; | |
470 | ||
471 | if (!(file->f_mode & FMODE_READ)) | |
472 | return -EBADF; | |
7f7f25e8 | 473 | if (!(file->f_mode & FMODE_CAN_READ)) |
1da177e4 LT |
474 | return -EINVAL; |
475 | if (unlikely(!access_ok(VERIFY_WRITE, buf, count))) | |
476 | return -EFAULT; | |
477 | ||
478 | ret = rw_verify_area(READ, file, pos, count); | |
e28cc715 LT |
479 | if (ret >= 0) { |
480 | count = ret; | |
6fb5032e | 481 | ret = __vfs_read(file, buf, count, pos); |
c43e259c | 482 | if (ret > 0) { |
2a12a9d7 | 483 | fsnotify_access(file); |
c43e259c | 484 | add_rchar(current, ret); |
1da177e4 | 485 | } |
c43e259c | 486 | inc_syscr(current); |
1da177e4 LT |
487 | } |
488 | ||
489 | return ret; | |
490 | } | |
491 | ||
492 | EXPORT_SYMBOL(vfs_read); | |
493 | ||
494 | ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos) | |
495 | { | |
027445c3 | 496 | struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = len }; |
1da177e4 LT |
497 | struct kiocb kiocb; |
498 | ssize_t ret; | |
499 | ||
500 | init_sync_kiocb(&kiocb, filp); | |
501 | kiocb.ki_pos = *ppos; | |
027445c3 | 502 | |
41003a7b | 503 | ret = filp->f_op->aio_write(&kiocb, &iov, 1, kiocb.ki_pos); |
599bd19b | 504 | BUG_ON(ret == -EIOCBQUEUED); |
1da177e4 LT |
505 | *ppos = kiocb.ki_pos; |
506 | return ret; | |
507 | } | |
508 | ||
509 | EXPORT_SYMBOL(do_sync_write); | |
510 | ||
293bc982 AV |
511 | ssize_t new_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos) |
512 | { | |
513 | struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = len }; | |
514 | struct kiocb kiocb; | |
515 | struct iov_iter iter; | |
516 | ssize_t ret; | |
517 | ||
518 | init_sync_kiocb(&kiocb, filp); | |
519 | kiocb.ki_pos = *ppos; | |
293bc982 AV |
520 | iov_iter_init(&iter, WRITE, &iov, 1, len); |
521 | ||
522 | ret = filp->f_op->write_iter(&kiocb, &iter); | |
599bd19b | 523 | BUG_ON(ret == -EIOCBQUEUED); |
293bc982 AV |
524 | *ppos = kiocb.ki_pos; |
525 | return ret; | |
526 | } | |
527 | ||
528 | EXPORT_SYMBOL(new_sync_write); | |
529 | ||
06ae43f3 AV |
530 | ssize_t __kernel_write(struct file *file, const char *buf, size_t count, loff_t *pos) |
531 | { | |
532 | mm_segment_t old_fs; | |
533 | const char __user *p; | |
534 | ssize_t ret; | |
535 | ||
7f7f25e8 | 536 | if (!(file->f_mode & FMODE_CAN_WRITE)) |
3e84f48e AV |
537 | return -EINVAL; |
538 | ||
06ae43f3 AV |
539 | old_fs = get_fs(); |
540 | set_fs(get_ds()); | |
541 | p = (__force const char __user *)buf; | |
542 | if (count > MAX_RW_COUNT) | |
543 | count = MAX_RW_COUNT; | |
544 | if (file->f_op->write) | |
545 | ret = file->f_op->write(file, p, count, pos); | |
293bc982 | 546 | else if (file->f_op->aio_write) |
06ae43f3 | 547 | ret = do_sync_write(file, p, count, pos); |
293bc982 AV |
548 | else |
549 | ret = new_sync_write(file, p, count, pos); | |
06ae43f3 AV |
550 | set_fs(old_fs); |
551 | if (ret > 0) { | |
552 | fsnotify_modify(file); | |
553 | add_wchar(current, ret); | |
554 | } | |
555 | inc_syscw(current); | |
556 | return ret; | |
557 | } | |
558 | ||
2ec3a12a AV |
559 | EXPORT_SYMBOL(__kernel_write); |
560 | ||
1da177e4 LT |
561 | ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_t *pos) |
562 | { | |
563 | ssize_t ret; | |
564 | ||
565 | if (!(file->f_mode & FMODE_WRITE)) | |
566 | return -EBADF; | |
7f7f25e8 | 567 | if (!(file->f_mode & FMODE_CAN_WRITE)) |
1da177e4 LT |
568 | return -EINVAL; |
569 | if (unlikely(!access_ok(VERIFY_READ, buf, count))) | |
570 | return -EFAULT; | |
571 | ||
572 | ret = rw_verify_area(WRITE, file, pos, count); | |
e28cc715 LT |
573 | if (ret >= 0) { |
574 | count = ret; | |
03d95eb2 | 575 | file_start_write(file); |
c43e259c JM |
576 | if (file->f_op->write) |
577 | ret = file->f_op->write(file, buf, count, pos); | |
293bc982 | 578 | else if (file->f_op->aio_write) |
c43e259c | 579 | ret = do_sync_write(file, buf, count, pos); |
293bc982 AV |
580 | else |
581 | ret = new_sync_write(file, buf, count, pos); | |
c43e259c | 582 | if (ret > 0) { |
2a12a9d7 | 583 | fsnotify_modify(file); |
c43e259c | 584 | add_wchar(current, ret); |
1da177e4 | 585 | } |
c43e259c | 586 | inc_syscw(current); |
03d95eb2 | 587 | file_end_write(file); |
1da177e4 LT |
588 | } |
589 | ||
590 | return ret; | |
591 | } | |
592 | ||
593 | EXPORT_SYMBOL(vfs_write); | |
594 | ||
595 | static inline loff_t file_pos_read(struct file *file) | |
596 | { | |
597 | return file->f_pos; | |
598 | } | |
599 | ||
600 | static inline void file_pos_write(struct file *file, loff_t pos) | |
601 | { | |
602 | file->f_pos = pos; | |
603 | } | |
604 | ||
3cdad428 | 605 | SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count) |
1da177e4 | 606 | { |
9c225f26 | 607 | struct fd f = fdget_pos(fd); |
1da177e4 | 608 | ssize_t ret = -EBADF; |
1da177e4 | 609 | |
2903ff01 AV |
610 | if (f.file) { |
611 | loff_t pos = file_pos_read(f.file); | |
612 | ret = vfs_read(f.file, buf, count, &pos); | |
5faf153e AV |
613 | if (ret >= 0) |
614 | file_pos_write(f.file, pos); | |
9c225f26 | 615 | fdput_pos(f); |
1da177e4 | 616 | } |
1da177e4 LT |
617 | return ret; |
618 | } | |
1da177e4 | 619 | |
3cdad428 HC |
620 | SYSCALL_DEFINE3(write, unsigned int, fd, const char __user *, buf, |
621 | size_t, count) | |
1da177e4 | 622 | { |
9c225f26 | 623 | struct fd f = fdget_pos(fd); |
1da177e4 | 624 | ssize_t ret = -EBADF; |
1da177e4 | 625 | |
2903ff01 AV |
626 | if (f.file) { |
627 | loff_t pos = file_pos_read(f.file); | |
628 | ret = vfs_write(f.file, buf, count, &pos); | |
5faf153e AV |
629 | if (ret >= 0) |
630 | file_pos_write(f.file, pos); | |
9c225f26 | 631 | fdput_pos(f); |
1da177e4 LT |
632 | } |
633 | ||
634 | return ret; | |
635 | } | |
636 | ||
4a0fd5bf AV |
637 | SYSCALL_DEFINE4(pread64, unsigned int, fd, char __user *, buf, |
638 | size_t, count, loff_t, pos) | |
1da177e4 | 639 | { |
2903ff01 | 640 | struct fd f; |
1da177e4 | 641 | ssize_t ret = -EBADF; |
1da177e4 LT |
642 | |
643 | if (pos < 0) | |
644 | return -EINVAL; | |
645 | ||
2903ff01 AV |
646 | f = fdget(fd); |
647 | if (f.file) { | |
1da177e4 | 648 | ret = -ESPIPE; |
2903ff01 AV |
649 | if (f.file->f_mode & FMODE_PREAD) |
650 | ret = vfs_read(f.file, buf, count, &pos); | |
651 | fdput(f); | |
1da177e4 LT |
652 | } |
653 | ||
654 | return ret; | |
655 | } | |
656 | ||
4a0fd5bf AV |
657 | SYSCALL_DEFINE4(pwrite64, unsigned int, fd, const char __user *, buf, |
658 | size_t, count, loff_t, pos) | |
1da177e4 | 659 | { |
2903ff01 | 660 | struct fd f; |
1da177e4 | 661 | ssize_t ret = -EBADF; |
1da177e4 LT |
662 | |
663 | if (pos < 0) | |
664 | return -EINVAL; | |
665 | ||
2903ff01 AV |
666 | f = fdget(fd); |
667 | if (f.file) { | |
1da177e4 | 668 | ret = -ESPIPE; |
2903ff01 AV |
669 | if (f.file->f_mode & FMODE_PWRITE) |
670 | ret = vfs_write(f.file, buf, count, &pos); | |
671 | fdput(f); | |
1da177e4 LT |
672 | } |
673 | ||
674 | return ret; | |
675 | } | |
676 | ||
677 | /* | |
678 | * Reduce an iovec's length in-place. Return the resulting number of segments | |
679 | */ | |
680 | unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to) | |
681 | { | |
682 | unsigned long seg = 0; | |
683 | size_t len = 0; | |
684 | ||
685 | while (seg < nr_segs) { | |
686 | seg++; | |
687 | if (len + iov->iov_len >= to) { | |
688 | iov->iov_len = to - len; | |
689 | break; | |
690 | } | |
691 | len += iov->iov_len; | |
692 | iov++; | |
693 | } | |
694 | return seg; | |
695 | } | |
19295529 | 696 | EXPORT_SYMBOL(iov_shorten); |
1da177e4 | 697 | |
ac15ac06 AV |
698 | static ssize_t do_iter_readv_writev(struct file *filp, struct iov_iter *iter, |
699 | loff_t *ppos, iter_fn_t fn) | |
293bc982 AV |
700 | { |
701 | struct kiocb kiocb; | |
293bc982 AV |
702 | ssize_t ret; |
703 | ||
704 | init_sync_kiocb(&kiocb, filp); | |
705 | kiocb.ki_pos = *ppos; | |
293bc982 | 706 | |
ac15ac06 | 707 | ret = fn(&kiocb, iter); |
599bd19b | 708 | BUG_ON(ret == -EIOCBQUEUED); |
293bc982 AV |
709 | *ppos = kiocb.ki_pos; |
710 | return ret; | |
711 | } | |
712 | ||
ac15ac06 AV |
713 | static ssize_t do_sync_readv_writev(struct file *filp, struct iov_iter *iter, |
714 | loff_t *ppos, iov_fn_t fn) | |
ee0b3e67 BP |
715 | { |
716 | struct kiocb kiocb; | |
717 | ssize_t ret; | |
718 | ||
719 | init_sync_kiocb(&kiocb, filp); | |
720 | kiocb.ki_pos = *ppos; | |
ee0b3e67 | 721 | |
ac15ac06 | 722 | ret = fn(&kiocb, iter->iov, iter->nr_segs, kiocb.ki_pos); |
599bd19b | 723 | BUG_ON(ret == -EIOCBQUEUED); |
ee0b3e67 BP |
724 | *ppos = kiocb.ki_pos; |
725 | return ret; | |
726 | } | |
727 | ||
728 | /* Do it by hand, with file-ops */ | |
ac15ac06 AV |
729 | static ssize_t do_loop_readv_writev(struct file *filp, struct iov_iter *iter, |
730 | loff_t *ppos, io_fn_t fn) | |
ee0b3e67 | 731 | { |
ee0b3e67 BP |
732 | ssize_t ret = 0; |
733 | ||
ac15ac06 AV |
734 | while (iov_iter_count(iter)) { |
735 | struct iovec iovec = iov_iter_iovec(iter); | |
ee0b3e67 BP |
736 | ssize_t nr; |
737 | ||
ac15ac06 | 738 | nr = fn(filp, iovec.iov_base, iovec.iov_len, ppos); |
ee0b3e67 BP |
739 | |
740 | if (nr < 0) { | |
741 | if (!ret) | |
742 | ret = nr; | |
743 | break; | |
744 | } | |
745 | ret += nr; | |
ac15ac06 | 746 | if (nr != iovec.iov_len) |
ee0b3e67 | 747 | break; |
ac15ac06 | 748 | iov_iter_advance(iter, nr); |
ee0b3e67 BP |
749 | } |
750 | ||
751 | return ret; | |
752 | } | |
753 | ||
1da177e4 LT |
754 | /* A write operation does a read from user space and vice versa */ |
755 | #define vrfy_dir(type) ((type) == READ ? VERIFY_WRITE : VERIFY_READ) | |
756 | ||
eed4e51f BP |
757 | ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector, |
758 | unsigned long nr_segs, unsigned long fast_segs, | |
759 | struct iovec *fast_pointer, | |
ac34ebb3 | 760 | struct iovec **ret_pointer) |
435f49a5 | 761 | { |
eed4e51f | 762 | unsigned long seg; |
435f49a5 | 763 | ssize_t ret; |
eed4e51f BP |
764 | struct iovec *iov = fast_pointer; |
765 | ||
435f49a5 LT |
766 | /* |
767 | * SuS says "The readv() function *may* fail if the iovcnt argument | |
768 | * was less than or equal to 0, or greater than {IOV_MAX}. Linux has | |
769 | * traditionally returned zero for zero segments, so... | |
770 | */ | |
eed4e51f BP |
771 | if (nr_segs == 0) { |
772 | ret = 0; | |
435f49a5 | 773 | goto out; |
eed4e51f BP |
774 | } |
775 | ||
435f49a5 LT |
776 | /* |
777 | * First get the "struct iovec" from user memory and | |
778 | * verify all the pointers | |
779 | */ | |
eed4e51f BP |
780 | if (nr_segs > UIO_MAXIOV) { |
781 | ret = -EINVAL; | |
435f49a5 | 782 | goto out; |
eed4e51f BP |
783 | } |
784 | if (nr_segs > fast_segs) { | |
435f49a5 | 785 | iov = kmalloc(nr_segs*sizeof(struct iovec), GFP_KERNEL); |
eed4e51f BP |
786 | if (iov == NULL) { |
787 | ret = -ENOMEM; | |
435f49a5 | 788 | goto out; |
eed4e51f | 789 | } |
435f49a5 | 790 | } |
eed4e51f BP |
791 | if (copy_from_user(iov, uvector, nr_segs*sizeof(*uvector))) { |
792 | ret = -EFAULT; | |
435f49a5 | 793 | goto out; |
eed4e51f BP |
794 | } |
795 | ||
435f49a5 | 796 | /* |
eed4e51f BP |
797 | * According to the Single Unix Specification we should return EINVAL |
798 | * if an element length is < 0 when cast to ssize_t or if the | |
799 | * total length would overflow the ssize_t return value of the | |
800 | * system call. | |
435f49a5 LT |
801 | * |
802 | * Linux caps all read/write calls to MAX_RW_COUNT, and avoids the | |
803 | * overflow case. | |
804 | */ | |
eed4e51f | 805 | ret = 0; |
435f49a5 LT |
806 | for (seg = 0; seg < nr_segs; seg++) { |
807 | void __user *buf = iov[seg].iov_base; | |
808 | ssize_t len = (ssize_t)iov[seg].iov_len; | |
eed4e51f BP |
809 | |
810 | /* see if we we're about to use an invalid len or if | |
811 | * it's about to overflow ssize_t */ | |
435f49a5 | 812 | if (len < 0) { |
eed4e51f | 813 | ret = -EINVAL; |
435f49a5 | 814 | goto out; |
eed4e51f | 815 | } |
ac34ebb3 | 816 | if (type >= 0 |
fcf63409 | 817 | && unlikely(!access_ok(vrfy_dir(type), buf, len))) { |
eed4e51f | 818 | ret = -EFAULT; |
435f49a5 LT |
819 | goto out; |
820 | } | |
821 | if (len > MAX_RW_COUNT - ret) { | |
822 | len = MAX_RW_COUNT - ret; | |
823 | iov[seg].iov_len = len; | |
eed4e51f | 824 | } |
eed4e51f | 825 | ret += len; |
435f49a5 | 826 | } |
eed4e51f BP |
827 | out: |
828 | *ret_pointer = iov; | |
829 | return ret; | |
830 | } | |
831 | ||
1da177e4 LT |
832 | static ssize_t do_readv_writev(int type, struct file *file, |
833 | const struct iovec __user * uvector, | |
834 | unsigned long nr_segs, loff_t *pos) | |
835 | { | |
1da177e4 LT |
836 | size_t tot_len; |
837 | struct iovec iovstack[UIO_FASTIOV]; | |
ee0b3e67 | 838 | struct iovec *iov = iovstack; |
ac15ac06 | 839 | struct iov_iter iter; |
1da177e4 | 840 | ssize_t ret; |
1da177e4 LT |
841 | io_fn_t fn; |
842 | iov_fn_t fnv; | |
293bc982 | 843 | iter_fn_t iter_fn; |
1da177e4 | 844 | |
eed4e51f | 845 | ret = rw_copy_check_uvector(type, uvector, nr_segs, |
ac34ebb3 | 846 | ARRAY_SIZE(iovstack), iovstack, &iov); |
eed4e51f | 847 | if (ret <= 0) |
1da177e4 | 848 | goto out; |
ac15ac06 | 849 | iov_iter_init(&iter, type, iov, nr_segs, ret); |
1da177e4 | 850 | |
eed4e51f | 851 | tot_len = ret; |
1da177e4 | 852 | ret = rw_verify_area(type, file, pos, tot_len); |
e28cc715 | 853 | if (ret < 0) |
411b67b4 | 854 | goto out; |
1da177e4 LT |
855 | |
856 | fnv = NULL; | |
857 | if (type == READ) { | |
858 | fn = file->f_op->read; | |
ee0b3e67 | 859 | fnv = file->f_op->aio_read; |
293bc982 | 860 | iter_fn = file->f_op->read_iter; |
1da177e4 LT |
861 | } else { |
862 | fn = (io_fn_t)file->f_op->write; | |
ee0b3e67 | 863 | fnv = file->f_op->aio_write; |
293bc982 | 864 | iter_fn = file->f_op->write_iter; |
03d95eb2 | 865 | file_start_write(file); |
1da177e4 LT |
866 | } |
867 | ||
293bc982 | 868 | if (iter_fn) |
ac15ac06 | 869 | ret = do_iter_readv_writev(file, &iter, pos, iter_fn); |
293bc982 | 870 | else if (fnv) |
ac15ac06 | 871 | ret = do_sync_readv_writev(file, &iter, pos, fnv); |
ee0b3e67 | 872 | else |
ac15ac06 | 873 | ret = do_loop_readv_writev(file, &iter, pos, fn); |
1da177e4 | 874 | |
03d95eb2 AV |
875 | if (type != READ) |
876 | file_end_write(file); | |
877 | ||
1da177e4 LT |
878 | out: |
879 | if (iov != iovstack) | |
880 | kfree(iov); | |
0eeca283 RL |
881 | if ((ret + (type == READ)) > 0) { |
882 | if (type == READ) | |
2a12a9d7 | 883 | fsnotify_access(file); |
0eeca283 | 884 | else |
2a12a9d7 | 885 | fsnotify_modify(file); |
0eeca283 | 886 | } |
1da177e4 | 887 | return ret; |
1da177e4 LT |
888 | } |
889 | ||
890 | ssize_t vfs_readv(struct file *file, const struct iovec __user *vec, | |
891 | unsigned long vlen, loff_t *pos) | |
892 | { | |
893 | if (!(file->f_mode & FMODE_READ)) | |
894 | return -EBADF; | |
7f7f25e8 | 895 | if (!(file->f_mode & FMODE_CAN_READ)) |
1da177e4 LT |
896 | return -EINVAL; |
897 | ||
898 | return do_readv_writev(READ, file, vec, vlen, pos); | |
899 | } | |
900 | ||
901 | EXPORT_SYMBOL(vfs_readv); | |
902 | ||
903 | ssize_t vfs_writev(struct file *file, const struct iovec __user *vec, | |
904 | unsigned long vlen, loff_t *pos) | |
905 | { | |
906 | if (!(file->f_mode & FMODE_WRITE)) | |
907 | return -EBADF; | |
7f7f25e8 | 908 | if (!(file->f_mode & FMODE_CAN_WRITE)) |
1da177e4 LT |
909 | return -EINVAL; |
910 | ||
911 | return do_readv_writev(WRITE, file, vec, vlen, pos); | |
912 | } | |
913 | ||
914 | EXPORT_SYMBOL(vfs_writev); | |
915 | ||
3cdad428 HC |
916 | SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec, |
917 | unsigned long, vlen) | |
1da177e4 | 918 | { |
9c225f26 | 919 | struct fd f = fdget_pos(fd); |
1da177e4 | 920 | ssize_t ret = -EBADF; |
1da177e4 | 921 | |
2903ff01 AV |
922 | if (f.file) { |
923 | loff_t pos = file_pos_read(f.file); | |
924 | ret = vfs_readv(f.file, vec, vlen, &pos); | |
5faf153e AV |
925 | if (ret >= 0) |
926 | file_pos_write(f.file, pos); | |
9c225f26 | 927 | fdput_pos(f); |
1da177e4 LT |
928 | } |
929 | ||
930 | if (ret > 0) | |
4b98d11b AD |
931 | add_rchar(current, ret); |
932 | inc_syscr(current); | |
1da177e4 LT |
933 | return ret; |
934 | } | |
935 | ||
3cdad428 HC |
936 | SYSCALL_DEFINE3(writev, unsigned long, fd, const struct iovec __user *, vec, |
937 | unsigned long, vlen) | |
1da177e4 | 938 | { |
9c225f26 | 939 | struct fd f = fdget_pos(fd); |
1da177e4 | 940 | ssize_t ret = -EBADF; |
1da177e4 | 941 | |
2903ff01 AV |
942 | if (f.file) { |
943 | loff_t pos = file_pos_read(f.file); | |
944 | ret = vfs_writev(f.file, vec, vlen, &pos); | |
5faf153e AV |
945 | if (ret >= 0) |
946 | file_pos_write(f.file, pos); | |
9c225f26 | 947 | fdput_pos(f); |
1da177e4 LT |
948 | } |
949 | ||
950 | if (ret > 0) | |
4b98d11b AD |
951 | add_wchar(current, ret); |
952 | inc_syscw(current); | |
1da177e4 LT |
953 | return ret; |
954 | } | |
955 | ||
601cc11d LT |
956 | static inline loff_t pos_from_hilo(unsigned long high, unsigned long low) |
957 | { | |
958 | #define HALF_LONG_BITS (BITS_PER_LONG / 2) | |
959 | return (((loff_t)high << HALF_LONG_BITS) << HALF_LONG_BITS) | low; | |
960 | } | |
961 | ||
f3554f4b | 962 | SYSCALL_DEFINE5(preadv, unsigned long, fd, const struct iovec __user *, vec, |
601cc11d | 963 | unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h) |
f3554f4b | 964 | { |
601cc11d | 965 | loff_t pos = pos_from_hilo(pos_h, pos_l); |
2903ff01 | 966 | struct fd f; |
f3554f4b | 967 | ssize_t ret = -EBADF; |
f3554f4b GH |
968 | |
969 | if (pos < 0) | |
970 | return -EINVAL; | |
971 | ||
2903ff01 AV |
972 | f = fdget(fd); |
973 | if (f.file) { | |
f3554f4b | 974 | ret = -ESPIPE; |
2903ff01 AV |
975 | if (f.file->f_mode & FMODE_PREAD) |
976 | ret = vfs_readv(f.file, vec, vlen, &pos); | |
977 | fdput(f); | |
f3554f4b GH |
978 | } |
979 | ||
980 | if (ret > 0) | |
981 | add_rchar(current, ret); | |
982 | inc_syscr(current); | |
983 | return ret; | |
984 | } | |
985 | ||
986 | SYSCALL_DEFINE5(pwritev, unsigned long, fd, const struct iovec __user *, vec, | |
601cc11d | 987 | unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h) |
f3554f4b | 988 | { |
601cc11d | 989 | loff_t pos = pos_from_hilo(pos_h, pos_l); |
2903ff01 | 990 | struct fd f; |
f3554f4b | 991 | ssize_t ret = -EBADF; |
f3554f4b GH |
992 | |
993 | if (pos < 0) | |
994 | return -EINVAL; | |
995 | ||
2903ff01 AV |
996 | f = fdget(fd); |
997 | if (f.file) { | |
f3554f4b | 998 | ret = -ESPIPE; |
2903ff01 AV |
999 | if (f.file->f_mode & FMODE_PWRITE) |
1000 | ret = vfs_writev(f.file, vec, vlen, &pos); | |
1001 | fdput(f); | |
f3554f4b GH |
1002 | } |
1003 | ||
1004 | if (ret > 0) | |
1005 | add_wchar(current, ret); | |
1006 | inc_syscw(current); | |
1007 | return ret; | |
1008 | } | |
1009 | ||
72ec3516 AV |
1010 | #ifdef CONFIG_COMPAT |
1011 | ||
1012 | static ssize_t compat_do_readv_writev(int type, struct file *file, | |
1013 | const struct compat_iovec __user *uvector, | |
1014 | unsigned long nr_segs, loff_t *pos) | |
1015 | { | |
1016 | compat_ssize_t tot_len; | |
1017 | struct iovec iovstack[UIO_FASTIOV]; | |
1018 | struct iovec *iov = iovstack; | |
ac15ac06 | 1019 | struct iov_iter iter; |
72ec3516 AV |
1020 | ssize_t ret; |
1021 | io_fn_t fn; | |
1022 | iov_fn_t fnv; | |
293bc982 | 1023 | iter_fn_t iter_fn; |
72ec3516 | 1024 | |
72ec3516 AV |
1025 | ret = compat_rw_copy_check_uvector(type, uvector, nr_segs, |
1026 | UIO_FASTIOV, iovstack, &iov); | |
1027 | if (ret <= 0) | |
1028 | goto out; | |
ac15ac06 | 1029 | iov_iter_init(&iter, type, iov, nr_segs, ret); |
72ec3516 AV |
1030 | |
1031 | tot_len = ret; | |
1032 | ret = rw_verify_area(type, file, pos, tot_len); | |
1033 | if (ret < 0) | |
1034 | goto out; | |
1035 | ||
1036 | fnv = NULL; | |
1037 | if (type == READ) { | |
1038 | fn = file->f_op->read; | |
1039 | fnv = file->f_op->aio_read; | |
293bc982 | 1040 | iter_fn = file->f_op->read_iter; |
72ec3516 AV |
1041 | } else { |
1042 | fn = (io_fn_t)file->f_op->write; | |
1043 | fnv = file->f_op->aio_write; | |
293bc982 | 1044 | iter_fn = file->f_op->write_iter; |
03d95eb2 | 1045 | file_start_write(file); |
72ec3516 AV |
1046 | } |
1047 | ||
293bc982 | 1048 | if (iter_fn) |
ac15ac06 | 1049 | ret = do_iter_readv_writev(file, &iter, pos, iter_fn); |
293bc982 | 1050 | else if (fnv) |
ac15ac06 | 1051 | ret = do_sync_readv_writev(file, &iter, pos, fnv); |
03d95eb2 | 1052 | else |
ac15ac06 | 1053 | ret = do_loop_readv_writev(file, &iter, pos, fn); |
72ec3516 | 1054 | |
03d95eb2 AV |
1055 | if (type != READ) |
1056 | file_end_write(file); | |
1057 | ||
72ec3516 AV |
1058 | out: |
1059 | if (iov != iovstack) | |
1060 | kfree(iov); | |
1061 | if ((ret + (type == READ)) > 0) { | |
1062 | if (type == READ) | |
1063 | fsnotify_access(file); | |
1064 | else | |
1065 | fsnotify_modify(file); | |
1066 | } | |
1067 | return ret; | |
1068 | } | |
1069 | ||
1070 | static size_t compat_readv(struct file *file, | |
1071 | const struct compat_iovec __user *vec, | |
1072 | unsigned long vlen, loff_t *pos) | |
1073 | { | |
1074 | ssize_t ret = -EBADF; | |
1075 | ||
1076 | if (!(file->f_mode & FMODE_READ)) | |
1077 | goto out; | |
1078 | ||
1079 | ret = -EINVAL; | |
7f7f25e8 | 1080 | if (!(file->f_mode & FMODE_CAN_READ)) |
72ec3516 AV |
1081 | goto out; |
1082 | ||
1083 | ret = compat_do_readv_writev(READ, file, vec, vlen, pos); | |
1084 | ||
1085 | out: | |
1086 | if (ret > 0) | |
1087 | add_rchar(current, ret); | |
1088 | inc_syscr(current); | |
1089 | return ret; | |
1090 | } | |
1091 | ||
dfd948e3 | 1092 | COMPAT_SYSCALL_DEFINE3(readv, compat_ulong_t, fd, |
72ec3516 | 1093 | const struct compat_iovec __user *,vec, |
dfd948e3 | 1094 | compat_ulong_t, vlen) |
72ec3516 | 1095 | { |
9c225f26 | 1096 | struct fd f = fdget_pos(fd); |
72ec3516 AV |
1097 | ssize_t ret; |
1098 | loff_t pos; | |
1099 | ||
1100 | if (!f.file) | |
1101 | return -EBADF; | |
1102 | pos = f.file->f_pos; | |
1103 | ret = compat_readv(f.file, vec, vlen, &pos); | |
5faf153e AV |
1104 | if (ret >= 0) |
1105 | f.file->f_pos = pos; | |
9c225f26 | 1106 | fdput_pos(f); |
72ec3516 AV |
1107 | return ret; |
1108 | } | |
1109 | ||
378a10f3 HC |
1110 | static long __compat_sys_preadv64(unsigned long fd, |
1111 | const struct compat_iovec __user *vec, | |
1112 | unsigned long vlen, loff_t pos) | |
72ec3516 AV |
1113 | { |
1114 | struct fd f; | |
1115 | ssize_t ret; | |
1116 | ||
1117 | if (pos < 0) | |
1118 | return -EINVAL; | |
1119 | f = fdget(fd); | |
1120 | if (!f.file) | |
1121 | return -EBADF; | |
1122 | ret = -ESPIPE; | |
1123 | if (f.file->f_mode & FMODE_PREAD) | |
1124 | ret = compat_readv(f.file, vec, vlen, &pos); | |
1125 | fdput(f); | |
1126 | return ret; | |
1127 | } | |
1128 | ||
378a10f3 HC |
1129 | #ifdef __ARCH_WANT_COMPAT_SYS_PREADV64 |
1130 | COMPAT_SYSCALL_DEFINE4(preadv64, unsigned long, fd, | |
1131 | const struct compat_iovec __user *,vec, | |
1132 | unsigned long, vlen, loff_t, pos) | |
1133 | { | |
1134 | return __compat_sys_preadv64(fd, vec, vlen, pos); | |
1135 | } | |
1136 | #endif | |
1137 | ||
dfd948e3 | 1138 | COMPAT_SYSCALL_DEFINE5(preadv, compat_ulong_t, fd, |
72ec3516 | 1139 | const struct compat_iovec __user *,vec, |
dfd948e3 | 1140 | compat_ulong_t, vlen, u32, pos_low, u32, pos_high) |
72ec3516 AV |
1141 | { |
1142 | loff_t pos = ((loff_t)pos_high << 32) | pos_low; | |
378a10f3 HC |
1143 | |
1144 | return __compat_sys_preadv64(fd, vec, vlen, pos); | |
72ec3516 AV |
1145 | } |
1146 | ||
1147 | static size_t compat_writev(struct file *file, | |
1148 | const struct compat_iovec __user *vec, | |
1149 | unsigned long vlen, loff_t *pos) | |
1150 | { | |
1151 | ssize_t ret = -EBADF; | |
1152 | ||
1153 | if (!(file->f_mode & FMODE_WRITE)) | |
1154 | goto out; | |
1155 | ||
1156 | ret = -EINVAL; | |
7f7f25e8 | 1157 | if (!(file->f_mode & FMODE_CAN_WRITE)) |
72ec3516 AV |
1158 | goto out; |
1159 | ||
1160 | ret = compat_do_readv_writev(WRITE, file, vec, vlen, pos); | |
1161 | ||
1162 | out: | |
1163 | if (ret > 0) | |
1164 | add_wchar(current, ret); | |
1165 | inc_syscw(current); | |
1166 | return ret; | |
1167 | } | |
1168 | ||
dfd948e3 | 1169 | COMPAT_SYSCALL_DEFINE3(writev, compat_ulong_t, fd, |
72ec3516 | 1170 | const struct compat_iovec __user *, vec, |
dfd948e3 | 1171 | compat_ulong_t, vlen) |
72ec3516 | 1172 | { |
9c225f26 | 1173 | struct fd f = fdget_pos(fd); |
72ec3516 AV |
1174 | ssize_t ret; |
1175 | loff_t pos; | |
1176 | ||
1177 | if (!f.file) | |
1178 | return -EBADF; | |
1179 | pos = f.file->f_pos; | |
1180 | ret = compat_writev(f.file, vec, vlen, &pos); | |
5faf153e AV |
1181 | if (ret >= 0) |
1182 | f.file->f_pos = pos; | |
9c225f26 | 1183 | fdput_pos(f); |
72ec3516 AV |
1184 | return ret; |
1185 | } | |
1186 | ||
378a10f3 HC |
1187 | static long __compat_sys_pwritev64(unsigned long fd, |
1188 | const struct compat_iovec __user *vec, | |
1189 | unsigned long vlen, loff_t pos) | |
72ec3516 AV |
1190 | { |
1191 | struct fd f; | |
1192 | ssize_t ret; | |
1193 | ||
1194 | if (pos < 0) | |
1195 | return -EINVAL; | |
1196 | f = fdget(fd); | |
1197 | if (!f.file) | |
1198 | return -EBADF; | |
1199 | ret = -ESPIPE; | |
1200 | if (f.file->f_mode & FMODE_PWRITE) | |
1201 | ret = compat_writev(f.file, vec, vlen, &pos); | |
1202 | fdput(f); | |
1203 | return ret; | |
1204 | } | |
1205 | ||
378a10f3 HC |
1206 | #ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64 |
1207 | COMPAT_SYSCALL_DEFINE4(pwritev64, unsigned long, fd, | |
1208 | const struct compat_iovec __user *,vec, | |
1209 | unsigned long, vlen, loff_t, pos) | |
1210 | { | |
1211 | return __compat_sys_pwritev64(fd, vec, vlen, pos); | |
1212 | } | |
1213 | #endif | |
1214 | ||
dfd948e3 | 1215 | COMPAT_SYSCALL_DEFINE5(pwritev, compat_ulong_t, fd, |
72ec3516 | 1216 | const struct compat_iovec __user *,vec, |
dfd948e3 | 1217 | compat_ulong_t, vlen, u32, pos_low, u32, pos_high) |
72ec3516 AV |
1218 | { |
1219 | loff_t pos = ((loff_t)pos_high << 32) | pos_low; | |
378a10f3 HC |
1220 | |
1221 | return __compat_sys_pwritev64(fd, vec, vlen, pos); | |
72ec3516 AV |
1222 | } |
1223 | #endif | |
1224 | ||
19f4fc3a AV |
1225 | static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, |
1226 | size_t count, loff_t max) | |
1da177e4 | 1227 | { |
2903ff01 AV |
1228 | struct fd in, out; |
1229 | struct inode *in_inode, *out_inode; | |
1da177e4 | 1230 | loff_t pos; |
7995bd28 | 1231 | loff_t out_pos; |
1da177e4 | 1232 | ssize_t retval; |
2903ff01 | 1233 | int fl; |
1da177e4 LT |
1234 | |
1235 | /* | |
1236 | * Get input file, and verify that it is ok.. | |
1237 | */ | |
1238 | retval = -EBADF; | |
2903ff01 AV |
1239 | in = fdget(in_fd); |
1240 | if (!in.file) | |
1da177e4 | 1241 | goto out; |
2903ff01 | 1242 | if (!(in.file->f_mode & FMODE_READ)) |
1da177e4 | 1243 | goto fput_in; |
1da177e4 | 1244 | retval = -ESPIPE; |
7995bd28 AV |
1245 | if (!ppos) { |
1246 | pos = in.file->f_pos; | |
1247 | } else { | |
1248 | pos = *ppos; | |
2903ff01 | 1249 | if (!(in.file->f_mode & FMODE_PREAD)) |
1da177e4 | 1250 | goto fput_in; |
7995bd28 AV |
1251 | } |
1252 | retval = rw_verify_area(READ, in.file, &pos, count); | |
e28cc715 | 1253 | if (retval < 0) |
1da177e4 | 1254 | goto fput_in; |
e28cc715 | 1255 | count = retval; |
1da177e4 | 1256 | |
1da177e4 LT |
1257 | /* |
1258 | * Get output file, and verify that it is ok.. | |
1259 | */ | |
1260 | retval = -EBADF; | |
2903ff01 AV |
1261 | out = fdget(out_fd); |
1262 | if (!out.file) | |
1da177e4 | 1263 | goto fput_in; |
2903ff01 | 1264 | if (!(out.file->f_mode & FMODE_WRITE)) |
1da177e4 LT |
1265 | goto fput_out; |
1266 | retval = -EINVAL; | |
496ad9aa AV |
1267 | in_inode = file_inode(in.file); |
1268 | out_inode = file_inode(out.file); | |
7995bd28 AV |
1269 | out_pos = out.file->f_pos; |
1270 | retval = rw_verify_area(WRITE, out.file, &out_pos, count); | |
e28cc715 | 1271 | if (retval < 0) |
1da177e4 | 1272 | goto fput_out; |
e28cc715 | 1273 | count = retval; |
1da177e4 | 1274 | |
1da177e4 LT |
1275 | if (!max) |
1276 | max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes); | |
1277 | ||
1da177e4 LT |
1278 | if (unlikely(pos + count > max)) { |
1279 | retval = -EOVERFLOW; | |
1280 | if (pos >= max) | |
1281 | goto fput_out; | |
1282 | count = max - pos; | |
1283 | } | |
1284 | ||
d96e6e71 | 1285 | fl = 0; |
534f2aaa | 1286 | #if 0 |
d96e6e71 JA |
1287 | /* |
1288 | * We need to debate whether we can enable this or not. The | |
1289 | * man page documents EAGAIN return for the output at least, | |
1290 | * and the application is arguably buggy if it doesn't expect | |
1291 | * EAGAIN on a non-blocking file descriptor. | |
1292 | */ | |
2903ff01 | 1293 | if (in.file->f_flags & O_NONBLOCK) |
d96e6e71 | 1294 | fl = SPLICE_F_NONBLOCK; |
534f2aaa | 1295 | #endif |
50cd2c57 | 1296 | file_start_write(out.file); |
7995bd28 | 1297 | retval = do_splice_direct(in.file, &pos, out.file, &out_pos, count, fl); |
50cd2c57 | 1298 | file_end_write(out.file); |
1da177e4 LT |
1299 | |
1300 | if (retval > 0) { | |
4b98d11b AD |
1301 | add_rchar(current, retval); |
1302 | add_wchar(current, retval); | |
a68c2f12 SW |
1303 | fsnotify_access(in.file); |
1304 | fsnotify_modify(out.file); | |
7995bd28 AV |
1305 | out.file->f_pos = out_pos; |
1306 | if (ppos) | |
1307 | *ppos = pos; | |
1308 | else | |
1309 | in.file->f_pos = pos; | |
1da177e4 | 1310 | } |
1da177e4 | 1311 | |
4b98d11b AD |
1312 | inc_syscr(current); |
1313 | inc_syscw(current); | |
7995bd28 | 1314 | if (pos > max) |
1da177e4 LT |
1315 | retval = -EOVERFLOW; |
1316 | ||
1317 | fput_out: | |
2903ff01 | 1318 | fdput(out); |
1da177e4 | 1319 | fput_in: |
2903ff01 | 1320 | fdput(in); |
1da177e4 LT |
1321 | out: |
1322 | return retval; | |
1323 | } | |
1324 | ||
002c8976 | 1325 | SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, off_t __user *, offset, size_t, count) |
1da177e4 LT |
1326 | { |
1327 | loff_t pos; | |
1328 | off_t off; | |
1329 | ssize_t ret; | |
1330 | ||
1331 | if (offset) { | |
1332 | if (unlikely(get_user(off, offset))) | |
1333 | return -EFAULT; | |
1334 | pos = off; | |
1335 | ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS); | |
1336 | if (unlikely(put_user(pos, offset))) | |
1337 | return -EFAULT; | |
1338 | return ret; | |
1339 | } | |
1340 | ||
1341 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1342 | } | |
1343 | ||
002c8976 | 1344 | SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, loff_t __user *, offset, size_t, count) |
1da177e4 LT |
1345 | { |
1346 | loff_t pos; | |
1347 | ssize_t ret; | |
1348 | ||
1349 | if (offset) { | |
1350 | if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t)))) | |
1351 | return -EFAULT; | |
1352 | ret = do_sendfile(out_fd, in_fd, &pos, count, 0); | |
1353 | if (unlikely(put_user(pos, offset))) | |
1354 | return -EFAULT; | |
1355 | return ret; | |
1356 | } | |
1357 | ||
1358 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1359 | } | |
19f4fc3a AV |
1360 | |
1361 | #ifdef CONFIG_COMPAT | |
1362 | COMPAT_SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, | |
1363 | compat_off_t __user *, offset, compat_size_t, count) | |
1364 | { | |
1365 | loff_t pos; | |
1366 | off_t off; | |
1367 | ssize_t ret; | |
1368 | ||
1369 | if (offset) { | |
1370 | if (unlikely(get_user(off, offset))) | |
1371 | return -EFAULT; | |
1372 | pos = off; | |
1373 | ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS); | |
1374 | if (unlikely(put_user(pos, offset))) | |
1375 | return -EFAULT; | |
1376 | return ret; | |
1377 | } | |
1378 | ||
1379 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1380 | } | |
1381 | ||
1382 | COMPAT_SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, | |
1383 | compat_loff_t __user *, offset, compat_size_t, count) | |
1384 | { | |
1385 | loff_t pos; | |
1386 | ssize_t ret; | |
1387 | ||
1388 | if (offset) { | |
1389 | if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t)))) | |
1390 | return -EFAULT; | |
1391 | ret = do_sendfile(out_fd, in_fd, &pos, count, 0); | |
1392 | if (unlikely(put_user(pos, offset))) | |
1393 | return -EFAULT; | |
1394 | return ret; | |
1395 | } | |
1396 | ||
1397 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1398 | } | |
1399 | #endif |