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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 | |
293bc982 AV |
698 | static ssize_t do_iter_readv_writev(struct file *filp, int rw, const struct iovec *iov, |
699 | unsigned long nr_segs, size_t len, loff_t *ppos, iter_fn_t fn) | |
700 | { | |
701 | struct kiocb kiocb; | |
702 | struct iov_iter iter; | |
703 | ssize_t ret; | |
704 | ||
705 | init_sync_kiocb(&kiocb, filp); | |
706 | kiocb.ki_pos = *ppos; | |
293bc982 AV |
707 | |
708 | iov_iter_init(&iter, rw, iov, nr_segs, len); | |
709 | ret = fn(&kiocb, &iter); | |
599bd19b | 710 | BUG_ON(ret == -EIOCBQUEUED); |
293bc982 AV |
711 | *ppos = kiocb.ki_pos; |
712 | return ret; | |
713 | } | |
714 | ||
72ec3516 | 715 | static ssize_t do_sync_readv_writev(struct file *filp, const struct iovec *iov, |
ee0b3e67 BP |
716 | unsigned long nr_segs, size_t len, loff_t *ppos, iov_fn_t fn) |
717 | { | |
718 | struct kiocb kiocb; | |
719 | ssize_t ret; | |
720 | ||
721 | init_sync_kiocb(&kiocb, filp); | |
722 | kiocb.ki_pos = *ppos; | |
ee0b3e67 | 723 | |
41003a7b | 724 | ret = fn(&kiocb, iov, nr_segs, kiocb.ki_pos); |
599bd19b | 725 | BUG_ON(ret == -EIOCBQUEUED); |
ee0b3e67 BP |
726 | *ppos = kiocb.ki_pos; |
727 | return ret; | |
728 | } | |
729 | ||
730 | /* Do it by hand, with file-ops */ | |
72ec3516 | 731 | static ssize_t do_loop_readv_writev(struct file *filp, struct iovec *iov, |
ee0b3e67 BP |
732 | unsigned long nr_segs, loff_t *ppos, io_fn_t fn) |
733 | { | |
734 | struct iovec *vector = iov; | |
735 | ssize_t ret = 0; | |
736 | ||
737 | while (nr_segs > 0) { | |
738 | void __user *base; | |
739 | size_t len; | |
740 | ssize_t nr; | |
741 | ||
742 | base = vector->iov_base; | |
743 | len = vector->iov_len; | |
744 | vector++; | |
745 | nr_segs--; | |
746 | ||
747 | nr = fn(filp, base, len, ppos); | |
748 | ||
749 | if (nr < 0) { | |
750 | if (!ret) | |
751 | ret = nr; | |
752 | break; | |
753 | } | |
754 | ret += nr; | |
755 | if (nr != len) | |
756 | break; | |
757 | } | |
758 | ||
759 | return ret; | |
760 | } | |
761 | ||
1da177e4 LT |
762 | /* A write operation does a read from user space and vice versa */ |
763 | #define vrfy_dir(type) ((type) == READ ? VERIFY_WRITE : VERIFY_READ) | |
764 | ||
eed4e51f BP |
765 | ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector, |
766 | unsigned long nr_segs, unsigned long fast_segs, | |
767 | struct iovec *fast_pointer, | |
ac34ebb3 | 768 | struct iovec **ret_pointer) |
435f49a5 | 769 | { |
eed4e51f | 770 | unsigned long seg; |
435f49a5 | 771 | ssize_t ret; |
eed4e51f BP |
772 | struct iovec *iov = fast_pointer; |
773 | ||
435f49a5 LT |
774 | /* |
775 | * SuS says "The readv() function *may* fail if the iovcnt argument | |
776 | * was less than or equal to 0, or greater than {IOV_MAX}. Linux has | |
777 | * traditionally returned zero for zero segments, so... | |
778 | */ | |
eed4e51f BP |
779 | if (nr_segs == 0) { |
780 | ret = 0; | |
435f49a5 | 781 | goto out; |
eed4e51f BP |
782 | } |
783 | ||
435f49a5 LT |
784 | /* |
785 | * First get the "struct iovec" from user memory and | |
786 | * verify all the pointers | |
787 | */ | |
eed4e51f BP |
788 | if (nr_segs > UIO_MAXIOV) { |
789 | ret = -EINVAL; | |
435f49a5 | 790 | goto out; |
eed4e51f BP |
791 | } |
792 | if (nr_segs > fast_segs) { | |
435f49a5 | 793 | iov = kmalloc(nr_segs*sizeof(struct iovec), GFP_KERNEL); |
eed4e51f BP |
794 | if (iov == NULL) { |
795 | ret = -ENOMEM; | |
435f49a5 | 796 | goto out; |
eed4e51f | 797 | } |
435f49a5 | 798 | } |
eed4e51f BP |
799 | if (copy_from_user(iov, uvector, nr_segs*sizeof(*uvector))) { |
800 | ret = -EFAULT; | |
435f49a5 | 801 | goto out; |
eed4e51f BP |
802 | } |
803 | ||
435f49a5 | 804 | /* |
eed4e51f BP |
805 | * According to the Single Unix Specification we should return EINVAL |
806 | * if an element length is < 0 when cast to ssize_t or if the | |
807 | * total length would overflow the ssize_t return value of the | |
808 | * system call. | |
435f49a5 LT |
809 | * |
810 | * Linux caps all read/write calls to MAX_RW_COUNT, and avoids the | |
811 | * overflow case. | |
812 | */ | |
eed4e51f | 813 | ret = 0; |
435f49a5 LT |
814 | for (seg = 0; seg < nr_segs; seg++) { |
815 | void __user *buf = iov[seg].iov_base; | |
816 | ssize_t len = (ssize_t)iov[seg].iov_len; | |
eed4e51f BP |
817 | |
818 | /* see if we we're about to use an invalid len or if | |
819 | * it's about to overflow ssize_t */ | |
435f49a5 | 820 | if (len < 0) { |
eed4e51f | 821 | ret = -EINVAL; |
435f49a5 | 822 | goto out; |
eed4e51f | 823 | } |
ac34ebb3 | 824 | if (type >= 0 |
fcf63409 | 825 | && unlikely(!access_ok(vrfy_dir(type), buf, len))) { |
eed4e51f | 826 | ret = -EFAULT; |
435f49a5 LT |
827 | goto out; |
828 | } | |
829 | if (len > MAX_RW_COUNT - ret) { | |
830 | len = MAX_RW_COUNT - ret; | |
831 | iov[seg].iov_len = len; | |
eed4e51f | 832 | } |
eed4e51f | 833 | ret += len; |
435f49a5 | 834 | } |
eed4e51f BP |
835 | out: |
836 | *ret_pointer = iov; | |
837 | return ret; | |
838 | } | |
839 | ||
1da177e4 LT |
840 | static ssize_t do_readv_writev(int type, struct file *file, |
841 | const struct iovec __user * uvector, | |
842 | unsigned long nr_segs, loff_t *pos) | |
843 | { | |
1da177e4 LT |
844 | size_t tot_len; |
845 | struct iovec iovstack[UIO_FASTIOV]; | |
ee0b3e67 | 846 | struct iovec *iov = iovstack; |
1da177e4 | 847 | ssize_t ret; |
1da177e4 LT |
848 | io_fn_t fn; |
849 | iov_fn_t fnv; | |
293bc982 | 850 | iter_fn_t iter_fn; |
1da177e4 | 851 | |
eed4e51f | 852 | ret = rw_copy_check_uvector(type, uvector, nr_segs, |
ac34ebb3 | 853 | ARRAY_SIZE(iovstack), iovstack, &iov); |
eed4e51f | 854 | if (ret <= 0) |
1da177e4 | 855 | goto out; |
1da177e4 | 856 | |
eed4e51f | 857 | tot_len = ret; |
1da177e4 | 858 | ret = rw_verify_area(type, file, pos, tot_len); |
e28cc715 | 859 | if (ret < 0) |
411b67b4 | 860 | goto out; |
1da177e4 LT |
861 | |
862 | fnv = NULL; | |
863 | if (type == READ) { | |
864 | fn = file->f_op->read; | |
ee0b3e67 | 865 | fnv = file->f_op->aio_read; |
293bc982 | 866 | iter_fn = file->f_op->read_iter; |
1da177e4 LT |
867 | } else { |
868 | fn = (io_fn_t)file->f_op->write; | |
ee0b3e67 | 869 | fnv = file->f_op->aio_write; |
293bc982 | 870 | iter_fn = file->f_op->write_iter; |
03d95eb2 | 871 | file_start_write(file); |
1da177e4 LT |
872 | } |
873 | ||
293bc982 AV |
874 | if (iter_fn) |
875 | ret = do_iter_readv_writev(file, type, iov, nr_segs, tot_len, | |
876 | pos, iter_fn); | |
877 | else if (fnv) | |
ee0b3e67 BP |
878 | ret = do_sync_readv_writev(file, iov, nr_segs, tot_len, |
879 | pos, fnv); | |
880 | else | |
881 | ret = do_loop_readv_writev(file, iov, nr_segs, pos, fn); | |
1da177e4 | 882 | |
03d95eb2 AV |
883 | if (type != READ) |
884 | file_end_write(file); | |
885 | ||
1da177e4 LT |
886 | out: |
887 | if (iov != iovstack) | |
888 | kfree(iov); | |
0eeca283 RL |
889 | if ((ret + (type == READ)) > 0) { |
890 | if (type == READ) | |
2a12a9d7 | 891 | fsnotify_access(file); |
0eeca283 | 892 | else |
2a12a9d7 | 893 | fsnotify_modify(file); |
0eeca283 | 894 | } |
1da177e4 | 895 | return ret; |
1da177e4 LT |
896 | } |
897 | ||
898 | ssize_t vfs_readv(struct file *file, const struct iovec __user *vec, | |
899 | unsigned long vlen, loff_t *pos) | |
900 | { | |
901 | if (!(file->f_mode & FMODE_READ)) | |
902 | return -EBADF; | |
7f7f25e8 | 903 | if (!(file->f_mode & FMODE_CAN_READ)) |
1da177e4 LT |
904 | return -EINVAL; |
905 | ||
906 | return do_readv_writev(READ, file, vec, vlen, pos); | |
907 | } | |
908 | ||
909 | EXPORT_SYMBOL(vfs_readv); | |
910 | ||
911 | ssize_t vfs_writev(struct file *file, const struct iovec __user *vec, | |
912 | unsigned long vlen, loff_t *pos) | |
913 | { | |
914 | if (!(file->f_mode & FMODE_WRITE)) | |
915 | return -EBADF; | |
7f7f25e8 | 916 | if (!(file->f_mode & FMODE_CAN_WRITE)) |
1da177e4 LT |
917 | return -EINVAL; |
918 | ||
919 | return do_readv_writev(WRITE, file, vec, vlen, pos); | |
920 | } | |
921 | ||
922 | EXPORT_SYMBOL(vfs_writev); | |
923 | ||
3cdad428 HC |
924 | SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec, |
925 | unsigned long, vlen) | |
1da177e4 | 926 | { |
9c225f26 | 927 | struct fd f = fdget_pos(fd); |
1da177e4 | 928 | ssize_t ret = -EBADF; |
1da177e4 | 929 | |
2903ff01 AV |
930 | if (f.file) { |
931 | loff_t pos = file_pos_read(f.file); | |
932 | ret = vfs_readv(f.file, vec, vlen, &pos); | |
5faf153e AV |
933 | if (ret >= 0) |
934 | file_pos_write(f.file, pos); | |
9c225f26 | 935 | fdput_pos(f); |
1da177e4 LT |
936 | } |
937 | ||
938 | if (ret > 0) | |
4b98d11b AD |
939 | add_rchar(current, ret); |
940 | inc_syscr(current); | |
1da177e4 LT |
941 | return ret; |
942 | } | |
943 | ||
3cdad428 HC |
944 | SYSCALL_DEFINE3(writev, unsigned long, fd, const struct iovec __user *, vec, |
945 | unsigned long, vlen) | |
1da177e4 | 946 | { |
9c225f26 | 947 | struct fd f = fdget_pos(fd); |
1da177e4 | 948 | ssize_t ret = -EBADF; |
1da177e4 | 949 | |
2903ff01 AV |
950 | if (f.file) { |
951 | loff_t pos = file_pos_read(f.file); | |
952 | ret = vfs_writev(f.file, vec, vlen, &pos); | |
5faf153e AV |
953 | if (ret >= 0) |
954 | file_pos_write(f.file, pos); | |
9c225f26 | 955 | fdput_pos(f); |
1da177e4 LT |
956 | } |
957 | ||
958 | if (ret > 0) | |
4b98d11b AD |
959 | add_wchar(current, ret); |
960 | inc_syscw(current); | |
1da177e4 LT |
961 | return ret; |
962 | } | |
963 | ||
601cc11d LT |
964 | static inline loff_t pos_from_hilo(unsigned long high, unsigned long low) |
965 | { | |
966 | #define HALF_LONG_BITS (BITS_PER_LONG / 2) | |
967 | return (((loff_t)high << HALF_LONG_BITS) << HALF_LONG_BITS) | low; | |
968 | } | |
969 | ||
f3554f4b | 970 | SYSCALL_DEFINE5(preadv, unsigned long, fd, const struct iovec __user *, vec, |
601cc11d | 971 | unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h) |
f3554f4b | 972 | { |
601cc11d | 973 | loff_t pos = pos_from_hilo(pos_h, pos_l); |
2903ff01 | 974 | struct fd f; |
f3554f4b | 975 | ssize_t ret = -EBADF; |
f3554f4b GH |
976 | |
977 | if (pos < 0) | |
978 | return -EINVAL; | |
979 | ||
2903ff01 AV |
980 | f = fdget(fd); |
981 | if (f.file) { | |
f3554f4b | 982 | ret = -ESPIPE; |
2903ff01 AV |
983 | if (f.file->f_mode & FMODE_PREAD) |
984 | ret = vfs_readv(f.file, vec, vlen, &pos); | |
985 | fdput(f); | |
f3554f4b GH |
986 | } |
987 | ||
988 | if (ret > 0) | |
989 | add_rchar(current, ret); | |
990 | inc_syscr(current); | |
991 | return ret; | |
992 | } | |
993 | ||
994 | SYSCALL_DEFINE5(pwritev, unsigned long, fd, const struct iovec __user *, vec, | |
601cc11d | 995 | unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h) |
f3554f4b | 996 | { |
601cc11d | 997 | loff_t pos = pos_from_hilo(pos_h, pos_l); |
2903ff01 | 998 | struct fd f; |
f3554f4b | 999 | ssize_t ret = -EBADF; |
f3554f4b GH |
1000 | |
1001 | if (pos < 0) | |
1002 | return -EINVAL; | |
1003 | ||
2903ff01 AV |
1004 | f = fdget(fd); |
1005 | if (f.file) { | |
f3554f4b | 1006 | ret = -ESPIPE; |
2903ff01 AV |
1007 | if (f.file->f_mode & FMODE_PWRITE) |
1008 | ret = vfs_writev(f.file, vec, vlen, &pos); | |
1009 | fdput(f); | |
f3554f4b GH |
1010 | } |
1011 | ||
1012 | if (ret > 0) | |
1013 | add_wchar(current, ret); | |
1014 | inc_syscw(current); | |
1015 | return ret; | |
1016 | } | |
1017 | ||
72ec3516 AV |
1018 | #ifdef CONFIG_COMPAT |
1019 | ||
1020 | static ssize_t compat_do_readv_writev(int type, struct file *file, | |
1021 | const struct compat_iovec __user *uvector, | |
1022 | unsigned long nr_segs, loff_t *pos) | |
1023 | { | |
1024 | compat_ssize_t tot_len; | |
1025 | struct iovec iovstack[UIO_FASTIOV]; | |
1026 | struct iovec *iov = iovstack; | |
1027 | ssize_t ret; | |
1028 | io_fn_t fn; | |
1029 | iov_fn_t fnv; | |
293bc982 | 1030 | iter_fn_t iter_fn; |
72ec3516 | 1031 | |
72ec3516 AV |
1032 | ret = compat_rw_copy_check_uvector(type, uvector, nr_segs, |
1033 | UIO_FASTIOV, iovstack, &iov); | |
1034 | if (ret <= 0) | |
1035 | goto out; | |
1036 | ||
1037 | tot_len = ret; | |
1038 | ret = rw_verify_area(type, file, pos, tot_len); | |
1039 | if (ret < 0) | |
1040 | goto out; | |
1041 | ||
1042 | fnv = NULL; | |
1043 | if (type == READ) { | |
1044 | fn = file->f_op->read; | |
1045 | fnv = file->f_op->aio_read; | |
293bc982 | 1046 | iter_fn = file->f_op->read_iter; |
72ec3516 AV |
1047 | } else { |
1048 | fn = (io_fn_t)file->f_op->write; | |
1049 | fnv = file->f_op->aio_write; | |
293bc982 | 1050 | iter_fn = file->f_op->write_iter; |
03d95eb2 | 1051 | file_start_write(file); |
72ec3516 AV |
1052 | } |
1053 | ||
293bc982 AV |
1054 | if (iter_fn) |
1055 | ret = do_iter_readv_writev(file, type, iov, nr_segs, tot_len, | |
1056 | pos, iter_fn); | |
1057 | else if (fnv) | |
72ec3516 AV |
1058 | ret = do_sync_readv_writev(file, iov, nr_segs, tot_len, |
1059 | pos, fnv); | |
03d95eb2 | 1060 | else |
72ec3516 AV |
1061 | ret = do_loop_readv_writev(file, iov, nr_segs, pos, fn); |
1062 | ||
03d95eb2 AV |
1063 | if (type != READ) |
1064 | file_end_write(file); | |
1065 | ||
72ec3516 AV |
1066 | out: |
1067 | if (iov != iovstack) | |
1068 | kfree(iov); | |
1069 | if ((ret + (type == READ)) > 0) { | |
1070 | if (type == READ) | |
1071 | fsnotify_access(file); | |
1072 | else | |
1073 | fsnotify_modify(file); | |
1074 | } | |
1075 | return ret; | |
1076 | } | |
1077 | ||
1078 | static size_t compat_readv(struct file *file, | |
1079 | const struct compat_iovec __user *vec, | |
1080 | unsigned long vlen, loff_t *pos) | |
1081 | { | |
1082 | ssize_t ret = -EBADF; | |
1083 | ||
1084 | if (!(file->f_mode & FMODE_READ)) | |
1085 | goto out; | |
1086 | ||
1087 | ret = -EINVAL; | |
7f7f25e8 | 1088 | if (!(file->f_mode & FMODE_CAN_READ)) |
72ec3516 AV |
1089 | goto out; |
1090 | ||
1091 | ret = compat_do_readv_writev(READ, file, vec, vlen, pos); | |
1092 | ||
1093 | out: | |
1094 | if (ret > 0) | |
1095 | add_rchar(current, ret); | |
1096 | inc_syscr(current); | |
1097 | return ret; | |
1098 | } | |
1099 | ||
dfd948e3 | 1100 | COMPAT_SYSCALL_DEFINE3(readv, compat_ulong_t, fd, |
72ec3516 | 1101 | const struct compat_iovec __user *,vec, |
dfd948e3 | 1102 | compat_ulong_t, vlen) |
72ec3516 | 1103 | { |
9c225f26 | 1104 | struct fd f = fdget_pos(fd); |
72ec3516 AV |
1105 | ssize_t ret; |
1106 | loff_t pos; | |
1107 | ||
1108 | if (!f.file) | |
1109 | return -EBADF; | |
1110 | pos = f.file->f_pos; | |
1111 | ret = compat_readv(f.file, vec, vlen, &pos); | |
5faf153e AV |
1112 | if (ret >= 0) |
1113 | f.file->f_pos = pos; | |
9c225f26 | 1114 | fdput_pos(f); |
72ec3516 AV |
1115 | return ret; |
1116 | } | |
1117 | ||
378a10f3 HC |
1118 | static long __compat_sys_preadv64(unsigned long fd, |
1119 | const struct compat_iovec __user *vec, | |
1120 | unsigned long vlen, loff_t pos) | |
72ec3516 AV |
1121 | { |
1122 | struct fd f; | |
1123 | ssize_t ret; | |
1124 | ||
1125 | if (pos < 0) | |
1126 | return -EINVAL; | |
1127 | f = fdget(fd); | |
1128 | if (!f.file) | |
1129 | return -EBADF; | |
1130 | ret = -ESPIPE; | |
1131 | if (f.file->f_mode & FMODE_PREAD) | |
1132 | ret = compat_readv(f.file, vec, vlen, &pos); | |
1133 | fdput(f); | |
1134 | return ret; | |
1135 | } | |
1136 | ||
378a10f3 HC |
1137 | #ifdef __ARCH_WANT_COMPAT_SYS_PREADV64 |
1138 | COMPAT_SYSCALL_DEFINE4(preadv64, unsigned long, fd, | |
1139 | const struct compat_iovec __user *,vec, | |
1140 | unsigned long, vlen, loff_t, pos) | |
1141 | { | |
1142 | return __compat_sys_preadv64(fd, vec, vlen, pos); | |
1143 | } | |
1144 | #endif | |
1145 | ||
dfd948e3 | 1146 | COMPAT_SYSCALL_DEFINE5(preadv, compat_ulong_t, fd, |
72ec3516 | 1147 | const struct compat_iovec __user *,vec, |
dfd948e3 | 1148 | compat_ulong_t, vlen, u32, pos_low, u32, pos_high) |
72ec3516 AV |
1149 | { |
1150 | loff_t pos = ((loff_t)pos_high << 32) | pos_low; | |
378a10f3 HC |
1151 | |
1152 | return __compat_sys_preadv64(fd, vec, vlen, pos); | |
72ec3516 AV |
1153 | } |
1154 | ||
1155 | static size_t compat_writev(struct file *file, | |
1156 | const struct compat_iovec __user *vec, | |
1157 | unsigned long vlen, loff_t *pos) | |
1158 | { | |
1159 | ssize_t ret = -EBADF; | |
1160 | ||
1161 | if (!(file->f_mode & FMODE_WRITE)) | |
1162 | goto out; | |
1163 | ||
1164 | ret = -EINVAL; | |
7f7f25e8 | 1165 | if (!(file->f_mode & FMODE_CAN_WRITE)) |
72ec3516 AV |
1166 | goto out; |
1167 | ||
1168 | ret = compat_do_readv_writev(WRITE, file, vec, vlen, pos); | |
1169 | ||
1170 | out: | |
1171 | if (ret > 0) | |
1172 | add_wchar(current, ret); | |
1173 | inc_syscw(current); | |
1174 | return ret; | |
1175 | } | |
1176 | ||
dfd948e3 | 1177 | COMPAT_SYSCALL_DEFINE3(writev, compat_ulong_t, fd, |
72ec3516 | 1178 | const struct compat_iovec __user *, vec, |
dfd948e3 | 1179 | compat_ulong_t, vlen) |
72ec3516 | 1180 | { |
9c225f26 | 1181 | struct fd f = fdget_pos(fd); |
72ec3516 AV |
1182 | ssize_t ret; |
1183 | loff_t pos; | |
1184 | ||
1185 | if (!f.file) | |
1186 | return -EBADF; | |
1187 | pos = f.file->f_pos; | |
1188 | ret = compat_writev(f.file, vec, vlen, &pos); | |
5faf153e AV |
1189 | if (ret >= 0) |
1190 | f.file->f_pos = pos; | |
9c225f26 | 1191 | fdput_pos(f); |
72ec3516 AV |
1192 | return ret; |
1193 | } | |
1194 | ||
378a10f3 HC |
1195 | static long __compat_sys_pwritev64(unsigned long fd, |
1196 | const struct compat_iovec __user *vec, | |
1197 | unsigned long vlen, loff_t pos) | |
72ec3516 AV |
1198 | { |
1199 | struct fd f; | |
1200 | ssize_t ret; | |
1201 | ||
1202 | if (pos < 0) | |
1203 | return -EINVAL; | |
1204 | f = fdget(fd); | |
1205 | if (!f.file) | |
1206 | return -EBADF; | |
1207 | ret = -ESPIPE; | |
1208 | if (f.file->f_mode & FMODE_PWRITE) | |
1209 | ret = compat_writev(f.file, vec, vlen, &pos); | |
1210 | fdput(f); | |
1211 | return ret; | |
1212 | } | |
1213 | ||
378a10f3 HC |
1214 | #ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64 |
1215 | COMPAT_SYSCALL_DEFINE4(pwritev64, unsigned long, fd, | |
1216 | const struct compat_iovec __user *,vec, | |
1217 | unsigned long, vlen, loff_t, pos) | |
1218 | { | |
1219 | return __compat_sys_pwritev64(fd, vec, vlen, pos); | |
1220 | } | |
1221 | #endif | |
1222 | ||
dfd948e3 | 1223 | COMPAT_SYSCALL_DEFINE5(pwritev, compat_ulong_t, fd, |
72ec3516 | 1224 | const struct compat_iovec __user *,vec, |
dfd948e3 | 1225 | compat_ulong_t, vlen, u32, pos_low, u32, pos_high) |
72ec3516 AV |
1226 | { |
1227 | loff_t pos = ((loff_t)pos_high << 32) | pos_low; | |
378a10f3 HC |
1228 | |
1229 | return __compat_sys_pwritev64(fd, vec, vlen, pos); | |
72ec3516 AV |
1230 | } |
1231 | #endif | |
1232 | ||
19f4fc3a AV |
1233 | static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, |
1234 | size_t count, loff_t max) | |
1da177e4 | 1235 | { |
2903ff01 AV |
1236 | struct fd in, out; |
1237 | struct inode *in_inode, *out_inode; | |
1da177e4 | 1238 | loff_t pos; |
7995bd28 | 1239 | loff_t out_pos; |
1da177e4 | 1240 | ssize_t retval; |
2903ff01 | 1241 | int fl; |
1da177e4 LT |
1242 | |
1243 | /* | |
1244 | * Get input file, and verify that it is ok.. | |
1245 | */ | |
1246 | retval = -EBADF; | |
2903ff01 AV |
1247 | in = fdget(in_fd); |
1248 | if (!in.file) | |
1da177e4 | 1249 | goto out; |
2903ff01 | 1250 | if (!(in.file->f_mode & FMODE_READ)) |
1da177e4 | 1251 | goto fput_in; |
1da177e4 | 1252 | retval = -ESPIPE; |
7995bd28 AV |
1253 | if (!ppos) { |
1254 | pos = in.file->f_pos; | |
1255 | } else { | |
1256 | pos = *ppos; | |
2903ff01 | 1257 | if (!(in.file->f_mode & FMODE_PREAD)) |
1da177e4 | 1258 | goto fput_in; |
7995bd28 AV |
1259 | } |
1260 | retval = rw_verify_area(READ, in.file, &pos, count); | |
e28cc715 | 1261 | if (retval < 0) |
1da177e4 | 1262 | goto fput_in; |
e28cc715 | 1263 | count = retval; |
1da177e4 | 1264 | |
1da177e4 LT |
1265 | /* |
1266 | * Get output file, and verify that it is ok.. | |
1267 | */ | |
1268 | retval = -EBADF; | |
2903ff01 AV |
1269 | out = fdget(out_fd); |
1270 | if (!out.file) | |
1da177e4 | 1271 | goto fput_in; |
2903ff01 | 1272 | if (!(out.file->f_mode & FMODE_WRITE)) |
1da177e4 LT |
1273 | goto fput_out; |
1274 | retval = -EINVAL; | |
496ad9aa AV |
1275 | in_inode = file_inode(in.file); |
1276 | out_inode = file_inode(out.file); | |
7995bd28 AV |
1277 | out_pos = out.file->f_pos; |
1278 | retval = rw_verify_area(WRITE, out.file, &out_pos, count); | |
e28cc715 | 1279 | if (retval < 0) |
1da177e4 | 1280 | goto fput_out; |
e28cc715 | 1281 | count = retval; |
1da177e4 | 1282 | |
1da177e4 LT |
1283 | if (!max) |
1284 | max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes); | |
1285 | ||
1da177e4 LT |
1286 | if (unlikely(pos + count > max)) { |
1287 | retval = -EOVERFLOW; | |
1288 | if (pos >= max) | |
1289 | goto fput_out; | |
1290 | count = max - pos; | |
1291 | } | |
1292 | ||
d96e6e71 | 1293 | fl = 0; |
534f2aaa | 1294 | #if 0 |
d96e6e71 JA |
1295 | /* |
1296 | * We need to debate whether we can enable this or not. The | |
1297 | * man page documents EAGAIN return for the output at least, | |
1298 | * and the application is arguably buggy if it doesn't expect | |
1299 | * EAGAIN on a non-blocking file descriptor. | |
1300 | */ | |
2903ff01 | 1301 | if (in.file->f_flags & O_NONBLOCK) |
d96e6e71 | 1302 | fl = SPLICE_F_NONBLOCK; |
534f2aaa | 1303 | #endif |
50cd2c57 | 1304 | file_start_write(out.file); |
7995bd28 | 1305 | retval = do_splice_direct(in.file, &pos, out.file, &out_pos, count, fl); |
50cd2c57 | 1306 | file_end_write(out.file); |
1da177e4 LT |
1307 | |
1308 | if (retval > 0) { | |
4b98d11b AD |
1309 | add_rchar(current, retval); |
1310 | add_wchar(current, retval); | |
a68c2f12 SW |
1311 | fsnotify_access(in.file); |
1312 | fsnotify_modify(out.file); | |
7995bd28 AV |
1313 | out.file->f_pos = out_pos; |
1314 | if (ppos) | |
1315 | *ppos = pos; | |
1316 | else | |
1317 | in.file->f_pos = pos; | |
1da177e4 | 1318 | } |
1da177e4 | 1319 | |
4b98d11b AD |
1320 | inc_syscr(current); |
1321 | inc_syscw(current); | |
7995bd28 | 1322 | if (pos > max) |
1da177e4 LT |
1323 | retval = -EOVERFLOW; |
1324 | ||
1325 | fput_out: | |
2903ff01 | 1326 | fdput(out); |
1da177e4 | 1327 | fput_in: |
2903ff01 | 1328 | fdput(in); |
1da177e4 LT |
1329 | out: |
1330 | return retval; | |
1331 | } | |
1332 | ||
002c8976 | 1333 | SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, off_t __user *, offset, size_t, count) |
1da177e4 LT |
1334 | { |
1335 | loff_t pos; | |
1336 | off_t off; | |
1337 | ssize_t ret; | |
1338 | ||
1339 | if (offset) { | |
1340 | if (unlikely(get_user(off, offset))) | |
1341 | return -EFAULT; | |
1342 | pos = off; | |
1343 | ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS); | |
1344 | if (unlikely(put_user(pos, offset))) | |
1345 | return -EFAULT; | |
1346 | return ret; | |
1347 | } | |
1348 | ||
1349 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1350 | } | |
1351 | ||
002c8976 | 1352 | SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, loff_t __user *, offset, size_t, count) |
1da177e4 LT |
1353 | { |
1354 | loff_t pos; | |
1355 | ssize_t ret; | |
1356 | ||
1357 | if (offset) { | |
1358 | if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t)))) | |
1359 | return -EFAULT; | |
1360 | ret = do_sendfile(out_fd, in_fd, &pos, count, 0); | |
1361 | if (unlikely(put_user(pos, offset))) | |
1362 | return -EFAULT; | |
1363 | return ret; | |
1364 | } | |
1365 | ||
1366 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1367 | } | |
19f4fc3a AV |
1368 | |
1369 | #ifdef CONFIG_COMPAT | |
1370 | COMPAT_SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, | |
1371 | compat_off_t __user *, offset, compat_size_t, count) | |
1372 | { | |
1373 | loff_t pos; | |
1374 | off_t off; | |
1375 | ssize_t ret; | |
1376 | ||
1377 | if (offset) { | |
1378 | if (unlikely(get_user(off, offset))) | |
1379 | return -EFAULT; | |
1380 | pos = off; | |
1381 | ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS); | |
1382 | if (unlikely(put_user(pos, offset))) | |
1383 | return -EFAULT; | |
1384 | return ret; | |
1385 | } | |
1386 | ||
1387 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1388 | } | |
1389 | ||
1390 | COMPAT_SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, | |
1391 | compat_loff_t __user *, offset, compat_size_t, count) | |
1392 | { | |
1393 | loff_t pos; | |
1394 | ssize_t ret; | |
1395 | ||
1396 | if (offset) { | |
1397 | if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t)))) | |
1398 | return -EFAULT; | |
1399 | ret = do_sendfile(out_fd, in_fd, &pos, count, 0); | |
1400 | if (unlikely(put_user(pos, offset))) | |
1401 | return -EFAULT; | |
1402 | return ret; | |
1403 | } | |
1404 | ||
1405 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1406 | } | |
1407 | #endif |