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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> |
12 | #include <linux/aio.h> |
13 | #include <linux/fsnotify.h> |
14 | #include <linux/security.h> |
15 | #include <linux/export.h> |
16 | #include <linux/syscalls.h> |
17 | #include <linux/pagemap.h> |
18 | #include <linux/splice.h> |
19 | #include <linux/compat.h> |
20 | #include "internal.h" |
21 | |
22 | #include <asm/uaccess.h> |
23 | #include <asm/unistd.h> |
24 | |
25 | typedef ssize_t (*io_fn_t)(struct file *, char __user *, size_t, loff_t *); |
26 | typedef ssize_t (*iov_fn_t)(struct kiocb *, const struct iovec *, |
27 | unsigned long, loff_t); |
28 | |
29 | const struct file_operations generic_ro_fops = { |
30 | .llseek = generic_file_llseek, |
31 | .read = do_sync_read, |
32 | .aio_read = generic_file_aio_read, |
33 | .mmap = generic_file_readonly_mmap, |
34 | .splice_read = generic_file_splice_read, |
35 | }; |
36 | |
37 | EXPORT_SYMBOL(generic_ro_fops); |
38 | |
39 | static inline int unsigned_offsets(struct file *file) |
40 | { |
41 | return file->f_mode & FMODE_UNSIGNED_OFFSET; |
42 | } |
43 | |
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) |
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 | } |
69 | EXPORT_SYMBOL(vfs_setpos); |
70 | |
71 | /** |
72 | * generic_file_llseek_size - generic llseek implementation for regular files |
73 | * @file: file structure to seek on |
74 | * @offset: file offset to seek to |
75 | * @whence: type of seek |
76 | * @size: max size of this file in file system |
77 | * @eof: offset used for SEEK_END position |
78 | * |
79 | * This is a variant of generic_file_llseek that allows passing in a custom |
80 | * maximum file size and a custom EOF position, for e.g. hashed directories |
81 | * |
82 | * Synchronization: |
83 | * SEEK_SET and SEEK_END are unsynchronized (but atomic on 64bit platforms) |
84 | * SEEK_CUR is synchronized against other SEEK_CURs, but not read/writes. |
85 | * read/writes behave like SEEK_SET against seeks. |
86 | */ |
87 | loff_t |
88 | generic_file_llseek_size(struct file *file, loff_t offset, int whence, |
89 | loff_t maxsize, loff_t eof) |
90 | { |
91 | switch (whence) { |
92 | case SEEK_END: |
93 | offset += eof; |
94 | break; |
95 | case SEEK_CUR: |
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; |
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); |
110 | offset = vfs_setpos(file, file->f_pos + offset, maxsize); |
111 | spin_unlock(&file->f_lock); |
112 | return offset; |
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 | */ |
118 | if (offset >= eof) |
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 | */ |
126 | if (offset >= eof) |
127 | return -ENXIO; |
128 | offset = eof; |
129 | break; |
130 | } |
131 | |
132 | return vfs_setpos(file, offset, maxsize); |
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 |
140 | * @whence: type of seek |
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 |
144 | * @offset and @whence. |
145 | */ |
146 | loff_t generic_file_llseek(struct file *file, loff_t offset, int whence) |
147 | { |
148 | struct inode *inode = file->f_mapping->host; |
149 | |
150 | return generic_file_llseek_size(file, offset, whence, |
151 | inode->i_sb->s_maxbytes, |
152 | i_size_read(inode)); |
153 | } |
154 | EXPORT_SYMBOL(generic_file_llseek); |
155 | |
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 | |
176 | /** |
177 | * noop_llseek - No Operation Performed llseek implementation |
178 | * @file: file structure to seek on |
179 | * @offset: file offset to seek to |
180 | * @whence: type of seek |
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 | */ |
187 | loff_t noop_llseek(struct file *file, loff_t offset, int whence) |
188 | { |
189 | return file->f_pos; |
190 | } |
191 | EXPORT_SYMBOL(noop_llseek); |
192 | |
193 | loff_t no_llseek(struct file *file, loff_t offset, int whence) |
194 | { |
195 | return -ESPIPE; |
196 | } |
197 | EXPORT_SYMBOL(no_llseek); |
198 | |
199 | loff_t default_llseek(struct file *file, loff_t offset, int whence) |
200 | { |
201 | struct inode *inode = file_inode(file); |
202 | loff_t retval; |
203 | |
204 | mutex_lock(&inode->i_mutex); |
205 | switch (whence) { |
206 | case SEEK_END: |
207 | offset += i_size_read(inode); |
208 | break; |
209 | case SEEK_CUR: |
210 | if (offset == 0) { |
211 | retval = file->f_pos; |
212 | goto out; |
213 | } |
214 | offset += file->f_pos; |
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 | */ |
222 | if (offset >= inode->i_size) { |
223 | retval = -ENXIO; |
224 | goto out; |
225 | } |
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 | */ |
233 | if (offset >= inode->i_size) { |
234 | retval = -ENXIO; |
235 | goto out; |
236 | } |
237 | offset = inode->i_size; |
238 | break; |
239 | } |
240 | retval = -EINVAL; |
241 | if (offset >= 0 || unsigned_offsets(file)) { |
242 | if (offset != file->f_pos) { |
243 | file->f_pos = offset; |
244 | file->f_version = 0; |
245 | } |
246 | retval = offset; |
247 | } |
248 | out: |
249 | mutex_unlock(&inode->i_mutex); |
250 | return retval; |
251 | } |
252 | EXPORT_SYMBOL(default_llseek); |
253 | |
254 | loff_t vfs_llseek(struct file *file, loff_t offset, int whence) |
255 | { |
256 | loff_t (*fn)(struct file *, loff_t, int); |
257 | |
258 | fn = no_llseek; |
259 | if (file->f_mode & FMODE_LSEEK) { |
260 | if (file->f_op && file->f_op->llseek) |
261 | fn = file->f_op->llseek; |
262 | } |
263 | return fn(file, offset, whence); |
264 | } |
265 | EXPORT_SYMBOL(vfs_llseek); |
266 | |
267 | SYSCALL_DEFINE3(lseek, unsigned int, fd, off_t, offset, unsigned int, whence) |
268 | { |
269 | off_t retval; |
270 | struct fd f = fdget(fd); |
271 | if (!f.file) |
272 | return -EBADF; |
273 | |
274 | retval = -EINVAL; |
275 | if (whence <= SEEK_MAX) { |
276 | loff_t res = vfs_llseek(f.file, offset, whence); |
277 | retval = res; |
278 | if (res != (loff_t)retval) |
279 | retval = -EOVERFLOW; /* LFS: should only happen on 32 bit platforms */ |
280 | } |
281 | fdput(f); |
282 | return retval; |
283 | } |
284 | |
285 | #ifdef CONFIG_COMPAT |
286 | COMPAT_SYSCALL_DEFINE3(lseek, unsigned int, fd, compat_off_t, offset, unsigned int, whence) |
287 | { |
288 | return sys_lseek(fd, offset, whence); |
289 | } |
290 | #endif |
291 | |
292 | #ifdef __ARCH_WANT_SYS_LLSEEK |
293 | SYSCALL_DEFINE5(llseek, unsigned int, fd, unsigned long, offset_high, |
294 | unsigned long, offset_low, loff_t __user *, result, |
295 | unsigned int, whence) |
296 | { |
297 | int retval; |
298 | struct fd f = fdget(fd); |
299 | loff_t offset; |
300 | |
301 | if (!f.file) |
302 | return -EBADF; |
303 | |
304 | retval = -EINVAL; |
305 | if (whence > SEEK_MAX) |
306 | goto out_putf; |
307 | |
308 | offset = vfs_llseek(f.file, ((loff_t) offset_high << 32) | offset_low, |
309 | whence); |
310 | |
311 | retval = (int)offset; |
312 | if (offset >= 0) { |
313 | retval = -EFAULT; |
314 | if (!copy_to_user(result, &offset, sizeof(offset))) |
315 | retval = 0; |
316 | } |
317 | out_putf: |
318 | fdput(f); |
319 | return retval; |
320 | } |
321 | #endif |
322 | |
323 | /* |
324 | * rw_verify_area doesn't like huge counts. We limit |
325 | * them to something that fits in "int" so that others |
326 | * won't have to do range checks all the time. |
327 | */ |
328 | int rw_verify_area(int read_write, struct file *file, const loff_t *ppos, size_t count) |
329 | { |
330 | struct inode *inode; |
331 | loff_t pos; |
332 | int retval = -EINVAL; |
333 | |
334 | inode = file_inode(file); |
335 | if (unlikely((ssize_t) count < 0)) |
336 | return retval; |
337 | pos = *ppos; |
338 | if (unlikely(pos < 0)) { |
339 | if (!unsigned_offsets(file)) |
340 | return retval; |
341 | if (count >= -pos) /* both values are in 0..LLONG_MAX */ |
342 | return -EOVERFLOW; |
343 | } else if (unlikely((loff_t) (pos + count) < 0)) { |
344 | if (!unsigned_offsets(file)) |
345 | return retval; |
346 | } |
347 | |
348 | if (unlikely(inode->i_flock && mandatory_lock(inode))) { |
349 | retval = locks_mandatory_area( |
350 | read_write == READ ? FLOCK_VERIFY_READ : FLOCK_VERIFY_WRITE, |
351 | inode, file, pos, count); |
352 | if (retval < 0) |
353 | return retval; |
354 | } |
355 | retval = security_file_permission(file, |
356 | read_write == READ ? MAY_READ : MAY_WRITE); |
357 | if (retval) |
358 | return retval; |
359 | return count > MAX_RW_COUNT ? MAX_RW_COUNT : count; |
360 | } |
361 | |
362 | ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos) |
363 | { |
364 | struct iovec iov = { .iov_base = buf, .iov_len = len }; |
365 | struct kiocb kiocb; |
366 | ssize_t ret; |
367 | |
368 | init_sync_kiocb(&kiocb, filp); |
369 | kiocb.ki_pos = *ppos; |
370 | kiocb.ki_left = len; |
371 | kiocb.ki_nbytes = len; |
372 | |
373 | ret = filp->f_op->aio_read(&kiocb, &iov, 1, kiocb.ki_pos); |
374 | if (-EIOCBQUEUED == ret) |
375 | ret = wait_on_sync_kiocb(&kiocb); |
376 | *ppos = kiocb.ki_pos; |
377 | return ret; |
378 | } |
379 | |
380 | EXPORT_SYMBOL(do_sync_read); |
381 | |
382 | ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos) |
383 | { |
384 | ssize_t ret; |
385 | |
386 | if (!(file->f_mode & FMODE_READ)) |
387 | return -EBADF; |
388 | if (!file->f_op || (!file->f_op->read && !file->f_op->aio_read)) |
389 | return -EINVAL; |
390 | if (unlikely(!access_ok(VERIFY_WRITE, buf, count))) |
391 | return -EFAULT; |
392 | |
393 | ret = rw_verify_area(READ, file, pos, count); |
394 | if (ret >= 0) { |
395 | count = ret; |
396 | if (file->f_op->read) |
397 | ret = file->f_op->read(file, buf, count, pos); |
398 | else |
399 | ret = do_sync_read(file, buf, count, pos); |
400 | if (ret > 0) { |
401 | fsnotify_access(file); |
402 | add_rchar(current, ret); |
403 | } |
404 | inc_syscr(current); |
405 | } |
406 | |
407 | return ret; |
408 | } |
409 | |
410 | EXPORT_SYMBOL(vfs_read); |
411 | |
412 | ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos) |
413 | { |
414 | struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = len }; |
415 | struct kiocb kiocb; |
416 | ssize_t ret; |
417 | |
418 | init_sync_kiocb(&kiocb, filp); |
419 | kiocb.ki_pos = *ppos; |
420 | kiocb.ki_left = len; |
421 | kiocb.ki_nbytes = len; |
422 | |
423 | ret = filp->f_op->aio_write(&kiocb, &iov, 1, kiocb.ki_pos); |
424 | if (-EIOCBQUEUED == ret) |
425 | ret = wait_on_sync_kiocb(&kiocb); |
426 | *ppos = kiocb.ki_pos; |
427 | return ret; |
428 | } |
429 | |
430 | EXPORT_SYMBOL(do_sync_write); |
431 | |
432 | ssize_t __kernel_write(struct file *file, const char *buf, size_t count, loff_t *pos) |
433 | { |
434 | mm_segment_t old_fs; |
435 | const char __user *p; |
436 | ssize_t ret; |
437 | |
438 | if (!file->f_op || (!file->f_op->write && !file->f_op->aio_write)) |
439 | return -EINVAL; |
440 | |
441 | old_fs = get_fs(); |
442 | set_fs(get_ds()); |
443 | p = (__force const char __user *)buf; |
444 | if (count > MAX_RW_COUNT) |
445 | count = MAX_RW_COUNT; |
446 | if (file->f_op->write) |
447 | ret = file->f_op->write(file, p, count, pos); |
448 | else |
449 | ret = do_sync_write(file, p, count, pos); |
450 | set_fs(old_fs); |
451 | if (ret > 0) { |
452 | fsnotify_modify(file); |
453 | add_wchar(current, ret); |
454 | } |
455 | inc_syscw(current); |
456 | return ret; |
457 | } |
458 | |
459 | ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_t *pos) |
460 | { |
461 | ssize_t ret; |
462 | |
463 | if (!(file->f_mode & FMODE_WRITE)) |
464 | return -EBADF; |
465 | if (!file->f_op || (!file->f_op->write && !file->f_op->aio_write)) |
466 | return -EINVAL; |
467 | if (unlikely(!access_ok(VERIFY_READ, buf, count))) |
468 | return -EFAULT; |
469 | |
470 | ret = rw_verify_area(WRITE, file, pos, count); |
471 | if (ret >= 0) { |
472 | count = ret; |
473 | file_start_write(file); |
474 | if (file->f_op->write) |
475 | ret = file->f_op->write(file, buf, count, pos); |
476 | else |
477 | ret = do_sync_write(file, buf, count, pos); |
478 | if (ret > 0) { |
479 | fsnotify_modify(file); |
480 | add_wchar(current, ret); |
481 | } |
482 | inc_syscw(current); |
483 | file_end_write(file); |
484 | } |
485 | |
486 | return ret; |
487 | } |
488 | |
489 | EXPORT_SYMBOL(vfs_write); |
490 | |
491 | static inline loff_t file_pos_read(struct file *file) |
492 | { |
493 | return file->f_pos; |
494 | } |
495 | |
496 | static inline void file_pos_write(struct file *file, loff_t pos) |
497 | { |
498 | file->f_pos = pos; |
499 | } |
500 | |
501 | SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count) |
502 | { |
503 | struct fd f = fdget(fd); |
504 | ssize_t ret = -EBADF; |
505 | |
506 | if (f.file) { |
507 | loff_t pos = file_pos_read(f.file); |
508 | ret = vfs_read(f.file, buf, count, &pos); |
509 | if (ret >= 0) |
510 | file_pos_write(f.file, pos); |
511 | fdput(f); |
512 | } |
513 | return ret; |
514 | } |
515 | |
516 | SYSCALL_DEFINE3(write, unsigned int, fd, const char __user *, buf, |
517 | size_t, count) |
518 | { |
519 | struct fd f = fdget(fd); |
520 | ssize_t ret = -EBADF; |
521 | |
522 | if (f.file) { |
523 | loff_t pos = file_pos_read(f.file); |
524 | ret = vfs_write(f.file, buf, count, &pos); |
525 | if (ret >= 0) |
526 | file_pos_write(f.file, pos); |
527 | fdput(f); |
528 | } |
529 | |
530 | return ret; |
531 | } |
532 | |
533 | SYSCALL_DEFINE4(pread64, unsigned int, fd, char __user *, buf, |
534 | size_t, count, loff_t, pos) |
535 | { |
536 | struct fd f; |
537 | ssize_t ret = -EBADF; |
538 | |
539 | if (pos < 0) |
540 | return -EINVAL; |
541 | |
542 | f = fdget(fd); |
543 | if (f.file) { |
544 | ret = -ESPIPE; |
545 | if (f.file->f_mode & FMODE_PREAD) |
546 | ret = vfs_read(f.file, buf, count, &pos); |
547 | fdput(f); |
548 | } |
549 | |
550 | return ret; |
551 | } |
552 | |
553 | SYSCALL_DEFINE4(pwrite64, unsigned int, fd, const char __user *, buf, |
554 | size_t, count, loff_t, pos) |
555 | { |
556 | struct fd f; |
557 | ssize_t ret = -EBADF; |
558 | |
559 | if (pos < 0) |
560 | return -EINVAL; |
561 | |
562 | f = fdget(fd); |
563 | if (f.file) { |
564 | ret = -ESPIPE; |
565 | if (f.file->f_mode & FMODE_PWRITE) |
566 | ret = vfs_write(f.file, buf, count, &pos); |
567 | fdput(f); |
568 | } |
569 | |
570 | return ret; |
571 | } |
572 | |
573 | /* |
574 | * Reduce an iovec's length in-place. Return the resulting number of segments |
575 | */ |
576 | unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to) |
577 | { |
578 | unsigned long seg = 0; |
579 | size_t len = 0; |
580 | |
581 | while (seg < nr_segs) { |
582 | seg++; |
583 | if (len + iov->iov_len >= to) { |
584 | iov->iov_len = to - len; |
585 | break; |
586 | } |
587 | len += iov->iov_len; |
588 | iov++; |
589 | } |
590 | return seg; |
591 | } |
592 | EXPORT_SYMBOL(iov_shorten); |
593 | |
594 | static ssize_t do_sync_readv_writev(struct file *filp, const struct iovec *iov, |
595 | unsigned long nr_segs, size_t len, loff_t *ppos, iov_fn_t fn) |
596 | { |
597 | struct kiocb kiocb; |
598 | ssize_t ret; |
599 | |
600 | init_sync_kiocb(&kiocb, filp); |
601 | kiocb.ki_pos = *ppos; |
602 | kiocb.ki_left = len; |
603 | kiocb.ki_nbytes = len; |
604 | |
605 | ret = fn(&kiocb, iov, nr_segs, kiocb.ki_pos); |
606 | if (ret == -EIOCBQUEUED) |
607 | ret = wait_on_sync_kiocb(&kiocb); |
608 | *ppos = kiocb.ki_pos; |
609 | return ret; |
610 | } |
611 | |
612 | /* Do it by hand, with file-ops */ |
613 | static ssize_t do_loop_readv_writev(struct file *filp, struct iovec *iov, |
614 | unsigned long nr_segs, loff_t *ppos, io_fn_t fn) |
615 | { |
616 | struct iovec *vector = iov; |
617 | ssize_t ret = 0; |
618 | |
619 | while (nr_segs > 0) { |
620 | void __user *base; |
621 | size_t len; |
622 | ssize_t nr; |
623 | |
624 | base = vector->iov_base; |
625 | len = vector->iov_len; |
626 | vector++; |
627 | nr_segs--; |
628 | |
629 | nr = fn(filp, base, len, ppos); |
630 | |
631 | if (nr < 0) { |
632 | if (!ret) |
633 | ret = nr; |
634 | break; |
635 | } |
636 | ret += nr; |
637 | if (nr != len) |
638 | break; |
639 | } |
640 | |
641 | return ret; |
642 | } |
643 | |
644 | /* A write operation does a read from user space and vice versa */ |
645 | #define vrfy_dir(type) ((type) == READ ? VERIFY_WRITE : VERIFY_READ) |
646 | |
647 | ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector, |
648 | unsigned long nr_segs, unsigned long fast_segs, |
649 | struct iovec *fast_pointer, |
650 | struct iovec **ret_pointer) |
651 | { |
652 | unsigned long seg; |
653 | ssize_t ret; |
654 | struct iovec *iov = fast_pointer; |
655 | |
656 | /* |
657 | * SuS says "The readv() function *may* fail if the iovcnt argument |
658 | * was less than or equal to 0, or greater than {IOV_MAX}. Linux has |
659 | * traditionally returned zero for zero segments, so... |
660 | */ |
661 | if (nr_segs == 0) { |
662 | ret = 0; |
663 | goto out; |
664 | } |
665 | |
666 | /* |
667 | * First get the "struct iovec" from user memory and |
668 | * verify all the pointers |
669 | */ |
670 | if (nr_segs > UIO_MAXIOV) { |
671 | ret = -EINVAL; |
672 | goto out; |
673 | } |
674 | if (nr_segs > fast_segs) { |
675 | iov = kmalloc(nr_segs*sizeof(struct iovec), GFP_KERNEL); |
676 | if (iov == NULL) { |
677 | ret = -ENOMEM; |
678 | goto out; |
679 | } |
680 | } |
681 | if (copy_from_user(iov, uvector, nr_segs*sizeof(*uvector))) { |
682 | ret = -EFAULT; |
683 | goto out; |
684 | } |
685 | |
686 | /* |
687 | * According to the Single Unix Specification we should return EINVAL |
688 | * if an element length is < 0 when cast to ssize_t or if the |
689 | * total length would overflow the ssize_t return value of the |
690 | * system call. |
691 | * |
692 | * Linux caps all read/write calls to MAX_RW_COUNT, and avoids the |
693 | * overflow case. |
694 | */ |
695 | ret = 0; |
696 | for (seg = 0; seg < nr_segs; seg++) { |
697 | void __user *buf = iov[seg].iov_base; |
698 | ssize_t len = (ssize_t)iov[seg].iov_len; |
699 | |
700 | /* see if we we're about to use an invalid len or if |
701 | * it's about to overflow ssize_t */ |
702 | if (len < 0) { |
703 | ret = -EINVAL; |
704 | goto out; |
705 | } |
706 | if (type >= 0 |
707 | && unlikely(!access_ok(vrfy_dir(type), buf, len))) { |
708 | ret = -EFAULT; |
709 | goto out; |
710 | } |
711 | if (len > MAX_RW_COUNT - ret) { |
712 | len = MAX_RW_COUNT - ret; |
713 | iov[seg].iov_len = len; |
714 | } |
715 | ret += len; |
716 | } |
717 | out: |
718 | *ret_pointer = iov; |
719 | return ret; |
720 | } |
721 | |
722 | static ssize_t do_readv_writev(int type, struct file *file, |
723 | const struct iovec __user * uvector, |
724 | unsigned long nr_segs, loff_t *pos) |
725 | { |
726 | size_t tot_len; |
727 | struct iovec iovstack[UIO_FASTIOV]; |
728 | struct iovec *iov = iovstack; |
729 | ssize_t ret; |
730 | io_fn_t fn; |
731 | iov_fn_t fnv; |
732 | |
733 | if (!file->f_op) { |
734 | ret = -EINVAL; |
735 | goto out; |
736 | } |
737 | |
738 | ret = rw_copy_check_uvector(type, uvector, nr_segs, |
739 | ARRAY_SIZE(iovstack), iovstack, &iov); |
740 | if (ret <= 0) |
741 | goto out; |
742 | |
743 | tot_len = ret; |
744 | ret = rw_verify_area(type, file, pos, tot_len); |
745 | if (ret < 0) |
746 | goto out; |
747 | |
748 | fnv = NULL; |
749 | if (type == READ) { |
750 | fn = file->f_op->read; |
751 | fnv = file->f_op->aio_read; |
752 | } else { |
753 | fn = (io_fn_t)file->f_op->write; |
754 | fnv = file->f_op->aio_write; |
755 | file_start_write(file); |
756 | } |
757 | |
758 | if (fnv) |
759 | ret = do_sync_readv_writev(file, iov, nr_segs, tot_len, |
760 | pos, fnv); |
761 | else |
762 | ret = do_loop_readv_writev(file, iov, nr_segs, pos, fn); |
763 | |
764 | if (type != READ) |
765 | file_end_write(file); |
766 | |
767 | out: |
768 | if (iov != iovstack) |
769 | kfree(iov); |
770 | if ((ret + (type == READ)) > 0) { |
771 | if (type == READ) |
772 | fsnotify_access(file); |
773 | else |
774 | fsnotify_modify(file); |
775 | } |
776 | return ret; |
777 | } |
778 | |
779 | ssize_t vfs_readv(struct file *file, const struct iovec __user *vec, |
780 | unsigned long vlen, loff_t *pos) |
781 | { |
782 | if (!(file->f_mode & FMODE_READ)) |
783 | return -EBADF; |
784 | if (!file->f_op || (!file->f_op->aio_read && !file->f_op->read)) |
785 | return -EINVAL; |
786 | |
787 | return do_readv_writev(READ, file, vec, vlen, pos); |
788 | } |
789 | |
790 | EXPORT_SYMBOL(vfs_readv); |
791 | |
792 | ssize_t vfs_writev(struct file *file, const struct iovec __user *vec, |
793 | unsigned long vlen, loff_t *pos) |
794 | { |
795 | if (!(file->f_mode & FMODE_WRITE)) |
796 | return -EBADF; |
797 | if (!file->f_op || (!file->f_op->aio_write && !file->f_op->write)) |
798 | return -EINVAL; |
799 | |
800 | return do_readv_writev(WRITE, file, vec, vlen, pos); |
801 | } |
802 | |
803 | EXPORT_SYMBOL(vfs_writev); |
804 | |
805 | SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec, |
806 | unsigned long, vlen) |
807 | { |
808 | struct fd f = fdget(fd); |
809 | ssize_t ret = -EBADF; |
810 | |
811 | if (f.file) { |
812 | loff_t pos = file_pos_read(f.file); |
813 | ret = vfs_readv(f.file, vec, vlen, &pos); |
814 | if (ret >= 0) |
815 | file_pos_write(f.file, pos); |
816 | fdput(f); |
817 | } |
818 | |
819 | if (ret > 0) |
820 | add_rchar(current, ret); |
821 | inc_syscr(current); |
822 | return ret; |
823 | } |
824 | |
825 | SYSCALL_DEFINE3(writev, unsigned long, fd, const struct iovec __user *, vec, |
826 | unsigned long, vlen) |
827 | { |
828 | struct fd f = fdget(fd); |
829 | ssize_t ret = -EBADF; |
830 | |
831 | if (f.file) { |
832 | loff_t pos = file_pos_read(f.file); |
833 | ret = vfs_writev(f.file, vec, vlen, &pos); |
834 | if (ret >= 0) |
835 | file_pos_write(f.file, pos); |
836 | fdput(f); |
837 | } |
838 | |
839 | if (ret > 0) |
840 | add_wchar(current, ret); |
841 | inc_syscw(current); |
842 | return ret; |
843 | } |
844 | |
845 | static inline loff_t pos_from_hilo(unsigned long high, unsigned long low) |
846 | { |
847 | #define HALF_LONG_BITS (BITS_PER_LONG / 2) |
848 | return (((loff_t)high << HALF_LONG_BITS) << HALF_LONG_BITS) | low; |
849 | } |
850 | |
851 | SYSCALL_DEFINE5(preadv, unsigned long, fd, const struct iovec __user *, vec, |
852 | unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h) |
853 | { |
854 | loff_t pos = pos_from_hilo(pos_h, pos_l); |
855 | struct fd f; |
856 | ssize_t ret = -EBADF; |
857 | |
858 | if (pos < 0) |
859 | return -EINVAL; |
860 | |
861 | f = fdget(fd); |
862 | if (f.file) { |
863 | ret = -ESPIPE; |
864 | if (f.file->f_mode & FMODE_PREAD) |
865 | ret = vfs_readv(f.file, vec, vlen, &pos); |
866 | fdput(f); |
867 | } |
868 | |
869 | if (ret > 0) |
870 | add_rchar(current, ret); |
871 | inc_syscr(current); |
872 | return ret; |
873 | } |
874 | |
875 | SYSCALL_DEFINE5(pwritev, unsigned long, fd, const struct iovec __user *, vec, |
876 | unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h) |
877 | { |
878 | loff_t pos = pos_from_hilo(pos_h, pos_l); |
879 | struct fd f; |
880 | ssize_t ret = -EBADF; |
881 | |
882 | if (pos < 0) |
883 | return -EINVAL; |
884 | |
885 | f = fdget(fd); |
886 | if (f.file) { |
887 | ret = -ESPIPE; |
888 | if (f.file->f_mode & FMODE_PWRITE) |
889 | ret = vfs_writev(f.file, vec, vlen, &pos); |
890 | fdput(f); |
891 | } |
892 | |
893 | if (ret > 0) |
894 | add_wchar(current, ret); |
895 | inc_syscw(current); |
896 | return ret; |
897 | } |
898 | |
899 | #ifdef CONFIG_COMPAT |
900 | |
901 | static ssize_t compat_do_readv_writev(int type, struct file *file, |
902 | const struct compat_iovec __user *uvector, |
903 | unsigned long nr_segs, loff_t *pos) |
904 | { |
905 | compat_ssize_t tot_len; |
906 | struct iovec iovstack[UIO_FASTIOV]; |
907 | struct iovec *iov = iovstack; |
908 | ssize_t ret; |
909 | io_fn_t fn; |
910 | iov_fn_t fnv; |
911 | |
912 | ret = -EINVAL; |
913 | if (!file->f_op) |
914 | goto out; |
915 | |
916 | ret = -EFAULT; |
917 | if (!access_ok(VERIFY_READ, uvector, nr_segs*sizeof(*uvector))) |
918 | goto out; |
919 | |
920 | ret = compat_rw_copy_check_uvector(type, uvector, nr_segs, |
921 | UIO_FASTIOV, iovstack, &iov); |
922 | if (ret <= 0) |
923 | goto out; |
924 | |
925 | tot_len = ret; |
926 | ret = rw_verify_area(type, file, pos, tot_len); |
927 | if (ret < 0) |
928 | goto out; |
929 | |
930 | fnv = NULL; |
931 | if (type == READ) { |
932 | fn = file->f_op->read; |
933 | fnv = file->f_op->aio_read; |
934 | } else { |
935 | fn = (io_fn_t)file->f_op->write; |
936 | fnv = file->f_op->aio_write; |
937 | file_start_write(file); |
938 | } |
939 | |
940 | if (fnv) |
941 | ret = do_sync_readv_writev(file, iov, nr_segs, tot_len, |
942 | pos, fnv); |
943 | else |
944 | ret = do_loop_readv_writev(file, iov, nr_segs, pos, fn); |
945 | |
946 | if (type != READ) |
947 | file_end_write(file); |
948 | |
949 | out: |
950 | if (iov != iovstack) |
951 | kfree(iov); |
952 | if ((ret + (type == READ)) > 0) { |
953 | if (type == READ) |
954 | fsnotify_access(file); |
955 | else |
956 | fsnotify_modify(file); |
957 | } |
958 | return ret; |
959 | } |
960 | |
961 | static size_t compat_readv(struct file *file, |
962 | const struct compat_iovec __user *vec, |
963 | unsigned long vlen, loff_t *pos) |
964 | { |
965 | ssize_t ret = -EBADF; |
966 | |
967 | if (!(file->f_mode & FMODE_READ)) |
968 | goto out; |
969 | |
970 | ret = -EINVAL; |
971 | if (!file->f_op || (!file->f_op->aio_read && !file->f_op->read)) |
972 | goto out; |
973 | |
974 | ret = compat_do_readv_writev(READ, file, vec, vlen, pos); |
975 | |
976 | out: |
977 | if (ret > 0) |
978 | add_rchar(current, ret); |
979 | inc_syscr(current); |
980 | return ret; |
981 | } |
982 | |
983 | COMPAT_SYSCALL_DEFINE3(readv, unsigned long, fd, |
984 | const struct compat_iovec __user *,vec, |
985 | unsigned long, vlen) |
986 | { |
987 | struct fd f = fdget(fd); |
988 | ssize_t ret; |
989 | loff_t pos; |
990 | |
991 | if (!f.file) |
992 | return -EBADF; |
993 | pos = f.file->f_pos; |
994 | ret = compat_readv(f.file, vec, vlen, &pos); |
995 | if (ret >= 0) |
996 | f.file->f_pos = pos; |
997 | fdput(f); |
998 | return ret; |
999 | } |
1000 | |
1001 | COMPAT_SYSCALL_DEFINE4(preadv64, unsigned long, fd, |
1002 | const struct compat_iovec __user *,vec, |
1003 | unsigned long, vlen, loff_t, pos) |
1004 | { |
1005 | struct fd f; |
1006 | ssize_t ret; |
1007 | |
1008 | if (pos < 0) |
1009 | return -EINVAL; |
1010 | f = fdget(fd); |
1011 | if (!f.file) |
1012 | return -EBADF; |
1013 | ret = -ESPIPE; |
1014 | if (f.file->f_mode & FMODE_PREAD) |
1015 | ret = compat_readv(f.file, vec, vlen, &pos); |
1016 | fdput(f); |
1017 | return ret; |
1018 | } |
1019 | |
1020 | COMPAT_SYSCALL_DEFINE5(preadv, unsigned long, fd, |
1021 | const struct compat_iovec __user *,vec, |
1022 | unsigned long, vlen, u32, pos_low, u32, pos_high) |
1023 | { |
1024 | loff_t pos = ((loff_t)pos_high << 32) | pos_low; |
1025 | return compat_sys_preadv64(fd, vec, vlen, pos); |
1026 | } |
1027 | |
1028 | static size_t compat_writev(struct file *file, |
1029 | const struct compat_iovec __user *vec, |
1030 | unsigned long vlen, loff_t *pos) |
1031 | { |
1032 | ssize_t ret = -EBADF; |
1033 | |
1034 | if (!(file->f_mode & FMODE_WRITE)) |
1035 | goto out; |
1036 | |
1037 | ret = -EINVAL; |
1038 | if (!file->f_op || (!file->f_op->aio_write && !file->f_op->write)) |
1039 | goto out; |
1040 | |
1041 | ret = compat_do_readv_writev(WRITE, file, vec, vlen, pos); |
1042 | |
1043 | out: |
1044 | if (ret > 0) |
1045 | add_wchar(current, ret); |
1046 | inc_syscw(current); |
1047 | return ret; |
1048 | } |
1049 | |
1050 | COMPAT_SYSCALL_DEFINE3(writev, unsigned long, fd, |
1051 | const struct compat_iovec __user *, vec, |
1052 | unsigned long, vlen) |
1053 | { |
1054 | struct fd f = fdget(fd); |
1055 | ssize_t ret; |
1056 | loff_t pos; |
1057 | |
1058 | if (!f.file) |
1059 | return -EBADF; |
1060 | pos = f.file->f_pos; |
1061 | ret = compat_writev(f.file, vec, vlen, &pos); |
1062 | if (ret >= 0) |
1063 | f.file->f_pos = pos; |
1064 | fdput(f); |
1065 | return ret; |
1066 | } |
1067 | |
1068 | COMPAT_SYSCALL_DEFINE4(pwritev64, unsigned long, fd, |
1069 | const struct compat_iovec __user *,vec, |
1070 | unsigned long, vlen, loff_t, pos) |
1071 | { |
1072 | struct fd f; |
1073 | ssize_t ret; |
1074 | |
1075 | if (pos < 0) |
1076 | return -EINVAL; |
1077 | f = fdget(fd); |
1078 | if (!f.file) |
1079 | return -EBADF; |
1080 | ret = -ESPIPE; |
1081 | if (f.file->f_mode & FMODE_PWRITE) |
1082 | ret = compat_writev(f.file, vec, vlen, &pos); |
1083 | fdput(f); |
1084 | return ret; |
1085 | } |
1086 | |
1087 | COMPAT_SYSCALL_DEFINE5(pwritev, unsigned long, fd, |
1088 | const struct compat_iovec __user *,vec, |
1089 | unsigned long, vlen, u32, pos_low, u32, pos_high) |
1090 | { |
1091 | loff_t pos = ((loff_t)pos_high << 32) | pos_low; |
1092 | return compat_sys_pwritev64(fd, vec, vlen, pos); |
1093 | } |
1094 | #endif |
1095 | |
1096 | static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, |
1097 | size_t count, loff_t max) |
1098 | { |
1099 | struct fd in, out; |
1100 | struct inode *in_inode, *out_inode; |
1101 | loff_t pos; |
1102 | loff_t out_pos; |
1103 | ssize_t retval; |
1104 | int fl; |
1105 | |
1106 | /* |
1107 | * Get input file, and verify that it is ok.. |
1108 | */ |
1109 | retval = -EBADF; |
1110 | in = fdget(in_fd); |
1111 | if (!in.file) |
1112 | goto out; |
1113 | if (!(in.file->f_mode & FMODE_READ)) |
1114 | goto fput_in; |
1115 | retval = -ESPIPE; |
1116 | if (!ppos) { |
1117 | pos = in.file->f_pos; |
1118 | } else { |
1119 | pos = *ppos; |
1120 | if (!(in.file->f_mode & FMODE_PREAD)) |
1121 | goto fput_in; |
1122 | } |
1123 | retval = rw_verify_area(READ, in.file, &pos, count); |
1124 | if (retval < 0) |
1125 | goto fput_in; |
1126 | count = retval; |
1127 | |
1128 | /* |
1129 | * Get output file, and verify that it is ok.. |
1130 | */ |
1131 | retval = -EBADF; |
1132 | out = fdget(out_fd); |
1133 | if (!out.file) |
1134 | goto fput_in; |
1135 | if (!(out.file->f_mode & FMODE_WRITE)) |
1136 | goto fput_out; |
1137 | retval = -EINVAL; |
1138 | in_inode = file_inode(in.file); |
1139 | out_inode = file_inode(out.file); |
1140 | out_pos = out.file->f_pos; |
1141 | retval = rw_verify_area(WRITE, out.file, &out_pos, count); |
1142 | if (retval < 0) |
1143 | goto fput_out; |
1144 | count = retval; |
1145 | |
1146 | if (!max) |
1147 | max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes); |
1148 | |
1149 | if (unlikely(pos + count > max)) { |
1150 | retval = -EOVERFLOW; |
1151 | if (pos >= max) |
1152 | goto fput_out; |
1153 | count = max - pos; |
1154 | } |
1155 | |
1156 | fl = 0; |
1157 | #if 0 |
1158 | /* |
1159 | * We need to debate whether we can enable this or not. The |
1160 | * man page documents EAGAIN return for the output at least, |
1161 | * and the application is arguably buggy if it doesn't expect |
1162 | * EAGAIN on a non-blocking file descriptor. |
1163 | */ |
1164 | if (in.file->f_flags & O_NONBLOCK) |
1165 | fl = SPLICE_F_NONBLOCK; |
1166 | #endif |
1167 | file_start_write(out.file); |
1168 | retval = do_splice_direct(in.file, &pos, out.file, &out_pos, count, fl); |
1169 | file_end_write(out.file); |
1170 | |
1171 | if (retval > 0) { |
1172 | add_rchar(current, retval); |
1173 | add_wchar(current, retval); |
1174 | fsnotify_access(in.file); |
1175 | fsnotify_modify(out.file); |
1176 | out.file->f_pos = out_pos; |
1177 | if (ppos) |
1178 | *ppos = pos; |
1179 | else |
1180 | in.file->f_pos = pos; |
1181 | } |
1182 | |
1183 | inc_syscr(current); |
1184 | inc_syscw(current); |
1185 | if (pos > max) |
1186 | retval = -EOVERFLOW; |
1187 | |
1188 | fput_out: |
1189 | fdput(out); |
1190 | fput_in: |
1191 | fdput(in); |
1192 | out: |
1193 | return retval; |
1194 | } |
1195 | |
1196 | SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, off_t __user *, offset, size_t, count) |
1197 | { |
1198 | loff_t pos; |
1199 | off_t off; |
1200 | ssize_t ret; |
1201 | |
1202 | if (offset) { |
1203 | if (unlikely(get_user(off, offset))) |
1204 | return -EFAULT; |
1205 | pos = off; |
1206 | ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS); |
1207 | if (unlikely(put_user(pos, offset))) |
1208 | return -EFAULT; |
1209 | return ret; |
1210 | } |
1211 | |
1212 | return do_sendfile(out_fd, in_fd, NULL, count, 0); |
1213 | } |
1214 | |
1215 | SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, loff_t __user *, offset, size_t, count) |
1216 | { |
1217 | loff_t pos; |
1218 | ssize_t ret; |
1219 | |
1220 | if (offset) { |
1221 | if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t)))) |
1222 | return -EFAULT; |
1223 | ret = do_sendfile(out_fd, in_fd, &pos, count, 0); |
1224 | if (unlikely(put_user(pos, offset))) |
1225 | return -EFAULT; |
1226 | return ret; |
1227 | } |
1228 | |
1229 | return do_sendfile(out_fd, in_fd, NULL, count, 0); |
1230 | } |
1231 | |
1232 | #ifdef CONFIG_COMPAT |
1233 | COMPAT_SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, |
1234 | compat_off_t __user *, offset, compat_size_t, count) |
1235 | { |
1236 | loff_t pos; |
1237 | off_t off; |
1238 | ssize_t ret; |
1239 | |
1240 | if (offset) { |
1241 | if (unlikely(get_user(off, offset))) |
1242 | return -EFAULT; |
1243 | pos = off; |
1244 | ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS); |
1245 | if (unlikely(put_user(pos, offset))) |
1246 | return -EFAULT; |
1247 | return ret; |
1248 | } |
1249 | |
1250 | return do_sendfile(out_fd, in_fd, NULL, count, 0); |
1251 | } |
1252 | |
1253 | COMPAT_SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, |
1254 | compat_loff_t __user *, offset, compat_size_t, count) |
1255 | { |
1256 | loff_t pos; |
1257 | ssize_t ret; |
1258 | |
1259 | if (offset) { |
1260 | if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t)))) |
1261 | return -EFAULT; |
1262 | ret = do_sendfile(out_fd, in_fd, &pos, count, 0); |
1263 | if (unlikely(put_user(pos, offset))) |
1264 | return -EFAULT; |
1265 | return ret; |
1266 | } |
1267 | |
1268 | return do_sendfile(out_fd, in_fd, NULL, count, 0); |
1269 | } |
1270 | #endif |
1271 |
Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master
Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9