Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/fs/read_write.c | |
3 | * | |
4 | * Copyright (C) 1991, 1992 Linus Torvalds | |
5 | */ | |
6 | ||
7 | #include <linux/slab.h> | |
8 | #include <linux/stat.h> | |
9 | #include <linux/fcntl.h> | |
10 | #include <linux/file.h> | |
11 | #include <linux/uio.h> | |
12 | #include <linux/smp_lock.h> | |
0eeca283 | 13 | #include <linux/fsnotify.h> |
1da177e4 LT |
14 | #include <linux/security.h> |
15 | #include <linux/module.h> | |
16 | #include <linux/syscalls.h> | |
e28cc715 | 17 | #include <linux/pagemap.h> |
d6b29d7c | 18 | #include <linux/splice.h> |
ee0b3e67 | 19 | #include "read_write.h" |
1da177e4 LT |
20 | |
21 | #include <asm/uaccess.h> | |
22 | #include <asm/unistd.h> | |
23 | ||
4b6f5d20 | 24 | const struct file_operations generic_ro_fops = { |
1da177e4 | 25 | .llseek = generic_file_llseek, |
543ade1f BP |
26 | .read = do_sync_read, |
27 | .aio_read = generic_file_aio_read, | |
1da177e4 | 28 | .mmap = generic_file_readonly_mmap, |
534f2aaa | 29 | .splice_read = generic_file_splice_read, |
1da177e4 LT |
30 | }; |
31 | ||
32 | EXPORT_SYMBOL(generic_ro_fops); | |
33 | ||
3a8cff4f CH |
34 | /** |
35 | * generic_file_llseek_unlocked - lockless generic llseek implementation | |
36 | * @file: file structure to seek on | |
37 | * @offset: file offset to seek to | |
38 | * @origin: type of seek | |
39 | * | |
40 | * Updates the file offset to the value specified by @offset and @origin. | |
41 | * Locking must be provided by the caller. | |
42 | */ | |
9465efc9 AK |
43 | loff_t |
44 | generic_file_llseek_unlocked(struct file *file, loff_t offset, int origin) | |
1da177e4 | 45 | { |
1da177e4 LT |
46 | struct inode *inode = file->f_mapping->host; |
47 | ||
1da177e4 | 48 | switch (origin) { |
3a8cff4f CH |
49 | case SEEK_END: |
50 | offset += inode->i_size; | |
51 | break; | |
52 | case SEEK_CUR: | |
5b6f1eb9 AK |
53 | /* |
54 | * Here we special-case the lseek(fd, 0, SEEK_CUR) | |
55 | * position-querying operation. Avoid rewriting the "same" | |
56 | * f_pos value back to the file because a concurrent read(), | |
57 | * write() or lseek() might have altered it | |
58 | */ | |
59 | if (offset == 0) | |
60 | return file->f_pos; | |
3a8cff4f CH |
61 | offset += file->f_pos; |
62 | break; | |
1da177e4 | 63 | } |
3a8cff4f CH |
64 | |
65 | if (offset < 0 || offset > inode->i_sb->s_maxbytes) | |
66 | return -EINVAL; | |
67 | ||
68 | /* Special lock needed here? */ | |
69 | if (offset != file->f_pos) { | |
70 | file->f_pos = offset; | |
71 | file->f_version = 0; | |
1da177e4 | 72 | } |
3a8cff4f CH |
73 | |
74 | return offset; | |
1da177e4 | 75 | } |
9465efc9 | 76 | EXPORT_SYMBOL(generic_file_llseek_unlocked); |
1da177e4 | 77 | |
3a8cff4f CH |
78 | /** |
79 | * generic_file_llseek - generic llseek implementation for regular files | |
80 | * @file: file structure to seek on | |
81 | * @offset: file offset to seek to | |
82 | * @origin: type of seek | |
83 | * | |
84 | * This is a generic implemenation of ->llseek useable for all normal local | |
85 | * filesystems. It just updates the file offset to the value specified by | |
86 | * @offset and @origin under i_mutex. | |
87 | */ | |
9465efc9 | 88 | loff_t generic_file_llseek(struct file *file, loff_t offset, int origin) |
1da177e4 | 89 | { |
3a8cff4f CH |
90 | loff_t rval; |
91 | ||
9465efc9 | 92 | mutex_lock(&file->f_dentry->d_inode->i_mutex); |
3a8cff4f | 93 | rval = generic_file_llseek_unlocked(file, offset, origin); |
9465efc9 | 94 | mutex_unlock(&file->f_dentry->d_inode->i_mutex); |
3a8cff4f CH |
95 | |
96 | return rval; | |
1da177e4 | 97 | } |
9465efc9 | 98 | EXPORT_SYMBOL(generic_file_llseek); |
1da177e4 LT |
99 | |
100 | loff_t no_llseek(struct file *file, loff_t offset, int origin) | |
101 | { | |
102 | return -ESPIPE; | |
103 | } | |
104 | EXPORT_SYMBOL(no_llseek); | |
105 | ||
106 | loff_t default_llseek(struct file *file, loff_t offset, int origin) | |
107 | { | |
16abef0e | 108 | loff_t retval; |
1da177e4 LT |
109 | |
110 | lock_kernel(); | |
111 | switch (origin) { | |
7b8e8924 | 112 | case SEEK_END: |
0f7fc9e4 | 113 | offset += i_size_read(file->f_path.dentry->d_inode); |
1da177e4 | 114 | break; |
7b8e8924 | 115 | case SEEK_CUR: |
5b6f1eb9 AK |
116 | if (offset == 0) { |
117 | retval = file->f_pos; | |
118 | goto out; | |
119 | } | |
1da177e4 LT |
120 | offset += file->f_pos; |
121 | } | |
122 | retval = -EINVAL; | |
123 | if (offset >= 0) { | |
124 | if (offset != file->f_pos) { | |
125 | file->f_pos = offset; | |
126 | file->f_version = 0; | |
127 | } | |
128 | retval = offset; | |
129 | } | |
5b6f1eb9 | 130 | out: |
1da177e4 LT |
131 | unlock_kernel(); |
132 | return retval; | |
133 | } | |
134 | EXPORT_SYMBOL(default_llseek); | |
135 | ||
136 | loff_t vfs_llseek(struct file *file, loff_t offset, int origin) | |
137 | { | |
138 | loff_t (*fn)(struct file *, loff_t, int); | |
139 | ||
140 | fn = no_llseek; | |
141 | if (file->f_mode & FMODE_LSEEK) { | |
142 | fn = default_llseek; | |
143 | if (file->f_op && file->f_op->llseek) | |
144 | fn = file->f_op->llseek; | |
145 | } | |
146 | return fn(file, offset, origin); | |
147 | } | |
148 | EXPORT_SYMBOL(vfs_llseek); | |
149 | ||
2ed7c03e | 150 | asmlinkage long sys_lseek(unsigned int fd, off_t offset, unsigned int origin) |
1da177e4 LT |
151 | { |
152 | off_t retval; | |
153 | struct file * file; | |
154 | int fput_needed; | |
155 | ||
156 | retval = -EBADF; | |
157 | file = fget_light(fd, &fput_needed); | |
158 | if (!file) | |
159 | goto bad; | |
160 | ||
161 | retval = -EINVAL; | |
1ae7075b | 162 | if (origin <= SEEK_MAX) { |
1da177e4 LT |
163 | loff_t res = vfs_llseek(file, offset, origin); |
164 | retval = res; | |
165 | if (res != (loff_t)retval) | |
166 | retval = -EOVERFLOW; /* LFS: should only happen on 32 bit platforms */ | |
167 | } | |
168 | fput_light(file, fput_needed); | |
169 | bad: | |
170 | return retval; | |
171 | } | |
172 | ||
173 | #ifdef __ARCH_WANT_SYS_LLSEEK | |
174 | asmlinkage long sys_llseek(unsigned int fd, unsigned long offset_high, | |
175 | unsigned long offset_low, loff_t __user * result, | |
176 | unsigned int origin) | |
177 | { | |
178 | int retval; | |
179 | struct file * file; | |
180 | loff_t offset; | |
181 | int fput_needed; | |
182 | ||
183 | retval = -EBADF; | |
184 | file = fget_light(fd, &fput_needed); | |
185 | if (!file) | |
186 | goto bad; | |
187 | ||
188 | retval = -EINVAL; | |
1ae7075b | 189 | if (origin > SEEK_MAX) |
1da177e4 LT |
190 | goto out_putf; |
191 | ||
192 | offset = vfs_llseek(file, ((loff_t) offset_high << 32) | offset_low, | |
193 | origin); | |
194 | ||
195 | retval = (int)offset; | |
196 | if (offset >= 0) { | |
197 | retval = -EFAULT; | |
198 | if (!copy_to_user(result, &offset, sizeof(offset))) | |
199 | retval = 0; | |
200 | } | |
201 | out_putf: | |
202 | fput_light(file, fput_needed); | |
203 | bad: | |
204 | return retval; | |
205 | } | |
206 | #endif | |
207 | ||
e28cc715 LT |
208 | /* |
209 | * rw_verify_area doesn't like huge counts. We limit | |
210 | * them to something that fits in "int" so that others | |
211 | * won't have to do range checks all the time. | |
212 | */ | |
213 | #define MAX_RW_COUNT (INT_MAX & PAGE_CACHE_MASK) | |
1da177e4 LT |
214 | |
215 | int rw_verify_area(int read_write, struct file *file, loff_t *ppos, size_t count) | |
216 | { | |
217 | struct inode *inode; | |
218 | loff_t pos; | |
c43e259c | 219 | int retval = -EINVAL; |
1da177e4 | 220 | |
163da958 | 221 | inode = file->f_path.dentry->d_inode; |
e28cc715 | 222 | if (unlikely((ssize_t) count < 0)) |
c43e259c | 223 | return retval; |
1da177e4 LT |
224 | pos = *ppos; |
225 | if (unlikely((pos < 0) || (loff_t) (pos + count) < 0)) | |
c43e259c | 226 | return retval; |
1da177e4 | 227 | |
a16877ca | 228 | if (unlikely(inode->i_flock && mandatory_lock(inode))) { |
c43e259c | 229 | retval = locks_mandatory_area( |
e28cc715 LT |
230 | read_write == READ ? FLOCK_VERIFY_READ : FLOCK_VERIFY_WRITE, |
231 | inode, file, pos, count); | |
232 | if (retval < 0) | |
233 | return retval; | |
234 | } | |
c43e259c JM |
235 | retval = security_file_permission(file, |
236 | read_write == READ ? MAY_READ : MAY_WRITE); | |
237 | if (retval) | |
238 | return retval; | |
e28cc715 | 239 | return count > MAX_RW_COUNT ? MAX_RW_COUNT : count; |
1da177e4 LT |
240 | } |
241 | ||
63e68809 BL |
242 | static void wait_on_retry_sync_kiocb(struct kiocb *iocb) |
243 | { | |
244 | set_current_state(TASK_UNINTERRUPTIBLE); | |
245 | if (!kiocbIsKicked(iocb)) | |
246 | schedule(); | |
247 | else | |
248 | kiocbClearKicked(iocb); | |
249 | __set_current_state(TASK_RUNNING); | |
250 | } | |
251 | ||
1da177e4 LT |
252 | ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos) |
253 | { | |
027445c3 | 254 | struct iovec iov = { .iov_base = buf, .iov_len = len }; |
1da177e4 LT |
255 | struct kiocb kiocb; |
256 | ssize_t ret; | |
257 | ||
258 | init_sync_kiocb(&kiocb, filp); | |
259 | kiocb.ki_pos = *ppos; | |
027445c3 BP |
260 | kiocb.ki_left = len; |
261 | ||
262 | for (;;) { | |
263 | ret = filp->f_op->aio_read(&kiocb, &iov, 1, kiocb.ki_pos); | |
264 | if (ret != -EIOCBRETRY) | |
265 | break; | |
63e68809 | 266 | wait_on_retry_sync_kiocb(&kiocb); |
027445c3 | 267 | } |
63e68809 | 268 | |
1da177e4 LT |
269 | if (-EIOCBQUEUED == ret) |
270 | ret = wait_on_sync_kiocb(&kiocb); | |
271 | *ppos = kiocb.ki_pos; | |
272 | return ret; | |
273 | } | |
274 | ||
275 | EXPORT_SYMBOL(do_sync_read); | |
276 | ||
277 | ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos) | |
278 | { | |
279 | ssize_t ret; | |
280 | ||
281 | if (!(file->f_mode & FMODE_READ)) | |
282 | return -EBADF; | |
283 | if (!file->f_op || (!file->f_op->read && !file->f_op->aio_read)) | |
284 | return -EINVAL; | |
285 | if (unlikely(!access_ok(VERIFY_WRITE, buf, count))) | |
286 | return -EFAULT; | |
287 | ||
288 | ret = rw_verify_area(READ, file, pos, count); | |
e28cc715 LT |
289 | if (ret >= 0) { |
290 | count = ret; | |
c43e259c JM |
291 | if (file->f_op->read) |
292 | ret = file->f_op->read(file, buf, count, pos); | |
293 | else | |
294 | ret = do_sync_read(file, buf, count, pos); | |
295 | if (ret > 0) { | |
296 | fsnotify_access(file->f_path.dentry); | |
297 | add_rchar(current, ret); | |
1da177e4 | 298 | } |
c43e259c | 299 | inc_syscr(current); |
1da177e4 LT |
300 | } |
301 | ||
302 | return ret; | |
303 | } | |
304 | ||
305 | EXPORT_SYMBOL(vfs_read); | |
306 | ||
307 | ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos) | |
308 | { | |
027445c3 | 309 | struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = len }; |
1da177e4 LT |
310 | struct kiocb kiocb; |
311 | ssize_t ret; | |
312 | ||
313 | init_sync_kiocb(&kiocb, filp); | |
314 | kiocb.ki_pos = *ppos; | |
027445c3 BP |
315 | kiocb.ki_left = len; |
316 | ||
317 | for (;;) { | |
318 | ret = filp->f_op->aio_write(&kiocb, &iov, 1, kiocb.ki_pos); | |
319 | if (ret != -EIOCBRETRY) | |
320 | break; | |
63e68809 | 321 | wait_on_retry_sync_kiocb(&kiocb); |
027445c3 | 322 | } |
63e68809 | 323 | |
1da177e4 LT |
324 | if (-EIOCBQUEUED == ret) |
325 | ret = wait_on_sync_kiocb(&kiocb); | |
326 | *ppos = kiocb.ki_pos; | |
327 | return ret; | |
328 | } | |
329 | ||
330 | EXPORT_SYMBOL(do_sync_write); | |
331 | ||
332 | ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_t *pos) | |
333 | { | |
334 | ssize_t ret; | |
335 | ||
336 | if (!(file->f_mode & FMODE_WRITE)) | |
337 | return -EBADF; | |
338 | if (!file->f_op || (!file->f_op->write && !file->f_op->aio_write)) | |
339 | return -EINVAL; | |
340 | if (unlikely(!access_ok(VERIFY_READ, buf, count))) | |
341 | return -EFAULT; | |
342 | ||
343 | ret = rw_verify_area(WRITE, file, pos, count); | |
e28cc715 LT |
344 | if (ret >= 0) { |
345 | count = ret; | |
c43e259c JM |
346 | if (file->f_op->write) |
347 | ret = file->f_op->write(file, buf, count, pos); | |
348 | else | |
349 | ret = do_sync_write(file, buf, count, pos); | |
350 | if (ret > 0) { | |
351 | fsnotify_modify(file->f_path.dentry); | |
352 | add_wchar(current, ret); | |
1da177e4 | 353 | } |
c43e259c | 354 | inc_syscw(current); |
1da177e4 LT |
355 | } |
356 | ||
357 | return ret; | |
358 | } | |
359 | ||
360 | EXPORT_SYMBOL(vfs_write); | |
361 | ||
362 | static inline loff_t file_pos_read(struct file *file) | |
363 | { | |
364 | return file->f_pos; | |
365 | } | |
366 | ||
367 | static inline void file_pos_write(struct file *file, loff_t pos) | |
368 | { | |
369 | file->f_pos = pos; | |
370 | } | |
371 | ||
2ed7c03e | 372 | asmlinkage long sys_read(unsigned int fd, char __user * buf, size_t count) |
1da177e4 LT |
373 | { |
374 | struct file *file; | |
375 | ssize_t ret = -EBADF; | |
376 | int fput_needed; | |
377 | ||
378 | file = fget_light(fd, &fput_needed); | |
379 | if (file) { | |
380 | loff_t pos = file_pos_read(file); | |
381 | ret = vfs_read(file, buf, count, &pos); | |
382 | file_pos_write(file, pos); | |
383 | fput_light(file, fput_needed); | |
384 | } | |
385 | ||
386 | return ret; | |
387 | } | |
1da177e4 | 388 | |
2ed7c03e | 389 | asmlinkage long sys_write(unsigned int fd, const char __user * buf, size_t count) |
1da177e4 LT |
390 | { |
391 | struct file *file; | |
392 | ssize_t ret = -EBADF; | |
393 | int fput_needed; | |
394 | ||
395 | file = fget_light(fd, &fput_needed); | |
396 | if (file) { | |
397 | loff_t pos = file_pos_read(file); | |
398 | ret = vfs_write(file, buf, count, &pos); | |
399 | file_pos_write(file, pos); | |
400 | fput_light(file, fput_needed); | |
401 | } | |
402 | ||
403 | return ret; | |
404 | } | |
405 | ||
6673e0c3 HC |
406 | SYSCALL_DEFINE(pread64)(unsigned int fd, char __user *buf, |
407 | size_t count, loff_t pos) | |
1da177e4 LT |
408 | { |
409 | struct file *file; | |
410 | ssize_t ret = -EBADF; | |
411 | int fput_needed; | |
412 | ||
413 | if (pos < 0) | |
414 | return -EINVAL; | |
415 | ||
416 | file = fget_light(fd, &fput_needed); | |
417 | if (file) { | |
418 | ret = -ESPIPE; | |
419 | if (file->f_mode & FMODE_PREAD) | |
420 | ret = vfs_read(file, buf, count, &pos); | |
421 | fput_light(file, fput_needed); | |
422 | } | |
423 | ||
424 | return ret; | |
425 | } | |
6673e0c3 HC |
426 | #ifdef CONFIG_HAVE_SYSCALL_WRAPPERS |
427 | asmlinkage long SyS_pread64(long fd, long buf, long count, loff_t pos) | |
428 | { | |
429 | return SYSC_pread64((unsigned int) fd, (char __user *) buf, | |
430 | (size_t) count, pos); | |
431 | } | |
432 | SYSCALL_ALIAS(sys_pread64, SyS_pread64); | |
433 | #endif | |
1da177e4 | 434 | |
6673e0c3 HC |
435 | SYSCALL_DEFINE(pwrite64)(unsigned int fd, const char __user *buf, |
436 | size_t count, loff_t pos) | |
1da177e4 LT |
437 | { |
438 | struct file *file; | |
439 | ssize_t ret = -EBADF; | |
440 | int fput_needed; | |
441 | ||
442 | if (pos < 0) | |
443 | return -EINVAL; | |
444 | ||
445 | file = fget_light(fd, &fput_needed); | |
446 | if (file) { | |
447 | ret = -ESPIPE; | |
448 | if (file->f_mode & FMODE_PWRITE) | |
449 | ret = vfs_write(file, buf, count, &pos); | |
450 | fput_light(file, fput_needed); | |
451 | } | |
452 | ||
453 | return ret; | |
454 | } | |
6673e0c3 HC |
455 | #ifdef CONFIG_HAVE_SYSCALL_WRAPPERS |
456 | asmlinkage long SyS_pwrite64(long fd, long buf, long count, loff_t pos) | |
457 | { | |
458 | return SYSC_pwrite64((unsigned int) fd, (const char __user *) buf, | |
459 | (size_t) count, pos); | |
460 | } | |
461 | SYSCALL_ALIAS(sys_pwrite64, SyS_pwrite64); | |
462 | #endif | |
1da177e4 LT |
463 | |
464 | /* | |
465 | * Reduce an iovec's length in-place. Return the resulting number of segments | |
466 | */ | |
467 | unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to) | |
468 | { | |
469 | unsigned long seg = 0; | |
470 | size_t len = 0; | |
471 | ||
472 | while (seg < nr_segs) { | |
473 | seg++; | |
474 | if (len + iov->iov_len >= to) { | |
475 | iov->iov_len = to - len; | |
476 | break; | |
477 | } | |
478 | len += iov->iov_len; | |
479 | iov++; | |
480 | } | |
481 | return seg; | |
482 | } | |
19295529 | 483 | EXPORT_SYMBOL(iov_shorten); |
1da177e4 | 484 | |
ee0b3e67 BP |
485 | ssize_t do_sync_readv_writev(struct file *filp, const struct iovec *iov, |
486 | unsigned long nr_segs, size_t len, loff_t *ppos, iov_fn_t fn) | |
487 | { | |
488 | struct kiocb kiocb; | |
489 | ssize_t ret; | |
490 | ||
491 | init_sync_kiocb(&kiocb, filp); | |
492 | kiocb.ki_pos = *ppos; | |
493 | kiocb.ki_left = len; | |
494 | kiocb.ki_nbytes = len; | |
495 | ||
496 | for (;;) { | |
497 | ret = fn(&kiocb, iov, nr_segs, kiocb.ki_pos); | |
498 | if (ret != -EIOCBRETRY) | |
499 | break; | |
500 | wait_on_retry_sync_kiocb(&kiocb); | |
501 | } | |
502 | ||
503 | if (ret == -EIOCBQUEUED) | |
504 | ret = wait_on_sync_kiocb(&kiocb); | |
505 | *ppos = kiocb.ki_pos; | |
506 | return ret; | |
507 | } | |
508 | ||
509 | /* Do it by hand, with file-ops */ | |
510 | ssize_t do_loop_readv_writev(struct file *filp, struct iovec *iov, | |
511 | unsigned long nr_segs, loff_t *ppos, io_fn_t fn) | |
512 | { | |
513 | struct iovec *vector = iov; | |
514 | ssize_t ret = 0; | |
515 | ||
516 | while (nr_segs > 0) { | |
517 | void __user *base; | |
518 | size_t len; | |
519 | ssize_t nr; | |
520 | ||
521 | base = vector->iov_base; | |
522 | len = vector->iov_len; | |
523 | vector++; | |
524 | nr_segs--; | |
525 | ||
526 | nr = fn(filp, base, len, ppos); | |
527 | ||
528 | if (nr < 0) { | |
529 | if (!ret) | |
530 | ret = nr; | |
531 | break; | |
532 | } | |
533 | ret += nr; | |
534 | if (nr != len) | |
535 | break; | |
536 | } | |
537 | ||
538 | return ret; | |
539 | } | |
540 | ||
1da177e4 LT |
541 | /* A write operation does a read from user space and vice versa */ |
542 | #define vrfy_dir(type) ((type) == READ ? VERIFY_WRITE : VERIFY_READ) | |
543 | ||
eed4e51f BP |
544 | ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector, |
545 | unsigned long nr_segs, unsigned long fast_segs, | |
546 | struct iovec *fast_pointer, | |
547 | struct iovec **ret_pointer) | |
548 | { | |
549 | unsigned long seg; | |
550 | ssize_t ret; | |
551 | struct iovec *iov = fast_pointer; | |
552 | ||
553 | /* | |
554 | * SuS says "The readv() function *may* fail if the iovcnt argument | |
555 | * was less than or equal to 0, or greater than {IOV_MAX}. Linux has | |
556 | * traditionally returned zero for zero segments, so... | |
557 | */ | |
558 | if (nr_segs == 0) { | |
559 | ret = 0; | |
560 | goto out; | |
561 | } | |
562 | ||
563 | /* | |
564 | * First get the "struct iovec" from user memory and | |
565 | * verify all the pointers | |
566 | */ | |
567 | if (nr_segs > UIO_MAXIOV) { | |
568 | ret = -EINVAL; | |
569 | goto out; | |
570 | } | |
571 | if (nr_segs > fast_segs) { | |
572 | iov = kmalloc(nr_segs*sizeof(struct iovec), GFP_KERNEL); | |
573 | if (iov == NULL) { | |
574 | ret = -ENOMEM; | |
575 | goto out; | |
576 | } | |
577 | } | |
578 | if (copy_from_user(iov, uvector, nr_segs*sizeof(*uvector))) { | |
579 | ret = -EFAULT; | |
580 | goto out; | |
581 | } | |
582 | ||
583 | /* | |
584 | * According to the Single Unix Specification we should return EINVAL | |
585 | * if an element length is < 0 when cast to ssize_t or if the | |
586 | * total length would overflow the ssize_t return value of the | |
587 | * system call. | |
588 | */ | |
589 | ret = 0; | |
590 | for (seg = 0; seg < nr_segs; seg++) { | |
591 | void __user *buf = iov[seg].iov_base; | |
592 | ssize_t len = (ssize_t)iov[seg].iov_len; | |
593 | ||
594 | /* see if we we're about to use an invalid len or if | |
595 | * it's about to overflow ssize_t */ | |
596 | if (len < 0 || (ret + len < ret)) { | |
597 | ret = -EINVAL; | |
598 | goto out; | |
599 | } | |
600 | if (unlikely(!access_ok(vrfy_dir(type), buf, len))) { | |
601 | ret = -EFAULT; | |
602 | goto out; | |
603 | } | |
604 | ||
605 | ret += len; | |
606 | } | |
607 | out: | |
608 | *ret_pointer = iov; | |
609 | return ret; | |
610 | } | |
611 | ||
1da177e4 LT |
612 | static ssize_t do_readv_writev(int type, struct file *file, |
613 | const struct iovec __user * uvector, | |
614 | unsigned long nr_segs, loff_t *pos) | |
615 | { | |
1da177e4 LT |
616 | size_t tot_len; |
617 | struct iovec iovstack[UIO_FASTIOV]; | |
ee0b3e67 | 618 | struct iovec *iov = iovstack; |
1da177e4 | 619 | ssize_t ret; |
1da177e4 LT |
620 | io_fn_t fn; |
621 | iov_fn_t fnv; | |
622 | ||
eed4e51f BP |
623 | if (!file->f_op) { |
624 | ret = -EINVAL; | |
1da177e4 | 625 | goto out; |
1da177e4 | 626 | } |
1da177e4 | 627 | |
eed4e51f BP |
628 | ret = rw_copy_check_uvector(type, uvector, nr_segs, |
629 | ARRAY_SIZE(iovstack), iovstack, &iov); | |
630 | if (ret <= 0) | |
1da177e4 | 631 | goto out; |
1da177e4 | 632 | |
eed4e51f | 633 | tot_len = ret; |
1da177e4 | 634 | ret = rw_verify_area(type, file, pos, tot_len); |
e28cc715 | 635 | if (ret < 0) |
411b67b4 | 636 | goto out; |
1da177e4 LT |
637 | |
638 | fnv = NULL; | |
639 | if (type == READ) { | |
640 | fn = file->f_op->read; | |
ee0b3e67 | 641 | fnv = file->f_op->aio_read; |
1da177e4 LT |
642 | } else { |
643 | fn = (io_fn_t)file->f_op->write; | |
ee0b3e67 | 644 | fnv = file->f_op->aio_write; |
1da177e4 LT |
645 | } |
646 | ||
ee0b3e67 BP |
647 | if (fnv) |
648 | ret = do_sync_readv_writev(file, iov, nr_segs, tot_len, | |
649 | pos, fnv); | |
650 | else | |
651 | ret = do_loop_readv_writev(file, iov, nr_segs, pos, fn); | |
1da177e4 | 652 | |
1da177e4 LT |
653 | out: |
654 | if (iov != iovstack) | |
655 | kfree(iov); | |
0eeca283 RL |
656 | if ((ret + (type == READ)) > 0) { |
657 | if (type == READ) | |
0f7fc9e4 | 658 | fsnotify_access(file->f_path.dentry); |
0eeca283 | 659 | else |
0f7fc9e4 | 660 | fsnotify_modify(file->f_path.dentry); |
0eeca283 | 661 | } |
1da177e4 | 662 | return ret; |
1da177e4 LT |
663 | } |
664 | ||
665 | ssize_t vfs_readv(struct file *file, const struct iovec __user *vec, | |
666 | unsigned long vlen, loff_t *pos) | |
667 | { | |
668 | if (!(file->f_mode & FMODE_READ)) | |
669 | return -EBADF; | |
ee0b3e67 | 670 | if (!file->f_op || (!file->f_op->aio_read && !file->f_op->read)) |
1da177e4 LT |
671 | return -EINVAL; |
672 | ||
673 | return do_readv_writev(READ, file, vec, vlen, pos); | |
674 | } | |
675 | ||
676 | EXPORT_SYMBOL(vfs_readv); | |
677 | ||
678 | ssize_t vfs_writev(struct file *file, const struct iovec __user *vec, | |
679 | unsigned long vlen, loff_t *pos) | |
680 | { | |
681 | if (!(file->f_mode & FMODE_WRITE)) | |
682 | return -EBADF; | |
ee0b3e67 | 683 | if (!file->f_op || (!file->f_op->aio_write && !file->f_op->write)) |
1da177e4 LT |
684 | return -EINVAL; |
685 | ||
686 | return do_readv_writev(WRITE, file, vec, vlen, pos); | |
687 | } | |
688 | ||
689 | EXPORT_SYMBOL(vfs_writev); | |
690 | ||
2ed7c03e | 691 | asmlinkage long |
1da177e4 LT |
692 | sys_readv(unsigned long fd, const struct iovec __user *vec, unsigned long vlen) |
693 | { | |
694 | struct file *file; | |
695 | ssize_t ret = -EBADF; | |
696 | int fput_needed; | |
697 | ||
698 | file = fget_light(fd, &fput_needed); | |
699 | if (file) { | |
700 | loff_t pos = file_pos_read(file); | |
701 | ret = vfs_readv(file, vec, vlen, &pos); | |
702 | file_pos_write(file, pos); | |
703 | fput_light(file, fput_needed); | |
704 | } | |
705 | ||
706 | if (ret > 0) | |
4b98d11b AD |
707 | add_rchar(current, ret); |
708 | inc_syscr(current); | |
1da177e4 LT |
709 | return ret; |
710 | } | |
711 | ||
2ed7c03e | 712 | asmlinkage long |
1da177e4 LT |
713 | sys_writev(unsigned long fd, const struct iovec __user *vec, unsigned long vlen) |
714 | { | |
715 | struct file *file; | |
716 | ssize_t ret = -EBADF; | |
717 | int fput_needed; | |
718 | ||
719 | file = fget_light(fd, &fput_needed); | |
720 | if (file) { | |
721 | loff_t pos = file_pos_read(file); | |
722 | ret = vfs_writev(file, vec, vlen, &pos); | |
723 | file_pos_write(file, pos); | |
724 | fput_light(file, fput_needed); | |
725 | } | |
726 | ||
727 | if (ret > 0) | |
4b98d11b AD |
728 | add_wchar(current, ret); |
729 | inc_syscw(current); | |
1da177e4 LT |
730 | return ret; |
731 | } | |
732 | ||
733 | static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, | |
734 | size_t count, loff_t max) | |
735 | { | |
736 | struct file * in_file, * out_file; | |
737 | struct inode * in_inode, * out_inode; | |
738 | loff_t pos; | |
739 | ssize_t retval; | |
534f2aaa | 740 | int fput_needed_in, fput_needed_out, fl; |
1da177e4 LT |
741 | |
742 | /* | |
743 | * Get input file, and verify that it is ok.. | |
744 | */ | |
745 | retval = -EBADF; | |
746 | in_file = fget_light(in_fd, &fput_needed_in); | |
747 | if (!in_file) | |
748 | goto out; | |
749 | if (!(in_file->f_mode & FMODE_READ)) | |
750 | goto fput_in; | |
751 | retval = -EINVAL; | |
0f7fc9e4 | 752 | in_inode = in_file->f_path.dentry->d_inode; |
1da177e4 LT |
753 | if (!in_inode) |
754 | goto fput_in; | |
d96e6e71 | 755 | if (!in_file->f_op || !in_file->f_op->splice_read) |
1da177e4 LT |
756 | goto fput_in; |
757 | retval = -ESPIPE; | |
758 | if (!ppos) | |
759 | ppos = &in_file->f_pos; | |
760 | else | |
761 | if (!(in_file->f_mode & FMODE_PREAD)) | |
762 | goto fput_in; | |
763 | retval = rw_verify_area(READ, in_file, ppos, count); | |
e28cc715 | 764 | if (retval < 0) |
1da177e4 | 765 | goto fput_in; |
e28cc715 | 766 | count = retval; |
1da177e4 | 767 | |
1da177e4 LT |
768 | /* |
769 | * Get output file, and verify that it is ok.. | |
770 | */ | |
771 | retval = -EBADF; | |
772 | out_file = fget_light(out_fd, &fput_needed_out); | |
773 | if (!out_file) | |
774 | goto fput_in; | |
775 | if (!(out_file->f_mode & FMODE_WRITE)) | |
776 | goto fput_out; | |
777 | retval = -EINVAL; | |
778 | if (!out_file->f_op || !out_file->f_op->sendpage) | |
779 | goto fput_out; | |
0f7fc9e4 | 780 | out_inode = out_file->f_path.dentry->d_inode; |
1da177e4 | 781 | retval = rw_verify_area(WRITE, out_file, &out_file->f_pos, count); |
e28cc715 | 782 | if (retval < 0) |
1da177e4 | 783 | goto fput_out; |
e28cc715 | 784 | count = retval; |
1da177e4 | 785 | |
1da177e4 LT |
786 | if (!max) |
787 | max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes); | |
788 | ||
789 | pos = *ppos; | |
790 | retval = -EINVAL; | |
791 | if (unlikely(pos < 0)) | |
792 | goto fput_out; | |
793 | if (unlikely(pos + count > max)) { | |
794 | retval = -EOVERFLOW; | |
795 | if (pos >= max) | |
796 | goto fput_out; | |
797 | count = max - pos; | |
798 | } | |
799 | ||
d96e6e71 | 800 | fl = 0; |
534f2aaa | 801 | #if 0 |
d96e6e71 JA |
802 | /* |
803 | * We need to debate whether we can enable this or not. The | |
804 | * man page documents EAGAIN return for the output at least, | |
805 | * and the application is arguably buggy if it doesn't expect | |
806 | * EAGAIN on a non-blocking file descriptor. | |
807 | */ | |
808 | if (in_file->f_flags & O_NONBLOCK) | |
809 | fl = SPLICE_F_NONBLOCK; | |
534f2aaa | 810 | #endif |
d96e6e71 | 811 | retval = do_splice_direct(in_file, ppos, out_file, count, fl); |
1da177e4 LT |
812 | |
813 | if (retval > 0) { | |
4b98d11b AD |
814 | add_rchar(current, retval); |
815 | add_wchar(current, retval); | |
1da177e4 | 816 | } |
1da177e4 | 817 | |
4b98d11b AD |
818 | inc_syscr(current); |
819 | inc_syscw(current); | |
1da177e4 LT |
820 | if (*ppos > max) |
821 | retval = -EOVERFLOW; | |
822 | ||
823 | fput_out: | |
824 | fput_light(out_file, fput_needed_out); | |
825 | fput_in: | |
826 | fput_light(in_file, fput_needed_in); | |
827 | out: | |
828 | return retval; | |
829 | } | |
830 | ||
2ed7c03e | 831 | asmlinkage long sys_sendfile(int out_fd, int in_fd, off_t __user *offset, size_t count) |
1da177e4 LT |
832 | { |
833 | loff_t pos; | |
834 | off_t off; | |
835 | ssize_t ret; | |
836 | ||
837 | if (offset) { | |
838 | if (unlikely(get_user(off, offset))) | |
839 | return -EFAULT; | |
840 | pos = off; | |
841 | ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS); | |
842 | if (unlikely(put_user(pos, offset))) | |
843 | return -EFAULT; | |
844 | return ret; | |
845 | } | |
846 | ||
847 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
848 | } | |
849 | ||
2ed7c03e | 850 | asmlinkage long sys_sendfile64(int out_fd, int in_fd, loff_t __user *offset, size_t count) |
1da177e4 LT |
851 | { |
852 | loff_t pos; | |
853 | ssize_t ret; | |
854 | ||
855 | if (offset) { | |
856 | if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t)))) | |
857 | return -EFAULT; | |
858 | ret = do_sendfile(out_fd, in_fd, &pos, count, 0); | |
859 | if (unlikely(put_user(pos, offset))) | |
860 | return -EFAULT; | |
861 | return ret; | |
862 | } | |
863 | ||
864 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
865 | } |