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 | ||
003d7ab4 | 150 | SYSCALL_DEFINE3(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 | |
003d7ab4 HC |
174 | SYSCALL_DEFINE5(llseek, unsigned int, fd, unsigned long, offset_high, |
175 | unsigned long, offset_low, loff_t __user *, result, | |
176 | unsigned int, origin) | |
1da177e4 LT |
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 | 260 | kiocb.ki_left = len; |
61964eba | 261 | kiocb.ki_nbytes = len; |
027445c3 BP |
262 | |
263 | for (;;) { | |
264 | ret = filp->f_op->aio_read(&kiocb, &iov, 1, kiocb.ki_pos); | |
265 | if (ret != -EIOCBRETRY) | |
266 | break; | |
63e68809 | 267 | wait_on_retry_sync_kiocb(&kiocb); |
027445c3 | 268 | } |
63e68809 | 269 | |
1da177e4 LT |
270 | if (-EIOCBQUEUED == ret) |
271 | ret = wait_on_sync_kiocb(&kiocb); | |
272 | *ppos = kiocb.ki_pos; | |
273 | return ret; | |
274 | } | |
275 | ||
276 | EXPORT_SYMBOL(do_sync_read); | |
277 | ||
278 | ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos) | |
279 | { | |
280 | ssize_t ret; | |
281 | ||
282 | if (!(file->f_mode & FMODE_READ)) | |
283 | return -EBADF; | |
284 | if (!file->f_op || (!file->f_op->read && !file->f_op->aio_read)) | |
285 | return -EINVAL; | |
286 | if (unlikely(!access_ok(VERIFY_WRITE, buf, count))) | |
287 | return -EFAULT; | |
288 | ||
289 | ret = rw_verify_area(READ, file, pos, count); | |
e28cc715 LT |
290 | if (ret >= 0) { |
291 | count = ret; | |
c43e259c JM |
292 | if (file->f_op->read) |
293 | ret = file->f_op->read(file, buf, count, pos); | |
294 | else | |
295 | ret = do_sync_read(file, buf, count, pos); | |
296 | if (ret > 0) { | |
297 | fsnotify_access(file->f_path.dentry); | |
298 | add_rchar(current, ret); | |
1da177e4 | 299 | } |
c43e259c | 300 | inc_syscr(current); |
1da177e4 LT |
301 | } |
302 | ||
303 | return ret; | |
304 | } | |
305 | ||
306 | EXPORT_SYMBOL(vfs_read); | |
307 | ||
308 | ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos) | |
309 | { | |
027445c3 | 310 | struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = len }; |
1da177e4 LT |
311 | struct kiocb kiocb; |
312 | ssize_t ret; | |
313 | ||
314 | init_sync_kiocb(&kiocb, filp); | |
315 | kiocb.ki_pos = *ppos; | |
027445c3 | 316 | kiocb.ki_left = len; |
61964eba | 317 | kiocb.ki_nbytes = len; |
027445c3 BP |
318 | |
319 | for (;;) { | |
320 | ret = filp->f_op->aio_write(&kiocb, &iov, 1, kiocb.ki_pos); | |
321 | if (ret != -EIOCBRETRY) | |
322 | break; | |
63e68809 | 323 | wait_on_retry_sync_kiocb(&kiocb); |
027445c3 | 324 | } |
63e68809 | 325 | |
1da177e4 LT |
326 | if (-EIOCBQUEUED == ret) |
327 | ret = wait_on_sync_kiocb(&kiocb); | |
328 | *ppos = kiocb.ki_pos; | |
329 | return ret; | |
330 | } | |
331 | ||
332 | EXPORT_SYMBOL(do_sync_write); | |
333 | ||
334 | ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_t *pos) | |
335 | { | |
336 | ssize_t ret; | |
337 | ||
338 | if (!(file->f_mode & FMODE_WRITE)) | |
339 | return -EBADF; | |
340 | if (!file->f_op || (!file->f_op->write && !file->f_op->aio_write)) | |
341 | return -EINVAL; | |
342 | if (unlikely(!access_ok(VERIFY_READ, buf, count))) | |
343 | return -EFAULT; | |
344 | ||
345 | ret = rw_verify_area(WRITE, file, pos, count); | |
e28cc715 LT |
346 | if (ret >= 0) { |
347 | count = ret; | |
c43e259c JM |
348 | if (file->f_op->write) |
349 | ret = file->f_op->write(file, buf, count, pos); | |
350 | else | |
351 | ret = do_sync_write(file, buf, count, pos); | |
352 | if (ret > 0) { | |
353 | fsnotify_modify(file->f_path.dentry); | |
354 | add_wchar(current, ret); | |
1da177e4 | 355 | } |
c43e259c | 356 | inc_syscw(current); |
1da177e4 LT |
357 | } |
358 | ||
359 | return ret; | |
360 | } | |
361 | ||
362 | EXPORT_SYMBOL(vfs_write); | |
363 | ||
364 | static inline loff_t file_pos_read(struct file *file) | |
365 | { | |
366 | return file->f_pos; | |
367 | } | |
368 | ||
369 | static inline void file_pos_write(struct file *file, loff_t pos) | |
370 | { | |
371 | file->f_pos = pos; | |
372 | } | |
373 | ||
3cdad428 | 374 | SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count) |
1da177e4 LT |
375 | { |
376 | struct file *file; | |
377 | ssize_t ret = -EBADF; | |
378 | int fput_needed; | |
379 | ||
380 | file = fget_light(fd, &fput_needed); | |
381 | if (file) { | |
382 | loff_t pos = file_pos_read(file); | |
383 | ret = vfs_read(file, buf, count, &pos); | |
384 | file_pos_write(file, pos); | |
385 | fput_light(file, fput_needed); | |
386 | } | |
387 | ||
388 | return ret; | |
389 | } | |
1da177e4 | 390 | |
3cdad428 HC |
391 | SYSCALL_DEFINE3(write, unsigned int, fd, const char __user *, buf, |
392 | size_t, count) | |
1da177e4 LT |
393 | { |
394 | struct file *file; | |
395 | ssize_t ret = -EBADF; | |
396 | int fput_needed; | |
397 | ||
398 | file = fget_light(fd, &fput_needed); | |
399 | if (file) { | |
400 | loff_t pos = file_pos_read(file); | |
401 | ret = vfs_write(file, buf, count, &pos); | |
402 | file_pos_write(file, pos); | |
403 | fput_light(file, fput_needed); | |
404 | } | |
405 | ||
406 | return ret; | |
407 | } | |
408 | ||
6673e0c3 HC |
409 | SYSCALL_DEFINE(pread64)(unsigned int fd, char __user *buf, |
410 | size_t count, loff_t pos) | |
1da177e4 LT |
411 | { |
412 | struct file *file; | |
413 | ssize_t ret = -EBADF; | |
414 | int fput_needed; | |
415 | ||
416 | if (pos < 0) | |
417 | return -EINVAL; | |
418 | ||
419 | file = fget_light(fd, &fput_needed); | |
420 | if (file) { | |
421 | ret = -ESPIPE; | |
422 | if (file->f_mode & FMODE_PREAD) | |
423 | ret = vfs_read(file, buf, count, &pos); | |
424 | fput_light(file, fput_needed); | |
425 | } | |
426 | ||
427 | return ret; | |
428 | } | |
6673e0c3 HC |
429 | #ifdef CONFIG_HAVE_SYSCALL_WRAPPERS |
430 | asmlinkage long SyS_pread64(long fd, long buf, long count, loff_t pos) | |
431 | { | |
432 | return SYSC_pread64((unsigned int) fd, (char __user *) buf, | |
433 | (size_t) count, pos); | |
434 | } | |
435 | SYSCALL_ALIAS(sys_pread64, SyS_pread64); | |
436 | #endif | |
1da177e4 | 437 | |
6673e0c3 HC |
438 | SYSCALL_DEFINE(pwrite64)(unsigned int fd, const char __user *buf, |
439 | size_t count, loff_t pos) | |
1da177e4 LT |
440 | { |
441 | struct file *file; | |
442 | ssize_t ret = -EBADF; | |
443 | int fput_needed; | |
444 | ||
445 | if (pos < 0) | |
446 | return -EINVAL; | |
447 | ||
448 | file = fget_light(fd, &fput_needed); | |
449 | if (file) { | |
450 | ret = -ESPIPE; | |
451 | if (file->f_mode & FMODE_PWRITE) | |
452 | ret = vfs_write(file, buf, count, &pos); | |
453 | fput_light(file, fput_needed); | |
454 | } | |
455 | ||
456 | return ret; | |
457 | } | |
6673e0c3 HC |
458 | #ifdef CONFIG_HAVE_SYSCALL_WRAPPERS |
459 | asmlinkage long SyS_pwrite64(long fd, long buf, long count, loff_t pos) | |
460 | { | |
461 | return SYSC_pwrite64((unsigned int) fd, (const char __user *) buf, | |
462 | (size_t) count, pos); | |
463 | } | |
464 | SYSCALL_ALIAS(sys_pwrite64, SyS_pwrite64); | |
465 | #endif | |
1da177e4 LT |
466 | |
467 | /* | |
468 | * Reduce an iovec's length in-place. Return the resulting number of segments | |
469 | */ | |
470 | unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to) | |
471 | { | |
472 | unsigned long seg = 0; | |
473 | size_t len = 0; | |
474 | ||
475 | while (seg < nr_segs) { | |
476 | seg++; | |
477 | if (len + iov->iov_len >= to) { | |
478 | iov->iov_len = to - len; | |
479 | break; | |
480 | } | |
481 | len += iov->iov_len; | |
482 | iov++; | |
483 | } | |
484 | return seg; | |
485 | } | |
19295529 | 486 | EXPORT_SYMBOL(iov_shorten); |
1da177e4 | 487 | |
ee0b3e67 BP |
488 | ssize_t do_sync_readv_writev(struct file *filp, const struct iovec *iov, |
489 | unsigned long nr_segs, size_t len, loff_t *ppos, iov_fn_t fn) | |
490 | { | |
491 | struct kiocb kiocb; | |
492 | ssize_t ret; | |
493 | ||
494 | init_sync_kiocb(&kiocb, filp); | |
495 | kiocb.ki_pos = *ppos; | |
496 | kiocb.ki_left = len; | |
497 | kiocb.ki_nbytes = len; | |
498 | ||
499 | for (;;) { | |
500 | ret = fn(&kiocb, iov, nr_segs, kiocb.ki_pos); | |
501 | if (ret != -EIOCBRETRY) | |
502 | break; | |
503 | wait_on_retry_sync_kiocb(&kiocb); | |
504 | } | |
505 | ||
506 | if (ret == -EIOCBQUEUED) | |
507 | ret = wait_on_sync_kiocb(&kiocb); | |
508 | *ppos = kiocb.ki_pos; | |
509 | return ret; | |
510 | } | |
511 | ||
512 | /* Do it by hand, with file-ops */ | |
513 | ssize_t do_loop_readv_writev(struct file *filp, struct iovec *iov, | |
514 | unsigned long nr_segs, loff_t *ppos, io_fn_t fn) | |
515 | { | |
516 | struct iovec *vector = iov; | |
517 | ssize_t ret = 0; | |
518 | ||
519 | while (nr_segs > 0) { | |
520 | void __user *base; | |
521 | size_t len; | |
522 | ssize_t nr; | |
523 | ||
524 | base = vector->iov_base; | |
525 | len = vector->iov_len; | |
526 | vector++; | |
527 | nr_segs--; | |
528 | ||
529 | nr = fn(filp, base, len, ppos); | |
530 | ||
531 | if (nr < 0) { | |
532 | if (!ret) | |
533 | ret = nr; | |
534 | break; | |
535 | } | |
536 | ret += nr; | |
537 | if (nr != len) | |
538 | break; | |
539 | } | |
540 | ||
541 | return ret; | |
542 | } | |
543 | ||
1da177e4 LT |
544 | /* A write operation does a read from user space and vice versa */ |
545 | #define vrfy_dir(type) ((type) == READ ? VERIFY_WRITE : VERIFY_READ) | |
546 | ||
eed4e51f BP |
547 | ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector, |
548 | unsigned long nr_segs, unsigned long fast_segs, | |
549 | struct iovec *fast_pointer, | |
550 | struct iovec **ret_pointer) | |
551 | { | |
552 | unsigned long seg; | |
553 | ssize_t ret; | |
554 | struct iovec *iov = fast_pointer; | |
555 | ||
556 | /* | |
557 | * SuS says "The readv() function *may* fail if the iovcnt argument | |
558 | * was less than or equal to 0, or greater than {IOV_MAX}. Linux has | |
559 | * traditionally returned zero for zero segments, so... | |
560 | */ | |
561 | if (nr_segs == 0) { | |
562 | ret = 0; | |
563 | goto out; | |
564 | } | |
565 | ||
566 | /* | |
567 | * First get the "struct iovec" from user memory and | |
568 | * verify all the pointers | |
569 | */ | |
570 | if (nr_segs > UIO_MAXIOV) { | |
571 | ret = -EINVAL; | |
572 | goto out; | |
573 | } | |
574 | if (nr_segs > fast_segs) { | |
575 | iov = kmalloc(nr_segs*sizeof(struct iovec), GFP_KERNEL); | |
576 | if (iov == NULL) { | |
577 | ret = -ENOMEM; | |
578 | goto out; | |
579 | } | |
580 | } | |
581 | if (copy_from_user(iov, uvector, nr_segs*sizeof(*uvector))) { | |
582 | ret = -EFAULT; | |
583 | goto out; | |
584 | } | |
585 | ||
586 | /* | |
587 | * According to the Single Unix Specification we should return EINVAL | |
588 | * if an element length is < 0 when cast to ssize_t or if the | |
589 | * total length would overflow the ssize_t return value of the | |
590 | * system call. | |
591 | */ | |
592 | ret = 0; | |
593 | for (seg = 0; seg < nr_segs; seg++) { | |
594 | void __user *buf = iov[seg].iov_base; | |
595 | ssize_t len = (ssize_t)iov[seg].iov_len; | |
596 | ||
597 | /* see if we we're about to use an invalid len or if | |
598 | * it's about to overflow ssize_t */ | |
599 | if (len < 0 || (ret + len < ret)) { | |
600 | ret = -EINVAL; | |
601 | goto out; | |
602 | } | |
603 | if (unlikely(!access_ok(vrfy_dir(type), buf, len))) { | |
604 | ret = -EFAULT; | |
605 | goto out; | |
606 | } | |
607 | ||
608 | ret += len; | |
609 | } | |
610 | out: | |
611 | *ret_pointer = iov; | |
612 | return ret; | |
613 | } | |
614 | ||
1da177e4 LT |
615 | static ssize_t do_readv_writev(int type, struct file *file, |
616 | const struct iovec __user * uvector, | |
617 | unsigned long nr_segs, loff_t *pos) | |
618 | { | |
1da177e4 LT |
619 | size_t tot_len; |
620 | struct iovec iovstack[UIO_FASTIOV]; | |
ee0b3e67 | 621 | struct iovec *iov = iovstack; |
1da177e4 | 622 | ssize_t ret; |
1da177e4 LT |
623 | io_fn_t fn; |
624 | iov_fn_t fnv; | |
625 | ||
eed4e51f BP |
626 | if (!file->f_op) { |
627 | ret = -EINVAL; | |
1da177e4 | 628 | goto out; |
1da177e4 | 629 | } |
1da177e4 | 630 | |
eed4e51f BP |
631 | ret = rw_copy_check_uvector(type, uvector, nr_segs, |
632 | ARRAY_SIZE(iovstack), iovstack, &iov); | |
633 | if (ret <= 0) | |
1da177e4 | 634 | goto out; |
1da177e4 | 635 | |
eed4e51f | 636 | tot_len = ret; |
1da177e4 | 637 | ret = rw_verify_area(type, file, pos, tot_len); |
e28cc715 | 638 | if (ret < 0) |
411b67b4 | 639 | goto out; |
1da177e4 LT |
640 | |
641 | fnv = NULL; | |
642 | if (type == READ) { | |
643 | fn = file->f_op->read; | |
ee0b3e67 | 644 | fnv = file->f_op->aio_read; |
1da177e4 LT |
645 | } else { |
646 | fn = (io_fn_t)file->f_op->write; | |
ee0b3e67 | 647 | fnv = file->f_op->aio_write; |
1da177e4 LT |
648 | } |
649 | ||
ee0b3e67 BP |
650 | if (fnv) |
651 | ret = do_sync_readv_writev(file, iov, nr_segs, tot_len, | |
652 | pos, fnv); | |
653 | else | |
654 | ret = do_loop_readv_writev(file, iov, nr_segs, pos, fn); | |
1da177e4 | 655 | |
1da177e4 LT |
656 | out: |
657 | if (iov != iovstack) | |
658 | kfree(iov); | |
0eeca283 RL |
659 | if ((ret + (type == READ)) > 0) { |
660 | if (type == READ) | |
0f7fc9e4 | 661 | fsnotify_access(file->f_path.dentry); |
0eeca283 | 662 | else |
0f7fc9e4 | 663 | fsnotify_modify(file->f_path.dentry); |
0eeca283 | 664 | } |
1da177e4 | 665 | return ret; |
1da177e4 LT |
666 | } |
667 | ||
668 | ssize_t vfs_readv(struct file *file, const struct iovec __user *vec, | |
669 | unsigned long vlen, loff_t *pos) | |
670 | { | |
671 | if (!(file->f_mode & FMODE_READ)) | |
672 | return -EBADF; | |
ee0b3e67 | 673 | if (!file->f_op || (!file->f_op->aio_read && !file->f_op->read)) |
1da177e4 LT |
674 | return -EINVAL; |
675 | ||
676 | return do_readv_writev(READ, file, vec, vlen, pos); | |
677 | } | |
678 | ||
679 | EXPORT_SYMBOL(vfs_readv); | |
680 | ||
681 | ssize_t vfs_writev(struct file *file, const struct iovec __user *vec, | |
682 | unsigned long vlen, loff_t *pos) | |
683 | { | |
684 | if (!(file->f_mode & FMODE_WRITE)) | |
685 | return -EBADF; | |
ee0b3e67 | 686 | if (!file->f_op || (!file->f_op->aio_write && !file->f_op->write)) |
1da177e4 LT |
687 | return -EINVAL; |
688 | ||
689 | return do_readv_writev(WRITE, file, vec, vlen, pos); | |
690 | } | |
691 | ||
692 | EXPORT_SYMBOL(vfs_writev); | |
693 | ||
3cdad428 HC |
694 | SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec, |
695 | unsigned long, vlen) | |
1da177e4 LT |
696 | { |
697 | struct file *file; | |
698 | ssize_t ret = -EBADF; | |
699 | int fput_needed; | |
700 | ||
701 | file = fget_light(fd, &fput_needed); | |
702 | if (file) { | |
703 | loff_t pos = file_pos_read(file); | |
704 | ret = vfs_readv(file, vec, vlen, &pos); | |
705 | file_pos_write(file, pos); | |
706 | fput_light(file, fput_needed); | |
707 | } | |
708 | ||
709 | if (ret > 0) | |
4b98d11b AD |
710 | add_rchar(current, ret); |
711 | inc_syscr(current); | |
1da177e4 LT |
712 | return ret; |
713 | } | |
714 | ||
3cdad428 HC |
715 | SYSCALL_DEFINE3(writev, unsigned long, fd, const struct iovec __user *, vec, |
716 | unsigned long, vlen) | |
1da177e4 LT |
717 | { |
718 | struct file *file; | |
719 | ssize_t ret = -EBADF; | |
720 | int fput_needed; | |
721 | ||
722 | file = fget_light(fd, &fput_needed); | |
723 | if (file) { | |
724 | loff_t pos = file_pos_read(file); | |
725 | ret = vfs_writev(file, vec, vlen, &pos); | |
726 | file_pos_write(file, pos); | |
727 | fput_light(file, fput_needed); | |
728 | } | |
729 | ||
730 | if (ret > 0) | |
4b98d11b AD |
731 | add_wchar(current, ret); |
732 | inc_syscw(current); | |
1da177e4 LT |
733 | return ret; |
734 | } | |
735 | ||
601cc11d LT |
736 | static inline loff_t pos_from_hilo(unsigned long high, unsigned long low) |
737 | { | |
738 | #define HALF_LONG_BITS (BITS_PER_LONG / 2) | |
739 | return (((loff_t)high << HALF_LONG_BITS) << HALF_LONG_BITS) | low; | |
740 | } | |
741 | ||
f3554f4b | 742 | SYSCALL_DEFINE5(preadv, unsigned long, fd, const struct iovec __user *, vec, |
601cc11d | 743 | unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h) |
f3554f4b | 744 | { |
601cc11d | 745 | loff_t pos = pos_from_hilo(pos_h, pos_l); |
f3554f4b GH |
746 | struct file *file; |
747 | ssize_t ret = -EBADF; | |
748 | int fput_needed; | |
749 | ||
750 | if (pos < 0) | |
751 | return -EINVAL; | |
752 | ||
753 | file = fget_light(fd, &fput_needed); | |
754 | if (file) { | |
755 | ret = -ESPIPE; | |
756 | if (file->f_mode & FMODE_PREAD) | |
757 | ret = vfs_readv(file, vec, vlen, &pos); | |
758 | fput_light(file, fput_needed); | |
759 | } | |
760 | ||
761 | if (ret > 0) | |
762 | add_rchar(current, ret); | |
763 | inc_syscr(current); | |
764 | return ret; | |
765 | } | |
766 | ||
767 | SYSCALL_DEFINE5(pwritev, unsigned long, fd, const struct iovec __user *, vec, | |
601cc11d | 768 | unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h) |
f3554f4b | 769 | { |
601cc11d | 770 | loff_t pos = pos_from_hilo(pos_h, pos_l); |
f3554f4b GH |
771 | struct file *file; |
772 | ssize_t ret = -EBADF; | |
773 | int fput_needed; | |
774 | ||
775 | if (pos < 0) | |
776 | return -EINVAL; | |
777 | ||
778 | file = fget_light(fd, &fput_needed); | |
779 | if (file) { | |
780 | ret = -ESPIPE; | |
781 | if (file->f_mode & FMODE_PWRITE) | |
782 | ret = vfs_writev(file, vec, vlen, &pos); | |
783 | fput_light(file, fput_needed); | |
784 | } | |
785 | ||
786 | if (ret > 0) | |
787 | add_wchar(current, ret); | |
788 | inc_syscw(current); | |
789 | return ret; | |
790 | } | |
791 | ||
1da177e4 LT |
792 | static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, |
793 | size_t count, loff_t max) | |
794 | { | |
795 | struct file * in_file, * out_file; | |
796 | struct inode * in_inode, * out_inode; | |
797 | loff_t pos; | |
798 | ssize_t retval; | |
534f2aaa | 799 | int fput_needed_in, fput_needed_out, fl; |
1da177e4 LT |
800 | |
801 | /* | |
802 | * Get input file, and verify that it is ok.. | |
803 | */ | |
804 | retval = -EBADF; | |
805 | in_file = fget_light(in_fd, &fput_needed_in); | |
806 | if (!in_file) | |
807 | goto out; | |
808 | if (!(in_file->f_mode & FMODE_READ)) | |
809 | goto fput_in; | |
1da177e4 LT |
810 | retval = -ESPIPE; |
811 | if (!ppos) | |
812 | ppos = &in_file->f_pos; | |
813 | else | |
814 | if (!(in_file->f_mode & FMODE_PREAD)) | |
815 | goto fput_in; | |
816 | retval = rw_verify_area(READ, in_file, ppos, count); | |
e28cc715 | 817 | if (retval < 0) |
1da177e4 | 818 | goto fput_in; |
e28cc715 | 819 | count = retval; |
1da177e4 | 820 | |
1da177e4 LT |
821 | /* |
822 | * Get output file, and verify that it is ok.. | |
823 | */ | |
824 | retval = -EBADF; | |
825 | out_file = fget_light(out_fd, &fput_needed_out); | |
826 | if (!out_file) | |
827 | goto fput_in; | |
828 | if (!(out_file->f_mode & FMODE_WRITE)) | |
829 | goto fput_out; | |
830 | retval = -EINVAL; | |
6818173b | 831 | in_inode = in_file->f_path.dentry->d_inode; |
0f7fc9e4 | 832 | out_inode = out_file->f_path.dentry->d_inode; |
1da177e4 | 833 | retval = rw_verify_area(WRITE, out_file, &out_file->f_pos, count); |
e28cc715 | 834 | if (retval < 0) |
1da177e4 | 835 | goto fput_out; |
e28cc715 | 836 | count = retval; |
1da177e4 | 837 | |
1da177e4 LT |
838 | if (!max) |
839 | max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes); | |
840 | ||
841 | pos = *ppos; | |
1da177e4 LT |
842 | if (unlikely(pos + count > max)) { |
843 | retval = -EOVERFLOW; | |
844 | if (pos >= max) | |
845 | goto fput_out; | |
846 | count = max - pos; | |
847 | } | |
848 | ||
d96e6e71 | 849 | fl = 0; |
534f2aaa | 850 | #if 0 |
d96e6e71 JA |
851 | /* |
852 | * We need to debate whether we can enable this or not. The | |
853 | * man page documents EAGAIN return for the output at least, | |
854 | * and the application is arguably buggy if it doesn't expect | |
855 | * EAGAIN on a non-blocking file descriptor. | |
856 | */ | |
857 | if (in_file->f_flags & O_NONBLOCK) | |
858 | fl = SPLICE_F_NONBLOCK; | |
534f2aaa | 859 | #endif |
d96e6e71 | 860 | retval = do_splice_direct(in_file, ppos, out_file, count, fl); |
1da177e4 LT |
861 | |
862 | if (retval > 0) { | |
4b98d11b AD |
863 | add_rchar(current, retval); |
864 | add_wchar(current, retval); | |
1da177e4 | 865 | } |
1da177e4 | 866 | |
4b98d11b AD |
867 | inc_syscr(current); |
868 | inc_syscw(current); | |
1da177e4 LT |
869 | if (*ppos > max) |
870 | retval = -EOVERFLOW; | |
871 | ||
872 | fput_out: | |
873 | fput_light(out_file, fput_needed_out); | |
874 | fput_in: | |
875 | fput_light(in_file, fput_needed_in); | |
876 | out: | |
877 | return retval; | |
878 | } | |
879 | ||
002c8976 | 880 | SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, off_t __user *, offset, size_t, count) |
1da177e4 LT |
881 | { |
882 | loff_t pos; | |
883 | off_t off; | |
884 | ssize_t ret; | |
885 | ||
886 | if (offset) { | |
887 | if (unlikely(get_user(off, offset))) | |
888 | return -EFAULT; | |
889 | pos = off; | |
890 | ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS); | |
891 | if (unlikely(put_user(pos, offset))) | |
892 | return -EFAULT; | |
893 | return ret; | |
894 | } | |
895 | ||
896 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
897 | } | |
898 | ||
002c8976 | 899 | SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, loff_t __user *, offset, size_t, count) |
1da177e4 LT |
900 | { |
901 | loff_t pos; | |
902 | ssize_t ret; | |
903 | ||
904 | if (offset) { | |
905 | if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t)))) | |
906 | return -EFAULT; | |
907 | ret = do_sendfile(out_fd, in_fd, &pos, count, 0); | |
908 | if (unlikely(put_user(pos, offset))) | |
909 | return -EFAULT; | |
910 | return ret; | |
911 | } | |
912 | ||
913 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
914 | } |