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> | |
a27bb332 | 12 | #include <linux/aio.h> |
0eeca283 | 13 | #include <linux/fsnotify.h> |
1da177e4 | 14 | #include <linux/security.h> |
630d9c47 | 15 | #include <linux/export.h> |
1da177e4 | 16 | #include <linux/syscalls.h> |
e28cc715 | 17 | #include <linux/pagemap.h> |
d6b29d7c | 18 | #include <linux/splice.h> |
561c6731 | 19 | #include <linux/compat.h> |
06ae43f3 | 20 | #include "internal.h" |
1da177e4 LT |
21 | |
22 | #include <asm/uaccess.h> | |
23 | #include <asm/unistd.h> | |
24 | ||
c0bd14af AV |
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 | ||
4b6f5d20 | 29 | const struct file_operations generic_ro_fops = { |
1da177e4 | 30 | .llseek = generic_file_llseek, |
543ade1f BP |
31 | .read = do_sync_read, |
32 | .aio_read = generic_file_aio_read, | |
1da177e4 | 33 | .mmap = generic_file_readonly_mmap, |
534f2aaa | 34 | .splice_read = generic_file_splice_read, |
1da177e4 LT |
35 | }; |
36 | ||
37 | EXPORT_SYMBOL(generic_ro_fops); | |
38 | ||
cccb5a1e | 39 | static inline int unsigned_offsets(struct file *file) |
4a3956c7 | 40 | { |
cccb5a1e | 41 | return file->f_mode & FMODE_UNSIGNED_OFFSET; |
4a3956c7 KH |
42 | } |
43 | ||
46a1c2c7 JL |
44 | /** |
45 | * vfs_setpos - update the file offset for lseek | |
46 | * @file: file structure in question | |
47 | * @offset: file offset to seek to | |
48 | * @maxsize: maximum file size | |
49 | * | |
50 | * This is a low-level filesystem helper for updating the file offset to | |
51 | * the value specified by @offset if the given offset is valid and it is | |
52 | * not equal to the current file offset. | |
53 | * | |
54 | * Return the specified offset on success and -EINVAL on invalid offset. | |
55 | */ | |
56 | loff_t vfs_setpos(struct file *file, loff_t offset, loff_t maxsize) | |
ef3d0fd2 AK |
57 | { |
58 | if (offset < 0 && !unsigned_offsets(file)) | |
59 | return -EINVAL; | |
60 | if (offset > maxsize) | |
61 | return -EINVAL; | |
62 | ||
63 | if (offset != file->f_pos) { | |
64 | file->f_pos = offset; | |
65 | file->f_version = 0; | |
66 | } | |
67 | return offset; | |
68 | } | |
46a1c2c7 | 69 | EXPORT_SYMBOL(vfs_setpos); |
ef3d0fd2 | 70 | |
3a8cff4f | 71 | /** |
5760495a | 72 | * generic_file_llseek_size - generic llseek implementation for regular files |
3a8cff4f CH |
73 | * @file: file structure to seek on |
74 | * @offset: file offset to seek to | |
965c8e59 | 75 | * @whence: type of seek |
e8b96eb5 ES |
76 | * @size: max size of this file in file system |
77 | * @eof: offset used for SEEK_END position | |
3a8cff4f | 78 | * |
5760495a | 79 | * This is a variant of generic_file_llseek that allows passing in a custom |
e8b96eb5 | 80 | * maximum file size and a custom EOF position, for e.g. hashed directories |
ef3d0fd2 AK |
81 | * |
82 | * Synchronization: | |
5760495a | 83 | * SEEK_SET and SEEK_END are unsynchronized (but atomic on 64bit platforms) |
ef3d0fd2 AK |
84 | * SEEK_CUR is synchronized against other SEEK_CURs, but not read/writes. |
85 | * read/writes behave like SEEK_SET against seeks. | |
3a8cff4f | 86 | */ |
9465efc9 | 87 | loff_t |
965c8e59 | 88 | generic_file_llseek_size(struct file *file, loff_t offset, int whence, |
e8b96eb5 | 89 | loff_t maxsize, loff_t eof) |
1da177e4 | 90 | { |
965c8e59 | 91 | switch (whence) { |
3a8cff4f | 92 | case SEEK_END: |
e8b96eb5 | 93 | offset += eof; |
3a8cff4f CH |
94 | break; |
95 | case SEEK_CUR: | |
5b6f1eb9 AK |
96 | /* |
97 | * Here we special-case the lseek(fd, 0, SEEK_CUR) | |
98 | * position-querying operation. Avoid rewriting the "same" | |
99 | * f_pos value back to the file because a concurrent read(), | |
100 | * write() or lseek() might have altered it | |
101 | */ | |
102 | if (offset == 0) | |
103 | return file->f_pos; | |
ef3d0fd2 AK |
104 | /* |
105 | * f_lock protects against read/modify/write race with other | |
106 | * SEEK_CURs. Note that parallel writes and reads behave | |
107 | * like SEEK_SET. | |
108 | */ | |
109 | spin_lock(&file->f_lock); | |
46a1c2c7 | 110 | offset = vfs_setpos(file, file->f_pos + offset, maxsize); |
ef3d0fd2 AK |
111 | spin_unlock(&file->f_lock); |
112 | return offset; | |
982d8165 JB |
113 | case SEEK_DATA: |
114 | /* | |
115 | * In the generic case the entire file is data, so as long as | |
116 | * offset isn't at the end of the file then the offset is data. | |
117 | */ | |
e8b96eb5 | 118 | if (offset >= eof) |
982d8165 JB |
119 | return -ENXIO; |
120 | break; | |
121 | case SEEK_HOLE: | |
122 | /* | |
123 | * There is a virtual hole at the end of the file, so as long as | |
124 | * offset isn't i_size or larger, return i_size. | |
125 | */ | |
e8b96eb5 | 126 | if (offset >= eof) |
982d8165 | 127 | return -ENXIO; |
e8b96eb5 | 128 | offset = eof; |
982d8165 | 129 | break; |
1da177e4 | 130 | } |
3a8cff4f | 131 | |
46a1c2c7 | 132 | return vfs_setpos(file, offset, maxsize); |
5760495a AK |
133 | } |
134 | EXPORT_SYMBOL(generic_file_llseek_size); | |
135 | ||
136 | /** | |
137 | * generic_file_llseek - generic llseek implementation for regular files | |
138 | * @file: file structure to seek on | |
139 | * @offset: file offset to seek to | |
965c8e59 | 140 | * @whence: type of seek |
5760495a AK |
141 | * |
142 | * This is a generic implemenation of ->llseek useable for all normal local | |
143 | * filesystems. It just updates the file offset to the value specified by | |
546ae2d2 | 144 | * @offset and @whence. |
5760495a | 145 | */ |
965c8e59 | 146 | loff_t generic_file_llseek(struct file *file, loff_t offset, int whence) |
5760495a AK |
147 | { |
148 | struct inode *inode = file->f_mapping->host; | |
149 | ||
965c8e59 | 150 | return generic_file_llseek_size(file, offset, whence, |
e8b96eb5 ES |
151 | inode->i_sb->s_maxbytes, |
152 | i_size_read(inode)); | |
1da177e4 | 153 | } |
9465efc9 | 154 | EXPORT_SYMBOL(generic_file_llseek); |
1da177e4 | 155 | |
1bf9d14d AV |
156 | /** |
157 | * fixed_size_llseek - llseek implementation for fixed-sized devices | |
158 | * @file: file structure to seek on | |
159 | * @offset: file offset to seek to | |
160 | * @whence: type of seek | |
161 | * @size: size of the file | |
162 | * | |
163 | */ | |
164 | loff_t fixed_size_llseek(struct file *file, loff_t offset, int whence, loff_t size) | |
165 | { | |
166 | switch (whence) { | |
167 | case SEEK_SET: case SEEK_CUR: case SEEK_END: | |
168 | return generic_file_llseek_size(file, offset, whence, | |
169 | size, size); | |
170 | default: | |
171 | return -EINVAL; | |
172 | } | |
173 | } | |
174 | EXPORT_SYMBOL(fixed_size_llseek); | |
175 | ||
ae6afc3f B |
176 | /** |
177 | * noop_llseek - No Operation Performed llseek implementation | |
178 | * @file: file structure to seek on | |
179 | * @offset: file offset to seek to | |
965c8e59 | 180 | * @whence: type of seek |
ae6afc3f B |
181 | * |
182 | * This is an implementation of ->llseek useable for the rare special case when | |
183 | * userspace expects the seek to succeed but the (device) file is actually not | |
184 | * able to perform the seek. In this case you use noop_llseek() instead of | |
185 | * falling back to the default implementation of ->llseek. | |
186 | */ | |
965c8e59 | 187 | loff_t noop_llseek(struct file *file, loff_t offset, int whence) |
ae6afc3f B |
188 | { |
189 | return file->f_pos; | |
190 | } | |
191 | EXPORT_SYMBOL(noop_llseek); | |
192 | ||
965c8e59 | 193 | loff_t no_llseek(struct file *file, loff_t offset, int whence) |
1da177e4 LT |
194 | { |
195 | return -ESPIPE; | |
196 | } | |
197 | EXPORT_SYMBOL(no_llseek); | |
198 | ||
965c8e59 | 199 | loff_t default_llseek(struct file *file, loff_t offset, int whence) |
1da177e4 | 200 | { |
496ad9aa | 201 | struct inode *inode = file_inode(file); |
16abef0e | 202 | loff_t retval; |
1da177e4 | 203 | |
982d8165 | 204 | mutex_lock(&inode->i_mutex); |
965c8e59 | 205 | switch (whence) { |
7b8e8924 | 206 | case SEEK_END: |
982d8165 | 207 | offset += i_size_read(inode); |
1da177e4 | 208 | break; |
7b8e8924 | 209 | case SEEK_CUR: |
5b6f1eb9 AK |
210 | if (offset == 0) { |
211 | retval = file->f_pos; | |
212 | goto out; | |
213 | } | |
1da177e4 | 214 | offset += file->f_pos; |
982d8165 JB |
215 | break; |
216 | case SEEK_DATA: | |
217 | /* | |
218 | * In the generic case the entire file is data, so as | |
219 | * long as offset isn't at the end of the file then the | |
220 | * offset is data. | |
221 | */ | |
bacb2d81 DC |
222 | if (offset >= inode->i_size) { |
223 | retval = -ENXIO; | |
224 | goto out; | |
225 | } | |
982d8165 JB |
226 | break; |
227 | case SEEK_HOLE: | |
228 | /* | |
229 | * There is a virtual hole at the end of the file, so | |
230 | * as long as offset isn't i_size or larger, return | |
231 | * i_size. | |
232 | */ | |
bacb2d81 DC |
233 | if (offset >= inode->i_size) { |
234 | retval = -ENXIO; | |
235 | goto out; | |
236 | } | |
982d8165 JB |
237 | offset = inode->i_size; |
238 | break; | |
1da177e4 LT |
239 | } |
240 | retval = -EINVAL; | |
cccb5a1e | 241 | if (offset >= 0 || unsigned_offsets(file)) { |
1da177e4 LT |
242 | if (offset != file->f_pos) { |
243 | file->f_pos = offset; | |
244 | file->f_version = 0; | |
245 | } | |
246 | retval = offset; | |
247 | } | |
5b6f1eb9 | 248 | out: |
982d8165 | 249 | mutex_unlock(&inode->i_mutex); |
1da177e4 LT |
250 | return retval; |
251 | } | |
252 | EXPORT_SYMBOL(default_llseek); | |
253 | ||
965c8e59 | 254 | loff_t vfs_llseek(struct file *file, loff_t offset, int whence) |
1da177e4 LT |
255 | { |
256 | loff_t (*fn)(struct file *, loff_t, int); | |
257 | ||
258 | fn = no_llseek; | |
259 | if (file->f_mode & FMODE_LSEEK) { | |
72c2d531 | 260 | if (file->f_op->llseek) |
1da177e4 LT |
261 | fn = file->f_op->llseek; |
262 | } | |
965c8e59 | 263 | return fn(file, offset, whence); |
1da177e4 LT |
264 | } |
265 | EXPORT_SYMBOL(vfs_llseek); | |
266 | ||
9c225f26 LT |
267 | static inline struct fd fdget_pos(int fd) |
268 | { | |
bd2a31d5 | 269 | return __to_fd(__fdget_pos(fd)); |
9c225f26 LT |
270 | } |
271 | ||
272 | static inline void fdput_pos(struct fd f) | |
273 | { | |
274 | if (f.flags & FDPUT_POS_UNLOCK) | |
275 | mutex_unlock(&f.file->f_pos_lock); | |
276 | fdput(f); | |
277 | } | |
278 | ||
965c8e59 | 279 | SYSCALL_DEFINE3(lseek, unsigned int, fd, off_t, offset, unsigned int, whence) |
1da177e4 LT |
280 | { |
281 | off_t retval; | |
9c225f26 | 282 | struct fd f = fdget_pos(fd); |
2903ff01 AV |
283 | if (!f.file) |
284 | return -EBADF; | |
1da177e4 LT |
285 | |
286 | retval = -EINVAL; | |
965c8e59 AM |
287 | if (whence <= SEEK_MAX) { |
288 | loff_t res = vfs_llseek(f.file, offset, whence); | |
1da177e4 LT |
289 | retval = res; |
290 | if (res != (loff_t)retval) | |
291 | retval = -EOVERFLOW; /* LFS: should only happen on 32 bit platforms */ | |
292 | } | |
9c225f26 | 293 | fdput_pos(f); |
1da177e4 LT |
294 | return retval; |
295 | } | |
296 | ||
561c6731 AV |
297 | #ifdef CONFIG_COMPAT |
298 | COMPAT_SYSCALL_DEFINE3(lseek, unsigned int, fd, compat_off_t, offset, unsigned int, whence) | |
299 | { | |
300 | return sys_lseek(fd, offset, whence); | |
301 | } | |
302 | #endif | |
303 | ||
1da177e4 | 304 | #ifdef __ARCH_WANT_SYS_LLSEEK |
003d7ab4 HC |
305 | SYSCALL_DEFINE5(llseek, unsigned int, fd, unsigned long, offset_high, |
306 | unsigned long, offset_low, loff_t __user *, result, | |
965c8e59 | 307 | unsigned int, whence) |
1da177e4 LT |
308 | { |
309 | int retval; | |
d7a15f8d | 310 | struct fd f = fdget_pos(fd); |
1da177e4 | 311 | loff_t offset; |
1da177e4 | 312 | |
2903ff01 AV |
313 | if (!f.file) |
314 | return -EBADF; | |
1da177e4 LT |
315 | |
316 | retval = -EINVAL; | |
965c8e59 | 317 | if (whence > SEEK_MAX) |
1da177e4 LT |
318 | goto out_putf; |
319 | ||
2903ff01 | 320 | offset = vfs_llseek(f.file, ((loff_t) offset_high << 32) | offset_low, |
965c8e59 | 321 | whence); |
1da177e4 LT |
322 | |
323 | retval = (int)offset; | |
324 | if (offset >= 0) { | |
325 | retval = -EFAULT; | |
326 | if (!copy_to_user(result, &offset, sizeof(offset))) | |
327 | retval = 0; | |
328 | } | |
329 | out_putf: | |
d7a15f8d | 330 | fdput_pos(f); |
1da177e4 LT |
331 | return retval; |
332 | } | |
333 | #endif | |
334 | ||
e28cc715 LT |
335 | /* |
336 | * rw_verify_area doesn't like huge counts. We limit | |
337 | * them to something that fits in "int" so that others | |
338 | * won't have to do range checks all the time. | |
339 | */ | |
68d70d03 | 340 | int rw_verify_area(int read_write, struct file *file, const loff_t *ppos, size_t count) |
1da177e4 LT |
341 | { |
342 | struct inode *inode; | |
343 | loff_t pos; | |
c43e259c | 344 | int retval = -EINVAL; |
1da177e4 | 345 | |
496ad9aa | 346 | inode = file_inode(file); |
e28cc715 | 347 | if (unlikely((ssize_t) count < 0)) |
c43e259c | 348 | return retval; |
1da177e4 | 349 | pos = *ppos; |
cccb5a1e AV |
350 | if (unlikely(pos < 0)) { |
351 | if (!unsigned_offsets(file)) | |
352 | return retval; | |
353 | if (count >= -pos) /* both values are in 0..LLONG_MAX */ | |
354 | return -EOVERFLOW; | |
355 | } else if (unlikely((loff_t) (pos + count) < 0)) { | |
356 | if (!unsigned_offsets(file)) | |
4a3956c7 KH |
357 | return retval; |
358 | } | |
1da177e4 | 359 | |
a16877ca | 360 | if (unlikely(inode->i_flock && mandatory_lock(inode))) { |
c43e259c | 361 | retval = locks_mandatory_area( |
e28cc715 LT |
362 | read_write == READ ? FLOCK_VERIFY_READ : FLOCK_VERIFY_WRITE, |
363 | inode, file, pos, count); | |
364 | if (retval < 0) | |
365 | return retval; | |
366 | } | |
c43e259c JM |
367 | retval = security_file_permission(file, |
368 | read_write == READ ? MAY_READ : MAY_WRITE); | |
369 | if (retval) | |
370 | return retval; | |
e28cc715 | 371 | return count > MAX_RW_COUNT ? MAX_RW_COUNT : count; |
1da177e4 LT |
372 | } |
373 | ||
374 | ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos) | |
375 | { | |
027445c3 | 376 | struct iovec iov = { .iov_base = buf, .iov_len = len }; |
1da177e4 LT |
377 | struct kiocb kiocb; |
378 | ssize_t ret; | |
379 | ||
380 | init_sync_kiocb(&kiocb, filp); | |
381 | kiocb.ki_pos = *ppos; | |
61964eba | 382 | kiocb.ki_nbytes = len; |
027445c3 | 383 | |
41003a7b | 384 | ret = filp->f_op->aio_read(&kiocb, &iov, 1, kiocb.ki_pos); |
1da177e4 LT |
385 | if (-EIOCBQUEUED == ret) |
386 | ret = wait_on_sync_kiocb(&kiocb); | |
387 | *ppos = kiocb.ki_pos; | |
388 | return ret; | |
389 | } | |
390 | ||
391 | EXPORT_SYMBOL(do_sync_read); | |
392 | ||
393 | ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos) | |
394 | { | |
395 | ssize_t ret; | |
396 | ||
397 | if (!(file->f_mode & FMODE_READ)) | |
398 | return -EBADF; | |
72c2d531 | 399 | if (!file->f_op->read && !file->f_op->aio_read) |
1da177e4 LT |
400 | return -EINVAL; |
401 | if (unlikely(!access_ok(VERIFY_WRITE, buf, count))) | |
402 | return -EFAULT; | |
403 | ||
404 | ret = rw_verify_area(READ, file, pos, count); | |
e28cc715 LT |
405 | if (ret >= 0) { |
406 | count = ret; | |
c43e259c JM |
407 | if (file->f_op->read) |
408 | ret = file->f_op->read(file, buf, count, pos); | |
409 | else | |
410 | ret = do_sync_read(file, buf, count, pos); | |
411 | if (ret > 0) { | |
2a12a9d7 | 412 | fsnotify_access(file); |
c43e259c | 413 | add_rchar(current, ret); |
1da177e4 | 414 | } |
c43e259c | 415 | inc_syscr(current); |
1da177e4 LT |
416 | } |
417 | ||
418 | return ret; | |
419 | } | |
420 | ||
421 | EXPORT_SYMBOL(vfs_read); | |
422 | ||
423 | ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos) | |
424 | { | |
027445c3 | 425 | struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = len }; |
1da177e4 LT |
426 | struct kiocb kiocb; |
427 | ssize_t ret; | |
428 | ||
429 | init_sync_kiocb(&kiocb, filp); | |
430 | kiocb.ki_pos = *ppos; | |
61964eba | 431 | kiocb.ki_nbytes = len; |
027445c3 | 432 | |
41003a7b | 433 | ret = filp->f_op->aio_write(&kiocb, &iov, 1, kiocb.ki_pos); |
1da177e4 LT |
434 | if (-EIOCBQUEUED == ret) |
435 | ret = wait_on_sync_kiocb(&kiocb); | |
436 | *ppos = kiocb.ki_pos; | |
437 | return ret; | |
438 | } | |
439 | ||
440 | EXPORT_SYMBOL(do_sync_write); | |
441 | ||
06ae43f3 AV |
442 | ssize_t __kernel_write(struct file *file, const char *buf, size_t count, loff_t *pos) |
443 | { | |
444 | mm_segment_t old_fs; | |
445 | const char __user *p; | |
446 | ssize_t ret; | |
447 | ||
72c2d531 | 448 | if (!file->f_op->write && !file->f_op->aio_write) |
3e84f48e AV |
449 | return -EINVAL; |
450 | ||
06ae43f3 AV |
451 | old_fs = get_fs(); |
452 | set_fs(get_ds()); | |
453 | p = (__force const char __user *)buf; | |
454 | if (count > MAX_RW_COUNT) | |
455 | count = MAX_RW_COUNT; | |
456 | if (file->f_op->write) | |
457 | ret = file->f_op->write(file, p, count, pos); | |
458 | else | |
459 | ret = do_sync_write(file, p, count, pos); | |
460 | set_fs(old_fs); | |
461 | if (ret > 0) { | |
462 | fsnotify_modify(file); | |
463 | add_wchar(current, ret); | |
464 | } | |
465 | inc_syscw(current); | |
466 | return ret; | |
467 | } | |
468 | ||
1da177e4 LT |
469 | ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_t *pos) |
470 | { | |
471 | ssize_t ret; | |
472 | ||
473 | if (!(file->f_mode & FMODE_WRITE)) | |
474 | return -EBADF; | |
72c2d531 | 475 | if (!file->f_op->write && !file->f_op->aio_write) |
1da177e4 LT |
476 | return -EINVAL; |
477 | if (unlikely(!access_ok(VERIFY_READ, buf, count))) | |
478 | return -EFAULT; | |
479 | ||
480 | ret = rw_verify_area(WRITE, file, pos, count); | |
e28cc715 LT |
481 | if (ret >= 0) { |
482 | count = ret; | |
03d95eb2 | 483 | file_start_write(file); |
c43e259c JM |
484 | if (file->f_op->write) |
485 | ret = file->f_op->write(file, buf, count, pos); | |
486 | else | |
487 | ret = do_sync_write(file, buf, count, pos); | |
488 | if (ret > 0) { | |
2a12a9d7 | 489 | fsnotify_modify(file); |
c43e259c | 490 | add_wchar(current, ret); |
1da177e4 | 491 | } |
c43e259c | 492 | inc_syscw(current); |
03d95eb2 | 493 | file_end_write(file); |
1da177e4 LT |
494 | } |
495 | ||
496 | return ret; | |
497 | } | |
498 | ||
499 | EXPORT_SYMBOL(vfs_write); | |
500 | ||
501 | static inline loff_t file_pos_read(struct file *file) | |
502 | { | |
503 | return file->f_pos; | |
504 | } | |
505 | ||
506 | static inline void file_pos_write(struct file *file, loff_t pos) | |
507 | { | |
508 | file->f_pos = pos; | |
509 | } | |
510 | ||
3cdad428 | 511 | SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count) |
1da177e4 | 512 | { |
9c225f26 | 513 | struct fd f = fdget_pos(fd); |
1da177e4 | 514 | ssize_t ret = -EBADF; |
1da177e4 | 515 | |
2903ff01 AV |
516 | if (f.file) { |
517 | loff_t pos = file_pos_read(f.file); | |
518 | ret = vfs_read(f.file, buf, count, &pos); | |
5faf153e AV |
519 | if (ret >= 0) |
520 | file_pos_write(f.file, pos); | |
9c225f26 | 521 | fdput_pos(f); |
1da177e4 | 522 | } |
1da177e4 LT |
523 | return ret; |
524 | } | |
1da177e4 | 525 | |
3cdad428 HC |
526 | SYSCALL_DEFINE3(write, unsigned int, fd, const char __user *, buf, |
527 | size_t, count) | |
1da177e4 | 528 | { |
9c225f26 | 529 | struct fd f = fdget_pos(fd); |
1da177e4 | 530 | ssize_t ret = -EBADF; |
1da177e4 | 531 | |
2903ff01 AV |
532 | if (f.file) { |
533 | loff_t pos = file_pos_read(f.file); | |
534 | ret = vfs_write(f.file, buf, count, &pos); | |
5faf153e AV |
535 | if (ret >= 0) |
536 | file_pos_write(f.file, pos); | |
9c225f26 | 537 | fdput_pos(f); |
1da177e4 LT |
538 | } |
539 | ||
540 | return ret; | |
541 | } | |
542 | ||
4a0fd5bf AV |
543 | SYSCALL_DEFINE4(pread64, unsigned int, fd, char __user *, buf, |
544 | size_t, count, loff_t, pos) | |
1da177e4 | 545 | { |
2903ff01 | 546 | struct fd f; |
1da177e4 | 547 | ssize_t ret = -EBADF; |
1da177e4 LT |
548 | |
549 | if (pos < 0) | |
550 | return -EINVAL; | |
551 | ||
2903ff01 AV |
552 | f = fdget(fd); |
553 | if (f.file) { | |
1da177e4 | 554 | ret = -ESPIPE; |
2903ff01 AV |
555 | if (f.file->f_mode & FMODE_PREAD) |
556 | ret = vfs_read(f.file, buf, count, &pos); | |
557 | fdput(f); | |
1da177e4 LT |
558 | } |
559 | ||
560 | return ret; | |
561 | } | |
562 | ||
4a0fd5bf AV |
563 | SYSCALL_DEFINE4(pwrite64, unsigned int, fd, const char __user *, buf, |
564 | size_t, count, loff_t, pos) | |
1da177e4 | 565 | { |
2903ff01 | 566 | struct fd f; |
1da177e4 | 567 | ssize_t ret = -EBADF; |
1da177e4 LT |
568 | |
569 | if (pos < 0) | |
570 | return -EINVAL; | |
571 | ||
2903ff01 AV |
572 | f = fdget(fd); |
573 | if (f.file) { | |
1da177e4 | 574 | ret = -ESPIPE; |
2903ff01 AV |
575 | if (f.file->f_mode & FMODE_PWRITE) |
576 | ret = vfs_write(f.file, buf, count, &pos); | |
577 | fdput(f); | |
1da177e4 LT |
578 | } |
579 | ||
580 | return ret; | |
581 | } | |
582 | ||
583 | /* | |
584 | * Reduce an iovec's length in-place. Return the resulting number of segments | |
585 | */ | |
586 | unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to) | |
587 | { | |
588 | unsigned long seg = 0; | |
589 | size_t len = 0; | |
590 | ||
591 | while (seg < nr_segs) { | |
592 | seg++; | |
593 | if (len + iov->iov_len >= to) { | |
594 | iov->iov_len = to - len; | |
595 | break; | |
596 | } | |
597 | len += iov->iov_len; | |
598 | iov++; | |
599 | } | |
600 | return seg; | |
601 | } | |
19295529 | 602 | EXPORT_SYMBOL(iov_shorten); |
1da177e4 | 603 | |
72ec3516 | 604 | static ssize_t do_sync_readv_writev(struct file *filp, const struct iovec *iov, |
ee0b3e67 BP |
605 | unsigned long nr_segs, size_t len, loff_t *ppos, iov_fn_t fn) |
606 | { | |
607 | struct kiocb kiocb; | |
608 | ssize_t ret; | |
609 | ||
610 | init_sync_kiocb(&kiocb, filp); | |
611 | kiocb.ki_pos = *ppos; | |
ee0b3e67 BP |
612 | kiocb.ki_nbytes = len; |
613 | ||
41003a7b | 614 | ret = fn(&kiocb, iov, nr_segs, kiocb.ki_pos); |
ee0b3e67 BP |
615 | if (ret == -EIOCBQUEUED) |
616 | ret = wait_on_sync_kiocb(&kiocb); | |
617 | *ppos = kiocb.ki_pos; | |
618 | return ret; | |
619 | } | |
620 | ||
621 | /* Do it by hand, with file-ops */ | |
72ec3516 | 622 | static ssize_t do_loop_readv_writev(struct file *filp, struct iovec *iov, |
ee0b3e67 BP |
623 | unsigned long nr_segs, loff_t *ppos, io_fn_t fn) |
624 | { | |
625 | struct iovec *vector = iov; | |
626 | ssize_t ret = 0; | |
627 | ||
628 | while (nr_segs > 0) { | |
629 | void __user *base; | |
630 | size_t len; | |
631 | ssize_t nr; | |
632 | ||
633 | base = vector->iov_base; | |
634 | len = vector->iov_len; | |
635 | vector++; | |
636 | nr_segs--; | |
637 | ||
638 | nr = fn(filp, base, len, ppos); | |
639 | ||
640 | if (nr < 0) { | |
641 | if (!ret) | |
642 | ret = nr; | |
643 | break; | |
644 | } | |
645 | ret += nr; | |
646 | if (nr != len) | |
647 | break; | |
648 | } | |
649 | ||
650 | return ret; | |
651 | } | |
652 | ||
1da177e4 LT |
653 | /* A write operation does a read from user space and vice versa */ |
654 | #define vrfy_dir(type) ((type) == READ ? VERIFY_WRITE : VERIFY_READ) | |
655 | ||
eed4e51f BP |
656 | ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector, |
657 | unsigned long nr_segs, unsigned long fast_segs, | |
658 | struct iovec *fast_pointer, | |
ac34ebb3 | 659 | struct iovec **ret_pointer) |
435f49a5 | 660 | { |
eed4e51f | 661 | unsigned long seg; |
435f49a5 | 662 | ssize_t ret; |
eed4e51f BP |
663 | struct iovec *iov = fast_pointer; |
664 | ||
435f49a5 LT |
665 | /* |
666 | * SuS says "The readv() function *may* fail if the iovcnt argument | |
667 | * was less than or equal to 0, or greater than {IOV_MAX}. Linux has | |
668 | * traditionally returned zero for zero segments, so... | |
669 | */ | |
eed4e51f BP |
670 | if (nr_segs == 0) { |
671 | ret = 0; | |
435f49a5 | 672 | goto out; |
eed4e51f BP |
673 | } |
674 | ||
435f49a5 LT |
675 | /* |
676 | * First get the "struct iovec" from user memory and | |
677 | * verify all the pointers | |
678 | */ | |
eed4e51f BP |
679 | if (nr_segs > UIO_MAXIOV) { |
680 | ret = -EINVAL; | |
435f49a5 | 681 | goto out; |
eed4e51f BP |
682 | } |
683 | if (nr_segs > fast_segs) { | |
435f49a5 | 684 | iov = kmalloc(nr_segs*sizeof(struct iovec), GFP_KERNEL); |
eed4e51f BP |
685 | if (iov == NULL) { |
686 | ret = -ENOMEM; | |
435f49a5 | 687 | goto out; |
eed4e51f | 688 | } |
435f49a5 | 689 | } |
eed4e51f BP |
690 | if (copy_from_user(iov, uvector, nr_segs*sizeof(*uvector))) { |
691 | ret = -EFAULT; | |
435f49a5 | 692 | goto out; |
eed4e51f BP |
693 | } |
694 | ||
435f49a5 | 695 | /* |
eed4e51f BP |
696 | * According to the Single Unix Specification we should return EINVAL |
697 | * if an element length is < 0 when cast to ssize_t or if the | |
698 | * total length would overflow the ssize_t return value of the | |
699 | * system call. | |
435f49a5 LT |
700 | * |
701 | * Linux caps all read/write calls to MAX_RW_COUNT, and avoids the | |
702 | * overflow case. | |
703 | */ | |
eed4e51f | 704 | ret = 0; |
435f49a5 LT |
705 | for (seg = 0; seg < nr_segs; seg++) { |
706 | void __user *buf = iov[seg].iov_base; | |
707 | ssize_t len = (ssize_t)iov[seg].iov_len; | |
eed4e51f BP |
708 | |
709 | /* see if we we're about to use an invalid len or if | |
710 | * it's about to overflow ssize_t */ | |
435f49a5 | 711 | if (len < 0) { |
eed4e51f | 712 | ret = -EINVAL; |
435f49a5 | 713 | goto out; |
eed4e51f | 714 | } |
ac34ebb3 | 715 | if (type >= 0 |
fcf63409 | 716 | && unlikely(!access_ok(vrfy_dir(type), buf, len))) { |
eed4e51f | 717 | ret = -EFAULT; |
435f49a5 LT |
718 | goto out; |
719 | } | |
720 | if (len > MAX_RW_COUNT - ret) { | |
721 | len = MAX_RW_COUNT - ret; | |
722 | iov[seg].iov_len = len; | |
eed4e51f | 723 | } |
eed4e51f | 724 | ret += len; |
435f49a5 | 725 | } |
eed4e51f BP |
726 | out: |
727 | *ret_pointer = iov; | |
728 | return ret; | |
729 | } | |
730 | ||
1da177e4 LT |
731 | static ssize_t do_readv_writev(int type, struct file *file, |
732 | const struct iovec __user * uvector, | |
733 | unsigned long nr_segs, loff_t *pos) | |
734 | { | |
1da177e4 LT |
735 | size_t tot_len; |
736 | struct iovec iovstack[UIO_FASTIOV]; | |
ee0b3e67 | 737 | struct iovec *iov = iovstack; |
1da177e4 | 738 | ssize_t ret; |
1da177e4 LT |
739 | io_fn_t fn; |
740 | iov_fn_t fnv; | |
741 | ||
eed4e51f | 742 | ret = rw_copy_check_uvector(type, uvector, nr_segs, |
ac34ebb3 | 743 | ARRAY_SIZE(iovstack), iovstack, &iov); |
eed4e51f | 744 | if (ret <= 0) |
1da177e4 | 745 | goto out; |
1da177e4 | 746 | |
eed4e51f | 747 | tot_len = ret; |
1da177e4 | 748 | ret = rw_verify_area(type, file, pos, tot_len); |
e28cc715 | 749 | if (ret < 0) |
411b67b4 | 750 | goto out; |
1da177e4 LT |
751 | |
752 | fnv = NULL; | |
753 | if (type == READ) { | |
754 | fn = file->f_op->read; | |
ee0b3e67 | 755 | fnv = file->f_op->aio_read; |
1da177e4 LT |
756 | } else { |
757 | fn = (io_fn_t)file->f_op->write; | |
ee0b3e67 | 758 | fnv = file->f_op->aio_write; |
03d95eb2 | 759 | file_start_write(file); |
1da177e4 LT |
760 | } |
761 | ||
ee0b3e67 BP |
762 | if (fnv) |
763 | ret = do_sync_readv_writev(file, iov, nr_segs, tot_len, | |
764 | pos, fnv); | |
765 | else | |
766 | ret = do_loop_readv_writev(file, iov, nr_segs, pos, fn); | |
1da177e4 | 767 | |
03d95eb2 AV |
768 | if (type != READ) |
769 | file_end_write(file); | |
770 | ||
1da177e4 LT |
771 | out: |
772 | if (iov != iovstack) | |
773 | kfree(iov); | |
0eeca283 RL |
774 | if ((ret + (type == READ)) > 0) { |
775 | if (type == READ) | |
2a12a9d7 | 776 | fsnotify_access(file); |
0eeca283 | 777 | else |
2a12a9d7 | 778 | fsnotify_modify(file); |
0eeca283 | 779 | } |
1da177e4 | 780 | return ret; |
1da177e4 LT |
781 | } |
782 | ||
783 | ssize_t vfs_readv(struct file *file, const struct iovec __user *vec, | |
784 | unsigned long vlen, loff_t *pos) | |
785 | { | |
786 | if (!(file->f_mode & FMODE_READ)) | |
787 | return -EBADF; | |
72c2d531 | 788 | if (!file->f_op->aio_read && !file->f_op->read) |
1da177e4 LT |
789 | return -EINVAL; |
790 | ||
791 | return do_readv_writev(READ, file, vec, vlen, pos); | |
792 | } | |
793 | ||
794 | EXPORT_SYMBOL(vfs_readv); | |
795 | ||
796 | ssize_t vfs_writev(struct file *file, const struct iovec __user *vec, | |
797 | unsigned long vlen, loff_t *pos) | |
798 | { | |
799 | if (!(file->f_mode & FMODE_WRITE)) | |
800 | return -EBADF; | |
72c2d531 | 801 | if (!file->f_op->aio_write && !file->f_op->write) |
1da177e4 LT |
802 | return -EINVAL; |
803 | ||
804 | return do_readv_writev(WRITE, file, vec, vlen, pos); | |
805 | } | |
806 | ||
807 | EXPORT_SYMBOL(vfs_writev); | |
808 | ||
3cdad428 HC |
809 | SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec, |
810 | unsigned long, vlen) | |
1da177e4 | 811 | { |
9c225f26 | 812 | struct fd f = fdget_pos(fd); |
1da177e4 | 813 | ssize_t ret = -EBADF; |
1da177e4 | 814 | |
2903ff01 AV |
815 | if (f.file) { |
816 | loff_t pos = file_pos_read(f.file); | |
817 | ret = vfs_readv(f.file, vec, vlen, &pos); | |
5faf153e AV |
818 | if (ret >= 0) |
819 | file_pos_write(f.file, pos); | |
9c225f26 | 820 | fdput_pos(f); |
1da177e4 LT |
821 | } |
822 | ||
823 | if (ret > 0) | |
4b98d11b AD |
824 | add_rchar(current, ret); |
825 | inc_syscr(current); | |
1da177e4 LT |
826 | return ret; |
827 | } | |
828 | ||
3cdad428 HC |
829 | SYSCALL_DEFINE3(writev, unsigned long, fd, const struct iovec __user *, vec, |
830 | unsigned long, vlen) | |
1da177e4 | 831 | { |
9c225f26 | 832 | struct fd f = fdget_pos(fd); |
1da177e4 | 833 | ssize_t ret = -EBADF; |
1da177e4 | 834 | |
2903ff01 AV |
835 | if (f.file) { |
836 | loff_t pos = file_pos_read(f.file); | |
837 | ret = vfs_writev(f.file, vec, vlen, &pos); | |
5faf153e AV |
838 | if (ret >= 0) |
839 | file_pos_write(f.file, pos); | |
9c225f26 | 840 | fdput_pos(f); |
1da177e4 LT |
841 | } |
842 | ||
843 | if (ret > 0) | |
4b98d11b AD |
844 | add_wchar(current, ret); |
845 | inc_syscw(current); | |
1da177e4 LT |
846 | return ret; |
847 | } | |
848 | ||
601cc11d LT |
849 | static inline loff_t pos_from_hilo(unsigned long high, unsigned long low) |
850 | { | |
851 | #define HALF_LONG_BITS (BITS_PER_LONG / 2) | |
852 | return (((loff_t)high << HALF_LONG_BITS) << HALF_LONG_BITS) | low; | |
853 | } | |
854 | ||
f3554f4b | 855 | SYSCALL_DEFINE5(preadv, unsigned long, fd, const struct iovec __user *, vec, |
601cc11d | 856 | unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h) |
f3554f4b | 857 | { |
601cc11d | 858 | loff_t pos = pos_from_hilo(pos_h, pos_l); |
2903ff01 | 859 | struct fd f; |
f3554f4b | 860 | ssize_t ret = -EBADF; |
f3554f4b GH |
861 | |
862 | if (pos < 0) | |
863 | return -EINVAL; | |
864 | ||
2903ff01 AV |
865 | f = fdget(fd); |
866 | if (f.file) { | |
f3554f4b | 867 | ret = -ESPIPE; |
2903ff01 AV |
868 | if (f.file->f_mode & FMODE_PREAD) |
869 | ret = vfs_readv(f.file, vec, vlen, &pos); | |
870 | fdput(f); | |
f3554f4b GH |
871 | } |
872 | ||
873 | if (ret > 0) | |
874 | add_rchar(current, ret); | |
875 | inc_syscr(current); | |
876 | return ret; | |
877 | } | |
878 | ||
879 | SYSCALL_DEFINE5(pwritev, unsigned long, fd, const struct iovec __user *, vec, | |
601cc11d | 880 | unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h) |
f3554f4b | 881 | { |
601cc11d | 882 | loff_t pos = pos_from_hilo(pos_h, pos_l); |
2903ff01 | 883 | struct fd f; |
f3554f4b | 884 | ssize_t ret = -EBADF; |
f3554f4b GH |
885 | |
886 | if (pos < 0) | |
887 | return -EINVAL; | |
888 | ||
2903ff01 AV |
889 | f = fdget(fd); |
890 | if (f.file) { | |
f3554f4b | 891 | ret = -ESPIPE; |
2903ff01 AV |
892 | if (f.file->f_mode & FMODE_PWRITE) |
893 | ret = vfs_writev(f.file, vec, vlen, &pos); | |
894 | fdput(f); | |
f3554f4b GH |
895 | } |
896 | ||
897 | if (ret > 0) | |
898 | add_wchar(current, ret); | |
899 | inc_syscw(current); | |
900 | return ret; | |
901 | } | |
902 | ||
72ec3516 AV |
903 | #ifdef CONFIG_COMPAT |
904 | ||
905 | static ssize_t compat_do_readv_writev(int type, struct file *file, | |
906 | const struct compat_iovec __user *uvector, | |
907 | unsigned long nr_segs, loff_t *pos) | |
908 | { | |
909 | compat_ssize_t tot_len; | |
910 | struct iovec iovstack[UIO_FASTIOV]; | |
911 | struct iovec *iov = iovstack; | |
912 | ssize_t ret; | |
913 | io_fn_t fn; | |
914 | iov_fn_t fnv; | |
915 | ||
72ec3516 AV |
916 | ret = compat_rw_copy_check_uvector(type, uvector, nr_segs, |
917 | UIO_FASTIOV, iovstack, &iov); | |
918 | if (ret <= 0) | |
919 | goto out; | |
920 | ||
921 | tot_len = ret; | |
922 | ret = rw_verify_area(type, file, pos, tot_len); | |
923 | if (ret < 0) | |
924 | goto out; | |
925 | ||
926 | fnv = NULL; | |
927 | if (type == READ) { | |
928 | fn = file->f_op->read; | |
929 | fnv = file->f_op->aio_read; | |
930 | } else { | |
931 | fn = (io_fn_t)file->f_op->write; | |
932 | fnv = file->f_op->aio_write; | |
03d95eb2 | 933 | file_start_write(file); |
72ec3516 AV |
934 | } |
935 | ||
03d95eb2 | 936 | if (fnv) |
72ec3516 AV |
937 | ret = do_sync_readv_writev(file, iov, nr_segs, tot_len, |
938 | pos, fnv); | |
03d95eb2 | 939 | else |
72ec3516 AV |
940 | ret = do_loop_readv_writev(file, iov, nr_segs, pos, fn); |
941 | ||
03d95eb2 AV |
942 | if (type != READ) |
943 | file_end_write(file); | |
944 | ||
72ec3516 AV |
945 | out: |
946 | if (iov != iovstack) | |
947 | kfree(iov); | |
948 | if ((ret + (type == READ)) > 0) { | |
949 | if (type == READ) | |
950 | fsnotify_access(file); | |
951 | else | |
952 | fsnotify_modify(file); | |
953 | } | |
954 | return ret; | |
955 | } | |
956 | ||
957 | static size_t compat_readv(struct file *file, | |
958 | const struct compat_iovec __user *vec, | |
959 | unsigned long vlen, loff_t *pos) | |
960 | { | |
961 | ssize_t ret = -EBADF; | |
962 | ||
963 | if (!(file->f_mode & FMODE_READ)) | |
964 | goto out; | |
965 | ||
966 | ret = -EINVAL; | |
72c2d531 | 967 | if (!file->f_op->aio_read && !file->f_op->read) |
72ec3516 AV |
968 | goto out; |
969 | ||
970 | ret = compat_do_readv_writev(READ, file, vec, vlen, pos); | |
971 | ||
972 | out: | |
973 | if (ret > 0) | |
974 | add_rchar(current, ret); | |
975 | inc_syscr(current); | |
976 | return ret; | |
977 | } | |
978 | ||
dfd948e3 | 979 | COMPAT_SYSCALL_DEFINE3(readv, compat_ulong_t, fd, |
72ec3516 | 980 | const struct compat_iovec __user *,vec, |
dfd948e3 | 981 | compat_ulong_t, vlen) |
72ec3516 | 982 | { |
9c225f26 | 983 | struct fd f = fdget_pos(fd); |
72ec3516 AV |
984 | ssize_t ret; |
985 | loff_t pos; | |
986 | ||
987 | if (!f.file) | |
988 | return -EBADF; | |
989 | pos = f.file->f_pos; | |
990 | ret = compat_readv(f.file, vec, vlen, &pos); | |
5faf153e AV |
991 | if (ret >= 0) |
992 | f.file->f_pos = pos; | |
9c225f26 | 993 | fdput_pos(f); |
72ec3516 AV |
994 | return ret; |
995 | } | |
996 | ||
378a10f3 HC |
997 | static long __compat_sys_preadv64(unsigned long fd, |
998 | const struct compat_iovec __user *vec, | |
999 | unsigned long vlen, loff_t pos) | |
72ec3516 AV |
1000 | { |
1001 | struct fd f; | |
1002 | ssize_t ret; | |
1003 | ||
1004 | if (pos < 0) | |
1005 | return -EINVAL; | |
1006 | f = fdget(fd); | |
1007 | if (!f.file) | |
1008 | return -EBADF; | |
1009 | ret = -ESPIPE; | |
1010 | if (f.file->f_mode & FMODE_PREAD) | |
1011 | ret = compat_readv(f.file, vec, vlen, &pos); | |
1012 | fdput(f); | |
1013 | return ret; | |
1014 | } | |
1015 | ||
378a10f3 HC |
1016 | #ifdef __ARCH_WANT_COMPAT_SYS_PREADV64 |
1017 | COMPAT_SYSCALL_DEFINE4(preadv64, unsigned long, fd, | |
1018 | const struct compat_iovec __user *,vec, | |
1019 | unsigned long, vlen, loff_t, pos) | |
1020 | { | |
1021 | return __compat_sys_preadv64(fd, vec, vlen, pos); | |
1022 | } | |
1023 | #endif | |
1024 | ||
dfd948e3 | 1025 | COMPAT_SYSCALL_DEFINE5(preadv, compat_ulong_t, fd, |
72ec3516 | 1026 | const struct compat_iovec __user *,vec, |
dfd948e3 | 1027 | compat_ulong_t, vlen, u32, pos_low, u32, pos_high) |
72ec3516 AV |
1028 | { |
1029 | loff_t pos = ((loff_t)pos_high << 32) | pos_low; | |
378a10f3 HC |
1030 | |
1031 | return __compat_sys_preadv64(fd, vec, vlen, pos); | |
72ec3516 AV |
1032 | } |
1033 | ||
1034 | static size_t compat_writev(struct file *file, | |
1035 | const struct compat_iovec __user *vec, | |
1036 | unsigned long vlen, loff_t *pos) | |
1037 | { | |
1038 | ssize_t ret = -EBADF; | |
1039 | ||
1040 | if (!(file->f_mode & FMODE_WRITE)) | |
1041 | goto out; | |
1042 | ||
1043 | ret = -EINVAL; | |
72c2d531 | 1044 | if (!file->f_op->aio_write && !file->f_op->write) |
72ec3516 AV |
1045 | goto out; |
1046 | ||
1047 | ret = compat_do_readv_writev(WRITE, file, vec, vlen, pos); | |
1048 | ||
1049 | out: | |
1050 | if (ret > 0) | |
1051 | add_wchar(current, ret); | |
1052 | inc_syscw(current); | |
1053 | return ret; | |
1054 | } | |
1055 | ||
dfd948e3 | 1056 | COMPAT_SYSCALL_DEFINE3(writev, compat_ulong_t, fd, |
72ec3516 | 1057 | const struct compat_iovec __user *, vec, |
dfd948e3 | 1058 | compat_ulong_t, vlen) |
72ec3516 | 1059 | { |
9c225f26 | 1060 | struct fd f = fdget_pos(fd); |
72ec3516 AV |
1061 | ssize_t ret; |
1062 | loff_t pos; | |
1063 | ||
1064 | if (!f.file) | |
1065 | return -EBADF; | |
1066 | pos = f.file->f_pos; | |
1067 | ret = compat_writev(f.file, vec, vlen, &pos); | |
5faf153e AV |
1068 | if (ret >= 0) |
1069 | f.file->f_pos = pos; | |
9c225f26 | 1070 | fdput_pos(f); |
72ec3516 AV |
1071 | return ret; |
1072 | } | |
1073 | ||
378a10f3 HC |
1074 | static long __compat_sys_pwritev64(unsigned long fd, |
1075 | const struct compat_iovec __user *vec, | |
1076 | unsigned long vlen, loff_t pos) | |
72ec3516 AV |
1077 | { |
1078 | struct fd f; | |
1079 | ssize_t ret; | |
1080 | ||
1081 | if (pos < 0) | |
1082 | return -EINVAL; | |
1083 | f = fdget(fd); | |
1084 | if (!f.file) | |
1085 | return -EBADF; | |
1086 | ret = -ESPIPE; | |
1087 | if (f.file->f_mode & FMODE_PWRITE) | |
1088 | ret = compat_writev(f.file, vec, vlen, &pos); | |
1089 | fdput(f); | |
1090 | return ret; | |
1091 | } | |
1092 | ||
378a10f3 HC |
1093 | #ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64 |
1094 | COMPAT_SYSCALL_DEFINE4(pwritev64, unsigned long, fd, | |
1095 | const struct compat_iovec __user *,vec, | |
1096 | unsigned long, vlen, loff_t, pos) | |
1097 | { | |
1098 | return __compat_sys_pwritev64(fd, vec, vlen, pos); | |
1099 | } | |
1100 | #endif | |
1101 | ||
dfd948e3 | 1102 | COMPAT_SYSCALL_DEFINE5(pwritev, compat_ulong_t, fd, |
72ec3516 | 1103 | const struct compat_iovec __user *,vec, |
dfd948e3 | 1104 | compat_ulong_t, vlen, u32, pos_low, u32, pos_high) |
72ec3516 AV |
1105 | { |
1106 | loff_t pos = ((loff_t)pos_high << 32) | pos_low; | |
378a10f3 HC |
1107 | |
1108 | return __compat_sys_pwritev64(fd, vec, vlen, pos); | |
72ec3516 AV |
1109 | } |
1110 | #endif | |
1111 | ||
19f4fc3a AV |
1112 | static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, |
1113 | size_t count, loff_t max) | |
1da177e4 | 1114 | { |
2903ff01 AV |
1115 | struct fd in, out; |
1116 | struct inode *in_inode, *out_inode; | |
1da177e4 | 1117 | loff_t pos; |
7995bd28 | 1118 | loff_t out_pos; |
1da177e4 | 1119 | ssize_t retval; |
2903ff01 | 1120 | int fl; |
1da177e4 LT |
1121 | |
1122 | /* | |
1123 | * Get input file, and verify that it is ok.. | |
1124 | */ | |
1125 | retval = -EBADF; | |
2903ff01 AV |
1126 | in = fdget(in_fd); |
1127 | if (!in.file) | |
1da177e4 | 1128 | goto out; |
2903ff01 | 1129 | if (!(in.file->f_mode & FMODE_READ)) |
1da177e4 | 1130 | goto fput_in; |
1da177e4 | 1131 | retval = -ESPIPE; |
7995bd28 AV |
1132 | if (!ppos) { |
1133 | pos = in.file->f_pos; | |
1134 | } else { | |
1135 | pos = *ppos; | |
2903ff01 | 1136 | if (!(in.file->f_mode & FMODE_PREAD)) |
1da177e4 | 1137 | goto fput_in; |
7995bd28 AV |
1138 | } |
1139 | retval = rw_verify_area(READ, in.file, &pos, count); | |
e28cc715 | 1140 | if (retval < 0) |
1da177e4 | 1141 | goto fput_in; |
e28cc715 | 1142 | count = retval; |
1da177e4 | 1143 | |
1da177e4 LT |
1144 | /* |
1145 | * Get output file, and verify that it is ok.. | |
1146 | */ | |
1147 | retval = -EBADF; | |
2903ff01 AV |
1148 | out = fdget(out_fd); |
1149 | if (!out.file) | |
1da177e4 | 1150 | goto fput_in; |
2903ff01 | 1151 | if (!(out.file->f_mode & FMODE_WRITE)) |
1da177e4 LT |
1152 | goto fput_out; |
1153 | retval = -EINVAL; | |
496ad9aa AV |
1154 | in_inode = file_inode(in.file); |
1155 | out_inode = file_inode(out.file); | |
7995bd28 AV |
1156 | out_pos = out.file->f_pos; |
1157 | retval = rw_verify_area(WRITE, out.file, &out_pos, count); | |
e28cc715 | 1158 | if (retval < 0) |
1da177e4 | 1159 | goto fput_out; |
e28cc715 | 1160 | count = retval; |
1da177e4 | 1161 | |
1da177e4 LT |
1162 | if (!max) |
1163 | max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes); | |
1164 | ||
1da177e4 LT |
1165 | if (unlikely(pos + count > max)) { |
1166 | retval = -EOVERFLOW; | |
1167 | if (pos >= max) | |
1168 | goto fput_out; | |
1169 | count = max - pos; | |
1170 | } | |
1171 | ||
d96e6e71 | 1172 | fl = 0; |
534f2aaa | 1173 | #if 0 |
d96e6e71 JA |
1174 | /* |
1175 | * We need to debate whether we can enable this or not. The | |
1176 | * man page documents EAGAIN return for the output at least, | |
1177 | * and the application is arguably buggy if it doesn't expect | |
1178 | * EAGAIN on a non-blocking file descriptor. | |
1179 | */ | |
2903ff01 | 1180 | if (in.file->f_flags & O_NONBLOCK) |
d96e6e71 | 1181 | fl = SPLICE_F_NONBLOCK; |
534f2aaa | 1182 | #endif |
50cd2c57 | 1183 | file_start_write(out.file); |
7995bd28 | 1184 | retval = do_splice_direct(in.file, &pos, out.file, &out_pos, count, fl); |
50cd2c57 | 1185 | file_end_write(out.file); |
1da177e4 LT |
1186 | |
1187 | if (retval > 0) { | |
4b98d11b AD |
1188 | add_rchar(current, retval); |
1189 | add_wchar(current, retval); | |
a68c2f12 SW |
1190 | fsnotify_access(in.file); |
1191 | fsnotify_modify(out.file); | |
7995bd28 AV |
1192 | out.file->f_pos = out_pos; |
1193 | if (ppos) | |
1194 | *ppos = pos; | |
1195 | else | |
1196 | in.file->f_pos = pos; | |
1da177e4 | 1197 | } |
1da177e4 | 1198 | |
4b98d11b AD |
1199 | inc_syscr(current); |
1200 | inc_syscw(current); | |
7995bd28 | 1201 | if (pos > max) |
1da177e4 LT |
1202 | retval = -EOVERFLOW; |
1203 | ||
1204 | fput_out: | |
2903ff01 | 1205 | fdput(out); |
1da177e4 | 1206 | fput_in: |
2903ff01 | 1207 | fdput(in); |
1da177e4 LT |
1208 | out: |
1209 | return retval; | |
1210 | } | |
1211 | ||
002c8976 | 1212 | SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, off_t __user *, offset, size_t, count) |
1da177e4 LT |
1213 | { |
1214 | loff_t pos; | |
1215 | off_t off; | |
1216 | ssize_t ret; | |
1217 | ||
1218 | if (offset) { | |
1219 | if (unlikely(get_user(off, offset))) | |
1220 | return -EFAULT; | |
1221 | pos = off; | |
1222 | ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS); | |
1223 | if (unlikely(put_user(pos, offset))) | |
1224 | return -EFAULT; | |
1225 | return ret; | |
1226 | } | |
1227 | ||
1228 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1229 | } | |
1230 | ||
002c8976 | 1231 | SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, loff_t __user *, offset, size_t, count) |
1da177e4 LT |
1232 | { |
1233 | loff_t pos; | |
1234 | ssize_t ret; | |
1235 | ||
1236 | if (offset) { | |
1237 | if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t)))) | |
1238 | return -EFAULT; | |
1239 | ret = do_sendfile(out_fd, in_fd, &pos, count, 0); | |
1240 | if (unlikely(put_user(pos, offset))) | |
1241 | return -EFAULT; | |
1242 | return ret; | |
1243 | } | |
1244 | ||
1245 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1246 | } | |
19f4fc3a AV |
1247 | |
1248 | #ifdef CONFIG_COMPAT | |
1249 | COMPAT_SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, | |
1250 | compat_off_t __user *, offset, compat_size_t, count) | |
1251 | { | |
1252 | loff_t pos; | |
1253 | off_t off; | |
1254 | ssize_t ret; | |
1255 | ||
1256 | if (offset) { | |
1257 | if (unlikely(get_user(off, offset))) | |
1258 | return -EFAULT; | |
1259 | pos = off; | |
1260 | ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS); | |
1261 | if (unlikely(put_user(pos, offset))) | |
1262 | return -EFAULT; | |
1263 | return ret; | |
1264 | } | |
1265 | ||
1266 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1267 | } | |
1268 | ||
1269 | COMPAT_SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, | |
1270 | compat_loff_t __user *, offset, compat_size_t, count) | |
1271 | { | |
1272 | loff_t pos; | |
1273 | ssize_t ret; | |
1274 | ||
1275 | if (offset) { | |
1276 | if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t)))) | |
1277 | return -EFAULT; | |
1278 | ret = do_sendfile(out_fd, in_fd, &pos, count, 0); | |
1279 | if (unlikely(put_user(pos, offset))) | |
1280 | return -EFAULT; | |
1281 | return ret; | |
1282 | } | |
1283 | ||
1284 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1285 | } | |
1286 | #endif |