| 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/fsnotify.h>
|
| 13 | #include <linux/security.h>
|
| 14 | #include <linux/export.h>
|
| 15 | #include <linux/syscalls.h>
|
| 16 | #include <linux/pagemap.h>
|
| 17 | #include <linux/splice.h>
|
| 18 | #include <linux/compat.h>
|
| 19 | #include "internal.h"
|
| 20 |
|
| 21 | #include <asm/uaccess.h>
|
| 22 | #include <asm/unistd.h>
|
| 23 |
|
| 24 | typedef ssize_t (*io_fn_t)(struct file *, char __user *, size_t, loff_t *);
|
| 25 | typedef ssize_t (*iter_fn_t)(struct kiocb *, struct iov_iter *);
|
| 26 |
|
| 27 | const struct file_operations generic_ro_fops = {
|
| 28 | .llseek = generic_file_llseek,
|
| 29 | .read_iter = generic_file_read_iter,
|
| 30 | .mmap = generic_file_readonly_mmap,
|
| 31 | .splice_read = generic_file_splice_read,
|
| 32 | };
|
| 33 |
|
| 34 | EXPORT_SYMBOL(generic_ro_fops);
|
| 35 |
|
| 36 | static inline int unsigned_offsets(struct file *file)
|
| 37 | {
|
| 38 | return file->f_mode & FMODE_UNSIGNED_OFFSET;
|
| 39 | }
|
| 40 |
|
| 41 | |
| 42 | * vfs_setpos - update the file offset for lseek
|
| 43 | * @file: file structure in question
|
| 44 | * @offset: file offset to seek to
|
| 45 | * @maxsize: maximum file size
|
| 46 | *
|
| 47 | * This is a low-level filesystem helper for updating the file offset to
|
| 48 | * the value specified by @offset if the given offset is valid and it is
|
| 49 | * not equal to the current file offset.
|
| 50 | *
|
| 51 | * Return the specified offset on success and -EINVAL on invalid offset.
|
| 52 |
|
| 53 | loff_t vfs_setpos(struct file *file, loff_t offset, loff_t maxsize)
|
| 54 | {
|
| 55 | if (offset < 0 && !unsigned_offsets(file))
|
| 56 | return -EINVAL;
|
| 57 | if (offset > maxsize)
|
| 58 | return -EINVAL;
|
| 59 |
|
| 60 | if (offset != file->f_pos) {
|
| 61 | file->f_pos = offset;
|
| 62 | file->f_version = 0;
|
| 63 | }
|
| 64 | return offset;
|
| 65 | }
|
| 66 | EXPORT_SYMBOL(vfs_setpos);
|
| 67 |
|
| 68 | |
| 69 | * generic_file_llseek_size - generic llseek implementation for regular files
|
| 70 | * @file: file structure to seek on
|
| 71 | * @offset: file offset to seek to
|
| 72 | * @whence: type of seek
|
| 73 | * @size: max size of this file in file system
|
| 74 | * @eof: offset used for SEEK_END position
|
| 75 | *
|
| 76 | * This is a variant of generic_file_llseek that allows passing in a custom
|
| 77 | * maximum file size and a custom EOF position, for e.g. hashed directories
|
| 78 | *
|
| 79 | * Synchronization:
|
| 80 | * SEEK_SET and SEEK_END are unsynchronized (but atomic on 64bit platforms)
|
| 81 | * SEEK_CUR is synchronized against other SEEK_CURs, but not read/writes.
|
| 82 | * read/writes behave like SEEK_SET against seeks.
|
| 83 |
|
| 84 | loff_t
|
| 85 | generic_file_llseek_size(struct file *file, loff_t offset, int whence,
|
| 86 | loff_t maxsize, loff_t eof)
|
| 87 | {
|
| 88 | switch (whence) {
|
| 89 | case SEEK_END:
|
| 90 | offset += eof;
|
| 91 | break;
|
| 92 | case SEEK_CUR:
|
| 93 | |
| 94 | * Here we special-case the lseek(fd, 0, SEEK_CUR)
|
| 95 | * position-querying operation. Avoid rewriting the "same"
|
| 96 | * f_pos value back to the file because a concurrent read(),
|
| 97 | * write() or lseek() might have altered it
|
| 98 |
|
| 99 | if (offset == 0)
|
| 100 | return file->f_pos;
|
| 101 | |
| 102 | * f_lock protects against read/modify/write race with other
|
| 103 | * SEEK_CURs. Note that parallel writes and reads behave
|
| 104 | * like SEEK_SET.
|
| 105 |
|
| 106 | spin_lock(&file->f_lock);
|
| 107 | offset = vfs_setpos(file, file->f_pos + offset, maxsize);
|
| 108 | spin_unlock(&file->f_lock);
|
| 109 | return offset;
|
| 110 | case SEEK_DATA:
|
| 111 | |
| 112 | * In the generic case the entire file is data, so as long as
|
| 113 | * offset isn't at the end of the file then the offset is data.
|
| 114 |
|
| 115 | if (offset >= eof)
|
| 116 | return -ENXIO;
|
| 117 | break;
|
| 118 | case SEEK_HOLE:
|
| 119 | |
| 120 | * There is a virtual hole at the end of the file, so as long as
|
| 121 | * offset isn't i_size or larger, return i_size.
|
| 122 |
|
| 123 | if (offset >= eof)
|
| 124 | return -ENXIO;
|
| 125 | offset = eof;
|
| 126 | break;
|
| 127 | }
|
| 128 |
|
| 129 | return vfs_setpos(file, offset, maxsize);
|
| 130 | }
|
| 131 | EXPORT_SYMBOL(generic_file_llseek_size);
|
| 132 |
|
| 133 | |
| 134 | * generic_file_llseek - generic llseek implementation for regular files
|
| 135 | * @file: file structure to seek on
|
| 136 | * @offset: file offset to seek to
|
| 137 | * @whence: type of seek
|
| 138 | *
|
| 139 | * This is a generic implemenation of ->llseek useable for all normal local
|
| 140 | * filesystems. It just updates the file offset to the value specified by
|
| 141 | * @offset and @whence.
|
| 142 |
|
| 143 | loff_t generic_file_llseek(struct file *file, loff_t offset, int whence)
|
| 144 | {
|
| 145 | struct inode *inode = file->f_mapping->host;
|
| 146 |
|
| 147 | return generic_file_llseek_size(file, offset, whence,
|
| 148 | inode->i_sb->s_maxbytes,
|
| 149 | i_size_read(inode));
|
| 150 | }
|
| 151 | EXPORT_SYMBOL(generic_file_llseek);
|
| 152 |
|
| 153 | |
| 154 | * fixed_size_llseek - llseek implementation for fixed-sized devices
|
| 155 | * @file: file structure to seek on
|
| 156 | * @offset: file offset to seek to
|
| 157 | * @whence: type of seek
|
| 158 | * @size: size of the file
|
| 159 | *
|
| 160 |
|
| 161 | loff_t fixed_size_llseek(struct file *file, loff_t offset, int whence, loff_t size)
|
| 162 | {
|
| 163 | switch (whence) {
|
| 164 | case SEEK_SET: case SEEK_CUR: case SEEK_END:
|
| 165 | return generic_file_llseek_size(file, offset, whence,
|
| 166 | size, size);
|
| 167 | default:
|
| 168 | return -EINVAL;
|
| 169 | }
|
| 170 | }
|
| 171 | EXPORT_SYMBOL(fixed_size_llseek);
|
| 172 |
|
| 173 | |
| 174 | * noop_llseek - No Operation Performed llseek implementation
|
| 175 | * @file: file structure to seek on
|
| 176 | * @offset: file offset to seek to
|
| 177 | * @whence: type of seek
|
| 178 | *
|
| 179 | * This is an implementation of ->llseek useable for the rare special case when
|
| 180 | * userspace expects the seek to succeed but the (device) file is actually not
|
| 181 | * able to perform the seek. In this case you use noop_llseek() instead of
|
| 182 | * falling back to the default implementation of ->llseek.
|
| 183 |
|
| 184 | loff_t noop_llseek(struct file *file, loff_t offset, int whence)
|
| 185 | {
|
| 186 | return file->f_pos;
|
| 187 | }
|
| 188 | EXPORT_SYMBOL(noop_llseek);
|
| 189 |
|
| 190 | loff_t no_llseek(struct file *file, loff_t offset, int whence)
|
| 191 | {
|
| 192 | return -ESPIPE;
|
| 193 | }
|
| 194 | EXPORT_SYMBOL(no_llseek);
|
| 195 |
|
| 196 | loff_t default_llseek(struct file *file, loff_t offset, int whence)
|
| 197 | {
|
| 198 | struct inode *inode = file_inode(file);
|
| 199 | loff_t retval;
|
| 200 |
|
| 201 | mutex_lock(&inode->i_mutex);
|
| 202 | switch (whence) {
|
| 203 | case SEEK_END:
|
| 204 | offset += i_size_read(inode);
|
| 205 | break;
|
| 206 | case SEEK_CUR:
|
| 207 | if (offset == 0) {
|
| 208 | retval = file->f_pos;
|
| 209 | goto out;
|
| 210 | }
|
| 211 | offset += file->f_pos;
|
| 212 | break;
|
| 213 | case SEEK_DATA:
|
| 214 | |
| 215 | * In the generic case the entire file is data, so as
|
| 216 | * long as offset isn't at the end of the file then the
|
| 217 | * offset is data.
|
| 218 |
|
| 219 | if (offset >= inode->i_size) {
|
| 220 | retval = -ENXIO;
|
| 221 | goto out;
|
| 222 | }
|
| 223 | break;
|
| 224 | case SEEK_HOLE:
|
| 225 | |
| 226 | * There is a virtual hole at the end of the file, so
|
| 227 | * as long as offset isn't i_size or larger, return
|
| 228 | * i_size.
|
| 229 |
|
| 230 | if (offset >= inode->i_size) {
|
| 231 | retval = -ENXIO;
|
| 232 | goto out;
|
| 233 | }
|
| 234 | offset = inode->i_size;
|
| 235 | break;
|
| 236 | }
|
| 237 | retval = -EINVAL;
|
| 238 | if (offset >= 0 || unsigned_offsets(file)) {
|
| 239 | if (offset != file->f_pos) {
|
| 240 | file->f_pos = offset;
|
| 241 | file->f_version = 0;
|
| 242 | }
|
| 243 | retval = offset;
|
| 244 | }
|
| 245 | out:
|
| 246 | mutex_unlock(&inode->i_mutex);
|
| 247 | return retval;
|
| 248 | }
|
| 249 | EXPORT_SYMBOL(default_llseek);
|
| 250 |
|
| 251 | loff_t vfs_llseek(struct file *file, loff_t offset, int whence)
|
| 252 | {
|
| 253 | loff_t (*fn)(struct file *, loff_t, int);
|
| 254 |
|
| 255 | fn = no_llseek;
|
| 256 | if (file->f_mode & FMODE_LSEEK) {
|
| 257 | if (file->f_op->llseek)
|
| 258 | fn = file->f_op->llseek;
|
| 259 | }
|
| 260 | return fn(file, offset, whence);
|
| 261 | }
|
| 262 | EXPORT_SYMBOL(vfs_llseek);
|
| 263 |
|
| 264 | static inline struct fd fdget_pos(int fd)
|
| 265 | {
|
| 266 | return __to_fd(__fdget_pos(fd));
|
| 267 | }
|
| 268 |
|
| 269 | static inline void fdput_pos(struct fd f)
|
| 270 | {
|
| 271 | if (f.flags & FDPUT_POS_UNLOCK)
|
| 272 | mutex_unlock(&f.file->f_pos_lock);
|
| 273 | fdput(f);
|
| 274 | }
|
| 275 |
|
| 276 | SYSCALL_DEFINE3(lseek, unsigned int, fd, off_t, offset, unsigned int, whence)
|
| 277 | {
|
| 278 | off_t retval;
|
| 279 | struct fd f = fdget_pos(fd);
|
| 280 | if (!f.file)
|
| 281 | return -EBADF;
|
| 282 |
|
| 283 | retval = -EINVAL;
|
| 284 | if (whence <= SEEK_MAX) {
|
| 285 | loff_t res = vfs_llseek(f.file, offset, whence);
|
| 286 | retval = res;
|
| 287 | if (res != (loff_t)retval)
|
| 288 | retval = -EOVERFLOW;
|
| 289 | }
|
| 290 | fdput_pos(f);
|
| 291 | return retval;
|
| 292 | }
|
| 293 |
|
| 294 | #ifdef CONFIG_COMPAT
|
| 295 | COMPAT_SYSCALL_DEFINE3(lseek, unsigned int, fd, compat_off_t, offset, unsigned int, whence)
|
| 296 | {
|
| 297 | return sys_lseek(fd, offset, whence);
|
| 298 | }
|
| 299 | #endif
|
| 300 |
|
| 301 | #ifdef __ARCH_WANT_SYS_LLSEEK
|
| 302 | SYSCALL_DEFINE5(llseek, unsigned int, fd, unsigned long, offset_high,
|
| 303 | unsigned long, offset_low, loff_t __user *, result,
|
| 304 | unsigned int, whence)
|
| 305 | {
|
| 306 | int retval;
|
| 307 | struct fd f = fdget_pos(fd);
|
| 308 | loff_t offset;
|
| 309 |
|
| 310 | if (!f.file)
|
| 311 | return -EBADF;
|
| 312 |
|
| 313 | retval = -EINVAL;
|
| 314 | if (whence > SEEK_MAX)
|
| 315 | goto out_putf;
|
| 316 |
|
| 317 | offset = vfs_llseek(f.file, ((loff_t) offset_high << 32) | offset_low,
|
| 318 | whence);
|
| 319 |
|
| 320 | retval = (int)offset;
|
| 321 | if (offset >= 0) {
|
| 322 | retval = -EFAULT;
|
| 323 | if (!copy_to_user(result, &offset, sizeof(offset)))
|
| 324 | retval = 0;
|
| 325 | }
|
| 326 | out_putf:
|
| 327 | fdput_pos(f);
|
| 328 | return retval;
|
| 329 | }
|
| 330 | #endif
|
| 331 |
|
| 332 | ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos)
|
| 333 | {
|
| 334 | struct kiocb kiocb;
|
| 335 | ssize_t ret;
|
| 336 |
|
| 337 | if (!file->f_op->read_iter)
|
| 338 | return -EINVAL;
|
| 339 |
|
| 340 | init_sync_kiocb(&kiocb, file);
|
| 341 | kiocb.ki_pos = *ppos;
|
| 342 |
|
| 343 | iter->type |= READ;
|
| 344 | ret = file->f_op->read_iter(&kiocb, iter);
|
| 345 | BUG_ON(ret == -EIOCBQUEUED);
|
| 346 | if (ret > 0)
|
| 347 | *ppos = kiocb.ki_pos;
|
| 348 | return ret;
|
| 349 | }
|
| 350 | EXPORT_SYMBOL(vfs_iter_read);
|
| 351 |
|
| 352 | ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos)
|
| 353 | {
|
| 354 | struct kiocb kiocb;
|
| 355 | ssize_t ret;
|
| 356 |
|
| 357 | if (!file->f_op->write_iter)
|
| 358 | return -EINVAL;
|
| 359 |
|
| 360 | init_sync_kiocb(&kiocb, file);
|
| 361 | kiocb.ki_pos = *ppos;
|
| 362 |
|
| 363 | iter->type |= WRITE;
|
| 364 | ret = file->f_op->write_iter(&kiocb, iter);
|
| 365 | BUG_ON(ret == -EIOCBQUEUED);
|
| 366 | if (ret > 0)
|
| 367 | *ppos = kiocb.ki_pos;
|
| 368 | return ret;
|
| 369 | }
|
| 370 | EXPORT_SYMBOL(vfs_iter_write);
|
| 371 |
|
| 372 | |
| 373 | * rw_verify_area doesn't like huge counts. We limit
|
| 374 | * them to something that fits in "int" so that others
|
| 375 | * won't have to do range checks all the time.
|
| 376 |
|
| 377 | int rw_verify_area(int read_write, struct file *file, const loff_t *ppos, size_t count)
|
| 378 | {
|
| 379 | struct inode *inode;
|
| 380 | loff_t pos;
|
| 381 | int retval = -EINVAL;
|
| 382 |
|
| 383 | inode = file_inode(file);
|
| 384 | if (unlikely((ssize_t) count < 0))
|
| 385 | return retval;
|
| 386 | pos = *ppos;
|
| 387 | if (unlikely(pos < 0)) {
|
| 388 | if (!unsigned_offsets(file))
|
| 389 | return retval;
|
| 390 | if (count >= -pos)
|
| 391 | return -EOVERFLOW;
|
| 392 | } else if (unlikely((loff_t) (pos + count) < 0)) {
|
| 393 | if (!unsigned_offsets(file))
|
| 394 | return retval;
|
| 395 | }
|
| 396 |
|
| 397 | if (unlikely(inode->i_flctx && mandatory_lock(inode))) {
|
| 398 | retval = locks_mandatory_area(
|
| 399 | read_write == READ ? FLOCK_VERIFY_READ : FLOCK_VERIFY_WRITE,
|
| 400 | inode, file, pos, count);
|
| 401 | if (retval < 0)
|
| 402 | return retval;
|
| 403 | }
|
| 404 | retval = security_file_permission(file,
|
| 405 | read_write == READ ? MAY_READ : MAY_WRITE);
|
| 406 | if (retval)
|
| 407 | return retval;
|
| 408 | return count > MAX_RW_COUNT ? MAX_RW_COUNT : count;
|
| 409 | }
|
| 410 |
|
| 411 | static ssize_t new_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos)
|
| 412 | {
|
| 413 | struct iovec iov = { .iov_base = buf, .iov_len = len };
|
| 414 | struct kiocb kiocb;
|
| 415 | struct iov_iter iter;
|
| 416 | ssize_t ret;
|
| 417 |
|
| 418 | init_sync_kiocb(&kiocb, filp);
|
| 419 | kiocb.ki_pos = *ppos;
|
| 420 | iov_iter_init(&iter, READ, &iov, 1, len);
|
| 421 |
|
| 422 | ret = filp->f_op->read_iter(&kiocb, &iter);
|
| 423 | BUG_ON(ret == -EIOCBQUEUED);
|
| 424 | *ppos = kiocb.ki_pos;
|
| 425 | return ret;
|
| 426 | }
|
| 427 |
|
| 428 | ssize_t __vfs_read(struct file *file, char __user *buf, size_t count,
|
| 429 | loff_t *pos)
|
| 430 | {
|
| 431 | if (file->f_op->read)
|
| 432 | return file->f_op->read(file, buf, count, pos);
|
| 433 | else if (file->f_op->read_iter)
|
| 434 | return new_sync_read(file, buf, count, pos);
|
| 435 | else
|
| 436 | return -EINVAL;
|
| 437 | }
|
| 438 | EXPORT_SYMBOL(__vfs_read);
|
| 439 |
|
| 440 | ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos)
|
| 441 | {
|
| 442 | ssize_t ret;
|
| 443 |
|
| 444 | if (!(file->f_mode & FMODE_READ))
|
| 445 | return -EBADF;
|
| 446 | if (!(file->f_mode & FMODE_CAN_READ))
|
| 447 | return -EINVAL;
|
| 448 | if (unlikely(!access_ok(VERIFY_WRITE, buf, count)))
|
| 449 | return -EFAULT;
|
| 450 |
|
| 451 | ret = rw_verify_area(READ, file, pos, count);
|
| 452 | if (ret >= 0) {
|
| 453 | count = ret;
|
| 454 | ret = __vfs_read(file, buf, count, pos);
|
| 455 | if (ret > 0) {
|
| 456 | fsnotify_access(file);
|
| 457 | add_rchar(current, ret);
|
| 458 | }
|
| 459 | inc_syscr(current);
|
| 460 | }
|
| 461 |
|
| 462 | return ret;
|
| 463 | }
|
| 464 |
|
| 465 | EXPORT_SYMBOL(vfs_read);
|
| 466 |
|
| 467 | static ssize_t new_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos)
|
| 468 | {
|
| 469 | struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = len };
|
| 470 | struct kiocb kiocb;
|
| 471 | struct iov_iter iter;
|
| 472 | ssize_t ret;
|
| 473 |
|
| 474 | init_sync_kiocb(&kiocb, filp);
|
| 475 | kiocb.ki_pos = *ppos;
|
| 476 | iov_iter_init(&iter, WRITE, &iov, 1, len);
|
| 477 |
|
| 478 | ret = filp->f_op->write_iter(&kiocb, &iter);
|
| 479 | BUG_ON(ret == -EIOCBQUEUED);
|
| 480 | if (ret > 0)
|
| 481 | *ppos = kiocb.ki_pos;
|
| 482 | return ret;
|
| 483 | }
|
| 484 |
|
| 485 | ssize_t __vfs_write(struct file *file, const char __user *p, size_t count,
|
| 486 | loff_t *pos)
|
| 487 | {
|
| 488 | if (file->f_op->write)
|
| 489 | return file->f_op->write(file, p, count, pos);
|
| 490 | else if (file->f_op->write_iter)
|
| 491 | return new_sync_write(file, p, count, pos);
|
| 492 | else
|
| 493 | return -EINVAL;
|
| 494 | }
|
| 495 | EXPORT_SYMBOL(__vfs_write);
|
| 496 |
|
| 497 | ssize_t __kernel_write(struct file *file, const char *buf, size_t count, loff_t *pos)
|
| 498 | {
|
| 499 | mm_segment_t old_fs;
|
| 500 | const char __user *p;
|
| 501 | ssize_t ret;
|
| 502 |
|
| 503 | if (!(file->f_mode & FMODE_CAN_WRITE))
|
| 504 | return -EINVAL;
|
| 505 |
|
| 506 | old_fs = get_fs();
|
| 507 | set_fs(get_ds());
|
| 508 | p = (__force const char __user *)buf;
|
| 509 | if (count > MAX_RW_COUNT)
|
| 510 | count = MAX_RW_COUNT;
|
| 511 | ret = __vfs_write(file, p, count, pos);
|
| 512 | set_fs(old_fs);
|
| 513 | if (ret > 0) {
|
| 514 | fsnotify_modify(file);
|
| 515 | add_wchar(current, ret);
|
| 516 | }
|
| 517 | inc_syscw(current);
|
| 518 | return ret;
|
| 519 | }
|
| 520 |
|
| 521 | EXPORT_SYMBOL(__kernel_write);
|
| 522 |
|
| 523 | ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_t *pos)
|
| 524 | {
|
| 525 | ssize_t ret;
|
| 526 |
|
| 527 | if (!(file->f_mode & FMODE_WRITE))
|
| 528 | return -EBADF;
|
| 529 | if (!(file->f_mode & FMODE_CAN_WRITE))
|
| 530 | return -EINVAL;
|
| 531 | if (unlikely(!access_ok(VERIFY_READ, buf, count)))
|
| 532 | return -EFAULT;
|
| 533 |
|
| 534 | ret = rw_verify_area(WRITE, file, pos, count);
|
| 535 | if (ret >= 0) {
|
| 536 | count = ret;
|
| 537 | file_start_write(file);
|
| 538 | ret = __vfs_write(file, buf, count, pos);
|
| 539 | if (ret > 0) {
|
| 540 | fsnotify_modify(file);
|
| 541 | add_wchar(current, ret);
|
| 542 | }
|
| 543 | inc_syscw(current);
|
| 544 | file_end_write(file);
|
| 545 | }
|
| 546 |
|
| 547 | return ret;
|
| 548 | }
|
| 549 |
|
| 550 | EXPORT_SYMBOL(vfs_write);
|
| 551 |
|
| 552 | static inline loff_t file_pos_read(struct file *file)
|
| 553 | {
|
| 554 | return file->f_pos;
|
| 555 | }
|
| 556 |
|
| 557 | static inline void file_pos_write(struct file *file, loff_t pos)
|
| 558 | {
|
| 559 | file->f_pos = pos;
|
| 560 | }
|
| 561 |
|
| 562 | SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count)
|
| 563 | {
|
| 564 | struct fd f = fdget_pos(fd);
|
| 565 | ssize_t ret = -EBADF;
|
| 566 |
|
| 567 | if (f.file) {
|
| 568 | loff_t pos = file_pos_read(f.file);
|
| 569 | ret = vfs_read(f.file, buf, count, &pos);
|
| 570 | if (ret >= 0)
|
| 571 | file_pos_write(f.file, pos);
|
| 572 | fdput_pos(f);
|
| 573 | }
|
| 574 | return ret;
|
| 575 | }
|
| 576 |
|
| 577 | SYSCALL_DEFINE3(write, unsigned int, fd, const char __user *, buf,
|
| 578 | size_t, count)
|
| 579 | {
|
| 580 | struct fd f = fdget_pos(fd);
|
| 581 | ssize_t ret = -EBADF;
|
| 582 |
|
| 583 | if (f.file) {
|
| 584 | loff_t pos = file_pos_read(f.file);
|
| 585 | ret = vfs_write(f.file, buf, count, &pos);
|
| 586 | if (ret >= 0)
|
| 587 | file_pos_write(f.file, pos);
|
| 588 | fdput_pos(f);
|
| 589 | }
|
| 590 |
|
| 591 | return ret;
|
| 592 | }
|
| 593 |
|
| 594 | SYSCALL_DEFINE4(pread64, unsigned int, fd, char __user *, buf,
|
| 595 | size_t, count, loff_t, pos)
|
| 596 | {
|
| 597 | struct fd f;
|
| 598 | ssize_t ret = -EBADF;
|
| 599 |
|
| 600 | if (pos < 0)
|
| 601 | return -EINVAL;
|
| 602 |
|
| 603 | f = fdget(fd);
|
| 604 | if (f.file) {
|
| 605 | ret = -ESPIPE;
|
| 606 | if (f.file->f_mode & FMODE_PREAD)
|
| 607 | ret = vfs_read(f.file, buf, count, &pos);
|
| 608 | fdput(f);
|
| 609 | }
|
| 610 |
|
| 611 | return ret;
|
| 612 | }
|
| 613 |
|
| 614 | SYSCALL_DEFINE4(pwrite64, unsigned int, fd, const char __user *, buf,
|
| 615 | size_t, count, loff_t, pos)
|
| 616 | {
|
| 617 | struct fd f;
|
| 618 | ssize_t ret = -EBADF;
|
| 619 |
|
| 620 | if (pos < 0)
|
| 621 | return -EINVAL;
|
| 622 |
|
| 623 | f = fdget(fd);
|
| 624 | if (f.file) {
|
| 625 | ret = -ESPIPE;
|
| 626 | if (f.file->f_mode & FMODE_PWRITE)
|
| 627 | ret = vfs_write(f.file, buf, count, &pos);
|
| 628 | fdput(f);
|
| 629 | }
|
| 630 |
|
| 631 | return ret;
|
| 632 | }
|
| 633 |
|
| 634 | |
| 635 | * Reduce an iovec's length in-place. Return the resulting number of segments
|
| 636 |
|
| 637 | unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to)
|
| 638 | {
|
| 639 | unsigned long seg = 0;
|
| 640 | size_t len = 0;
|
| 641 |
|
| 642 | while (seg < nr_segs) {
|
| 643 | seg++;
|
| 644 | if (len + iov->iov_len >= to) {
|
| 645 | iov->iov_len = to - len;
|
| 646 | break;
|
| 647 | }
|
| 648 | len += iov->iov_len;
|
| 649 | iov++;
|
| 650 | }
|
| 651 | return seg;
|
| 652 | }
|
| 653 | EXPORT_SYMBOL(iov_shorten);
|
| 654 |
|
| 655 | static ssize_t do_iter_readv_writev(struct file *filp, struct iov_iter *iter,
|
| 656 | loff_t *ppos, iter_fn_t fn)
|
| 657 | {
|
| 658 | struct kiocb kiocb;
|
| 659 | ssize_t ret;
|
| 660 |
|
| 661 | init_sync_kiocb(&kiocb, filp);
|
| 662 | kiocb.ki_pos = *ppos;
|
| 663 |
|
| 664 | ret = fn(&kiocb, iter);
|
| 665 | BUG_ON(ret == -EIOCBQUEUED);
|
| 666 | *ppos = kiocb.ki_pos;
|
| 667 | return ret;
|
| 668 | }
|
| 669 |
|
| 670 |
|
| 671 | static ssize_t do_loop_readv_writev(struct file *filp, struct iov_iter *iter,
|
| 672 | loff_t *ppos, io_fn_t fn)
|
| 673 | {
|
| 674 | ssize_t ret = 0;
|
| 675 |
|
| 676 | while (iov_iter_count(iter)) {
|
| 677 | struct iovec iovec = iov_iter_iovec(iter);
|
| 678 | ssize_t nr;
|
| 679 |
|
| 680 | nr = fn(filp, iovec.iov_base, iovec.iov_len, ppos);
|
| 681 |
|
| 682 | if (nr < 0) {
|
| 683 | if (!ret)
|
| 684 | ret = nr;
|
| 685 | break;
|
| 686 | }
|
| 687 | ret += nr;
|
| 688 | if (nr != iovec.iov_len)
|
| 689 | break;
|
| 690 | iov_iter_advance(iter, nr);
|
| 691 | }
|
| 692 |
|
| 693 | return ret;
|
| 694 | }
|
| 695 |
|
| 696 |
|
| 697 | #define vrfy_dir(type) ((type) == READ ? VERIFY_WRITE : VERIFY_READ)
|
| 698 |
|
| 699 | ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector,
|
| 700 | unsigned long nr_segs, unsigned long fast_segs,
|
| 701 | struct iovec *fast_pointer,
|
| 702 | struct iovec **ret_pointer)
|
| 703 | {
|
| 704 | unsigned long seg;
|
| 705 | ssize_t ret;
|
| 706 | struct iovec *iov = fast_pointer;
|
| 707 |
|
| 708 | |
| 709 | * SuS says "The readv() function *may* fail if the iovcnt argument
|
| 710 | * was less than or equal to 0, or greater than {IOV_MAX}. Linux has
|
| 711 | * traditionally returned zero for zero segments, so...
|
| 712 |
|
| 713 | if (nr_segs == 0) {
|
| 714 | ret = 0;
|
| 715 | goto out;
|
| 716 | }
|
| 717 |
|
| 718 | |
| 719 | * First get the "struct iovec" from user memory and
|
| 720 | * verify all the pointers
|
| 721 |
|
| 722 | if (nr_segs > UIO_MAXIOV) {
|
| 723 | ret = -EINVAL;
|
| 724 | goto out;
|
| 725 | }
|
| 726 | if (nr_segs > fast_segs) {
|
| 727 | iov = kmalloc(nr_segs*sizeof(struct iovec), GFP_KERNEL);
|
| 728 | if (iov == NULL) {
|
| 729 | ret = -ENOMEM;
|
| 730 | goto out;
|
| 731 | }
|
| 732 | }
|
| 733 | if (copy_from_user(iov, uvector, nr_segs*sizeof(*uvector))) {
|
| 734 | ret = -EFAULT;
|
| 735 | goto out;
|
| 736 | }
|
| 737 |
|
| 738 | |
| 739 | * According to the Single Unix Specification we should return EINVAL
|
| 740 | * if an element length is < 0 when cast to ssize_t or if the
|
| 741 | * total length would overflow the ssize_t return value of the
|
| 742 | * system call.
|
| 743 | *
|
| 744 | * Linux caps all read/write calls to MAX_RW_COUNT, and avoids the
|
| 745 | * overflow case.
|
| 746 |
|
| 747 | ret = 0;
|
| 748 | for (seg = 0; seg < nr_segs; seg++) {
|
| 749 | void __user *buf = iov[seg].iov_base;
|
| 750 | ssize_t len = (ssize_t)iov[seg].iov_len;
|
| 751 |
|
| 752 | |
| 753 | * it's about to overflow ssize_t
|
| 754 | if (len < 0) {
|
| 755 | ret = -EINVAL;
|
| 756 | goto out;
|
| 757 | }
|
| 758 | if (type >= 0
|
| 759 | && unlikely(!access_ok(vrfy_dir(type), buf, len))) {
|
| 760 | ret = -EFAULT;
|
| 761 | goto out;
|
| 762 | }
|
| 763 | if (len > MAX_RW_COUNT - ret) {
|
| 764 | len = MAX_RW_COUNT - ret;
|
| 765 | iov[seg].iov_len = len;
|
| 766 | }
|
| 767 | ret += len;
|
| 768 | }
|
| 769 | out:
|
| 770 | *ret_pointer = iov;
|
| 771 | return ret;
|
| 772 | }
|
| 773 |
|
| 774 | static ssize_t do_readv_writev(int type, struct file *file,
|
| 775 | const struct iovec __user * uvector,
|
| 776 | unsigned long nr_segs, loff_t *pos)
|
| 777 | {
|
| 778 | size_t tot_len;
|
| 779 | struct iovec iovstack[UIO_FASTIOV];
|
| 780 | struct iovec *iov = iovstack;
|
| 781 | struct iov_iter iter;
|
| 782 | ssize_t ret;
|
| 783 | io_fn_t fn;
|
| 784 | iter_fn_t iter_fn;
|
| 785 |
|
| 786 | ret = import_iovec(type, uvector, nr_segs,
|
| 787 | ARRAY_SIZE(iovstack), &iov, &iter);
|
| 788 | if (ret < 0)
|
| 789 | return ret;
|
| 790 |
|
| 791 | tot_len = iov_iter_count(&iter);
|
| 792 | if (!tot_len)
|
| 793 | goto out;
|
| 794 | ret = rw_verify_area(type, file, pos, tot_len);
|
| 795 | if (ret < 0)
|
| 796 | goto out;
|
| 797 |
|
| 798 | if (type == READ) {
|
| 799 | fn = file->f_op->read;
|
| 800 | iter_fn = file->f_op->read_iter;
|
| 801 | } else {
|
| 802 | fn = (io_fn_t)file->f_op->write;
|
| 803 | iter_fn = file->f_op->write_iter;
|
| 804 | file_start_write(file);
|
| 805 | }
|
| 806 |
|
| 807 | if (iter_fn)
|
| 808 | ret = do_iter_readv_writev(file, &iter, pos, iter_fn);
|
| 809 | else
|
| 810 | ret = do_loop_readv_writev(file, &iter, pos, fn);
|
| 811 |
|
| 812 | if (type != READ)
|
| 813 | file_end_write(file);
|
| 814 |
|
| 815 | out:
|
| 816 | kfree(iov);
|
| 817 | if ((ret + (type == READ)) > 0) {
|
| 818 | if (type == READ)
|
| 819 | fsnotify_access(file);
|
| 820 | else
|
| 821 | fsnotify_modify(file);
|
| 822 | }
|
| 823 | return ret;
|
| 824 | }
|
| 825 |
|
| 826 | ssize_t vfs_readv(struct file *file, const struct iovec __user *vec,
|
| 827 | unsigned long vlen, loff_t *pos)
|
| 828 | {
|
| 829 | if (!(file->f_mode & FMODE_READ))
|
| 830 | return -EBADF;
|
| 831 | if (!(file->f_mode & FMODE_CAN_READ))
|
| 832 | return -EINVAL;
|
| 833 |
|
| 834 | return do_readv_writev(READ, file, vec, vlen, pos);
|
| 835 | }
|
| 836 |
|
| 837 | EXPORT_SYMBOL(vfs_readv);
|
| 838 |
|
| 839 | ssize_t vfs_writev(struct file *file, const struct iovec __user *vec,
|
| 840 | unsigned long vlen, loff_t *pos)
|
| 841 | {
|
| 842 | if (!(file->f_mode & FMODE_WRITE))
|
| 843 | return -EBADF;
|
| 844 | if (!(file->f_mode & FMODE_CAN_WRITE))
|
| 845 | return -EINVAL;
|
| 846 |
|
| 847 | return do_readv_writev(WRITE, file, vec, vlen, pos);
|
| 848 | }
|
| 849 |
|
| 850 | EXPORT_SYMBOL(vfs_writev);
|
| 851 |
|
| 852 | SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec,
|
| 853 | unsigned long, vlen)
|
| 854 | {
|
| 855 | struct fd f = fdget_pos(fd);
|
| 856 | ssize_t ret = -EBADF;
|
| 857 |
|
| 858 | if (f.file) {
|
| 859 | loff_t pos = file_pos_read(f.file);
|
| 860 | ret = vfs_readv(f.file, vec, vlen, &pos);
|
| 861 | if (ret >= 0)
|
| 862 | file_pos_write(f.file, pos);
|
| 863 | fdput_pos(f);
|
| 864 | }
|
| 865 |
|
| 866 | if (ret > 0)
|
| 867 | add_rchar(current, ret);
|
| 868 | inc_syscr(current);
|
| 869 | return ret;
|
| 870 | }
|
| 871 |
|
| 872 | SYSCALL_DEFINE3(writev, unsigned long, fd, const struct iovec __user *, vec,
|
| 873 | unsigned long, vlen)
|
| 874 | {
|
| 875 | struct fd f = fdget_pos(fd);
|
| 876 | ssize_t ret = -EBADF;
|
| 877 |
|
| 878 | if (f.file) {
|
| 879 | loff_t pos = file_pos_read(f.file);
|
| 880 | ret = vfs_writev(f.file, vec, vlen, &pos);
|
| 881 | if (ret >= 0)
|
| 882 | file_pos_write(f.file, pos);
|
| 883 | fdput_pos(f);
|
| 884 | }
|
| 885 |
|
| 886 | if (ret > 0)
|
| 887 | add_wchar(current, ret);
|
| 888 | inc_syscw(current);
|
| 889 | return ret;
|
| 890 | }
|
| 891 |
|
| 892 | static inline loff_t pos_from_hilo(unsigned long high, unsigned long low)
|
| 893 | {
|
| 894 | #define HALF_LONG_BITS (BITS_PER_LONG / 2)
|
| 895 | return (((loff_t)high << HALF_LONG_BITS) << HALF_LONG_BITS) | low;
|
| 896 | }
|
| 897 |
|
| 898 | SYSCALL_DEFINE5(preadv, unsigned long, fd, const struct iovec __user *, vec,
|
| 899 | unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h)
|
| 900 | {
|
| 901 | loff_t pos = pos_from_hilo(pos_h, pos_l);
|
| 902 | struct fd f;
|
| 903 | ssize_t ret = -EBADF;
|
| 904 |
|
| 905 | if (pos < 0)
|
| 906 | return -EINVAL;
|
| 907 |
|
| 908 | f = fdget(fd);
|
| 909 | if (f.file) {
|
| 910 | ret = -ESPIPE;
|
| 911 | if (f.file->f_mode & FMODE_PREAD)
|
| 912 | ret = vfs_readv(f.file, vec, vlen, &pos);
|
| 913 | fdput(f);
|
| 914 | }
|
| 915 |
|
| 916 | if (ret > 0)
|
| 917 | add_rchar(current, ret);
|
| 918 | inc_syscr(current);
|
| 919 | return ret;
|
| 920 | }
|
| 921 |
|
| 922 | SYSCALL_DEFINE5(pwritev, unsigned long, fd, const struct iovec __user *, vec,
|
| 923 | unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h)
|
| 924 | {
|
| 925 | loff_t pos = pos_from_hilo(pos_h, pos_l);
|
| 926 | struct fd f;
|
| 927 | ssize_t ret = -EBADF;
|
| 928 |
|
| 929 | if (pos < 0)
|
| 930 | return -EINVAL;
|
| 931 |
|
| 932 | f = fdget(fd);
|
| 933 | if (f.file) {
|
| 934 | ret = -ESPIPE;
|
| 935 | if (f.file->f_mode & FMODE_PWRITE)
|
| 936 | ret = vfs_writev(f.file, vec, vlen, &pos);
|
| 937 | fdput(f);
|
| 938 | }
|
| 939 |
|
| 940 | if (ret > 0)
|
| 941 | add_wchar(current, ret);
|
| 942 | inc_syscw(current);
|
| 943 | return ret;
|
| 944 | }
|
| 945 |
|
| 946 | #ifdef CONFIG_COMPAT
|
| 947 |
|
| 948 | static ssize_t compat_do_readv_writev(int type, struct file *file,
|
| 949 | const struct compat_iovec __user *uvector,
|
| 950 | unsigned long nr_segs, loff_t *pos)
|
| 951 | {
|
| 952 | compat_ssize_t tot_len;
|
| 953 | struct iovec iovstack[UIO_FASTIOV];
|
| 954 | struct iovec *iov = iovstack;
|
| 955 | struct iov_iter iter;
|
| 956 | ssize_t ret;
|
| 957 | io_fn_t fn;
|
| 958 | iter_fn_t iter_fn;
|
| 959 |
|
| 960 | ret = compat_import_iovec(type, uvector, nr_segs,
|
| 961 | UIO_FASTIOV, &iov, &iter);
|
| 962 | if (ret < 0)
|
| 963 | return ret;
|
| 964 |
|
| 965 | tot_len = iov_iter_count(&iter);
|
| 966 | if (!tot_len)
|
| 967 | goto out;
|
| 968 | ret = rw_verify_area(type, file, pos, tot_len);
|
| 969 | if (ret < 0)
|
| 970 | goto out;
|
| 971 |
|
| 972 | if (type == READ) {
|
| 973 | fn = file->f_op->read;
|
| 974 | iter_fn = file->f_op->read_iter;
|
| 975 | } else {
|
| 976 | fn = (io_fn_t)file->f_op->write;
|
| 977 | iter_fn = file->f_op->write_iter;
|
| 978 | file_start_write(file);
|
| 979 | }
|
| 980 |
|
| 981 | if (iter_fn)
|
| 982 | ret = do_iter_readv_writev(file, &iter, pos, iter_fn);
|
| 983 | else
|
| 984 | ret = do_loop_readv_writev(file, &iter, pos, fn);
|
| 985 |
|
| 986 | if (type != READ)
|
| 987 | file_end_write(file);
|
| 988 |
|
| 989 | out:
|
| 990 | kfree(iov);
|
| 991 | if ((ret + (type == READ)) > 0) {
|
| 992 | if (type == READ)
|
| 993 | fsnotify_access(file);
|
| 994 | else
|
| 995 | fsnotify_modify(file);
|
| 996 | }
|
| 997 | return ret;
|
| 998 | }
|
| 999 |
|
| 1000 | static size_t compat_readv(struct file *file,
|
| 1001 | const struct compat_iovec __user *vec,
|
| 1002 | unsigned long vlen, loff_t *pos)
|
| 1003 | {
|
| 1004 | ssize_t ret = -EBADF;
|
| 1005 |
|
| 1006 | if (!(file->f_mode & FMODE_READ))
|
| 1007 | goto out;
|
| 1008 |
|
| 1009 | ret = -EINVAL;
|
| 1010 | if (!(file->f_mode & FMODE_CAN_READ))
|
| 1011 | goto out;
|
| 1012 |
|
| 1013 | ret = compat_do_readv_writev(READ, file, vec, vlen, pos);
|
| 1014 |
|
| 1015 | out:
|
| 1016 | if (ret > 0)
|
| 1017 | add_rchar(current, ret);
|
| 1018 | inc_syscr(current);
|
| 1019 | return ret;
|
| 1020 | }
|
| 1021 |
|
| 1022 | COMPAT_SYSCALL_DEFINE3(readv, compat_ulong_t, fd,
|
| 1023 | const struct compat_iovec __user *,vec,
|
| 1024 | compat_ulong_t, vlen)
|
| 1025 | {
|
| 1026 | struct fd f = fdget_pos(fd);
|
| 1027 | ssize_t ret;
|
| 1028 | loff_t pos;
|
| 1029 |
|
| 1030 | if (!f.file)
|
| 1031 | return -EBADF;
|
| 1032 | pos = f.file->f_pos;
|
| 1033 | ret = compat_readv(f.file, vec, vlen, &pos);
|
| 1034 | if (ret >= 0)
|
| 1035 | f.file->f_pos = pos;
|
| 1036 | fdput_pos(f);
|
| 1037 | return ret;
|
| 1038 | }
|
| 1039 |
|
| 1040 | static long __compat_sys_preadv64(unsigned long fd,
|
| 1041 | const struct compat_iovec __user *vec,
|
| 1042 | unsigned long vlen, loff_t pos)
|
| 1043 | {
|
| 1044 | struct fd f;
|
| 1045 | ssize_t ret;
|
| 1046 |
|
| 1047 | if (pos < 0)
|
| 1048 | return -EINVAL;
|
| 1049 | f = fdget(fd);
|
| 1050 | if (!f.file)
|
| 1051 | return -EBADF;
|
| 1052 | ret = -ESPIPE;
|
| 1053 | if (f.file->f_mode & FMODE_PREAD)
|
| 1054 | ret = compat_readv(f.file, vec, vlen, &pos);
|
| 1055 | fdput(f);
|
| 1056 | return ret;
|
| 1057 | }
|
| 1058 |
|
| 1059 | #ifdef __ARCH_WANT_COMPAT_SYS_PREADV64
|
| 1060 | COMPAT_SYSCALL_DEFINE4(preadv64, unsigned long, fd,
|
| 1061 | const struct compat_iovec __user *,vec,
|
| 1062 | unsigned long, vlen, loff_t, pos)
|
| 1063 | {
|
| 1064 | return __compat_sys_preadv64(fd, vec, vlen, pos);
|
| 1065 | }
|
| 1066 | #endif
|
| 1067 |
|
| 1068 | COMPAT_SYSCALL_DEFINE5(preadv, compat_ulong_t, fd,
|
| 1069 | const struct compat_iovec __user *,vec,
|
| 1070 | compat_ulong_t, vlen, u32, pos_low, u32, pos_high)
|
| 1071 | {
|
| 1072 | loff_t pos = ((loff_t)pos_high << 32) | pos_low;
|
| 1073 |
|
| 1074 | return __compat_sys_preadv64(fd, vec, vlen, pos);
|
| 1075 | }
|
| 1076 |
|
| 1077 | static size_t compat_writev(struct file *file,
|
| 1078 | const struct compat_iovec __user *vec,
|
| 1079 | unsigned long vlen, loff_t *pos)
|
| 1080 | {
|
| 1081 | ssize_t ret = -EBADF;
|
| 1082 |
|
| 1083 | if (!(file->f_mode & FMODE_WRITE))
|
| 1084 | goto out;
|
| 1085 |
|
| 1086 | ret = -EINVAL;
|
| 1087 | if (!(file->f_mode & FMODE_CAN_WRITE))
|
| 1088 | goto out;
|
| 1089 |
|
| 1090 | ret = compat_do_readv_writev(WRITE, file, vec, vlen, pos);
|
| 1091 |
|
| 1092 | out:
|
| 1093 | if (ret > 0)
|
| 1094 | add_wchar(current, ret);
|
| 1095 | inc_syscw(current);
|
| 1096 | return ret;
|
| 1097 | }
|
| 1098 |
|
| 1099 | COMPAT_SYSCALL_DEFINE3(writev, compat_ulong_t, fd,
|
| 1100 | const struct compat_iovec __user *, vec,
|
| 1101 | compat_ulong_t, vlen)
|
| 1102 | {
|
| 1103 | struct fd f = fdget_pos(fd);
|
| 1104 | ssize_t ret;
|
| 1105 | loff_t pos;
|
| 1106 |
|
| 1107 | if (!f.file)
|
| 1108 | return -EBADF;
|
| 1109 | pos = f.file->f_pos;
|
| 1110 | ret = compat_writev(f.file, vec, vlen, &pos);
|
| 1111 | if (ret >= 0)
|
| 1112 | f.file->f_pos = pos;
|
| 1113 | fdput_pos(f);
|
| 1114 | return ret;
|
| 1115 | }
|
| 1116 |
|
| 1117 | static long __compat_sys_pwritev64(unsigned long fd,
|
| 1118 | const struct compat_iovec __user *vec,
|
| 1119 | unsigned long vlen, loff_t pos)
|
| 1120 | {
|
| 1121 | struct fd f;
|
| 1122 | ssize_t ret;
|
| 1123 |
|
| 1124 | if (pos < 0)
|
| 1125 | return -EINVAL;
|
| 1126 | f = fdget(fd);
|
| 1127 | if (!f.file)
|
| 1128 | return -EBADF;
|
| 1129 | ret = -ESPIPE;
|
| 1130 | if (f.file->f_mode & FMODE_PWRITE)
|
| 1131 | ret = compat_writev(f.file, vec, vlen, &pos);
|
| 1132 | fdput(f);
|
| 1133 | return ret;
|
| 1134 | }
|
| 1135 |
|
| 1136 | #ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64
|
| 1137 | COMPAT_SYSCALL_DEFINE4(pwritev64, unsigned long, fd,
|
| 1138 | const struct compat_iovec __user *,vec,
|
| 1139 | unsigned long, vlen, loff_t, pos)
|
| 1140 | {
|
| 1141 | return __compat_sys_pwritev64(fd, vec, vlen, pos);
|
| 1142 | }
|
| 1143 | #endif
|
| 1144 |
|
| 1145 | COMPAT_SYSCALL_DEFINE5(pwritev, compat_ulong_t, fd,
|
| 1146 | const struct compat_iovec __user *,vec,
|
| 1147 | compat_ulong_t, vlen, u32, pos_low, u32, pos_high)
|
| 1148 | {
|
| 1149 | loff_t pos = ((loff_t)pos_high << 32) | pos_low;
|
| 1150 |
|
| 1151 | return __compat_sys_pwritev64(fd, vec, vlen, pos);
|
| 1152 | }
|
| 1153 | #endif
|
| 1154 |
|
| 1155 | static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,
|
| 1156 | size_t count, loff_t max)
|
| 1157 | {
|
| 1158 | struct fd in, out;
|
| 1159 | struct inode *in_inode, *out_inode;
|
| 1160 | loff_t pos;
|
| 1161 | loff_t out_pos;
|
| 1162 | ssize_t retval;
|
| 1163 | int fl;
|
| 1164 |
|
| 1165 | |
| 1166 | * Get input file, and verify that it is ok..
|
| 1167 |
|
| 1168 | retval = -EBADF;
|
| 1169 | in = fdget(in_fd);
|
| 1170 | if (!in.file)
|
| 1171 | goto out;
|
| 1172 | if (!(in.file->f_mode & FMODE_READ))
|
| 1173 | goto fput_in;
|
| 1174 | retval = -ESPIPE;
|
| 1175 | if (!ppos) {
|
| 1176 | pos = in.file->f_pos;
|
| 1177 | } else {
|
| 1178 | pos = *ppos;
|
| 1179 | if (!(in.file->f_mode & FMODE_PREAD))
|
| 1180 | goto fput_in;
|
| 1181 | }
|
| 1182 | retval = rw_verify_area(READ, in.file, &pos, count);
|
| 1183 | if (retval < 0)
|
| 1184 | goto fput_in;
|
| 1185 | count = retval;
|
| 1186 |
|
| 1187 | |
| 1188 | * Get output file, and verify that it is ok..
|
| 1189 |
|
| 1190 | retval = -EBADF;
|
| 1191 | out = fdget(out_fd);
|
| 1192 | if (!out.file)
|
| 1193 | goto fput_in;
|
| 1194 | if (!(out.file->f_mode & FMODE_WRITE))
|
| 1195 | goto fput_out;
|
| 1196 | retval = -EINVAL;
|
| 1197 | in_inode = file_inode(in.file);
|
| 1198 | out_inode = file_inode(out.file);
|
| 1199 | out_pos = out.file->f_pos;
|
| 1200 | retval = rw_verify_area(WRITE, out.file, &out_pos, count);
|
| 1201 | if (retval < 0)
|
| 1202 | goto fput_out;
|
| 1203 | count = retval;
|
| 1204 |
|
| 1205 | if (!max)
|
| 1206 | max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes);
|
| 1207 |
|
| 1208 | if (unlikely(pos + count > max)) {
|
| 1209 | retval = -EOVERFLOW;
|
| 1210 | if (pos >= max)
|
| 1211 | goto fput_out;
|
| 1212 | count = max - pos;
|
| 1213 | }
|
| 1214 |
|
| 1215 | fl = 0;
|
| 1216 | #if 0 |
| 1217 | /*
|
| 1218 | * We need to debate whether we can enable this or not. The
|
| 1219 | * man page documents EAGAIN return for the output at least,
|
| 1220 | * and the application is arguably buggy if it doesn't expect
|
| 1221 | * EAGAIN on a non-blocking file descriptor.
|
| 1222 | */
|
| 1223 | if (in.file->f_flags & O_NONBLOCK)
|
| 1224 | fl = SPLICE_F_NONBLOCK;
|
| 1225 | #endif
|
| 1226 | file_start_write(out.file);
|
| 1227 | retval = do_splice_direct(in.file, &pos, out.file, &out_pos, count, fl);
|
| 1228 | file_end_write(out.file);
|
| 1229 |
|
| 1230 | if (retval > 0) {
|
| 1231 | add_rchar(current, retval);
|
| 1232 | add_wchar(current, retval);
|
| 1233 | fsnotify_access(in.file);
|
| 1234 | fsnotify_modify(out.file);
|
| 1235 | out.file->f_pos = out_pos;
|
| 1236 | if (ppos)
|
| 1237 | *ppos = pos;
|
| 1238 | else
|
| 1239 | in.file->f_pos = pos;
|
| 1240 | }
|
| 1241 |
|
| 1242 | inc_syscr(current);
|
| 1243 | inc_syscw(current);
|
| 1244 | if (pos > max)
|
| 1245 | retval = -EOVERFLOW;
|
| 1246 |
|
| 1247 | fput_out:
|
| 1248 | fdput(out);
|
| 1249 | fput_in:
|
| 1250 | fdput(in);
|
| 1251 | out:
|
| 1252 | return retval;
|
| 1253 | }
|
| 1254 |
|
| 1255 | SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, off_t __user *, offset, size_t, count)
|
| 1256 | {
|
| 1257 | loff_t pos;
|
| 1258 | off_t off;
|
| 1259 | ssize_t ret;
|
| 1260 |
|
| 1261 | if (offset) {
|
| 1262 | if (unlikely(get_user(off, offset)))
|
| 1263 | return -EFAULT;
|
| 1264 | pos = off;
|
| 1265 | ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS);
|
| 1266 | if (unlikely(put_user(pos, offset)))
|
| 1267 | return -EFAULT;
|
| 1268 | return ret;
|
| 1269 | }
|
| 1270 |
|
| 1271 | return do_sendfile(out_fd, in_fd, NULL, count, 0);
|
| 1272 | }
|
| 1273 |
|
| 1274 | SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, loff_t __user *, offset, size_t, count)
|
| 1275 | {
|
| 1276 | loff_t pos;
|
| 1277 | ssize_t ret;
|
| 1278 |
|
| 1279 | if (offset) {
|
| 1280 | if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t))))
|
| 1281 | return -EFAULT;
|
| 1282 | ret = do_sendfile(out_fd, in_fd, &pos, count, 0);
|
| 1283 | if (unlikely(put_user(pos, offset)))
|
| 1284 | return -EFAULT;
|
| 1285 | return ret;
|
| 1286 | }
|
| 1287 |
|
| 1288 | return do_sendfile(out_fd, in_fd, NULL, count, 0);
|
| 1289 | }
|
| 1290 |
|
| 1291 | #ifdef CONFIG_COMPAT
|
| 1292 | COMPAT_SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd,
|
| 1293 | compat_off_t __user *, offset, compat_size_t, count)
|
| 1294 | {
|
| 1295 | loff_t pos;
|
| 1296 | off_t off;
|
| 1297 | ssize_t ret;
|
| 1298 |
|
| 1299 | if (offset) {
|
| 1300 | if (unlikely(get_user(off, offset)))
|
| 1301 | return -EFAULT;
|
| 1302 | pos = off;
|
| 1303 | ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS);
|
| 1304 | if (unlikely(put_user(pos, offset)))
|
| 1305 | return -EFAULT;
|
| 1306 | return ret;
|
| 1307 | }
|
| 1308 |
|
| 1309 | return do_sendfile(out_fd, in_fd, NULL, count, 0);
|
| 1310 | }
|
| 1311 |
|
| 1312 | COMPAT_SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd,
|
| 1313 | compat_loff_t __user *, offset, compat_size_t, count)
|
| 1314 | {
|
| 1315 | loff_t pos;
|
| 1316 | ssize_t ret;
|
| 1317 |
|
| 1318 | if (offset) {
|
| 1319 | if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t))))
|
| 1320 | return -EFAULT;
|
| 1321 | ret = do_sendfile(out_fd, in_fd, &pos, count, 0);
|
| 1322 | if (unlikely(put_user(pos, offset)))
|
| 1323 | return -EFAULT;
|
| 1324 | return ret;
|
| 1325 | }
|
| 1326 |
|
| 1327 | return do_sendfile(out_fd, in_fd, NULL, count, 0);
|
| 1328 | }
|
| 1329 | #endif
|