Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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> |
Robert Love | 0eeca28 | 2005-07-12 17:06:03 -0400 | [diff] [blame] | 12 | #include <linux/fsnotify.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 13 | #include <linux/security.h> |
Paul Gortmaker | 630d9c4 | 2011-11-16 23:57:37 -0500 | [diff] [blame] | 14 | #include <linux/export.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 15 | #include <linux/syscalls.h> |
Linus Torvalds | e28cc71 | 2006-01-04 16:20:40 -0800 | [diff] [blame] | 16 | #include <linux/pagemap.h> |
Jens Axboe | d6b29d7 | 2007-06-04 09:59:47 +0200 | [diff] [blame] | 17 | #include <linux/splice.h> |
Al Viro | 561c673 | 2013-02-24 10:52:26 -0500 | [diff] [blame] | 18 | #include <linux/compat.h> |
Al Viro | 06ae43f | 2013-03-20 13:19:30 -0400 | [diff] [blame] | 19 | #include "internal.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 20 | |
| 21 | #include <asm/uaccess.h> |
| 22 | #include <asm/unistd.h> |
| 23 | |
Al Viro | c0bd14af | 2013-05-04 15:00:54 -0400 | [diff] [blame] | 24 | typedef ssize_t (*io_fn_t)(struct file *, char __user *, size_t, loff_t *); |
| 25 | typedef ssize_t (*iov_fn_t)(struct kiocb *, const struct iovec *, |
| 26 | unsigned long, loff_t); |
| 27 | |
Arjan van de Ven | 4b6f5d2 | 2006-03-28 01:56:42 -0800 | [diff] [blame] | 28 | const struct file_operations generic_ro_fops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 29 | .llseek = generic_file_llseek, |
Badari Pulavarty | 543ade1 | 2006-09-30 23:28:48 -0700 | [diff] [blame] | 30 | .read = do_sync_read, |
| 31 | .aio_read = generic_file_aio_read, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | .mmap = generic_file_readonly_mmap, |
Jens Axboe | 534f2aa | 2007-06-01 14:52:37 +0200 | [diff] [blame] | 33 | .splice_read = generic_file_splice_read, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 34 | }; |
| 35 | |
| 36 | EXPORT_SYMBOL(generic_ro_fops); |
| 37 | |
Al Viro | cccb5a1 | 2010-12-17 07:44:05 -0500 | [diff] [blame] | 38 | static inline int unsigned_offsets(struct file *file) |
KAMEZAWA Hiroyuki | 4a3956c | 2010-10-01 14:20:22 -0700 | [diff] [blame] | 39 | { |
Al Viro | cccb5a1 | 2010-12-17 07:44:05 -0500 | [diff] [blame] | 40 | return file->f_mode & FMODE_UNSIGNED_OFFSET; |
KAMEZAWA Hiroyuki | 4a3956c | 2010-10-01 14:20:22 -0700 | [diff] [blame] | 41 | } |
| 42 | |
Andi Kleen | ef3d0fd | 2011-09-15 16:06:48 -0700 | [diff] [blame] | 43 | static loff_t lseek_execute(struct file *file, struct inode *inode, |
| 44 | loff_t offset, loff_t maxsize) |
| 45 | { |
| 46 | if (offset < 0 && !unsigned_offsets(file)) |
| 47 | return -EINVAL; |
| 48 | if (offset > maxsize) |
| 49 | return -EINVAL; |
| 50 | |
| 51 | if (offset != file->f_pos) { |
| 52 | file->f_pos = offset; |
| 53 | file->f_version = 0; |
| 54 | } |
| 55 | return offset; |
| 56 | } |
| 57 | |
Christoph Hellwig | 3a8cff4 | 2008-08-11 15:37:17 +0200 | [diff] [blame] | 58 | /** |
Andi Kleen | 5760495 | 2011-09-15 16:06:50 -0700 | [diff] [blame] | 59 | * generic_file_llseek_size - generic llseek implementation for regular files |
Christoph Hellwig | 3a8cff4 | 2008-08-11 15:37:17 +0200 | [diff] [blame] | 60 | * @file: file structure to seek on |
| 61 | * @offset: file offset to seek to |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 62 | * @whence: type of seek |
Eric Sandeen | e8b96eb | 2012-04-30 13:11:29 -0500 | [diff] [blame] | 63 | * @size: max size of this file in file system |
| 64 | * @eof: offset used for SEEK_END position |
Christoph Hellwig | 3a8cff4 | 2008-08-11 15:37:17 +0200 | [diff] [blame] | 65 | * |
Andi Kleen | 5760495 | 2011-09-15 16:06:50 -0700 | [diff] [blame] | 66 | * This is a variant of generic_file_llseek that allows passing in a custom |
Eric Sandeen | e8b96eb | 2012-04-30 13:11:29 -0500 | [diff] [blame] | 67 | * maximum file size and a custom EOF position, for e.g. hashed directories |
Andi Kleen | ef3d0fd | 2011-09-15 16:06:48 -0700 | [diff] [blame] | 68 | * |
| 69 | * Synchronization: |
Andi Kleen | 5760495 | 2011-09-15 16:06:50 -0700 | [diff] [blame] | 70 | * SEEK_SET and SEEK_END are unsynchronized (but atomic on 64bit platforms) |
Andi Kleen | ef3d0fd | 2011-09-15 16:06:48 -0700 | [diff] [blame] | 71 | * SEEK_CUR is synchronized against other SEEK_CURs, but not read/writes. |
| 72 | * read/writes behave like SEEK_SET against seeks. |
Christoph Hellwig | 3a8cff4 | 2008-08-11 15:37:17 +0200 | [diff] [blame] | 73 | */ |
Andi Kleen | 9465efc | 2008-06-27 11:05:24 +0200 | [diff] [blame] | 74 | loff_t |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 75 | generic_file_llseek_size(struct file *file, loff_t offset, int whence, |
Eric Sandeen | e8b96eb | 2012-04-30 13:11:29 -0500 | [diff] [blame] | 76 | loff_t maxsize, loff_t eof) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 77 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 78 | struct inode *inode = file->f_mapping->host; |
| 79 | |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 80 | switch (whence) { |
Christoph Hellwig | 3a8cff4 | 2008-08-11 15:37:17 +0200 | [diff] [blame] | 81 | case SEEK_END: |
Eric Sandeen | e8b96eb | 2012-04-30 13:11:29 -0500 | [diff] [blame] | 82 | offset += eof; |
Christoph Hellwig | 3a8cff4 | 2008-08-11 15:37:17 +0200 | [diff] [blame] | 83 | break; |
| 84 | case SEEK_CUR: |
Alain Knaff | 5b6f1eb | 2008-11-10 17:08:08 -0800 | [diff] [blame] | 85 | /* |
| 86 | * Here we special-case the lseek(fd, 0, SEEK_CUR) |
| 87 | * position-querying operation. Avoid rewriting the "same" |
| 88 | * f_pos value back to the file because a concurrent read(), |
| 89 | * write() or lseek() might have altered it |
| 90 | */ |
| 91 | if (offset == 0) |
| 92 | return file->f_pos; |
Andi Kleen | ef3d0fd | 2011-09-15 16:06:48 -0700 | [diff] [blame] | 93 | /* |
| 94 | * f_lock protects against read/modify/write race with other |
| 95 | * SEEK_CURs. Note that parallel writes and reads behave |
| 96 | * like SEEK_SET. |
| 97 | */ |
| 98 | spin_lock(&file->f_lock); |
| 99 | offset = lseek_execute(file, inode, file->f_pos + offset, |
Andi Kleen | 5760495 | 2011-09-15 16:06:50 -0700 | [diff] [blame] | 100 | maxsize); |
Andi Kleen | ef3d0fd | 2011-09-15 16:06:48 -0700 | [diff] [blame] | 101 | spin_unlock(&file->f_lock); |
| 102 | return offset; |
Josef Bacik | 982d816 | 2011-07-18 13:21:35 -0400 | [diff] [blame] | 103 | case SEEK_DATA: |
| 104 | /* |
| 105 | * In the generic case the entire file is data, so as long as |
| 106 | * offset isn't at the end of the file then the offset is data. |
| 107 | */ |
Eric Sandeen | e8b96eb | 2012-04-30 13:11:29 -0500 | [diff] [blame] | 108 | if (offset >= eof) |
Josef Bacik | 982d816 | 2011-07-18 13:21:35 -0400 | [diff] [blame] | 109 | return -ENXIO; |
| 110 | break; |
| 111 | case SEEK_HOLE: |
| 112 | /* |
| 113 | * There is a virtual hole at the end of the file, so as long as |
| 114 | * offset isn't i_size or larger, return i_size. |
| 115 | */ |
Eric Sandeen | e8b96eb | 2012-04-30 13:11:29 -0500 | [diff] [blame] | 116 | if (offset >= eof) |
Josef Bacik | 982d816 | 2011-07-18 13:21:35 -0400 | [diff] [blame] | 117 | return -ENXIO; |
Eric Sandeen | e8b96eb | 2012-04-30 13:11:29 -0500 | [diff] [blame] | 118 | offset = eof; |
Josef Bacik | 982d816 | 2011-07-18 13:21:35 -0400 | [diff] [blame] | 119 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 120 | } |
Christoph Hellwig | 3a8cff4 | 2008-08-11 15:37:17 +0200 | [diff] [blame] | 121 | |
Andi Kleen | 5760495 | 2011-09-15 16:06:50 -0700 | [diff] [blame] | 122 | return lseek_execute(file, inode, offset, maxsize); |
| 123 | } |
| 124 | EXPORT_SYMBOL(generic_file_llseek_size); |
| 125 | |
| 126 | /** |
| 127 | * generic_file_llseek - generic llseek implementation for regular files |
| 128 | * @file: file structure to seek on |
| 129 | * @offset: file offset to seek to |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 130 | * @whence: type of seek |
Andi Kleen | 5760495 | 2011-09-15 16:06:50 -0700 | [diff] [blame] | 131 | * |
| 132 | * This is a generic implemenation of ->llseek useable for all normal local |
| 133 | * filesystems. It just updates the file offset to the value specified by |
Ming Lei | 546ae2d | 2013-04-29 15:06:07 -0700 | [diff] [blame] | 134 | * @offset and @whence. |
Andi Kleen | 5760495 | 2011-09-15 16:06:50 -0700 | [diff] [blame] | 135 | */ |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 136 | loff_t generic_file_llseek(struct file *file, loff_t offset, int whence) |
Andi Kleen | 5760495 | 2011-09-15 16:06:50 -0700 | [diff] [blame] | 137 | { |
| 138 | struct inode *inode = file->f_mapping->host; |
| 139 | |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 140 | return generic_file_llseek_size(file, offset, whence, |
Eric Sandeen | e8b96eb | 2012-04-30 13:11:29 -0500 | [diff] [blame] | 141 | inode->i_sb->s_maxbytes, |
| 142 | i_size_read(inode)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 143 | } |
Andi Kleen | 9465efc | 2008-06-27 11:05:24 +0200 | [diff] [blame] | 144 | EXPORT_SYMBOL(generic_file_llseek); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 145 | |
jan Blunck | ae6afc3 | 2010-05-26 14:44:48 -0700 | [diff] [blame] | 146 | /** |
| 147 | * noop_llseek - No Operation Performed llseek implementation |
| 148 | * @file: file structure to seek on |
| 149 | * @offset: file offset to seek to |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 150 | * @whence: type of seek |
jan Blunck | ae6afc3 | 2010-05-26 14:44:48 -0700 | [diff] [blame] | 151 | * |
| 152 | * This is an implementation of ->llseek useable for the rare special case when |
| 153 | * userspace expects the seek to succeed but the (device) file is actually not |
| 154 | * able to perform the seek. In this case you use noop_llseek() instead of |
| 155 | * falling back to the default implementation of ->llseek. |
| 156 | */ |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 157 | loff_t noop_llseek(struct file *file, loff_t offset, int whence) |
jan Blunck | ae6afc3 | 2010-05-26 14:44:48 -0700 | [diff] [blame] | 158 | { |
| 159 | return file->f_pos; |
| 160 | } |
| 161 | EXPORT_SYMBOL(noop_llseek); |
| 162 | |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 163 | loff_t no_llseek(struct file *file, loff_t offset, int whence) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 164 | { |
| 165 | return -ESPIPE; |
| 166 | } |
| 167 | EXPORT_SYMBOL(no_llseek); |
| 168 | |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 169 | loff_t default_llseek(struct file *file, loff_t offset, int whence) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 170 | { |
Al Viro | 496ad9a | 2013-01-23 17:07:38 -0500 | [diff] [blame] | 171 | struct inode *inode = file_inode(file); |
David Sterba | 16abef0 | 2008-04-22 15:09:22 +0200 | [diff] [blame] | 172 | loff_t retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 173 | |
Josef Bacik | 982d816 | 2011-07-18 13:21:35 -0400 | [diff] [blame] | 174 | mutex_lock(&inode->i_mutex); |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 175 | switch (whence) { |
Chris Snook | 7b8e892 | 2007-05-08 00:24:13 -0700 | [diff] [blame] | 176 | case SEEK_END: |
Josef Bacik | 982d816 | 2011-07-18 13:21:35 -0400 | [diff] [blame] | 177 | offset += i_size_read(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 178 | break; |
Chris Snook | 7b8e892 | 2007-05-08 00:24:13 -0700 | [diff] [blame] | 179 | case SEEK_CUR: |
Alain Knaff | 5b6f1eb | 2008-11-10 17:08:08 -0800 | [diff] [blame] | 180 | if (offset == 0) { |
| 181 | retval = file->f_pos; |
| 182 | goto out; |
| 183 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 184 | offset += file->f_pos; |
Josef Bacik | 982d816 | 2011-07-18 13:21:35 -0400 | [diff] [blame] | 185 | break; |
| 186 | case SEEK_DATA: |
| 187 | /* |
| 188 | * In the generic case the entire file is data, so as |
| 189 | * long as offset isn't at the end of the file then the |
| 190 | * offset is data. |
| 191 | */ |
Dan Carpenter | bacb2d8 | 2011-07-26 17:25:20 +0300 | [diff] [blame] | 192 | if (offset >= inode->i_size) { |
| 193 | retval = -ENXIO; |
| 194 | goto out; |
| 195 | } |
Josef Bacik | 982d816 | 2011-07-18 13:21:35 -0400 | [diff] [blame] | 196 | break; |
| 197 | case SEEK_HOLE: |
| 198 | /* |
| 199 | * There is a virtual hole at the end of the file, so |
| 200 | * as long as offset isn't i_size or larger, return |
| 201 | * i_size. |
| 202 | */ |
Dan Carpenter | bacb2d8 | 2011-07-26 17:25:20 +0300 | [diff] [blame] | 203 | if (offset >= inode->i_size) { |
| 204 | retval = -ENXIO; |
| 205 | goto out; |
| 206 | } |
Josef Bacik | 982d816 | 2011-07-18 13:21:35 -0400 | [diff] [blame] | 207 | offset = inode->i_size; |
| 208 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 209 | } |
| 210 | retval = -EINVAL; |
Al Viro | cccb5a1 | 2010-12-17 07:44:05 -0500 | [diff] [blame] | 211 | if (offset >= 0 || unsigned_offsets(file)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 212 | if (offset != file->f_pos) { |
| 213 | file->f_pos = offset; |
| 214 | file->f_version = 0; |
| 215 | } |
| 216 | retval = offset; |
| 217 | } |
Alain Knaff | 5b6f1eb | 2008-11-10 17:08:08 -0800 | [diff] [blame] | 218 | out: |
Josef Bacik | 982d816 | 2011-07-18 13:21:35 -0400 | [diff] [blame] | 219 | mutex_unlock(&inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 220 | return retval; |
| 221 | } |
| 222 | EXPORT_SYMBOL(default_llseek); |
| 223 | |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 224 | loff_t vfs_llseek(struct file *file, loff_t offset, int whence) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 225 | { |
| 226 | loff_t (*fn)(struct file *, loff_t, int); |
| 227 | |
| 228 | fn = no_llseek; |
| 229 | if (file->f_mode & FMODE_LSEEK) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 230 | if (file->f_op && file->f_op->llseek) |
| 231 | fn = file->f_op->llseek; |
| 232 | } |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 233 | return fn(file, offset, whence); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 234 | } |
| 235 | EXPORT_SYMBOL(vfs_llseek); |
| 236 | |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 237 | SYSCALL_DEFINE3(lseek, unsigned int, fd, off_t, offset, unsigned int, whence) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 238 | { |
| 239 | off_t retval; |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 240 | struct fd f = fdget(fd); |
| 241 | if (!f.file) |
| 242 | return -EBADF; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 243 | |
| 244 | retval = -EINVAL; |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 245 | if (whence <= SEEK_MAX) { |
| 246 | loff_t res = vfs_llseek(f.file, offset, whence); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 247 | retval = res; |
| 248 | if (res != (loff_t)retval) |
| 249 | retval = -EOVERFLOW; /* LFS: should only happen on 32 bit platforms */ |
| 250 | } |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 251 | fdput(f); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 252 | return retval; |
| 253 | } |
| 254 | |
Al Viro | 561c673 | 2013-02-24 10:52:26 -0500 | [diff] [blame] | 255 | #ifdef CONFIG_COMPAT |
| 256 | COMPAT_SYSCALL_DEFINE3(lseek, unsigned int, fd, compat_off_t, offset, unsigned int, whence) |
| 257 | { |
| 258 | return sys_lseek(fd, offset, whence); |
| 259 | } |
| 260 | #endif |
| 261 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 262 | #ifdef __ARCH_WANT_SYS_LLSEEK |
Heiko Carstens | 003d7ab | 2009-01-14 14:14:21 +0100 | [diff] [blame] | 263 | SYSCALL_DEFINE5(llseek, unsigned int, fd, unsigned long, offset_high, |
| 264 | unsigned long, offset_low, loff_t __user *, result, |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 265 | unsigned int, whence) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 266 | { |
| 267 | int retval; |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 268 | struct fd f = fdget(fd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 269 | loff_t offset; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 270 | |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 271 | if (!f.file) |
| 272 | return -EBADF; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 273 | |
| 274 | retval = -EINVAL; |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 275 | if (whence > SEEK_MAX) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 276 | goto out_putf; |
| 277 | |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 278 | offset = vfs_llseek(f.file, ((loff_t) offset_high << 32) | offset_low, |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 279 | whence); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 280 | |
| 281 | retval = (int)offset; |
| 282 | if (offset >= 0) { |
| 283 | retval = -EFAULT; |
| 284 | if (!copy_to_user(result, &offset, sizeof(offset))) |
| 285 | retval = 0; |
| 286 | } |
| 287 | out_putf: |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 288 | fdput(f); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 289 | return retval; |
| 290 | } |
| 291 | #endif |
| 292 | |
Linus Torvalds | e28cc71 | 2006-01-04 16:20:40 -0800 | [diff] [blame] | 293 | /* |
| 294 | * rw_verify_area doesn't like huge counts. We limit |
| 295 | * them to something that fits in "int" so that others |
| 296 | * won't have to do range checks all the time. |
| 297 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 298 | int rw_verify_area(int read_write, struct file *file, loff_t *ppos, size_t count) |
| 299 | { |
| 300 | struct inode *inode; |
| 301 | loff_t pos; |
James Morris | c43e259 | 2008-01-12 22:05:48 +1100 | [diff] [blame] | 302 | int retval = -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 303 | |
Al Viro | 496ad9a | 2013-01-23 17:07:38 -0500 | [diff] [blame] | 304 | inode = file_inode(file); |
Linus Torvalds | e28cc71 | 2006-01-04 16:20:40 -0800 | [diff] [blame] | 305 | if (unlikely((ssize_t) count < 0)) |
James Morris | c43e259 | 2008-01-12 22:05:48 +1100 | [diff] [blame] | 306 | return retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 307 | pos = *ppos; |
Al Viro | cccb5a1 | 2010-12-17 07:44:05 -0500 | [diff] [blame] | 308 | if (unlikely(pos < 0)) { |
| 309 | if (!unsigned_offsets(file)) |
| 310 | return retval; |
| 311 | if (count >= -pos) /* both values are in 0..LLONG_MAX */ |
| 312 | return -EOVERFLOW; |
| 313 | } else if (unlikely((loff_t) (pos + count) < 0)) { |
| 314 | if (!unsigned_offsets(file)) |
KAMEZAWA Hiroyuki | 4a3956c | 2010-10-01 14:20:22 -0700 | [diff] [blame] | 315 | return retval; |
| 316 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 317 | |
Pavel Emelyanov | a16877c | 2007-10-01 14:41:11 -0700 | [diff] [blame] | 318 | if (unlikely(inode->i_flock && mandatory_lock(inode))) { |
James Morris | c43e259 | 2008-01-12 22:05:48 +1100 | [diff] [blame] | 319 | retval = locks_mandatory_area( |
Linus Torvalds | e28cc71 | 2006-01-04 16:20:40 -0800 | [diff] [blame] | 320 | read_write == READ ? FLOCK_VERIFY_READ : FLOCK_VERIFY_WRITE, |
| 321 | inode, file, pos, count); |
| 322 | if (retval < 0) |
| 323 | return retval; |
| 324 | } |
James Morris | c43e259 | 2008-01-12 22:05:48 +1100 | [diff] [blame] | 325 | retval = security_file_permission(file, |
| 326 | read_write == READ ? MAY_READ : MAY_WRITE); |
| 327 | if (retval) |
| 328 | return retval; |
Linus Torvalds | e28cc71 | 2006-01-04 16:20:40 -0800 | [diff] [blame] | 329 | return count > MAX_RW_COUNT ? MAX_RW_COUNT : count; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 330 | } |
| 331 | |
| 332 | ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos) |
| 333 | { |
Badari Pulavarty | 027445c | 2006-09-30 23:28:46 -0700 | [diff] [blame] | 334 | struct iovec iov = { .iov_base = buf, .iov_len = len }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 335 | struct kiocb kiocb; |
| 336 | ssize_t ret; |
| 337 | |
| 338 | init_sync_kiocb(&kiocb, filp); |
| 339 | kiocb.ki_pos = *ppos; |
Badari Pulavarty | 027445c | 2006-09-30 23:28:46 -0700 | [diff] [blame] | 340 | kiocb.ki_left = len; |
David Howells | 61964eb | 2010-03-24 17:09:19 +0000 | [diff] [blame] | 341 | kiocb.ki_nbytes = len; |
Badari Pulavarty | 027445c | 2006-09-30 23:28:46 -0700 | [diff] [blame] | 342 | |
Zach Brown | 41003a7 | 2013-05-07 16:18:25 -0700 | [diff] [blame^] | 343 | ret = filp->f_op->aio_read(&kiocb, &iov, 1, kiocb.ki_pos); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 344 | if (-EIOCBQUEUED == ret) |
| 345 | ret = wait_on_sync_kiocb(&kiocb); |
| 346 | *ppos = kiocb.ki_pos; |
| 347 | return ret; |
| 348 | } |
| 349 | |
| 350 | EXPORT_SYMBOL(do_sync_read); |
| 351 | |
| 352 | ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos) |
| 353 | { |
| 354 | ssize_t ret; |
| 355 | |
| 356 | if (!(file->f_mode & FMODE_READ)) |
| 357 | return -EBADF; |
| 358 | if (!file->f_op || (!file->f_op->read && !file->f_op->aio_read)) |
| 359 | return -EINVAL; |
| 360 | if (unlikely(!access_ok(VERIFY_WRITE, buf, count))) |
| 361 | return -EFAULT; |
| 362 | |
| 363 | ret = rw_verify_area(READ, file, pos, count); |
Linus Torvalds | e28cc71 | 2006-01-04 16:20:40 -0800 | [diff] [blame] | 364 | if (ret >= 0) { |
| 365 | count = ret; |
James Morris | c43e259 | 2008-01-12 22:05:48 +1100 | [diff] [blame] | 366 | if (file->f_op->read) |
| 367 | ret = file->f_op->read(file, buf, count, pos); |
| 368 | else |
| 369 | ret = do_sync_read(file, buf, count, pos); |
| 370 | if (ret > 0) { |
Eric Paris | 2a12a9d | 2009-12-17 21:24:21 -0500 | [diff] [blame] | 371 | fsnotify_access(file); |
James Morris | c43e259 | 2008-01-12 22:05:48 +1100 | [diff] [blame] | 372 | add_rchar(current, ret); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 373 | } |
James Morris | c43e259 | 2008-01-12 22:05:48 +1100 | [diff] [blame] | 374 | inc_syscr(current); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 375 | } |
| 376 | |
| 377 | return ret; |
| 378 | } |
| 379 | |
| 380 | EXPORT_SYMBOL(vfs_read); |
| 381 | |
| 382 | ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos) |
| 383 | { |
Badari Pulavarty | 027445c | 2006-09-30 23:28:46 -0700 | [diff] [blame] | 384 | struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = len }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 385 | struct kiocb kiocb; |
| 386 | ssize_t ret; |
| 387 | |
| 388 | init_sync_kiocb(&kiocb, filp); |
| 389 | kiocb.ki_pos = *ppos; |
Badari Pulavarty | 027445c | 2006-09-30 23:28:46 -0700 | [diff] [blame] | 390 | kiocb.ki_left = len; |
David Howells | 61964eb | 2010-03-24 17:09:19 +0000 | [diff] [blame] | 391 | kiocb.ki_nbytes = len; |
Badari Pulavarty | 027445c | 2006-09-30 23:28:46 -0700 | [diff] [blame] | 392 | |
Zach Brown | 41003a7 | 2013-05-07 16:18:25 -0700 | [diff] [blame^] | 393 | ret = filp->f_op->aio_write(&kiocb, &iov, 1, kiocb.ki_pos); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 394 | if (-EIOCBQUEUED == ret) |
| 395 | ret = wait_on_sync_kiocb(&kiocb); |
| 396 | *ppos = kiocb.ki_pos; |
| 397 | return ret; |
| 398 | } |
| 399 | |
| 400 | EXPORT_SYMBOL(do_sync_write); |
| 401 | |
Al Viro | 06ae43f | 2013-03-20 13:19:30 -0400 | [diff] [blame] | 402 | ssize_t __kernel_write(struct file *file, const char *buf, size_t count, loff_t *pos) |
| 403 | { |
| 404 | mm_segment_t old_fs; |
| 405 | const char __user *p; |
| 406 | ssize_t ret; |
| 407 | |
Al Viro | 3e84f48 | 2013-03-27 15:20:30 +0000 | [diff] [blame] | 408 | if (!file->f_op || (!file->f_op->write && !file->f_op->aio_write)) |
| 409 | return -EINVAL; |
| 410 | |
Al Viro | 06ae43f | 2013-03-20 13:19:30 -0400 | [diff] [blame] | 411 | old_fs = get_fs(); |
| 412 | set_fs(get_ds()); |
| 413 | p = (__force const char __user *)buf; |
| 414 | if (count > MAX_RW_COUNT) |
| 415 | count = MAX_RW_COUNT; |
| 416 | if (file->f_op->write) |
| 417 | ret = file->f_op->write(file, p, count, pos); |
| 418 | else |
| 419 | ret = do_sync_write(file, p, count, pos); |
| 420 | set_fs(old_fs); |
| 421 | if (ret > 0) { |
| 422 | fsnotify_modify(file); |
| 423 | add_wchar(current, ret); |
| 424 | } |
| 425 | inc_syscw(current); |
| 426 | return ret; |
| 427 | } |
| 428 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 429 | ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_t *pos) |
| 430 | { |
| 431 | ssize_t ret; |
| 432 | |
| 433 | if (!(file->f_mode & FMODE_WRITE)) |
| 434 | return -EBADF; |
| 435 | if (!file->f_op || (!file->f_op->write && !file->f_op->aio_write)) |
| 436 | return -EINVAL; |
| 437 | if (unlikely(!access_ok(VERIFY_READ, buf, count))) |
| 438 | return -EFAULT; |
| 439 | |
| 440 | ret = rw_verify_area(WRITE, file, pos, count); |
Linus Torvalds | e28cc71 | 2006-01-04 16:20:40 -0800 | [diff] [blame] | 441 | if (ret >= 0) { |
| 442 | count = ret; |
Al Viro | 03d95eb | 2013-03-20 13:04:20 -0400 | [diff] [blame] | 443 | file_start_write(file); |
James Morris | c43e259 | 2008-01-12 22:05:48 +1100 | [diff] [blame] | 444 | if (file->f_op->write) |
| 445 | ret = file->f_op->write(file, buf, count, pos); |
| 446 | else |
| 447 | ret = do_sync_write(file, buf, count, pos); |
| 448 | if (ret > 0) { |
Eric Paris | 2a12a9d | 2009-12-17 21:24:21 -0500 | [diff] [blame] | 449 | fsnotify_modify(file); |
James Morris | c43e259 | 2008-01-12 22:05:48 +1100 | [diff] [blame] | 450 | add_wchar(current, ret); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 451 | } |
James Morris | c43e259 | 2008-01-12 22:05:48 +1100 | [diff] [blame] | 452 | inc_syscw(current); |
Al Viro | 03d95eb | 2013-03-20 13:04:20 -0400 | [diff] [blame] | 453 | file_end_write(file); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 454 | } |
| 455 | |
| 456 | return ret; |
| 457 | } |
| 458 | |
| 459 | EXPORT_SYMBOL(vfs_write); |
| 460 | |
| 461 | static inline loff_t file_pos_read(struct file *file) |
| 462 | { |
| 463 | return file->f_pos; |
| 464 | } |
| 465 | |
| 466 | static inline void file_pos_write(struct file *file, loff_t pos) |
| 467 | { |
| 468 | file->f_pos = pos; |
| 469 | } |
| 470 | |
Heiko Carstens | 3cdad42 | 2009-01-14 14:14:22 +0100 | [diff] [blame] | 471 | SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 472 | { |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 473 | struct fd f = fdget(fd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 474 | ssize_t ret = -EBADF; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 475 | |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 476 | if (f.file) { |
| 477 | loff_t pos = file_pos_read(f.file); |
| 478 | ret = vfs_read(f.file, buf, count, &pos); |
| 479 | file_pos_write(f.file, pos); |
| 480 | fdput(f); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 481 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 482 | return ret; |
| 483 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 484 | |
Heiko Carstens | 3cdad42 | 2009-01-14 14:14:22 +0100 | [diff] [blame] | 485 | SYSCALL_DEFINE3(write, unsigned int, fd, const char __user *, buf, |
| 486 | size_t, count) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 487 | { |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 488 | struct fd f = fdget(fd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 489 | ssize_t ret = -EBADF; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 490 | |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 491 | if (f.file) { |
| 492 | loff_t pos = file_pos_read(f.file); |
| 493 | ret = vfs_write(f.file, buf, count, &pos); |
| 494 | file_pos_write(f.file, pos); |
| 495 | fdput(f); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 496 | } |
| 497 | |
| 498 | return ret; |
| 499 | } |
| 500 | |
Al Viro | 4a0fd5b | 2013-01-21 15:16:58 -0500 | [diff] [blame] | 501 | SYSCALL_DEFINE4(pread64, unsigned int, fd, char __user *, buf, |
| 502 | size_t, count, loff_t, pos) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 503 | { |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 504 | struct fd f; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 505 | ssize_t ret = -EBADF; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 506 | |
| 507 | if (pos < 0) |
| 508 | return -EINVAL; |
| 509 | |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 510 | f = fdget(fd); |
| 511 | if (f.file) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 512 | ret = -ESPIPE; |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 513 | if (f.file->f_mode & FMODE_PREAD) |
| 514 | ret = vfs_read(f.file, buf, count, &pos); |
| 515 | fdput(f); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 516 | } |
| 517 | |
| 518 | return ret; |
| 519 | } |
| 520 | |
Al Viro | 4a0fd5b | 2013-01-21 15:16:58 -0500 | [diff] [blame] | 521 | SYSCALL_DEFINE4(pwrite64, unsigned int, fd, const char __user *, buf, |
| 522 | size_t, count, loff_t, pos) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 523 | { |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 524 | struct fd f; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 525 | ssize_t ret = -EBADF; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 526 | |
| 527 | if (pos < 0) |
| 528 | return -EINVAL; |
| 529 | |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 530 | f = fdget(fd); |
| 531 | if (f.file) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 532 | ret = -ESPIPE; |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 533 | if (f.file->f_mode & FMODE_PWRITE) |
| 534 | ret = vfs_write(f.file, buf, count, &pos); |
| 535 | fdput(f); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 536 | } |
| 537 | |
| 538 | return ret; |
| 539 | } |
| 540 | |
| 541 | /* |
| 542 | * Reduce an iovec's length in-place. Return the resulting number of segments |
| 543 | */ |
| 544 | unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to) |
| 545 | { |
| 546 | unsigned long seg = 0; |
| 547 | size_t len = 0; |
| 548 | |
| 549 | while (seg < nr_segs) { |
| 550 | seg++; |
| 551 | if (len + iov->iov_len >= to) { |
| 552 | iov->iov_len = to - len; |
| 553 | break; |
| 554 | } |
| 555 | len += iov->iov_len; |
| 556 | iov++; |
| 557 | } |
| 558 | return seg; |
| 559 | } |
Eric Sandeen | 1929552 | 2008-01-28 23:58:27 -0500 | [diff] [blame] | 560 | EXPORT_SYMBOL(iov_shorten); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 561 | |
Al Viro | 72ec351 | 2013-03-20 10:42:10 -0400 | [diff] [blame] | 562 | static ssize_t do_sync_readv_writev(struct file *filp, const struct iovec *iov, |
Badari Pulavarty | ee0b3e6 | 2006-09-30 23:28:47 -0700 | [diff] [blame] | 563 | unsigned long nr_segs, size_t len, loff_t *ppos, iov_fn_t fn) |
| 564 | { |
| 565 | struct kiocb kiocb; |
| 566 | ssize_t ret; |
| 567 | |
| 568 | init_sync_kiocb(&kiocb, filp); |
| 569 | kiocb.ki_pos = *ppos; |
| 570 | kiocb.ki_left = len; |
| 571 | kiocb.ki_nbytes = len; |
| 572 | |
Zach Brown | 41003a7 | 2013-05-07 16:18:25 -0700 | [diff] [blame^] | 573 | ret = fn(&kiocb, iov, nr_segs, kiocb.ki_pos); |
Badari Pulavarty | ee0b3e6 | 2006-09-30 23:28:47 -0700 | [diff] [blame] | 574 | if (ret == -EIOCBQUEUED) |
| 575 | ret = wait_on_sync_kiocb(&kiocb); |
| 576 | *ppos = kiocb.ki_pos; |
| 577 | return ret; |
| 578 | } |
| 579 | |
| 580 | /* Do it by hand, with file-ops */ |
Al Viro | 72ec351 | 2013-03-20 10:42:10 -0400 | [diff] [blame] | 581 | static ssize_t do_loop_readv_writev(struct file *filp, struct iovec *iov, |
Badari Pulavarty | ee0b3e6 | 2006-09-30 23:28:47 -0700 | [diff] [blame] | 582 | unsigned long nr_segs, loff_t *ppos, io_fn_t fn) |
| 583 | { |
| 584 | struct iovec *vector = iov; |
| 585 | ssize_t ret = 0; |
| 586 | |
| 587 | while (nr_segs > 0) { |
| 588 | void __user *base; |
| 589 | size_t len; |
| 590 | ssize_t nr; |
| 591 | |
| 592 | base = vector->iov_base; |
| 593 | len = vector->iov_len; |
| 594 | vector++; |
| 595 | nr_segs--; |
| 596 | |
| 597 | nr = fn(filp, base, len, ppos); |
| 598 | |
| 599 | if (nr < 0) { |
| 600 | if (!ret) |
| 601 | ret = nr; |
| 602 | break; |
| 603 | } |
| 604 | ret += nr; |
| 605 | if (nr != len) |
| 606 | break; |
| 607 | } |
| 608 | |
| 609 | return ret; |
| 610 | } |
| 611 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 612 | /* A write operation does a read from user space and vice versa */ |
| 613 | #define vrfy_dir(type) ((type) == READ ? VERIFY_WRITE : VERIFY_READ) |
| 614 | |
Badari Pulavarty | eed4e51 | 2006-09-30 23:28:49 -0700 | [diff] [blame] | 615 | ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector, |
| 616 | unsigned long nr_segs, unsigned long fast_segs, |
| 617 | struct iovec *fast_pointer, |
Christopher Yeoh | ac34ebb | 2012-05-31 16:26:42 -0700 | [diff] [blame] | 618 | struct iovec **ret_pointer) |
Linus Torvalds | 435f49a | 2010-10-29 10:36:49 -0700 | [diff] [blame] | 619 | { |
Badari Pulavarty | eed4e51 | 2006-09-30 23:28:49 -0700 | [diff] [blame] | 620 | unsigned long seg; |
Linus Torvalds | 435f49a | 2010-10-29 10:36:49 -0700 | [diff] [blame] | 621 | ssize_t ret; |
Badari Pulavarty | eed4e51 | 2006-09-30 23:28:49 -0700 | [diff] [blame] | 622 | struct iovec *iov = fast_pointer; |
| 623 | |
Linus Torvalds | 435f49a | 2010-10-29 10:36:49 -0700 | [diff] [blame] | 624 | /* |
| 625 | * SuS says "The readv() function *may* fail if the iovcnt argument |
| 626 | * was less than or equal to 0, or greater than {IOV_MAX}. Linux has |
| 627 | * traditionally returned zero for zero segments, so... |
| 628 | */ |
Badari Pulavarty | eed4e51 | 2006-09-30 23:28:49 -0700 | [diff] [blame] | 629 | if (nr_segs == 0) { |
| 630 | ret = 0; |
Linus Torvalds | 435f49a | 2010-10-29 10:36:49 -0700 | [diff] [blame] | 631 | goto out; |
Badari Pulavarty | eed4e51 | 2006-09-30 23:28:49 -0700 | [diff] [blame] | 632 | } |
| 633 | |
Linus Torvalds | 435f49a | 2010-10-29 10:36:49 -0700 | [diff] [blame] | 634 | /* |
| 635 | * First get the "struct iovec" from user memory and |
| 636 | * verify all the pointers |
| 637 | */ |
Badari Pulavarty | eed4e51 | 2006-09-30 23:28:49 -0700 | [diff] [blame] | 638 | if (nr_segs > UIO_MAXIOV) { |
| 639 | ret = -EINVAL; |
Linus Torvalds | 435f49a | 2010-10-29 10:36:49 -0700 | [diff] [blame] | 640 | goto out; |
Badari Pulavarty | eed4e51 | 2006-09-30 23:28:49 -0700 | [diff] [blame] | 641 | } |
| 642 | if (nr_segs > fast_segs) { |
Linus Torvalds | 435f49a | 2010-10-29 10:36:49 -0700 | [diff] [blame] | 643 | iov = kmalloc(nr_segs*sizeof(struct iovec), GFP_KERNEL); |
Badari Pulavarty | eed4e51 | 2006-09-30 23:28:49 -0700 | [diff] [blame] | 644 | if (iov == NULL) { |
| 645 | ret = -ENOMEM; |
Linus Torvalds | 435f49a | 2010-10-29 10:36:49 -0700 | [diff] [blame] | 646 | goto out; |
Badari Pulavarty | eed4e51 | 2006-09-30 23:28:49 -0700 | [diff] [blame] | 647 | } |
Linus Torvalds | 435f49a | 2010-10-29 10:36:49 -0700 | [diff] [blame] | 648 | } |
Badari Pulavarty | eed4e51 | 2006-09-30 23:28:49 -0700 | [diff] [blame] | 649 | if (copy_from_user(iov, uvector, nr_segs*sizeof(*uvector))) { |
| 650 | ret = -EFAULT; |
Linus Torvalds | 435f49a | 2010-10-29 10:36:49 -0700 | [diff] [blame] | 651 | goto out; |
Badari Pulavarty | eed4e51 | 2006-09-30 23:28:49 -0700 | [diff] [blame] | 652 | } |
| 653 | |
Linus Torvalds | 435f49a | 2010-10-29 10:36:49 -0700 | [diff] [blame] | 654 | /* |
Badari Pulavarty | eed4e51 | 2006-09-30 23:28:49 -0700 | [diff] [blame] | 655 | * According to the Single Unix Specification we should return EINVAL |
| 656 | * if an element length is < 0 when cast to ssize_t or if the |
| 657 | * total length would overflow the ssize_t return value of the |
| 658 | * system call. |
Linus Torvalds | 435f49a | 2010-10-29 10:36:49 -0700 | [diff] [blame] | 659 | * |
| 660 | * Linux caps all read/write calls to MAX_RW_COUNT, and avoids the |
| 661 | * overflow case. |
| 662 | */ |
Badari Pulavarty | eed4e51 | 2006-09-30 23:28:49 -0700 | [diff] [blame] | 663 | ret = 0; |
Linus Torvalds | 435f49a | 2010-10-29 10:36:49 -0700 | [diff] [blame] | 664 | for (seg = 0; seg < nr_segs; seg++) { |
| 665 | void __user *buf = iov[seg].iov_base; |
| 666 | ssize_t len = (ssize_t)iov[seg].iov_len; |
Badari Pulavarty | eed4e51 | 2006-09-30 23:28:49 -0700 | [diff] [blame] | 667 | |
| 668 | /* see if we we're about to use an invalid len or if |
| 669 | * it's about to overflow ssize_t */ |
Linus Torvalds | 435f49a | 2010-10-29 10:36:49 -0700 | [diff] [blame] | 670 | if (len < 0) { |
Badari Pulavarty | eed4e51 | 2006-09-30 23:28:49 -0700 | [diff] [blame] | 671 | ret = -EINVAL; |
Linus Torvalds | 435f49a | 2010-10-29 10:36:49 -0700 | [diff] [blame] | 672 | goto out; |
Badari Pulavarty | eed4e51 | 2006-09-30 23:28:49 -0700 | [diff] [blame] | 673 | } |
Christopher Yeoh | ac34ebb | 2012-05-31 16:26:42 -0700 | [diff] [blame] | 674 | if (type >= 0 |
Christopher Yeoh | fcf6340 | 2011-10-31 17:06:39 -0700 | [diff] [blame] | 675 | && unlikely(!access_ok(vrfy_dir(type), buf, len))) { |
Badari Pulavarty | eed4e51 | 2006-09-30 23:28:49 -0700 | [diff] [blame] | 676 | ret = -EFAULT; |
Linus Torvalds | 435f49a | 2010-10-29 10:36:49 -0700 | [diff] [blame] | 677 | goto out; |
Badari Pulavarty | eed4e51 | 2006-09-30 23:28:49 -0700 | [diff] [blame] | 678 | } |
Linus Torvalds | 435f49a | 2010-10-29 10:36:49 -0700 | [diff] [blame] | 679 | if (len > MAX_RW_COUNT - ret) { |
| 680 | len = MAX_RW_COUNT - ret; |
| 681 | iov[seg].iov_len = len; |
| 682 | } |
Badari Pulavarty | eed4e51 | 2006-09-30 23:28:49 -0700 | [diff] [blame] | 683 | ret += len; |
Linus Torvalds | 435f49a | 2010-10-29 10:36:49 -0700 | [diff] [blame] | 684 | } |
Badari Pulavarty | eed4e51 | 2006-09-30 23:28:49 -0700 | [diff] [blame] | 685 | out: |
| 686 | *ret_pointer = iov; |
| 687 | return ret; |
| 688 | } |
| 689 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 690 | static ssize_t do_readv_writev(int type, struct file *file, |
| 691 | const struct iovec __user * uvector, |
| 692 | unsigned long nr_segs, loff_t *pos) |
| 693 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 694 | size_t tot_len; |
| 695 | struct iovec iovstack[UIO_FASTIOV]; |
Badari Pulavarty | ee0b3e6 | 2006-09-30 23:28:47 -0700 | [diff] [blame] | 696 | struct iovec *iov = iovstack; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 697 | ssize_t ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 698 | io_fn_t fn; |
| 699 | iov_fn_t fnv; |
| 700 | |
Badari Pulavarty | eed4e51 | 2006-09-30 23:28:49 -0700 | [diff] [blame] | 701 | if (!file->f_op) { |
| 702 | ret = -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 703 | goto out; |
| 704 | } |
| 705 | |
Badari Pulavarty | eed4e51 | 2006-09-30 23:28:49 -0700 | [diff] [blame] | 706 | ret = rw_copy_check_uvector(type, uvector, nr_segs, |
Christopher Yeoh | ac34ebb | 2012-05-31 16:26:42 -0700 | [diff] [blame] | 707 | ARRAY_SIZE(iovstack), iovstack, &iov); |
Badari Pulavarty | eed4e51 | 2006-09-30 23:28:49 -0700 | [diff] [blame] | 708 | if (ret <= 0) |
| 709 | goto out; |
| 710 | |
| 711 | tot_len = ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 712 | ret = rw_verify_area(type, file, pos, tot_len); |
Linus Torvalds | e28cc71 | 2006-01-04 16:20:40 -0800 | [diff] [blame] | 713 | if (ret < 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 714 | goto out; |
| 715 | |
| 716 | fnv = NULL; |
| 717 | if (type == READ) { |
| 718 | fn = file->f_op->read; |
Badari Pulavarty | ee0b3e6 | 2006-09-30 23:28:47 -0700 | [diff] [blame] | 719 | fnv = file->f_op->aio_read; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 720 | } else { |
| 721 | fn = (io_fn_t)file->f_op->write; |
Badari Pulavarty | ee0b3e6 | 2006-09-30 23:28:47 -0700 | [diff] [blame] | 722 | fnv = file->f_op->aio_write; |
Al Viro | 03d95eb | 2013-03-20 13:04:20 -0400 | [diff] [blame] | 723 | file_start_write(file); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 724 | } |
| 725 | |
Badari Pulavarty | ee0b3e6 | 2006-09-30 23:28:47 -0700 | [diff] [blame] | 726 | if (fnv) |
| 727 | ret = do_sync_readv_writev(file, iov, nr_segs, tot_len, |
| 728 | pos, fnv); |
| 729 | else |
| 730 | ret = do_loop_readv_writev(file, iov, nr_segs, pos, fn); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 731 | |
Al Viro | 03d95eb | 2013-03-20 13:04:20 -0400 | [diff] [blame] | 732 | if (type != READ) |
| 733 | file_end_write(file); |
| 734 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 735 | out: |
| 736 | if (iov != iovstack) |
| 737 | kfree(iov); |
Robert Love | 0eeca28 | 2005-07-12 17:06:03 -0400 | [diff] [blame] | 738 | if ((ret + (type == READ)) > 0) { |
| 739 | if (type == READ) |
Eric Paris | 2a12a9d | 2009-12-17 21:24:21 -0500 | [diff] [blame] | 740 | fsnotify_access(file); |
Robert Love | 0eeca28 | 2005-07-12 17:06:03 -0400 | [diff] [blame] | 741 | else |
Eric Paris | 2a12a9d | 2009-12-17 21:24:21 -0500 | [diff] [blame] | 742 | fsnotify_modify(file); |
Robert Love | 0eeca28 | 2005-07-12 17:06:03 -0400 | [diff] [blame] | 743 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 744 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 745 | } |
| 746 | |
| 747 | ssize_t vfs_readv(struct file *file, const struct iovec __user *vec, |
| 748 | unsigned long vlen, loff_t *pos) |
| 749 | { |
| 750 | if (!(file->f_mode & FMODE_READ)) |
| 751 | return -EBADF; |
Badari Pulavarty | ee0b3e6 | 2006-09-30 23:28:47 -0700 | [diff] [blame] | 752 | if (!file->f_op || (!file->f_op->aio_read && !file->f_op->read)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 753 | return -EINVAL; |
| 754 | |
| 755 | return do_readv_writev(READ, file, vec, vlen, pos); |
| 756 | } |
| 757 | |
| 758 | EXPORT_SYMBOL(vfs_readv); |
| 759 | |
| 760 | ssize_t vfs_writev(struct file *file, const struct iovec __user *vec, |
| 761 | unsigned long vlen, loff_t *pos) |
| 762 | { |
| 763 | if (!(file->f_mode & FMODE_WRITE)) |
| 764 | return -EBADF; |
Badari Pulavarty | ee0b3e6 | 2006-09-30 23:28:47 -0700 | [diff] [blame] | 765 | if (!file->f_op || (!file->f_op->aio_write && !file->f_op->write)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 766 | return -EINVAL; |
| 767 | |
| 768 | return do_readv_writev(WRITE, file, vec, vlen, pos); |
| 769 | } |
| 770 | |
| 771 | EXPORT_SYMBOL(vfs_writev); |
| 772 | |
Heiko Carstens | 3cdad42 | 2009-01-14 14:14:22 +0100 | [diff] [blame] | 773 | SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec, |
| 774 | unsigned long, vlen) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 775 | { |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 776 | struct fd f = fdget(fd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 777 | ssize_t ret = -EBADF; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 778 | |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 779 | if (f.file) { |
| 780 | loff_t pos = file_pos_read(f.file); |
| 781 | ret = vfs_readv(f.file, vec, vlen, &pos); |
| 782 | file_pos_write(f.file, pos); |
| 783 | fdput(f); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 784 | } |
| 785 | |
| 786 | if (ret > 0) |
Alexey Dobriyan | 4b98d11 | 2007-02-10 01:46:45 -0800 | [diff] [blame] | 787 | add_rchar(current, ret); |
| 788 | inc_syscr(current); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 789 | return ret; |
| 790 | } |
| 791 | |
Heiko Carstens | 3cdad42 | 2009-01-14 14:14:22 +0100 | [diff] [blame] | 792 | SYSCALL_DEFINE3(writev, unsigned long, fd, const struct iovec __user *, vec, |
| 793 | unsigned long, vlen) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 794 | { |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 795 | struct fd f = fdget(fd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 796 | ssize_t ret = -EBADF; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 797 | |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 798 | if (f.file) { |
| 799 | loff_t pos = file_pos_read(f.file); |
| 800 | ret = vfs_writev(f.file, vec, vlen, &pos); |
| 801 | file_pos_write(f.file, pos); |
| 802 | fdput(f); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 803 | } |
| 804 | |
| 805 | if (ret > 0) |
Alexey Dobriyan | 4b98d11 | 2007-02-10 01:46:45 -0800 | [diff] [blame] | 806 | add_wchar(current, ret); |
| 807 | inc_syscw(current); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 808 | return ret; |
| 809 | } |
| 810 | |
Linus Torvalds | 601cc11 | 2009-04-03 08:03:22 -0700 | [diff] [blame] | 811 | static inline loff_t pos_from_hilo(unsigned long high, unsigned long low) |
Gerd Hoffmann | f3554f4 | 2009-04-02 16:59:23 -0700 | [diff] [blame] | 812 | { |
Linus Torvalds | 601cc11 | 2009-04-03 08:03:22 -0700 | [diff] [blame] | 813 | #define HALF_LONG_BITS (BITS_PER_LONG / 2) |
| 814 | return (((loff_t)high << HALF_LONG_BITS) << HALF_LONG_BITS) | low; |
| 815 | } |
| 816 | |
| 817 | SYSCALL_DEFINE5(preadv, unsigned long, fd, const struct iovec __user *, vec, |
| 818 | unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h) |
| 819 | { |
| 820 | loff_t pos = pos_from_hilo(pos_h, pos_l); |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 821 | struct fd f; |
Gerd Hoffmann | f3554f4 | 2009-04-02 16:59:23 -0700 | [diff] [blame] | 822 | ssize_t ret = -EBADF; |
Gerd Hoffmann | f3554f4 | 2009-04-02 16:59:23 -0700 | [diff] [blame] | 823 | |
| 824 | if (pos < 0) |
| 825 | return -EINVAL; |
| 826 | |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 827 | f = fdget(fd); |
| 828 | if (f.file) { |
Gerd Hoffmann | f3554f4 | 2009-04-02 16:59:23 -0700 | [diff] [blame] | 829 | ret = -ESPIPE; |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 830 | if (f.file->f_mode & FMODE_PREAD) |
| 831 | ret = vfs_readv(f.file, vec, vlen, &pos); |
| 832 | fdput(f); |
Gerd Hoffmann | f3554f4 | 2009-04-02 16:59:23 -0700 | [diff] [blame] | 833 | } |
| 834 | |
| 835 | if (ret > 0) |
| 836 | add_rchar(current, ret); |
| 837 | inc_syscr(current); |
| 838 | return ret; |
| 839 | } |
| 840 | |
| 841 | SYSCALL_DEFINE5(pwritev, unsigned long, fd, const struct iovec __user *, vec, |
Linus Torvalds | 601cc11 | 2009-04-03 08:03:22 -0700 | [diff] [blame] | 842 | unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h) |
Gerd Hoffmann | f3554f4 | 2009-04-02 16:59:23 -0700 | [diff] [blame] | 843 | { |
Linus Torvalds | 601cc11 | 2009-04-03 08:03:22 -0700 | [diff] [blame] | 844 | loff_t pos = pos_from_hilo(pos_h, pos_l); |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 845 | struct fd f; |
Gerd Hoffmann | f3554f4 | 2009-04-02 16:59:23 -0700 | [diff] [blame] | 846 | ssize_t ret = -EBADF; |
Gerd Hoffmann | f3554f4 | 2009-04-02 16:59:23 -0700 | [diff] [blame] | 847 | |
| 848 | if (pos < 0) |
| 849 | return -EINVAL; |
| 850 | |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 851 | f = fdget(fd); |
| 852 | if (f.file) { |
Gerd Hoffmann | f3554f4 | 2009-04-02 16:59:23 -0700 | [diff] [blame] | 853 | ret = -ESPIPE; |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 854 | if (f.file->f_mode & FMODE_PWRITE) |
| 855 | ret = vfs_writev(f.file, vec, vlen, &pos); |
| 856 | fdput(f); |
Gerd Hoffmann | f3554f4 | 2009-04-02 16:59:23 -0700 | [diff] [blame] | 857 | } |
| 858 | |
| 859 | if (ret > 0) |
| 860 | add_wchar(current, ret); |
| 861 | inc_syscw(current); |
| 862 | return ret; |
| 863 | } |
| 864 | |
Al Viro | 72ec351 | 2013-03-20 10:42:10 -0400 | [diff] [blame] | 865 | #ifdef CONFIG_COMPAT |
| 866 | |
| 867 | static ssize_t compat_do_readv_writev(int type, struct file *file, |
| 868 | const struct compat_iovec __user *uvector, |
| 869 | unsigned long nr_segs, loff_t *pos) |
| 870 | { |
| 871 | compat_ssize_t tot_len; |
| 872 | struct iovec iovstack[UIO_FASTIOV]; |
| 873 | struct iovec *iov = iovstack; |
| 874 | ssize_t ret; |
| 875 | io_fn_t fn; |
| 876 | iov_fn_t fnv; |
| 877 | |
| 878 | ret = -EINVAL; |
| 879 | if (!file->f_op) |
| 880 | goto out; |
| 881 | |
| 882 | ret = -EFAULT; |
| 883 | if (!access_ok(VERIFY_READ, uvector, nr_segs*sizeof(*uvector))) |
| 884 | goto out; |
| 885 | |
| 886 | ret = compat_rw_copy_check_uvector(type, uvector, nr_segs, |
| 887 | UIO_FASTIOV, iovstack, &iov); |
| 888 | if (ret <= 0) |
| 889 | goto out; |
| 890 | |
| 891 | tot_len = ret; |
| 892 | ret = rw_verify_area(type, file, pos, tot_len); |
| 893 | if (ret < 0) |
| 894 | goto out; |
| 895 | |
| 896 | fnv = NULL; |
| 897 | if (type == READ) { |
| 898 | fn = file->f_op->read; |
| 899 | fnv = file->f_op->aio_read; |
| 900 | } else { |
| 901 | fn = (io_fn_t)file->f_op->write; |
| 902 | fnv = file->f_op->aio_write; |
Al Viro | 03d95eb | 2013-03-20 13:04:20 -0400 | [diff] [blame] | 903 | file_start_write(file); |
Al Viro | 72ec351 | 2013-03-20 10:42:10 -0400 | [diff] [blame] | 904 | } |
| 905 | |
Al Viro | 03d95eb | 2013-03-20 13:04:20 -0400 | [diff] [blame] | 906 | if (fnv) |
Al Viro | 72ec351 | 2013-03-20 10:42:10 -0400 | [diff] [blame] | 907 | ret = do_sync_readv_writev(file, iov, nr_segs, tot_len, |
| 908 | pos, fnv); |
Al Viro | 03d95eb | 2013-03-20 13:04:20 -0400 | [diff] [blame] | 909 | else |
Al Viro | 72ec351 | 2013-03-20 10:42:10 -0400 | [diff] [blame] | 910 | ret = do_loop_readv_writev(file, iov, nr_segs, pos, fn); |
| 911 | |
Al Viro | 03d95eb | 2013-03-20 13:04:20 -0400 | [diff] [blame] | 912 | if (type != READ) |
| 913 | file_end_write(file); |
| 914 | |
Al Viro | 72ec351 | 2013-03-20 10:42:10 -0400 | [diff] [blame] | 915 | out: |
| 916 | if (iov != iovstack) |
| 917 | kfree(iov); |
| 918 | if ((ret + (type == READ)) > 0) { |
| 919 | if (type == READ) |
| 920 | fsnotify_access(file); |
| 921 | else |
| 922 | fsnotify_modify(file); |
| 923 | } |
| 924 | return ret; |
| 925 | } |
| 926 | |
| 927 | static size_t compat_readv(struct file *file, |
| 928 | const struct compat_iovec __user *vec, |
| 929 | unsigned long vlen, loff_t *pos) |
| 930 | { |
| 931 | ssize_t ret = -EBADF; |
| 932 | |
| 933 | if (!(file->f_mode & FMODE_READ)) |
| 934 | goto out; |
| 935 | |
| 936 | ret = -EINVAL; |
| 937 | if (!file->f_op || (!file->f_op->aio_read && !file->f_op->read)) |
| 938 | goto out; |
| 939 | |
| 940 | ret = compat_do_readv_writev(READ, file, vec, vlen, pos); |
| 941 | |
| 942 | out: |
| 943 | if (ret > 0) |
| 944 | add_rchar(current, ret); |
| 945 | inc_syscr(current); |
| 946 | return ret; |
| 947 | } |
| 948 | |
| 949 | COMPAT_SYSCALL_DEFINE3(readv, unsigned long, fd, |
| 950 | const struct compat_iovec __user *,vec, |
| 951 | unsigned long, vlen) |
| 952 | { |
| 953 | struct fd f = fdget(fd); |
| 954 | ssize_t ret; |
| 955 | loff_t pos; |
| 956 | |
| 957 | if (!f.file) |
| 958 | return -EBADF; |
| 959 | pos = f.file->f_pos; |
| 960 | ret = compat_readv(f.file, vec, vlen, &pos); |
| 961 | f.file->f_pos = pos; |
| 962 | fdput(f); |
| 963 | return ret; |
| 964 | } |
| 965 | |
| 966 | COMPAT_SYSCALL_DEFINE4(preadv64, unsigned long, fd, |
| 967 | const struct compat_iovec __user *,vec, |
| 968 | unsigned long, vlen, loff_t, pos) |
| 969 | { |
| 970 | struct fd f; |
| 971 | ssize_t ret; |
| 972 | |
| 973 | if (pos < 0) |
| 974 | return -EINVAL; |
| 975 | f = fdget(fd); |
| 976 | if (!f.file) |
| 977 | return -EBADF; |
| 978 | ret = -ESPIPE; |
| 979 | if (f.file->f_mode & FMODE_PREAD) |
| 980 | ret = compat_readv(f.file, vec, vlen, &pos); |
| 981 | fdput(f); |
| 982 | return ret; |
| 983 | } |
| 984 | |
| 985 | COMPAT_SYSCALL_DEFINE5(preadv, unsigned long, fd, |
| 986 | const struct compat_iovec __user *,vec, |
| 987 | unsigned long, vlen, u32, pos_low, u32, pos_high) |
| 988 | { |
| 989 | loff_t pos = ((loff_t)pos_high << 32) | pos_low; |
| 990 | return compat_sys_preadv64(fd, vec, vlen, pos); |
| 991 | } |
| 992 | |
| 993 | static size_t compat_writev(struct file *file, |
| 994 | const struct compat_iovec __user *vec, |
| 995 | unsigned long vlen, loff_t *pos) |
| 996 | { |
| 997 | ssize_t ret = -EBADF; |
| 998 | |
| 999 | if (!(file->f_mode & FMODE_WRITE)) |
| 1000 | goto out; |
| 1001 | |
| 1002 | ret = -EINVAL; |
| 1003 | if (!file->f_op || (!file->f_op->aio_write && !file->f_op->write)) |
| 1004 | goto out; |
| 1005 | |
| 1006 | ret = compat_do_readv_writev(WRITE, file, vec, vlen, pos); |
| 1007 | |
| 1008 | out: |
| 1009 | if (ret > 0) |
| 1010 | add_wchar(current, ret); |
| 1011 | inc_syscw(current); |
| 1012 | return ret; |
| 1013 | } |
| 1014 | |
| 1015 | COMPAT_SYSCALL_DEFINE3(writev, unsigned long, fd, |
| 1016 | const struct compat_iovec __user *, vec, |
| 1017 | unsigned long, vlen) |
| 1018 | { |
| 1019 | struct fd f = fdget(fd); |
| 1020 | ssize_t ret; |
| 1021 | loff_t pos; |
| 1022 | |
| 1023 | if (!f.file) |
| 1024 | return -EBADF; |
| 1025 | pos = f.file->f_pos; |
| 1026 | ret = compat_writev(f.file, vec, vlen, &pos); |
| 1027 | f.file->f_pos = pos; |
| 1028 | fdput(f); |
| 1029 | return ret; |
| 1030 | } |
| 1031 | |
| 1032 | COMPAT_SYSCALL_DEFINE4(pwritev64, unsigned long, fd, |
| 1033 | const struct compat_iovec __user *,vec, |
| 1034 | unsigned long, vlen, loff_t, pos) |
| 1035 | { |
| 1036 | struct fd f; |
| 1037 | ssize_t ret; |
| 1038 | |
| 1039 | if (pos < 0) |
| 1040 | return -EINVAL; |
| 1041 | f = fdget(fd); |
| 1042 | if (!f.file) |
| 1043 | return -EBADF; |
| 1044 | ret = -ESPIPE; |
| 1045 | if (f.file->f_mode & FMODE_PWRITE) |
| 1046 | ret = compat_writev(f.file, vec, vlen, &pos); |
| 1047 | fdput(f); |
| 1048 | return ret; |
| 1049 | } |
| 1050 | |
| 1051 | COMPAT_SYSCALL_DEFINE5(pwritev, unsigned long, fd, |
| 1052 | const struct compat_iovec __user *,vec, |
| 1053 | unsigned long, vlen, u32, pos_low, u32, pos_high) |
| 1054 | { |
| 1055 | loff_t pos = ((loff_t)pos_high << 32) | pos_low; |
| 1056 | return compat_sys_pwritev64(fd, vec, vlen, pos); |
| 1057 | } |
| 1058 | #endif |
| 1059 | |
Al Viro | 19f4fc3 | 2013-02-24 02:17:03 -0500 | [diff] [blame] | 1060 | static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, |
| 1061 | size_t count, loff_t max) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1062 | { |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 1063 | struct fd in, out; |
| 1064 | struct inode *in_inode, *out_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1065 | loff_t pos; |
| 1066 | ssize_t retval; |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 1067 | int fl; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1068 | |
| 1069 | /* |
| 1070 | * Get input file, and verify that it is ok.. |
| 1071 | */ |
| 1072 | retval = -EBADF; |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 1073 | in = fdget(in_fd); |
| 1074 | if (!in.file) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1075 | goto out; |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 1076 | if (!(in.file->f_mode & FMODE_READ)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1077 | goto fput_in; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1078 | retval = -ESPIPE; |
| 1079 | if (!ppos) |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 1080 | ppos = &in.file->f_pos; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1081 | else |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 1082 | if (!(in.file->f_mode & FMODE_PREAD)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1083 | goto fput_in; |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 1084 | retval = rw_verify_area(READ, in.file, ppos, count); |
Linus Torvalds | e28cc71 | 2006-01-04 16:20:40 -0800 | [diff] [blame] | 1085 | if (retval < 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1086 | goto fput_in; |
Linus Torvalds | e28cc71 | 2006-01-04 16:20:40 -0800 | [diff] [blame] | 1087 | count = retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1088 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1089 | /* |
| 1090 | * Get output file, and verify that it is ok.. |
| 1091 | */ |
| 1092 | retval = -EBADF; |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 1093 | out = fdget(out_fd); |
| 1094 | if (!out.file) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1095 | goto fput_in; |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 1096 | if (!(out.file->f_mode & FMODE_WRITE)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1097 | goto fput_out; |
| 1098 | retval = -EINVAL; |
Al Viro | 496ad9a | 2013-01-23 17:07:38 -0500 | [diff] [blame] | 1099 | in_inode = file_inode(in.file); |
| 1100 | out_inode = file_inode(out.file); |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 1101 | retval = rw_verify_area(WRITE, out.file, &out.file->f_pos, count); |
Linus Torvalds | e28cc71 | 2006-01-04 16:20:40 -0800 | [diff] [blame] | 1102 | if (retval < 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1103 | goto fput_out; |
Linus Torvalds | e28cc71 | 2006-01-04 16:20:40 -0800 | [diff] [blame] | 1104 | count = retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1105 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1106 | if (!max) |
| 1107 | max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes); |
| 1108 | |
| 1109 | pos = *ppos; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1110 | if (unlikely(pos + count > max)) { |
| 1111 | retval = -EOVERFLOW; |
| 1112 | if (pos >= max) |
| 1113 | goto fput_out; |
| 1114 | count = max - pos; |
| 1115 | } |
| 1116 | |
Jens Axboe | d96e6e7 | 2007-06-11 12:18:52 +0200 | [diff] [blame] | 1117 | fl = 0; |
Jens Axboe | 534f2aa | 2007-06-01 14:52:37 +0200 | [diff] [blame] | 1118 | #if 0 |
Jens Axboe | d96e6e7 | 2007-06-11 12:18:52 +0200 | [diff] [blame] | 1119 | /* |
| 1120 | * We need to debate whether we can enable this or not. The |
| 1121 | * man page documents EAGAIN return for the output at least, |
| 1122 | * and the application is arguably buggy if it doesn't expect |
| 1123 | * EAGAIN on a non-blocking file descriptor. |
| 1124 | */ |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 1125 | if (in.file->f_flags & O_NONBLOCK) |
Jens Axboe | d96e6e7 | 2007-06-11 12:18:52 +0200 | [diff] [blame] | 1126 | fl = SPLICE_F_NONBLOCK; |
Jens Axboe | 534f2aa | 2007-06-01 14:52:37 +0200 | [diff] [blame] | 1127 | #endif |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 1128 | retval = do_splice_direct(in.file, ppos, out.file, count, fl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1129 | |
| 1130 | if (retval > 0) { |
Alexey Dobriyan | 4b98d11 | 2007-02-10 01:46:45 -0800 | [diff] [blame] | 1131 | add_rchar(current, retval); |
| 1132 | add_wchar(current, retval); |
Scott Wolchok | a68c2f1 | 2012-12-20 15:05:52 -0800 | [diff] [blame] | 1133 | fsnotify_access(in.file); |
| 1134 | fsnotify_modify(out.file); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1135 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1136 | |
Alexey Dobriyan | 4b98d11 | 2007-02-10 01:46:45 -0800 | [diff] [blame] | 1137 | inc_syscr(current); |
| 1138 | inc_syscw(current); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1139 | if (*ppos > max) |
| 1140 | retval = -EOVERFLOW; |
| 1141 | |
| 1142 | fput_out: |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 1143 | fdput(out); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1144 | fput_in: |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 1145 | fdput(in); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1146 | out: |
| 1147 | return retval; |
| 1148 | } |
| 1149 | |
Heiko Carstens | 002c897 | 2009-01-14 14:14:18 +0100 | [diff] [blame] | 1150 | SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, off_t __user *, offset, size_t, count) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1151 | { |
| 1152 | loff_t pos; |
| 1153 | off_t off; |
| 1154 | ssize_t ret; |
| 1155 | |
| 1156 | if (offset) { |
| 1157 | if (unlikely(get_user(off, offset))) |
| 1158 | return -EFAULT; |
| 1159 | pos = off; |
| 1160 | ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS); |
| 1161 | if (unlikely(put_user(pos, offset))) |
| 1162 | return -EFAULT; |
| 1163 | return ret; |
| 1164 | } |
| 1165 | |
| 1166 | return do_sendfile(out_fd, in_fd, NULL, count, 0); |
| 1167 | } |
| 1168 | |
Heiko Carstens | 002c897 | 2009-01-14 14:14:18 +0100 | [diff] [blame] | 1169 | SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, loff_t __user *, offset, size_t, count) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1170 | { |
| 1171 | loff_t pos; |
| 1172 | ssize_t ret; |
| 1173 | |
| 1174 | if (offset) { |
| 1175 | if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t)))) |
| 1176 | return -EFAULT; |
| 1177 | ret = do_sendfile(out_fd, in_fd, &pos, count, 0); |
| 1178 | if (unlikely(put_user(pos, offset))) |
| 1179 | return -EFAULT; |
| 1180 | return ret; |
| 1181 | } |
| 1182 | |
| 1183 | return do_sendfile(out_fd, in_fd, NULL, count, 0); |
| 1184 | } |
Al Viro | 19f4fc3 | 2013-02-24 02:17:03 -0500 | [diff] [blame] | 1185 | |
| 1186 | #ifdef CONFIG_COMPAT |
| 1187 | COMPAT_SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, |
| 1188 | compat_off_t __user *, offset, compat_size_t, count) |
| 1189 | { |
| 1190 | loff_t pos; |
| 1191 | off_t off; |
| 1192 | ssize_t ret; |
| 1193 | |
| 1194 | if (offset) { |
| 1195 | if (unlikely(get_user(off, offset))) |
| 1196 | return -EFAULT; |
| 1197 | pos = off; |
| 1198 | ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS); |
| 1199 | if (unlikely(put_user(pos, offset))) |
| 1200 | return -EFAULT; |
| 1201 | return ret; |
| 1202 | } |
| 1203 | |
| 1204 | return do_sendfile(out_fd, in_fd, NULL, count, 0); |
| 1205 | } |
| 1206 | |
| 1207 | COMPAT_SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, |
| 1208 | compat_loff_t __user *, offset, compat_size_t, count) |
| 1209 | { |
| 1210 | loff_t pos; |
| 1211 | ssize_t ret; |
| 1212 | |
| 1213 | if (offset) { |
| 1214 | if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t)))) |
| 1215 | return -EFAULT; |
| 1216 | ret = do_sendfile(out_fd, in_fd, &pos, count, 0); |
| 1217 | if (unlikely(put_user(pos, offset))) |
| 1218 | return -EFAULT; |
| 1219 | return ret; |
| 1220 | } |
| 1221 | |
| 1222 | return do_sendfile(out_fd, in_fd, NULL, count, 0); |
| 1223 | } |
| 1224 | #endif |