Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/fs/open.c |
| 3 | * |
| 4 | * Copyright (C) 1991, 1992 Linus Torvalds |
| 5 | */ |
| 6 | |
| 7 | #include <linux/string.h> |
| 8 | #include <linux/mm.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 9 | #include <linux/file.h> |
Al Viro | 9f3acc3 | 2008-04-24 07:44:08 -0400 | [diff] [blame] | 10 | #include <linux/fdtable.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 11 | #include <linux/quotaops.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/module.h> |
| 14 | #include <linux/slab.h> |
| 15 | #include <linux/tty.h> |
| 16 | #include <linux/namei.h> |
| 17 | #include <linux/backing-dev.h> |
Randy Dunlap | 16f7e0f | 2006-01-11 12:17:46 -0800 | [diff] [blame] | 18 | #include <linux/capability.h> |
Andrew G. Morgan | 086f731 | 2008-07-04 09:59:58 -0700 | [diff] [blame] | 19 | #include <linux/securebits.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 20 | #include <linux/security.h> |
| 21 | #include <linux/mount.h> |
| 22 | #include <linux/vfs.h> |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 23 | #include <linux/fcntl.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 24 | #include <asm/uaccess.h> |
| 25 | #include <linux/fs.h> |
Yoav Zach | ef3daed | 2005-06-23 00:09:58 -0700 | [diff] [blame] | 26 | #include <linux/personality.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 27 | #include <linux/pagemap.h> |
| 28 | #include <linux/syscalls.h> |
Dipankar Sarma | ab2af1f | 2005-09-09 13:04:13 -0700 | [diff] [blame] | 29 | #include <linux/rcupdate.h> |
Amy Griffis | 73241cc | 2005-11-03 16:00:25 +0000 | [diff] [blame] | 30 | #include <linux/audit.h> |
Amit Arora | 97ac735 | 2007-07-17 21:42:44 -0400 | [diff] [blame] | 31 | #include <linux/falloc.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | |
David Howells | 726c334 | 2006-06-23 02:02:58 -0700 | [diff] [blame] | 33 | int vfs_statfs(struct dentry *dentry, struct kstatfs *buf) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 34 | { |
| 35 | int retval = -ENODEV; |
| 36 | |
David Howells | 726c334 | 2006-06-23 02:02:58 -0700 | [diff] [blame] | 37 | if (dentry) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 38 | retval = -ENOSYS; |
David Howells | 726c334 | 2006-06-23 02:02:58 -0700 | [diff] [blame] | 39 | if (dentry->d_sb->s_op->statfs) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 40 | memset(buf, 0, sizeof(*buf)); |
David Howells | 726c334 | 2006-06-23 02:02:58 -0700 | [diff] [blame] | 41 | retval = security_sb_statfs(dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 42 | if (retval) |
| 43 | return retval; |
David Howells | 726c334 | 2006-06-23 02:02:58 -0700 | [diff] [blame] | 44 | retval = dentry->d_sb->s_op->statfs(dentry, buf); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 45 | if (retval == 0 && buf->f_frsize == 0) |
| 46 | buf->f_frsize = buf->f_bsize; |
| 47 | } |
| 48 | } |
| 49 | return retval; |
| 50 | } |
| 51 | |
| 52 | EXPORT_SYMBOL(vfs_statfs); |
| 53 | |
David Howells | 726c334 | 2006-06-23 02:02:58 -0700 | [diff] [blame] | 54 | static int vfs_statfs_native(struct dentry *dentry, struct statfs *buf) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 55 | { |
| 56 | struct kstatfs st; |
| 57 | int retval; |
| 58 | |
David Howells | 726c334 | 2006-06-23 02:02:58 -0700 | [diff] [blame] | 59 | retval = vfs_statfs(dentry, &st); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 60 | if (retval) |
| 61 | return retval; |
| 62 | |
| 63 | if (sizeof(*buf) == sizeof(st)) |
| 64 | memcpy(buf, &st, sizeof(st)); |
| 65 | else { |
| 66 | if (sizeof buf->f_blocks == 4) { |
Jon Tollefson | f4a67cc | 2008-07-23 21:27:55 -0700 | [diff] [blame] | 67 | if ((st.f_blocks | st.f_bfree | st.f_bavail | |
| 68 | st.f_bsize | st.f_frsize) & |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 69 | 0xffffffff00000000ULL) |
| 70 | return -EOVERFLOW; |
| 71 | /* |
| 72 | * f_files and f_ffree may be -1; it's okay to stuff |
| 73 | * that into 32 bits |
| 74 | */ |
| 75 | if (st.f_files != -1 && |
| 76 | (st.f_files & 0xffffffff00000000ULL)) |
| 77 | return -EOVERFLOW; |
| 78 | if (st.f_ffree != -1 && |
| 79 | (st.f_ffree & 0xffffffff00000000ULL)) |
| 80 | return -EOVERFLOW; |
| 81 | } |
| 82 | |
| 83 | buf->f_type = st.f_type; |
| 84 | buf->f_bsize = st.f_bsize; |
| 85 | buf->f_blocks = st.f_blocks; |
| 86 | buf->f_bfree = st.f_bfree; |
| 87 | buf->f_bavail = st.f_bavail; |
| 88 | buf->f_files = st.f_files; |
| 89 | buf->f_ffree = st.f_ffree; |
| 90 | buf->f_fsid = st.f_fsid; |
| 91 | buf->f_namelen = st.f_namelen; |
| 92 | buf->f_frsize = st.f_frsize; |
| 93 | memset(buf->f_spare, 0, sizeof(buf->f_spare)); |
| 94 | } |
| 95 | return 0; |
| 96 | } |
| 97 | |
David Howells | 726c334 | 2006-06-23 02:02:58 -0700 | [diff] [blame] | 98 | static int vfs_statfs64(struct dentry *dentry, struct statfs64 *buf) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 99 | { |
| 100 | struct kstatfs st; |
| 101 | int retval; |
| 102 | |
David Howells | 726c334 | 2006-06-23 02:02:58 -0700 | [diff] [blame] | 103 | retval = vfs_statfs(dentry, &st); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 104 | if (retval) |
| 105 | return retval; |
| 106 | |
| 107 | if (sizeof(*buf) == sizeof(st)) |
| 108 | memcpy(buf, &st, sizeof(st)); |
| 109 | else { |
| 110 | buf->f_type = st.f_type; |
| 111 | buf->f_bsize = st.f_bsize; |
| 112 | buf->f_blocks = st.f_blocks; |
| 113 | buf->f_bfree = st.f_bfree; |
| 114 | buf->f_bavail = st.f_bavail; |
| 115 | buf->f_files = st.f_files; |
| 116 | buf->f_ffree = st.f_ffree; |
| 117 | buf->f_fsid = st.f_fsid; |
| 118 | buf->f_namelen = st.f_namelen; |
| 119 | buf->f_frsize = st.f_frsize; |
| 120 | memset(buf->f_spare, 0, sizeof(buf->f_spare)); |
| 121 | } |
| 122 | return 0; |
| 123 | } |
| 124 | |
| 125 | asmlinkage long sys_statfs(const char __user * path, struct statfs __user * buf) |
| 126 | { |
| 127 | struct nameidata nd; |
| 128 | int error; |
| 129 | |
| 130 | error = user_path_walk(path, &nd); |
| 131 | if (!error) { |
| 132 | struct statfs tmp; |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 133 | error = vfs_statfs_native(nd.path.dentry, &tmp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 134 | if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) |
| 135 | error = -EFAULT; |
Jan Blunck | 1d957f9 | 2008-02-14 19:34:35 -0800 | [diff] [blame] | 136 | path_put(&nd.path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 137 | } |
| 138 | return error; |
| 139 | } |
| 140 | |
| 141 | |
| 142 | asmlinkage long sys_statfs64(const char __user *path, size_t sz, struct statfs64 __user *buf) |
| 143 | { |
| 144 | struct nameidata nd; |
| 145 | long error; |
| 146 | |
| 147 | if (sz != sizeof(*buf)) |
| 148 | return -EINVAL; |
| 149 | error = user_path_walk(path, &nd); |
| 150 | if (!error) { |
| 151 | struct statfs64 tmp; |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 152 | error = vfs_statfs64(nd.path.dentry, &tmp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 153 | if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) |
| 154 | error = -EFAULT; |
Jan Blunck | 1d957f9 | 2008-02-14 19:34:35 -0800 | [diff] [blame] | 155 | path_put(&nd.path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 156 | } |
| 157 | return error; |
| 158 | } |
| 159 | |
| 160 | |
| 161 | asmlinkage long sys_fstatfs(unsigned int fd, struct statfs __user * buf) |
| 162 | { |
| 163 | struct file * file; |
| 164 | struct statfs tmp; |
| 165 | int error; |
| 166 | |
| 167 | error = -EBADF; |
| 168 | file = fget(fd); |
| 169 | if (!file) |
| 170 | goto out; |
Josef "Jeff" Sipek | 0f7fc9e | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 171 | error = vfs_statfs_native(file->f_path.dentry, &tmp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 172 | if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) |
| 173 | error = -EFAULT; |
| 174 | fput(file); |
| 175 | out: |
| 176 | return error; |
| 177 | } |
| 178 | |
| 179 | asmlinkage long sys_fstatfs64(unsigned int fd, size_t sz, struct statfs64 __user *buf) |
| 180 | { |
| 181 | struct file * file; |
| 182 | struct statfs64 tmp; |
| 183 | int error; |
| 184 | |
| 185 | if (sz != sizeof(*buf)) |
| 186 | return -EINVAL; |
| 187 | |
| 188 | error = -EBADF; |
| 189 | file = fget(fd); |
| 190 | if (!file) |
| 191 | goto out; |
Josef "Jeff" Sipek | 0f7fc9e | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 192 | error = vfs_statfs64(file->f_path.dentry, &tmp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 193 | if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) |
| 194 | error = -EFAULT; |
| 195 | fput(file); |
| 196 | out: |
| 197 | return error; |
| 198 | } |
| 199 | |
NeilBrown | 4a30131 | 2006-01-08 01:02:39 -0800 | [diff] [blame] | 200 | int do_truncate(struct dentry *dentry, loff_t length, unsigned int time_attrs, |
| 201 | struct file *filp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 202 | { |
| 203 | int err; |
| 204 | struct iattr newattrs; |
| 205 | |
| 206 | /* Not pretty: "inode->i_size" shouldn't really be signed. But it is. */ |
| 207 | if (length < 0) |
| 208 | return -EINVAL; |
| 209 | |
| 210 | newattrs.ia_size = length; |
NeilBrown | 4a30131 | 2006-01-08 01:02:39 -0800 | [diff] [blame] | 211 | newattrs.ia_valid = ATTR_SIZE | time_attrs; |
Miklos Szeredi | cc4e69d | 2005-11-07 00:59:49 -0800 | [diff] [blame] | 212 | if (filp) { |
| 213 | newattrs.ia_file = filp; |
| 214 | newattrs.ia_valid |= ATTR_FILE; |
| 215 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 216 | |
Linus Torvalds | 7b82dc0 | 2007-05-08 20:10:00 -0700 | [diff] [blame] | 217 | /* Remove suid/sgid on truncate too */ |
| 218 | newattrs.ia_valid |= should_remove_suid(dentry); |
| 219 | |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 220 | mutex_lock(&dentry->d_inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 221 | err = notify_change(dentry, &newattrs); |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 222 | mutex_unlock(&dentry->d_inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 223 | return err; |
| 224 | } |
| 225 | |
Matt Mackall | b01ec0e | 2006-01-08 01:05:20 -0800 | [diff] [blame] | 226 | static long do_sys_truncate(const char __user * path, loff_t length) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 227 | { |
| 228 | struct nameidata nd; |
| 229 | struct inode * inode; |
| 230 | int error; |
| 231 | |
| 232 | error = -EINVAL; |
| 233 | if (length < 0) /* sorry, but loff_t says... */ |
| 234 | goto out; |
| 235 | |
| 236 | error = user_path_walk(path, &nd); |
| 237 | if (error) |
| 238 | goto out; |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 239 | inode = nd.path.dentry->d_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 240 | |
| 241 | /* For directories it's -EISDIR, for other non-regulars - -EINVAL */ |
| 242 | error = -EISDIR; |
| 243 | if (S_ISDIR(inode->i_mode)) |
| 244 | goto dput_and_out; |
| 245 | |
| 246 | error = -EINVAL; |
| 247 | if (!S_ISREG(inode->i_mode)) |
| 248 | goto dput_and_out; |
| 249 | |
Dave Hansen | 9ac9b84 | 2008-02-15 14:37:52 -0800 | [diff] [blame] | 250 | error = mnt_want_write(nd.path.mnt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 251 | if (error) |
| 252 | goto dput_and_out; |
| 253 | |
Dave Hansen | 9ac9b84 | 2008-02-15 14:37:52 -0800 | [diff] [blame] | 254 | error = vfs_permission(&nd, MAY_WRITE); |
| 255 | if (error) |
| 256 | goto mnt_drop_write_and_out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 257 | |
| 258 | error = -EPERM; |
Miklos Szeredi | c82e42d | 2008-06-24 16:50:12 +0200 | [diff] [blame] | 259 | if (IS_APPEND(inode)) |
Dave Hansen | 9ac9b84 | 2008-02-15 14:37:52 -0800 | [diff] [blame] | 260 | goto mnt_drop_write_and_out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 261 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 262 | error = get_write_access(inode); |
| 263 | if (error) |
Dave Hansen | 9ac9b84 | 2008-02-15 14:37:52 -0800 | [diff] [blame] | 264 | goto mnt_drop_write_and_out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 265 | |
david m. richter | 9700382 | 2007-07-31 00:39:12 -0700 | [diff] [blame] | 266 | /* |
| 267 | * Make sure that there are no leases. get_write_access() protects |
| 268 | * against the truncate racing with a lease-granting setlease(). |
| 269 | */ |
| 270 | error = break_lease(inode, FMODE_WRITE); |
| 271 | if (error) |
| 272 | goto put_write_and_out; |
| 273 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 274 | error = locks_verify_truncate(inode, NULL, length); |
| 275 | if (!error) { |
| 276 | DQUOT_INIT(inode); |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 277 | error = do_truncate(nd.path.dentry, length, 0, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 278 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 279 | |
david m. richter | 9700382 | 2007-07-31 00:39:12 -0700 | [diff] [blame] | 280 | put_write_and_out: |
| 281 | put_write_access(inode); |
Dave Hansen | 9ac9b84 | 2008-02-15 14:37:52 -0800 | [diff] [blame] | 282 | mnt_drop_write_and_out: |
| 283 | mnt_drop_write(nd.path.mnt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 284 | dput_and_out: |
Jan Blunck | 1d957f9 | 2008-02-14 19:34:35 -0800 | [diff] [blame] | 285 | path_put(&nd.path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 286 | out: |
| 287 | return error; |
| 288 | } |
| 289 | |
| 290 | asmlinkage long sys_truncate(const char __user * path, unsigned long length) |
| 291 | { |
| 292 | /* on 32-bit boxen it will cut the range 2^31--2^32-1 off */ |
| 293 | return do_sys_truncate(path, (long)length); |
| 294 | } |
| 295 | |
Matt Mackall | b01ec0e | 2006-01-08 01:05:20 -0800 | [diff] [blame] | 296 | static long do_sys_ftruncate(unsigned int fd, loff_t length, int small) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 297 | { |
| 298 | struct inode * inode; |
| 299 | struct dentry *dentry; |
| 300 | struct file * file; |
| 301 | int error; |
| 302 | |
| 303 | error = -EINVAL; |
| 304 | if (length < 0) |
| 305 | goto out; |
| 306 | error = -EBADF; |
| 307 | file = fget(fd); |
| 308 | if (!file) |
| 309 | goto out; |
| 310 | |
| 311 | /* explicitly opened as large or we are on 64-bit box */ |
| 312 | if (file->f_flags & O_LARGEFILE) |
| 313 | small = 0; |
| 314 | |
Josef "Jeff" Sipek | 0f7fc9e | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 315 | dentry = file->f_path.dentry; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 316 | inode = dentry->d_inode; |
| 317 | error = -EINVAL; |
| 318 | if (!S_ISREG(inode->i_mode) || !(file->f_mode & FMODE_WRITE)) |
| 319 | goto out_putf; |
| 320 | |
| 321 | error = -EINVAL; |
| 322 | /* Cannot ftruncate over 2^31 bytes without large file support */ |
| 323 | if (small && length > MAX_NON_LFS) |
| 324 | goto out_putf; |
| 325 | |
| 326 | error = -EPERM; |
| 327 | if (IS_APPEND(inode)) |
| 328 | goto out_putf; |
| 329 | |
| 330 | error = locks_verify_truncate(inode, file, length); |
| 331 | if (!error) |
Peter Staubach | 6e656be | 2006-06-25 05:48:36 -0700 | [diff] [blame] | 332 | error = do_truncate(dentry, length, ATTR_MTIME|ATTR_CTIME, file); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 333 | out_putf: |
| 334 | fput(file); |
| 335 | out: |
| 336 | return error; |
| 337 | } |
| 338 | |
| 339 | asmlinkage long sys_ftruncate(unsigned int fd, unsigned long length) |
| 340 | { |
Linus Torvalds | 0a489cb | 2006-04-18 13:02:48 -0700 | [diff] [blame] | 341 | long ret = do_sys_ftruncate(fd, length, 1); |
Linus Torvalds | 385910f | 2006-04-18 13:22:59 -0700 | [diff] [blame] | 342 | /* avoid REGPARM breakage on x86: */ |
Roland McGrath | 54a0151 | 2008-04-10 15:37:38 -0700 | [diff] [blame] | 343 | asmlinkage_protect(2, ret, fd, length); |
Linus Torvalds | 0a489cb | 2006-04-18 13:02:48 -0700 | [diff] [blame] | 344 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 345 | } |
| 346 | |
| 347 | /* LFS versions of truncate are only needed on 32 bit machines */ |
| 348 | #if BITS_PER_LONG == 32 |
| 349 | asmlinkage long sys_truncate64(const char __user * path, loff_t length) |
| 350 | { |
| 351 | return do_sys_truncate(path, length); |
| 352 | } |
| 353 | |
| 354 | asmlinkage long sys_ftruncate64(unsigned int fd, loff_t length) |
| 355 | { |
Linus Torvalds | 0a489cb | 2006-04-18 13:02:48 -0700 | [diff] [blame] | 356 | long ret = do_sys_ftruncate(fd, length, 0); |
Linus Torvalds | 385910f | 2006-04-18 13:22:59 -0700 | [diff] [blame] | 357 | /* avoid REGPARM breakage on x86: */ |
Roland McGrath | 54a0151 | 2008-04-10 15:37:38 -0700 | [diff] [blame] | 358 | asmlinkage_protect(2, ret, fd, length); |
Linus Torvalds | 0a489cb | 2006-04-18 13:02:48 -0700 | [diff] [blame] | 359 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 360 | } |
| 361 | #endif |
| 362 | |
Amit Arora | 97ac735 | 2007-07-17 21:42:44 -0400 | [diff] [blame] | 363 | asmlinkage long sys_fallocate(int fd, int mode, loff_t offset, loff_t len) |
| 364 | { |
| 365 | struct file *file; |
| 366 | struct inode *inode; |
| 367 | long ret = -EINVAL; |
| 368 | |
| 369 | if (offset < 0 || len <= 0) |
| 370 | goto out; |
| 371 | |
| 372 | /* Return error if mode is not supported */ |
| 373 | ret = -EOPNOTSUPP; |
| 374 | if (mode && !(mode & FALLOC_FL_KEEP_SIZE)) |
| 375 | goto out; |
| 376 | |
| 377 | ret = -EBADF; |
| 378 | file = fget(fd); |
| 379 | if (!file) |
| 380 | goto out; |
| 381 | if (!(file->f_mode & FMODE_WRITE)) |
| 382 | goto out_fput; |
| 383 | /* |
| 384 | * Revalidate the write permissions, in case security policy has |
| 385 | * changed since the files were opened. |
| 386 | */ |
| 387 | ret = security_file_permission(file, MAY_WRITE); |
| 388 | if (ret) |
| 389 | goto out_fput; |
| 390 | |
| 391 | inode = file->f_path.dentry->d_inode; |
| 392 | |
| 393 | ret = -ESPIPE; |
| 394 | if (S_ISFIFO(inode->i_mode)) |
| 395 | goto out_fput; |
| 396 | |
| 397 | ret = -ENODEV; |
| 398 | /* |
| 399 | * Let individual file system decide if it supports preallocation |
| 400 | * for directories or not. |
| 401 | */ |
| 402 | if (!S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode)) |
| 403 | goto out_fput; |
| 404 | |
| 405 | ret = -EFBIG; |
| 406 | /* Check for wrap through zero too */ |
| 407 | if (((offset + len) > inode->i_sb->s_maxbytes) || ((offset + len) < 0)) |
| 408 | goto out_fput; |
| 409 | |
| 410 | if (inode->i_op && inode->i_op->fallocate) |
| 411 | ret = inode->i_op->fallocate(inode, mode, offset, len); |
| 412 | else |
Ulrich Drepper | 0d786d4 | 2007-07-23 18:43:46 -0700 | [diff] [blame] | 413 | ret = -EOPNOTSUPP; |
Amit Arora | 97ac735 | 2007-07-17 21:42:44 -0400 | [diff] [blame] | 414 | |
| 415 | out_fput: |
| 416 | fput(file); |
| 417 | out: |
| 418 | return ret; |
| 419 | } |
| 420 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 421 | /* |
| 422 | * access() needs to use the real uid/gid, not the effective uid/gid. |
| 423 | * We do this by temporarily clearing all FS-related capabilities and |
| 424 | * switching the fsuid/fsgid around to the real ones. |
| 425 | */ |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 426 | asmlinkage long sys_faccessat(int dfd, const char __user *filename, int mode) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 427 | { |
| 428 | struct nameidata nd; |
| 429 | int old_fsuid, old_fsgid; |
Andrew G. Morgan | 086f731 | 2008-07-04 09:59:58 -0700 | [diff] [blame] | 430 | kernel_cap_t uninitialized_var(old_cap); /* !SECURE_NO_SETUID_FIXUP */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 431 | int res; |
| 432 | |
| 433 | if (mode & ~S_IRWXO) /* where's F_OK, X_OK, W_OK, R_OK? */ |
| 434 | return -EINVAL; |
| 435 | |
| 436 | old_fsuid = current->fsuid; |
| 437 | old_fsgid = current->fsgid; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 438 | |
| 439 | current->fsuid = current->uid; |
| 440 | current->fsgid = current->gid; |
| 441 | |
Andrew G. Morgan | 086f731 | 2008-07-04 09:59:58 -0700 | [diff] [blame] | 442 | if (!issecure(SECURE_NO_SETUID_FIXUP)) { |
| 443 | /* |
| 444 | * Clear the capabilities if we switch to a non-root user |
| 445 | */ |
| 446 | #ifndef CONFIG_SECURITY_FILE_CAPABILITIES |
| 447 | /* |
| 448 | * FIXME: There is a race here against sys_capset. The |
| 449 | * capabilities can change yet we will restore the old |
| 450 | * value below. We should hold task_capabilities_lock, |
| 451 | * but we cannot because user_path_walk can sleep. |
| 452 | */ |
| 453 | #endif /* ndef CONFIG_SECURITY_FILE_CAPABILITIES */ |
| 454 | if (current->uid) |
| 455 | old_cap = cap_set_effective(__cap_empty_set); |
| 456 | else |
| 457 | old_cap = cap_set_effective(current->cap_permitted); |
| 458 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 459 | |
Al Viro | a110343 | 2008-07-17 09:19:08 -0400 | [diff] [blame] | 460 | res = __user_walk_fd(dfd, filename, LOOKUP_FOLLOW, &nd); |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 461 | if (res) |
| 462 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 463 | |
Al Viro | 3052447 | 2008-07-22 00:02:33 -0400 | [diff] [blame^] | 464 | if ((mode & MAY_EXEC) && S_ISREG(nd.path.dentry->d_inode->i_mode)) { |
| 465 | /* |
| 466 | * MAY_EXEC on regular files is denied if the fs is mounted |
| 467 | * with the "noexec" flag. |
| 468 | */ |
| 469 | res = -EACCES; |
| 470 | if (nd.path.mnt->mnt_flags & MNT_NOEXEC) |
| 471 | goto out_path_release; |
| 472 | } |
| 473 | |
Al Viro | a110343 | 2008-07-17 09:19:08 -0400 | [diff] [blame] | 474 | res = vfs_permission(&nd, mode | MAY_ACCESS); |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 475 | /* SuS v2 requires we report a read only fs too */ |
| 476 | if(res || !(mode & S_IWOTH) || |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 477 | special_file(nd.path.dentry->d_inode->i_mode)) |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 478 | goto out_path_release; |
Dave Hansen | 2f676cb | 2008-02-15 14:37:55 -0800 | [diff] [blame] | 479 | /* |
| 480 | * This is a rare case where using __mnt_is_readonly() |
| 481 | * is OK without a mnt_want/drop_write() pair. Since |
| 482 | * no actual write to the fs is performed here, we do |
| 483 | * not need to telegraph to that to anyone. |
| 484 | * |
| 485 | * By doing this, we accept that this access is |
| 486 | * inherently racy and know that the fs may change |
| 487 | * state before we even see this result. |
| 488 | */ |
| 489 | if (__mnt_is_readonly(nd.path.mnt)) |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 490 | res = -EROFS; |
| 491 | |
| 492 | out_path_release: |
Jan Blunck | 1d957f9 | 2008-02-14 19:34:35 -0800 | [diff] [blame] | 493 | path_put(&nd.path); |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 494 | out: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 495 | current->fsuid = old_fsuid; |
| 496 | current->fsgid = old_fsgid; |
Andrew G. Morgan | 086f731 | 2008-07-04 09:59:58 -0700 | [diff] [blame] | 497 | |
| 498 | if (!issecure(SECURE_NO_SETUID_FIXUP)) |
| 499 | cap_set_effective(old_cap); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 500 | |
| 501 | return res; |
| 502 | } |
| 503 | |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 504 | asmlinkage long sys_access(const char __user *filename, int mode) |
| 505 | { |
| 506 | return sys_faccessat(AT_FDCWD, filename, mode); |
| 507 | } |
| 508 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 509 | asmlinkage long sys_chdir(const char __user * filename) |
| 510 | { |
| 511 | struct nameidata nd; |
| 512 | int error; |
| 513 | |
Al Viro | 8bb7922 | 2008-07-16 09:51:03 -0400 | [diff] [blame] | 514 | error = __user_walk(filename, LOOKUP_FOLLOW|LOOKUP_DIRECTORY, &nd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 515 | if (error) |
| 516 | goto out; |
| 517 | |
Al Viro | a110343 | 2008-07-17 09:19:08 -0400 | [diff] [blame] | 518 | error = vfs_permission(&nd, MAY_EXEC | MAY_ACCESS); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 519 | if (error) |
| 520 | goto dput_and_out; |
| 521 | |
Jan Blunck | ac748a0 | 2008-02-14 19:34:39 -0800 | [diff] [blame] | 522 | set_fs_pwd(current->fs, &nd.path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 523 | |
| 524 | dput_and_out: |
Jan Blunck | 1d957f9 | 2008-02-14 19:34:35 -0800 | [diff] [blame] | 525 | path_put(&nd.path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 526 | out: |
| 527 | return error; |
| 528 | } |
| 529 | |
| 530 | asmlinkage long sys_fchdir(unsigned int fd) |
| 531 | { |
| 532 | struct file *file; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 533 | struct inode *inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 534 | int error; |
| 535 | |
| 536 | error = -EBADF; |
| 537 | file = fget(fd); |
| 538 | if (!file) |
| 539 | goto out; |
| 540 | |
Jan Blunck | ac748a0 | 2008-02-14 19:34:39 -0800 | [diff] [blame] | 541 | inode = file->f_path.dentry->d_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 542 | |
| 543 | error = -ENOTDIR; |
| 544 | if (!S_ISDIR(inode->i_mode)) |
| 545 | goto out_putf; |
| 546 | |
Al Viro | a110343 | 2008-07-17 09:19:08 -0400 | [diff] [blame] | 547 | error = file_permission(file, MAY_EXEC | MAY_ACCESS); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 548 | if (!error) |
Jan Blunck | ac748a0 | 2008-02-14 19:34:39 -0800 | [diff] [blame] | 549 | set_fs_pwd(current->fs, &file->f_path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 550 | out_putf: |
| 551 | fput(file); |
| 552 | out: |
| 553 | return error; |
| 554 | } |
| 555 | |
| 556 | asmlinkage long sys_chroot(const char __user * filename) |
| 557 | { |
| 558 | struct nameidata nd; |
| 559 | int error; |
| 560 | |
Al Viro | 7f2da1e | 2008-05-10 20:44:54 -0400 | [diff] [blame] | 561 | error = __user_walk(filename, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &nd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 562 | if (error) |
| 563 | goto out; |
| 564 | |
Al Viro | a110343 | 2008-07-17 09:19:08 -0400 | [diff] [blame] | 565 | error = vfs_permission(&nd, MAY_EXEC | MAY_ACCESS); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 566 | if (error) |
| 567 | goto dput_and_out; |
| 568 | |
| 569 | error = -EPERM; |
| 570 | if (!capable(CAP_SYS_CHROOT)) |
| 571 | goto dput_and_out; |
| 572 | |
Jan Blunck | ac748a0 | 2008-02-14 19:34:39 -0800 | [diff] [blame] | 573 | set_fs_root(current->fs, &nd.path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 574 | error = 0; |
| 575 | dput_and_out: |
Jan Blunck | 1d957f9 | 2008-02-14 19:34:35 -0800 | [diff] [blame] | 576 | path_put(&nd.path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 577 | out: |
| 578 | return error; |
| 579 | } |
| 580 | |
| 581 | asmlinkage long sys_fchmod(unsigned int fd, mode_t mode) |
| 582 | { |
| 583 | struct inode * inode; |
| 584 | struct dentry * dentry; |
| 585 | struct file * file; |
| 586 | int err = -EBADF; |
| 587 | struct iattr newattrs; |
| 588 | |
| 589 | file = fget(fd); |
| 590 | if (!file) |
| 591 | goto out; |
| 592 | |
Josef "Jeff" Sipek | 0f7fc9e | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 593 | dentry = file->f_path.dentry; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 594 | inode = dentry->d_inode; |
| 595 | |
Al Viro | 5a190ae | 2007-06-07 12:19:32 -0400 | [diff] [blame] | 596 | audit_inode(NULL, dentry); |
Amy Griffis | 73241cc | 2005-11-03 16:00:25 +0000 | [diff] [blame] | 597 | |
Dave Hansen | 2af482a | 2008-02-15 14:37:50 -0800 | [diff] [blame] | 598 | err = mnt_want_write(file->f_path.mnt); |
| 599 | if (err) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 600 | goto out_putf; |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 601 | mutex_lock(&inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 602 | if (mode == (mode_t) -1) |
| 603 | mode = inode->i_mode; |
| 604 | newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO); |
| 605 | newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; |
| 606 | err = notify_change(dentry, &newattrs); |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 607 | mutex_unlock(&inode->i_mutex); |
Dave Hansen | 2af482a | 2008-02-15 14:37:50 -0800 | [diff] [blame] | 608 | mnt_drop_write(file->f_path.mnt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 609 | out_putf: |
| 610 | fput(file); |
| 611 | out: |
| 612 | return err; |
| 613 | } |
| 614 | |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 615 | asmlinkage long sys_fchmodat(int dfd, const char __user *filename, |
| 616 | mode_t mode) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 617 | { |
| 618 | struct nameidata nd; |
| 619 | struct inode * inode; |
| 620 | int error; |
| 621 | struct iattr newattrs; |
| 622 | |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 623 | error = __user_walk_fd(dfd, filename, LOOKUP_FOLLOW, &nd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 624 | if (error) |
| 625 | goto out; |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 626 | inode = nd.path.dentry->d_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 627 | |
Dave Hansen | 2af482a | 2008-02-15 14:37:50 -0800 | [diff] [blame] | 628 | error = mnt_want_write(nd.path.mnt); |
| 629 | if (error) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 630 | goto dput_and_out; |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 631 | mutex_lock(&inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 632 | if (mode == (mode_t) -1) |
| 633 | mode = inode->i_mode; |
| 634 | newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO); |
| 635 | newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 636 | error = notify_change(nd.path.dentry, &newattrs); |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 637 | mutex_unlock(&inode->i_mutex); |
Dave Hansen | 2af482a | 2008-02-15 14:37:50 -0800 | [diff] [blame] | 638 | mnt_drop_write(nd.path.mnt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 639 | dput_and_out: |
Jan Blunck | 1d957f9 | 2008-02-14 19:34:35 -0800 | [diff] [blame] | 640 | path_put(&nd.path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 641 | out: |
| 642 | return error; |
| 643 | } |
| 644 | |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 645 | asmlinkage long sys_chmod(const char __user *filename, mode_t mode) |
| 646 | { |
| 647 | return sys_fchmodat(AT_FDCWD, filename, mode); |
| 648 | } |
| 649 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 650 | static int chown_common(struct dentry * dentry, uid_t user, gid_t group) |
| 651 | { |
Miklos Szeredi | beb29e0 | 2008-07-01 15:01:29 +0200 | [diff] [blame] | 652 | struct inode *inode = dentry->d_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 653 | int error; |
| 654 | struct iattr newattrs; |
| 655 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 656 | newattrs.ia_valid = ATTR_CTIME; |
| 657 | if (user != (uid_t) -1) { |
| 658 | newattrs.ia_valid |= ATTR_UID; |
| 659 | newattrs.ia_uid = user; |
| 660 | } |
| 661 | if (group != (gid_t) -1) { |
| 662 | newattrs.ia_valid |= ATTR_GID; |
| 663 | newattrs.ia_gid = group; |
| 664 | } |
| 665 | if (!S_ISDIR(inode->i_mode)) |
Serge E. Hallyn | b537677 | 2007-10-16 23:31:36 -0700 | [diff] [blame] | 666 | newattrs.ia_valid |= |
| 667 | ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV; |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 668 | mutex_lock(&inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 669 | error = notify_change(dentry, &newattrs); |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 670 | mutex_unlock(&inode->i_mutex); |
Miklos Szeredi | beb29e0 | 2008-07-01 15:01:29 +0200 | [diff] [blame] | 671 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 672 | return error; |
| 673 | } |
| 674 | |
| 675 | asmlinkage long sys_chown(const char __user * filename, uid_t user, gid_t group) |
| 676 | { |
| 677 | struct nameidata nd; |
| 678 | int error; |
| 679 | |
| 680 | error = user_path_walk(filename, &nd); |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 681 | if (error) |
| 682 | goto out; |
Dave Hansen | 2af482a | 2008-02-15 14:37:50 -0800 | [diff] [blame] | 683 | error = mnt_want_write(nd.path.mnt); |
| 684 | if (error) |
| 685 | goto out_release; |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 686 | error = chown_common(nd.path.dentry, user, group); |
Dave Hansen | 2af482a | 2008-02-15 14:37:50 -0800 | [diff] [blame] | 687 | mnt_drop_write(nd.path.mnt); |
| 688 | out_release: |
Jan Blunck | 1d957f9 | 2008-02-14 19:34:35 -0800 | [diff] [blame] | 689 | path_put(&nd.path); |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 690 | out: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 691 | return error; |
| 692 | } |
| 693 | |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 694 | asmlinkage long sys_fchownat(int dfd, const char __user *filename, uid_t user, |
| 695 | gid_t group, int flag) |
| 696 | { |
| 697 | struct nameidata nd; |
| 698 | int error = -EINVAL; |
| 699 | int follow; |
| 700 | |
| 701 | if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0) |
| 702 | goto out; |
| 703 | |
| 704 | follow = (flag & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW; |
| 705 | error = __user_walk_fd(dfd, filename, follow, &nd); |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 706 | if (error) |
| 707 | goto out; |
Dave Hansen | 2af482a | 2008-02-15 14:37:50 -0800 | [diff] [blame] | 708 | error = mnt_want_write(nd.path.mnt); |
| 709 | if (error) |
| 710 | goto out_release; |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 711 | error = chown_common(nd.path.dentry, user, group); |
Dave Hansen | 2af482a | 2008-02-15 14:37:50 -0800 | [diff] [blame] | 712 | mnt_drop_write(nd.path.mnt); |
| 713 | out_release: |
Jan Blunck | 1d957f9 | 2008-02-14 19:34:35 -0800 | [diff] [blame] | 714 | path_put(&nd.path); |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 715 | out: |
| 716 | return error; |
| 717 | } |
| 718 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 719 | asmlinkage long sys_lchown(const char __user * filename, uid_t user, gid_t group) |
| 720 | { |
| 721 | struct nameidata nd; |
| 722 | int error; |
| 723 | |
| 724 | error = user_path_walk_link(filename, &nd); |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 725 | if (error) |
| 726 | goto out; |
Dave Hansen | 2af482a | 2008-02-15 14:37:50 -0800 | [diff] [blame] | 727 | error = mnt_want_write(nd.path.mnt); |
| 728 | if (error) |
| 729 | goto out_release; |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 730 | error = chown_common(nd.path.dentry, user, group); |
Dave Hansen | 2af482a | 2008-02-15 14:37:50 -0800 | [diff] [blame] | 731 | mnt_drop_write(nd.path.mnt); |
| 732 | out_release: |
Jan Blunck | 1d957f9 | 2008-02-14 19:34:35 -0800 | [diff] [blame] | 733 | path_put(&nd.path); |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 734 | out: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 735 | return error; |
| 736 | } |
| 737 | |
| 738 | |
| 739 | asmlinkage long sys_fchown(unsigned int fd, uid_t user, gid_t group) |
| 740 | { |
| 741 | struct file * file; |
| 742 | int error = -EBADF; |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 743 | struct dentry * dentry; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 744 | |
| 745 | file = fget(fd); |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 746 | if (!file) |
| 747 | goto out; |
| 748 | |
Dave Hansen | 2af482a | 2008-02-15 14:37:50 -0800 | [diff] [blame] | 749 | error = mnt_want_write(file->f_path.mnt); |
| 750 | if (error) |
| 751 | goto out_fput; |
Josef "Jeff" Sipek | 0f7fc9e | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 752 | dentry = file->f_path.dentry; |
Al Viro | 5a190ae | 2007-06-07 12:19:32 -0400 | [diff] [blame] | 753 | audit_inode(NULL, dentry); |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 754 | error = chown_common(dentry, user, group); |
Dave Hansen | 2af482a | 2008-02-15 14:37:50 -0800 | [diff] [blame] | 755 | mnt_drop_write(file->f_path.mnt); |
| 756 | out_fput: |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 757 | fput(file); |
| 758 | out: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 759 | return error; |
| 760 | } |
| 761 | |
Dave Hansen | 4a3fd21 | 2008-02-15 14:37:48 -0800 | [diff] [blame] | 762 | /* |
| 763 | * You have to be very careful that these write |
| 764 | * counts get cleaned up in error cases and |
| 765 | * upon __fput(). This should probably never |
| 766 | * be called outside of __dentry_open(). |
| 767 | */ |
| 768 | static inline int __get_file_write_access(struct inode *inode, |
| 769 | struct vfsmount *mnt) |
| 770 | { |
| 771 | int error; |
| 772 | error = get_write_access(inode); |
| 773 | if (error) |
| 774 | return error; |
| 775 | /* |
| 776 | * Do not take mount writer counts on |
| 777 | * special files since no writes to |
| 778 | * the mount itself will occur. |
| 779 | */ |
| 780 | if (!special_file(inode->i_mode)) { |
| 781 | /* |
| 782 | * Balanced in __fput() |
| 783 | */ |
| 784 | error = mnt_want_write(mnt); |
| 785 | if (error) |
| 786 | put_write_access(inode); |
| 787 | } |
| 788 | return error; |
| 789 | } |
| 790 | |
Peter Staubach | a1a5b3d | 2005-09-13 01:25:12 -0700 | [diff] [blame] | 791 | static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt, |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 792 | int flags, struct file *f, |
| 793 | int (*open)(struct inode *, struct file *)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 794 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 795 | struct inode *inode; |
| 796 | int error; |
| 797 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 798 | f->f_flags = flags; |
Peter Staubach | a1a5b3d | 2005-09-13 01:25:12 -0700 | [diff] [blame] | 799 | f->f_mode = ((flags+1) & O_ACCMODE) | FMODE_LSEEK | |
| 800 | FMODE_PREAD | FMODE_PWRITE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 801 | inode = dentry->d_inode; |
| 802 | if (f->f_mode & FMODE_WRITE) { |
Dave Hansen | 4a3fd21 | 2008-02-15 14:37:48 -0800 | [diff] [blame] | 803 | error = __get_file_write_access(inode, mnt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 804 | if (error) |
| 805 | goto cleanup_file; |
Dave Hansen | ad775f5 | 2008-02-15 14:38:01 -0800 | [diff] [blame] | 806 | if (!special_file(inode->i_mode)) |
| 807 | file_take_write(f); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 808 | } |
| 809 | |
| 810 | f->f_mapping = inode->i_mapping; |
Josef "Jeff" Sipek | 0f7fc9e | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 811 | f->f_path.dentry = dentry; |
| 812 | f->f_path.mnt = mnt; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 813 | f->f_pos = 0; |
| 814 | f->f_op = fops_get(inode->i_fop); |
| 815 | file_move(f, &inode->i_sb->s_files); |
| 816 | |
Yuichi Nakamura | 788e7dd | 2007-09-14 09:27:07 +0900 | [diff] [blame] | 817 | error = security_dentry_open(f); |
| 818 | if (error) |
| 819 | goto cleanup_all; |
| 820 | |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 821 | if (!open && f->f_op) |
| 822 | open = f->f_op->open; |
| 823 | if (open) { |
| 824 | error = open(inode, f); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 825 | if (error) |
| 826 | goto cleanup_all; |
| 827 | } |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 828 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 829 | f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC); |
| 830 | |
| 831 | file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping); |
| 832 | |
| 833 | /* NB: we're sure to have correct a_ops only after f_op->open */ |
| 834 | if (f->f_flags & O_DIRECT) { |
Carsten Otte | ceffc07 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 835 | if (!f->f_mapping->a_ops || |
| 836 | ((!f->f_mapping->a_ops->direct_IO) && |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 837 | (!f->f_mapping->a_ops->get_xip_mem))) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 838 | fput(f); |
| 839 | f = ERR_PTR(-EINVAL); |
| 840 | } |
| 841 | } |
| 842 | |
| 843 | return f; |
| 844 | |
| 845 | cleanup_all: |
| 846 | fops_put(f->f_op); |
Dave Hansen | 4a3fd21 | 2008-02-15 14:37:48 -0800 | [diff] [blame] | 847 | if (f->f_mode & FMODE_WRITE) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 848 | put_write_access(inode); |
Dave Hansen | ad775f5 | 2008-02-15 14:38:01 -0800 | [diff] [blame] | 849 | if (!special_file(inode->i_mode)) { |
| 850 | /* |
| 851 | * We don't consider this a real |
| 852 | * mnt_want/drop_write() pair |
| 853 | * because it all happenend right |
| 854 | * here, so just reset the state. |
| 855 | */ |
| 856 | file_reset_write(f); |
Dave Hansen | 4a3fd21 | 2008-02-15 14:37:48 -0800 | [diff] [blame] | 857 | mnt_drop_write(mnt); |
Dave Hansen | ad775f5 | 2008-02-15 14:38:01 -0800 | [diff] [blame] | 858 | } |
Dave Hansen | 4a3fd21 | 2008-02-15 14:37:48 -0800 | [diff] [blame] | 859 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 860 | file_kill(f); |
Josef "Jeff" Sipek | 0f7fc9e | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 861 | f->f_path.dentry = NULL; |
| 862 | f->f_path.mnt = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 863 | cleanup_file: |
| 864 | put_filp(f); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 865 | dput(dentry); |
| 866 | mntput(mnt); |
| 867 | return ERR_PTR(error); |
| 868 | } |
| 869 | |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 870 | /** |
| 871 | * lookup_instantiate_filp - instantiates the open intent filp |
| 872 | * @nd: pointer to nameidata |
| 873 | * @dentry: pointer to dentry |
| 874 | * @open: open callback |
| 875 | * |
| 876 | * Helper for filesystems that want to use lookup open intents and pass back |
| 877 | * a fully instantiated struct file to the caller. |
| 878 | * This function is meant to be called from within a filesystem's |
| 879 | * lookup method. |
Oleg Drokin | 9a56c21 | 2006-03-25 03:07:02 -0800 | [diff] [blame] | 880 | * Beware of calling it for non-regular files! Those ->open methods might block |
| 881 | * (e.g. in fifo_open), leaving you with parent locked (and in case of fifo, |
| 882 | * leading to a deadlock, as nobody can open that fifo anymore, because |
| 883 | * another process to open fifo will block on locked parent when doing lookup). |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 884 | * Note that in case of error, nd->intent.open.file is destroyed, but the |
| 885 | * path information remains valid. |
| 886 | * If the open callback is set to NULL, then the standard f_op->open() |
| 887 | * filesystem callback is substituted. |
| 888 | */ |
| 889 | struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry *dentry, |
| 890 | int (*open)(struct inode *, struct file *)) |
| 891 | { |
| 892 | if (IS_ERR(nd->intent.open.file)) |
| 893 | goto out; |
| 894 | if (IS_ERR(dentry)) |
| 895 | goto out_err; |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 896 | nd->intent.open.file = __dentry_open(dget(dentry), mntget(nd->path.mnt), |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 897 | nd->intent.open.flags - 1, |
| 898 | nd->intent.open.file, |
| 899 | open); |
| 900 | out: |
| 901 | return nd->intent.open.file; |
| 902 | out_err: |
| 903 | release_open_intent(nd); |
| 904 | nd->intent.open.file = (struct file *)dentry; |
| 905 | goto out; |
| 906 | } |
| 907 | EXPORT_SYMBOL_GPL(lookup_instantiate_filp); |
| 908 | |
| 909 | /** |
| 910 | * nameidata_to_filp - convert a nameidata to an open filp. |
| 911 | * @nd: pointer to nameidata |
| 912 | * @flags: open flags |
| 913 | * |
| 914 | * Note that this function destroys the original nameidata |
| 915 | */ |
| 916 | struct file *nameidata_to_filp(struct nameidata *nd, int flags) |
| 917 | { |
| 918 | struct file *filp; |
| 919 | |
| 920 | /* Pick up the filp from the open intent */ |
| 921 | filp = nd->intent.open.file; |
| 922 | /* Has the filesystem initialised the file for us? */ |
Josef "Jeff" Sipek | 0f7fc9e | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 923 | if (filp->f_path.dentry == NULL) |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 924 | filp = __dentry_open(nd->path.dentry, nd->path.mnt, flags, filp, |
| 925 | NULL); |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 926 | else |
Jan Blunck | 1d957f9 | 2008-02-14 19:34:35 -0800 | [diff] [blame] | 927 | path_put(&nd->path); |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 928 | return filp; |
| 929 | } |
| 930 | |
Peter Staubach | 6fdcc21 | 2005-11-07 00:59:42 -0800 | [diff] [blame] | 931 | /* |
| 932 | * dentry_open() will have done dput(dentry) and mntput(mnt) if it returns an |
| 933 | * error. |
| 934 | */ |
Peter Staubach | a1a5b3d | 2005-09-13 01:25:12 -0700 | [diff] [blame] | 935 | struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags) |
| 936 | { |
| 937 | int error; |
| 938 | struct file *f; |
| 939 | |
Christoph Hellwig | 322ee5b | 2008-02-15 14:37:24 -0800 | [diff] [blame] | 940 | /* |
| 941 | * We must always pass in a valid mount pointer. Historically |
| 942 | * callers got away with not passing it, but we must enforce this at |
| 943 | * the earliest possible point now to avoid strange problems deep in the |
| 944 | * filesystem stack. |
| 945 | */ |
| 946 | if (!mnt) { |
| 947 | printk(KERN_WARNING "%s called with NULL vfsmount\n", __func__); |
| 948 | dump_stack(); |
| 949 | return ERR_PTR(-EINVAL); |
| 950 | } |
| 951 | |
Peter Staubach | a1a5b3d | 2005-09-13 01:25:12 -0700 | [diff] [blame] | 952 | error = -ENFILE; |
| 953 | f = get_empty_filp(); |
Peter Staubach | 6fdcc21 | 2005-11-07 00:59:42 -0800 | [diff] [blame] | 954 | if (f == NULL) { |
| 955 | dput(dentry); |
| 956 | mntput(mnt); |
Peter Staubach | a1a5b3d | 2005-09-13 01:25:12 -0700 | [diff] [blame] | 957 | return ERR_PTR(error); |
Peter Staubach | 6fdcc21 | 2005-11-07 00:59:42 -0800 | [diff] [blame] | 958 | } |
Peter Staubach | a1a5b3d | 2005-09-13 01:25:12 -0700 | [diff] [blame] | 959 | |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 960 | return __dentry_open(dentry, mnt, flags, f, NULL); |
Peter Staubach | a1a5b3d | 2005-09-13 01:25:12 -0700 | [diff] [blame] | 961 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 962 | EXPORT_SYMBOL(dentry_open); |
| 963 | |
| 964 | /* |
| 965 | * Find an empty file descriptor entry, and mark it busy. |
| 966 | */ |
Ulrich Drepper | 4a19542 | 2007-07-15 23:40:34 -0700 | [diff] [blame] | 967 | int get_unused_fd_flags(int flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 968 | { |
| 969 | struct files_struct * files = current->files; |
| 970 | int fd, error; |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 971 | struct fdtable *fdt; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 972 | |
| 973 | error = -EMFILE; |
| 974 | spin_lock(&files->file_lock); |
| 975 | |
| 976 | repeat: |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 977 | fdt = files_fdtable(files); |
Vadim Lobanov | bbea9f6 | 2006-12-10 02:21:12 -0800 | [diff] [blame] | 978 | fd = find_next_zero_bit(fdt->open_fds->fds_bits, fdt->max_fds, |
Eric Dumazet | 0c9e63f | 2006-03-23 03:00:12 -0800 | [diff] [blame] | 979 | files->next_fd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 980 | |
| 981 | /* |
| 982 | * N.B. For clone tasks sharing a files structure, this test |
| 983 | * will limit the total number of files that can be opened. |
| 984 | */ |
| 985 | if (fd >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur) |
| 986 | goto out; |
| 987 | |
| 988 | /* Do we need to expand the fd array or fd set? */ |
| 989 | error = expand_files(files, fd); |
| 990 | if (error < 0) |
| 991 | goto out; |
| 992 | |
| 993 | if (error) { |
| 994 | /* |
| 995 | * If we needed to expand the fs array we |
| 996 | * might have blocked - try again. |
| 997 | */ |
| 998 | error = -EMFILE; |
| 999 | goto repeat; |
| 1000 | } |
| 1001 | |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 1002 | FD_SET(fd, fdt->open_fds); |
Ulrich Drepper | f23513e | 2007-07-15 23:40:32 -0700 | [diff] [blame] | 1003 | if (flags & O_CLOEXEC) |
| 1004 | FD_SET(fd, fdt->close_on_exec); |
| 1005 | else |
| 1006 | FD_CLR(fd, fdt->close_on_exec); |
Eric Dumazet | 0c9e63f | 2006-03-23 03:00:12 -0800 | [diff] [blame] | 1007 | files->next_fd = fd + 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1008 | #if 1 |
| 1009 | /* Sanity check */ |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 1010 | if (fdt->fd[fd] != NULL) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1011 | printk(KERN_WARNING "get_unused_fd: slot %d not NULL!\n", fd); |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 1012 | fdt->fd[fd] = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1013 | } |
| 1014 | #endif |
| 1015 | error = fd; |
| 1016 | |
| 1017 | out: |
| 1018 | spin_unlock(&files->file_lock); |
| 1019 | return error; |
| 1020 | } |
| 1021 | |
Ulrich Drepper | f23513e | 2007-07-15 23:40:32 -0700 | [diff] [blame] | 1022 | int get_unused_fd(void) |
| 1023 | { |
| 1024 | return get_unused_fd_flags(0); |
| 1025 | } |
| 1026 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1027 | EXPORT_SYMBOL(get_unused_fd); |
| 1028 | |
Matt Mackall | b01ec0e | 2006-01-08 01:05:20 -0800 | [diff] [blame] | 1029 | static void __put_unused_fd(struct files_struct *files, unsigned int fd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1030 | { |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 1031 | struct fdtable *fdt = files_fdtable(files); |
| 1032 | __FD_CLR(fd, fdt->open_fds); |
Eric Dumazet | 0c9e63f | 2006-03-23 03:00:12 -0800 | [diff] [blame] | 1033 | if (fd < files->next_fd) |
| 1034 | files->next_fd = fd; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1035 | } |
| 1036 | |
Harvey Harrison | fc9b52c | 2008-02-08 04:19:52 -0800 | [diff] [blame] | 1037 | void put_unused_fd(unsigned int fd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1038 | { |
| 1039 | struct files_struct *files = current->files; |
| 1040 | spin_lock(&files->file_lock); |
| 1041 | __put_unused_fd(files, fd); |
| 1042 | spin_unlock(&files->file_lock); |
| 1043 | } |
| 1044 | |
| 1045 | EXPORT_SYMBOL(put_unused_fd); |
| 1046 | |
| 1047 | /* |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 1048 | * Install a file pointer in the fd array. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1049 | * |
| 1050 | * The VFS is full of places where we drop the files lock between |
| 1051 | * setting the open_fds bitmap and installing the file in the file |
| 1052 | * array. At any such point, we are vulnerable to a dup2() race |
| 1053 | * installing a file in the array before us. We need to detect this and |
| 1054 | * fput() the struct file we are about to overwrite in this case. |
| 1055 | * |
| 1056 | * It should never happen - if we allow dup2() do it, _really_ bad things |
| 1057 | * will follow. |
| 1058 | */ |
| 1059 | |
Harvey Harrison | fc9b52c | 2008-02-08 04:19:52 -0800 | [diff] [blame] | 1060 | void fd_install(unsigned int fd, struct file *file) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1061 | { |
| 1062 | struct files_struct *files = current->files; |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 1063 | struct fdtable *fdt; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1064 | spin_lock(&files->file_lock); |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 1065 | fdt = files_fdtable(files); |
Dipankar Sarma | ab2af1f | 2005-09-09 13:04:13 -0700 | [diff] [blame] | 1066 | BUG_ON(fdt->fd[fd] != NULL); |
| 1067 | rcu_assign_pointer(fdt->fd[fd], file); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1068 | spin_unlock(&files->file_lock); |
| 1069 | } |
| 1070 | |
| 1071 | EXPORT_SYMBOL(fd_install); |
| 1072 | |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 1073 | long do_sys_open(int dfd, const char __user *filename, int flags, int mode) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1074 | { |
Miklos Szeredi | e922efc | 2005-09-06 15:18:25 -0700 | [diff] [blame] | 1075 | char *tmp = getname(filename); |
| 1076 | int fd = PTR_ERR(tmp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1077 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1078 | if (!IS_ERR(tmp)) { |
Ulrich Drepper | f23513e | 2007-07-15 23:40:32 -0700 | [diff] [blame] | 1079 | fd = get_unused_fd_flags(flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1080 | if (fd >= 0) { |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 1081 | struct file *f = do_filp_open(dfd, tmp, flags, mode); |
Telemaque Ndizihiwe | fed2fc1 | 2005-06-23 00:10:33 -0700 | [diff] [blame] | 1082 | if (IS_ERR(f)) { |
| 1083 | put_unused_fd(fd); |
| 1084 | fd = PTR_ERR(f); |
| 1085 | } else { |
Josef "Jeff" Sipek | 0f7fc9e | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 1086 | fsnotify_open(f->f_path.dentry); |
Telemaque Ndizihiwe | fed2fc1 | 2005-06-23 00:10:33 -0700 | [diff] [blame] | 1087 | fd_install(fd, f); |
| 1088 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1089 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1090 | putname(tmp); |
| 1091 | } |
| 1092 | return fd; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1093 | } |
Miklos Szeredi | e922efc | 2005-09-06 15:18:25 -0700 | [diff] [blame] | 1094 | |
| 1095 | asmlinkage long sys_open(const char __user *filename, int flags, int mode) |
| 1096 | { |
Linus Torvalds | 385910f | 2006-04-18 13:22:59 -0700 | [diff] [blame] | 1097 | long ret; |
| 1098 | |
Miklos Szeredi | e922efc | 2005-09-06 15:18:25 -0700 | [diff] [blame] | 1099 | if (force_o_largefile()) |
| 1100 | flags |= O_LARGEFILE; |
| 1101 | |
Linus Torvalds | 385910f | 2006-04-18 13:22:59 -0700 | [diff] [blame] | 1102 | ret = do_sys_open(AT_FDCWD, filename, flags, mode); |
| 1103 | /* avoid REGPARM breakage on x86: */ |
Roland McGrath | 54a0151 | 2008-04-10 15:37:38 -0700 | [diff] [blame] | 1104 | asmlinkage_protect(3, ret, filename, flags, mode); |
Linus Torvalds | 385910f | 2006-04-18 13:22:59 -0700 | [diff] [blame] | 1105 | return ret; |
Miklos Szeredi | e922efc | 2005-09-06 15:18:25 -0700 | [diff] [blame] | 1106 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1107 | |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 1108 | asmlinkage long sys_openat(int dfd, const char __user *filename, int flags, |
| 1109 | int mode) |
| 1110 | { |
Linus Torvalds | 385910f | 2006-04-18 13:22:59 -0700 | [diff] [blame] | 1111 | long ret; |
| 1112 | |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 1113 | if (force_o_largefile()) |
| 1114 | flags |= O_LARGEFILE; |
| 1115 | |
Linus Torvalds | 385910f | 2006-04-18 13:22:59 -0700 | [diff] [blame] | 1116 | ret = do_sys_open(dfd, filename, flags, mode); |
| 1117 | /* avoid REGPARM breakage on x86: */ |
Roland McGrath | 54a0151 | 2008-04-10 15:37:38 -0700 | [diff] [blame] | 1118 | asmlinkage_protect(4, ret, dfd, filename, flags, mode); |
Linus Torvalds | 385910f | 2006-04-18 13:22:59 -0700 | [diff] [blame] | 1119 | return ret; |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 1120 | } |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 1121 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1122 | #ifndef __alpha__ |
| 1123 | |
| 1124 | /* |
| 1125 | * For backward compatibility? Maybe this should be moved |
| 1126 | * into arch/i386 instead? |
| 1127 | */ |
| 1128 | asmlinkage long sys_creat(const char __user * pathname, int mode) |
| 1129 | { |
| 1130 | return sys_open(pathname, O_CREAT | O_WRONLY | O_TRUNC, mode); |
| 1131 | } |
| 1132 | |
| 1133 | #endif |
| 1134 | |
| 1135 | /* |
| 1136 | * "id" is the POSIX thread ID. We use the |
| 1137 | * files pointer for this.. |
| 1138 | */ |
| 1139 | int filp_close(struct file *filp, fl_owner_t id) |
| 1140 | { |
Christoph Lameter | 45778ca | 2005-06-23 00:10:17 -0700 | [diff] [blame] | 1141 | int retval = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1142 | |
| 1143 | if (!file_count(filp)) { |
| 1144 | printk(KERN_ERR "VFS: Close: file count is 0\n"); |
Christoph Lameter | 45778ca | 2005-06-23 00:10:17 -0700 | [diff] [blame] | 1145 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1146 | } |
| 1147 | |
Christoph Lameter | 45778ca | 2005-06-23 00:10:17 -0700 | [diff] [blame] | 1148 | if (filp->f_op && filp->f_op->flush) |
Miklos Szeredi | 75e1fcc | 2006-06-23 02:05:12 -0700 | [diff] [blame] | 1149 | retval = filp->f_op->flush(filp, id); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1150 | |
| 1151 | dnotify_flush(filp, id); |
| 1152 | locks_remove_posix(filp, id); |
| 1153 | fput(filp); |
| 1154 | return retval; |
| 1155 | } |
| 1156 | |
| 1157 | EXPORT_SYMBOL(filp_close); |
| 1158 | |
| 1159 | /* |
| 1160 | * Careful here! We test whether the file pointer is NULL before |
| 1161 | * releasing the fd. This ensures that one clone task can't release |
| 1162 | * an fd while another clone is opening it. |
| 1163 | */ |
| 1164 | asmlinkage long sys_close(unsigned int fd) |
| 1165 | { |
| 1166 | struct file * filp; |
| 1167 | struct files_struct *files = current->files; |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 1168 | struct fdtable *fdt; |
Ernie Petrides | ee731f4 | 2006-09-29 02:00:13 -0700 | [diff] [blame] | 1169 | int retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1170 | |
| 1171 | spin_lock(&files->file_lock); |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 1172 | fdt = files_fdtable(files); |
| 1173 | if (fd >= fdt->max_fds) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1174 | goto out_unlock; |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 1175 | filp = fdt->fd[fd]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1176 | if (!filp) |
| 1177 | goto out_unlock; |
Dipankar Sarma | ab2af1f | 2005-09-09 13:04:13 -0700 | [diff] [blame] | 1178 | rcu_assign_pointer(fdt->fd[fd], NULL); |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 1179 | FD_CLR(fd, fdt->close_on_exec); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1180 | __put_unused_fd(files, fd); |
| 1181 | spin_unlock(&files->file_lock); |
Ernie Petrides | ee731f4 | 2006-09-29 02:00:13 -0700 | [diff] [blame] | 1182 | retval = filp_close(filp, files); |
| 1183 | |
| 1184 | /* can't restart close syscall because file table entry was cleared */ |
| 1185 | if (unlikely(retval == -ERESTARTSYS || |
| 1186 | retval == -ERESTARTNOINTR || |
| 1187 | retval == -ERESTARTNOHAND || |
| 1188 | retval == -ERESTART_RESTARTBLOCK)) |
| 1189 | retval = -EINTR; |
| 1190 | |
| 1191 | return retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1192 | |
| 1193 | out_unlock: |
| 1194 | spin_unlock(&files->file_lock); |
| 1195 | return -EBADF; |
| 1196 | } |
| 1197 | |
| 1198 | EXPORT_SYMBOL(sys_close); |
| 1199 | |
| 1200 | /* |
| 1201 | * This routine simulates a hangup on the tty, to arrange that users |
| 1202 | * are given clean terminals at login time. |
| 1203 | */ |
| 1204 | asmlinkage long sys_vhangup(void) |
| 1205 | { |
| 1206 | if (capable(CAP_SYS_TTY_CONFIG)) { |
Peter Zijlstra | 24ec839 | 2006-12-08 02:36:04 -0800 | [diff] [blame] | 1207 | /* XXX: this needs locking */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1208 | tty_vhangup(current->signal->tty); |
| 1209 | return 0; |
| 1210 | } |
| 1211 | return -EPERM; |
| 1212 | } |
| 1213 | |
| 1214 | /* |
| 1215 | * Called when an inode is about to be open. |
| 1216 | * We use this to disallow opening large files on 32bit systems if |
| 1217 | * the caller didn't specify O_LARGEFILE. On 64bit systems we force |
| 1218 | * on this flag in sys_open. |
| 1219 | */ |
| 1220 | int generic_file_open(struct inode * inode, struct file * filp) |
| 1221 | { |
| 1222 | if (!(filp->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS) |
Alan Cox | a9c62a1 | 2007-10-16 23:30:22 -0700 | [diff] [blame] | 1223 | return -EOVERFLOW; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1224 | return 0; |
| 1225 | } |
| 1226 | |
| 1227 | EXPORT_SYMBOL(generic_file_open); |
| 1228 | |
| 1229 | /* |
| 1230 | * This is used by subsystems that don't want seekable |
| 1231 | * file descriptors |
| 1232 | */ |
| 1233 | int nonseekable_open(struct inode *inode, struct file *filp) |
| 1234 | { |
| 1235 | filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE); |
| 1236 | return 0; |
| 1237 | } |
| 1238 | |
| 1239 | EXPORT_SYMBOL(nonseekable_open); |