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> |
Robert Love | 0eeca28 | 2005-07-12 17:06:03 -0400 | [diff] [blame] | 11 | #include <linux/fsnotify.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 12 | #include <linux/module.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 13 | #include <linux/tty.h> |
| 14 | #include <linux/namei.h> |
| 15 | #include <linux/backing-dev.h> |
Randy Dunlap | 16f7e0f | 2006-01-11 12:17:46 -0800 | [diff] [blame] | 16 | #include <linux/capability.h> |
Andrew G. Morgan | 086f731 | 2008-07-04 09:59:58 -0700 | [diff] [blame] | 17 | #include <linux/securebits.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 18 | #include <linux/security.h> |
| 19 | #include <linux/mount.h> |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 20 | #include <linux/fcntl.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 21 | #include <linux/slab.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 22 | #include <asm/uaccess.h> |
| 23 | #include <linux/fs.h> |
Yoav Zach | ef3daed | 2005-06-23 00:09:58 -0700 | [diff] [blame] | 24 | #include <linux/personality.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 25 | #include <linux/pagemap.h> |
| 26 | #include <linux/syscalls.h> |
Dipankar Sarma | ab2af1f | 2005-09-09 13:04:13 -0700 | [diff] [blame] | 27 | #include <linux/rcupdate.h> |
Amy Griffis | 73241cc | 2005-11-03 16:00:25 +0000 | [diff] [blame] | 28 | #include <linux/audit.h> |
Amit Arora | 97ac735 | 2007-07-17 21:42:44 -0400 | [diff] [blame] | 29 | #include <linux/falloc.h> |
Al Viro | 5ad4e53 | 2009-03-29 19:50:06 -0400 | [diff] [blame] | 30 | #include <linux/fs_struct.h> |
Al Viro | b65a9cf | 2009-12-16 06:27:40 -0500 | [diff] [blame] | 31 | #include <linux/ima.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | |
Eric Paris | e81e3f4 | 2009-12-04 15:47:36 -0500 | [diff] [blame] | 33 | #include "internal.h" |
| 34 | |
NeilBrown | 4a30131 | 2006-01-08 01:02:39 -0800 | [diff] [blame] | 35 | int do_truncate(struct dentry *dentry, loff_t length, unsigned int time_attrs, |
| 36 | struct file *filp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 37 | { |
Amerigo Wang | 939a942 | 2009-08-20 19:29:03 -0700 | [diff] [blame] | 38 | int ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 39 | struct iattr newattrs; |
| 40 | |
| 41 | /* Not pretty: "inode->i_size" shouldn't really be signed. But it is. */ |
| 42 | if (length < 0) |
| 43 | return -EINVAL; |
| 44 | |
| 45 | newattrs.ia_size = length; |
NeilBrown | 4a30131 | 2006-01-08 01:02:39 -0800 | [diff] [blame] | 46 | newattrs.ia_valid = ATTR_SIZE | time_attrs; |
Miklos Szeredi | cc4e69d | 2005-11-07 00:59:49 -0800 | [diff] [blame] | 47 | if (filp) { |
| 48 | newattrs.ia_file = filp; |
| 49 | newattrs.ia_valid |= ATTR_FILE; |
| 50 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 51 | |
Linus Torvalds | 7b82dc0 | 2007-05-08 20:10:00 -0700 | [diff] [blame] | 52 | /* Remove suid/sgid on truncate too */ |
Amerigo Wang | 939a942 | 2009-08-20 19:29:03 -0700 | [diff] [blame] | 53 | ret = should_remove_suid(dentry); |
| 54 | if (ret) |
| 55 | newattrs.ia_valid |= ret | ATTR_FORCE; |
Linus Torvalds | 7b82dc0 | 2007-05-08 20:10:00 -0700 | [diff] [blame] | 56 | |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 57 | mutex_lock(&dentry->d_inode->i_mutex); |
Amerigo Wang | 939a942 | 2009-08-20 19:29:03 -0700 | [diff] [blame] | 58 | ret = notify_change(dentry, &newattrs); |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 59 | mutex_unlock(&dentry->d_inode->i_mutex); |
Amerigo Wang | 939a942 | 2009-08-20 19:29:03 -0700 | [diff] [blame] | 60 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 61 | } |
| 62 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 63 | static long do_sys_truncate(const char __user *pathname, loff_t length) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 64 | { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 65 | struct path path; |
| 66 | struct inode *inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 67 | int error; |
| 68 | |
| 69 | error = -EINVAL; |
| 70 | if (length < 0) /* sorry, but loff_t says... */ |
| 71 | goto out; |
| 72 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 73 | error = user_path(pathname, &path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 74 | if (error) |
| 75 | goto out; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 76 | inode = path.dentry->d_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 77 | |
| 78 | /* For directories it's -EISDIR, for other non-regulars - -EINVAL */ |
| 79 | error = -EISDIR; |
| 80 | if (S_ISDIR(inode->i_mode)) |
| 81 | goto dput_and_out; |
| 82 | |
| 83 | error = -EINVAL; |
| 84 | if (!S_ISREG(inode->i_mode)) |
| 85 | goto dput_and_out; |
| 86 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 87 | error = mnt_want_write(path.mnt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 88 | if (error) |
| 89 | goto dput_and_out; |
| 90 | |
Al Viro | 256984a | 2008-07-22 08:09:30 -0400 | [diff] [blame] | 91 | error = inode_permission(inode, MAY_WRITE); |
Dave Hansen | 9ac9b84 | 2008-02-15 14:37:52 -0800 | [diff] [blame] | 92 | if (error) |
| 93 | goto mnt_drop_write_and_out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 94 | |
| 95 | error = -EPERM; |
Miklos Szeredi | c82e42d | 2008-06-24 16:50:12 +0200 | [diff] [blame] | 96 | if (IS_APPEND(inode)) |
Dave Hansen | 9ac9b84 | 2008-02-15 14:37:52 -0800 | [diff] [blame] | 97 | goto mnt_drop_write_and_out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 98 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 99 | error = get_write_access(inode); |
| 100 | if (error) |
Dave Hansen | 9ac9b84 | 2008-02-15 14:37:52 -0800 | [diff] [blame] | 101 | goto mnt_drop_write_and_out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 102 | |
david m. richter | 9700382 | 2007-07-31 00:39:12 -0700 | [diff] [blame] | 103 | /* |
| 104 | * Make sure that there are no leases. get_write_access() protects |
| 105 | * against the truncate racing with a lease-granting setlease(). |
| 106 | */ |
Al Viro | 8737c93 | 2009-12-24 06:47:55 -0500 | [diff] [blame] | 107 | error = break_lease(inode, O_WRONLY); |
david m. richter | 9700382 | 2007-07-31 00:39:12 -0700 | [diff] [blame] | 108 | if (error) |
| 109 | goto put_write_and_out; |
| 110 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 111 | error = locks_verify_truncate(inode, NULL, length); |
Kentaro Takeda | be6d3e5 | 2008-12-17 13:24:15 +0900 | [diff] [blame] | 112 | if (!error) |
Tetsuo Handa | ea0d3ab | 2010-06-02 13:24:43 +0900 | [diff] [blame^] | 113 | error = security_path_truncate(&path); |
Christoph Hellwig | 907f455 | 2010-03-03 09:05:06 -0500 | [diff] [blame] | 114 | if (!error) |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 115 | error = do_truncate(path.dentry, length, 0, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 116 | |
david m. richter | 9700382 | 2007-07-31 00:39:12 -0700 | [diff] [blame] | 117 | put_write_and_out: |
| 118 | put_write_access(inode); |
Dave Hansen | 9ac9b84 | 2008-02-15 14:37:52 -0800 | [diff] [blame] | 119 | mnt_drop_write_and_out: |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 120 | mnt_drop_write(path.mnt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 121 | dput_and_out: |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 122 | path_put(&path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 123 | out: |
| 124 | return error; |
| 125 | } |
| 126 | |
Heiko Carstens | 4fd8da8 | 2009-09-23 17:49:55 +0200 | [diff] [blame] | 127 | SYSCALL_DEFINE2(truncate, const char __user *, path, long, length) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 128 | { |
Heiko Carstens | 4fd8da8 | 2009-09-23 17:49:55 +0200 | [diff] [blame] | 129 | return do_sys_truncate(path, length); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 130 | } |
| 131 | |
Matt Mackall | b01ec0e | 2006-01-08 01:05:20 -0800 | [diff] [blame] | 132 | 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] | 133 | { |
| 134 | struct inode * inode; |
| 135 | struct dentry *dentry; |
| 136 | struct file * file; |
| 137 | int error; |
| 138 | |
| 139 | error = -EINVAL; |
| 140 | if (length < 0) |
| 141 | goto out; |
| 142 | error = -EBADF; |
| 143 | file = fget(fd); |
| 144 | if (!file) |
| 145 | goto out; |
| 146 | |
| 147 | /* explicitly opened as large or we are on 64-bit box */ |
| 148 | if (file->f_flags & O_LARGEFILE) |
| 149 | small = 0; |
| 150 | |
Josef "Jeff" Sipek | 0f7fc9e | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 151 | dentry = file->f_path.dentry; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 152 | inode = dentry->d_inode; |
| 153 | error = -EINVAL; |
| 154 | if (!S_ISREG(inode->i_mode) || !(file->f_mode & FMODE_WRITE)) |
| 155 | goto out_putf; |
| 156 | |
| 157 | error = -EINVAL; |
| 158 | /* Cannot ftruncate over 2^31 bytes without large file support */ |
| 159 | if (small && length > MAX_NON_LFS) |
| 160 | goto out_putf; |
| 161 | |
| 162 | error = -EPERM; |
| 163 | if (IS_APPEND(inode)) |
| 164 | goto out_putf; |
| 165 | |
| 166 | error = locks_verify_truncate(inode, file, length); |
| 167 | if (!error) |
Tetsuo Handa | ea0d3ab | 2010-06-02 13:24:43 +0900 | [diff] [blame^] | 168 | error = security_path_truncate(&file->f_path); |
Kentaro Takeda | be6d3e5 | 2008-12-17 13:24:15 +0900 | [diff] [blame] | 169 | if (!error) |
Peter Staubach | 6e656be | 2006-06-25 05:48:36 -0700 | [diff] [blame] | 170 | error = do_truncate(dentry, length, ATTR_MTIME|ATTR_CTIME, file); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 171 | out_putf: |
| 172 | fput(file); |
| 173 | out: |
| 174 | return error; |
| 175 | } |
| 176 | |
Heiko Carstens | bdc480e | 2009-01-14 14:14:12 +0100 | [diff] [blame] | 177 | SYSCALL_DEFINE2(ftruncate, unsigned int, fd, unsigned long, length) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 178 | { |
Linus Torvalds | 0a489cb | 2006-04-18 13:02:48 -0700 | [diff] [blame] | 179 | long ret = do_sys_ftruncate(fd, length, 1); |
Linus Torvalds | 385910f | 2006-04-18 13:22:59 -0700 | [diff] [blame] | 180 | /* avoid REGPARM breakage on x86: */ |
Roland McGrath | 54a0151 | 2008-04-10 15:37:38 -0700 | [diff] [blame] | 181 | asmlinkage_protect(2, ret, fd, length); |
Linus Torvalds | 0a489cb | 2006-04-18 13:02:48 -0700 | [diff] [blame] | 182 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 183 | } |
| 184 | |
| 185 | /* LFS versions of truncate are only needed on 32 bit machines */ |
| 186 | #if BITS_PER_LONG == 32 |
Heiko Carstens | 6673e0c | 2009-01-14 14:14:02 +0100 | [diff] [blame] | 187 | SYSCALL_DEFINE(truncate64)(const char __user * path, loff_t length) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 188 | { |
| 189 | return do_sys_truncate(path, length); |
| 190 | } |
Heiko Carstens | 6673e0c | 2009-01-14 14:14:02 +0100 | [diff] [blame] | 191 | #ifdef CONFIG_HAVE_SYSCALL_WRAPPERS |
| 192 | asmlinkage long SyS_truncate64(long path, loff_t length) |
| 193 | { |
| 194 | return SYSC_truncate64((const char __user *) path, length); |
| 195 | } |
| 196 | SYSCALL_ALIAS(sys_truncate64, SyS_truncate64); |
| 197 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 198 | |
Heiko Carstens | 6673e0c | 2009-01-14 14:14:02 +0100 | [diff] [blame] | 199 | SYSCALL_DEFINE(ftruncate64)(unsigned int fd, loff_t length) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 200 | { |
Linus Torvalds | 0a489cb | 2006-04-18 13:02:48 -0700 | [diff] [blame] | 201 | long ret = do_sys_ftruncate(fd, length, 0); |
Linus Torvalds | 385910f | 2006-04-18 13:22:59 -0700 | [diff] [blame] | 202 | /* avoid REGPARM breakage on x86: */ |
Roland McGrath | 54a0151 | 2008-04-10 15:37:38 -0700 | [diff] [blame] | 203 | asmlinkage_protect(2, ret, fd, length); |
Linus Torvalds | 0a489cb | 2006-04-18 13:02:48 -0700 | [diff] [blame] | 204 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 205 | } |
Heiko Carstens | 6673e0c | 2009-01-14 14:14:02 +0100 | [diff] [blame] | 206 | #ifdef CONFIG_HAVE_SYSCALL_WRAPPERS |
| 207 | asmlinkage long SyS_ftruncate64(long fd, loff_t length) |
| 208 | { |
| 209 | return SYSC_ftruncate64((unsigned int) fd, length); |
| 210 | } |
| 211 | SYSCALL_ALIAS(sys_ftruncate64, SyS_ftruncate64); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 212 | #endif |
Heiko Carstens | 6673e0c | 2009-01-14 14:14:02 +0100 | [diff] [blame] | 213 | #endif /* BITS_PER_LONG == 32 */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 214 | |
Ankit Jain | 3e63cbb | 2009-06-19 14:28:07 -0400 | [diff] [blame] | 215 | |
| 216 | int do_fallocate(struct file *file, int mode, loff_t offset, loff_t len) |
Amit Arora | 97ac735 | 2007-07-17 21:42:44 -0400 | [diff] [blame] | 217 | { |
Ankit Jain | 3e63cbb | 2009-06-19 14:28:07 -0400 | [diff] [blame] | 218 | struct inode *inode = file->f_path.dentry->d_inode; |
| 219 | long ret; |
Amit Arora | 97ac735 | 2007-07-17 21:42:44 -0400 | [diff] [blame] | 220 | |
| 221 | if (offset < 0 || len <= 0) |
Ankit Jain | 3e63cbb | 2009-06-19 14:28:07 -0400 | [diff] [blame] | 222 | return -EINVAL; |
Amit Arora | 97ac735 | 2007-07-17 21:42:44 -0400 | [diff] [blame] | 223 | |
| 224 | /* Return error if mode is not supported */ |
Amit Arora | 97ac735 | 2007-07-17 21:42:44 -0400 | [diff] [blame] | 225 | if (mode && !(mode & FALLOC_FL_KEEP_SIZE)) |
Ankit Jain | 3e63cbb | 2009-06-19 14:28:07 -0400 | [diff] [blame] | 226 | return -EOPNOTSUPP; |
Amit Arora | 97ac735 | 2007-07-17 21:42:44 -0400 | [diff] [blame] | 227 | |
Amit Arora | 97ac735 | 2007-07-17 21:42:44 -0400 | [diff] [blame] | 228 | if (!(file->f_mode & FMODE_WRITE)) |
Ankit Jain | 3e63cbb | 2009-06-19 14:28:07 -0400 | [diff] [blame] | 229 | return -EBADF; |
Amit Arora | 97ac735 | 2007-07-17 21:42:44 -0400 | [diff] [blame] | 230 | /* |
| 231 | * Revalidate the write permissions, in case security policy has |
| 232 | * changed since the files were opened. |
| 233 | */ |
| 234 | ret = security_file_permission(file, MAY_WRITE); |
| 235 | if (ret) |
Ankit Jain | 3e63cbb | 2009-06-19 14:28:07 -0400 | [diff] [blame] | 236 | return ret; |
Amit Arora | 97ac735 | 2007-07-17 21:42:44 -0400 | [diff] [blame] | 237 | |
Amit Arora | 97ac735 | 2007-07-17 21:42:44 -0400 | [diff] [blame] | 238 | if (S_ISFIFO(inode->i_mode)) |
Ankit Jain | 3e63cbb | 2009-06-19 14:28:07 -0400 | [diff] [blame] | 239 | return -ESPIPE; |
Amit Arora | 97ac735 | 2007-07-17 21:42:44 -0400 | [diff] [blame] | 240 | |
Amit Arora | 97ac735 | 2007-07-17 21:42:44 -0400 | [diff] [blame] | 241 | /* |
| 242 | * Let individual file system decide if it supports preallocation |
| 243 | * for directories or not. |
| 244 | */ |
| 245 | if (!S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode)) |
Ankit Jain | 3e63cbb | 2009-06-19 14:28:07 -0400 | [diff] [blame] | 246 | return -ENODEV; |
Amit Arora | 97ac735 | 2007-07-17 21:42:44 -0400 | [diff] [blame] | 247 | |
Amit Arora | 97ac735 | 2007-07-17 21:42:44 -0400 | [diff] [blame] | 248 | /* Check for wrap through zero too */ |
| 249 | if (((offset + len) > inode->i_sb->s_maxbytes) || ((offset + len) < 0)) |
Ankit Jain | 3e63cbb | 2009-06-19 14:28:07 -0400 | [diff] [blame] | 250 | return -EFBIG; |
Amit Arora | 97ac735 | 2007-07-17 21:42:44 -0400 | [diff] [blame] | 251 | |
Ankit Jain | 3e63cbb | 2009-06-19 14:28:07 -0400 | [diff] [blame] | 252 | if (!inode->i_op->fallocate) |
| 253 | return -EOPNOTSUPP; |
Amit Arora | 97ac735 | 2007-07-17 21:42:44 -0400 | [diff] [blame] | 254 | |
Ankit Jain | 3e63cbb | 2009-06-19 14:28:07 -0400 | [diff] [blame] | 255 | return inode->i_op->fallocate(inode, mode, offset, len); |
Amit Arora | 97ac735 | 2007-07-17 21:42:44 -0400 | [diff] [blame] | 256 | } |
Ankit Jain | 3e63cbb | 2009-06-19 14:28:07 -0400 | [diff] [blame] | 257 | |
| 258 | SYSCALL_DEFINE(fallocate)(int fd, int mode, loff_t offset, loff_t len) |
| 259 | { |
| 260 | struct file *file; |
| 261 | int error = -EBADF; |
| 262 | |
| 263 | file = fget(fd); |
| 264 | if (file) { |
| 265 | error = do_fallocate(file, mode, offset, len); |
| 266 | fput(file); |
| 267 | } |
| 268 | |
| 269 | return error; |
| 270 | } |
| 271 | |
Heiko Carstens | 6673e0c | 2009-01-14 14:14:02 +0100 | [diff] [blame] | 272 | #ifdef CONFIG_HAVE_SYSCALL_WRAPPERS |
| 273 | asmlinkage long SyS_fallocate(long fd, long mode, loff_t offset, loff_t len) |
| 274 | { |
| 275 | return SYSC_fallocate((int)fd, (int)mode, offset, len); |
| 276 | } |
| 277 | SYSCALL_ALIAS(sys_fallocate, SyS_fallocate); |
| 278 | #endif |
Amit Arora | 97ac735 | 2007-07-17 21:42:44 -0400 | [diff] [blame] | 279 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 280 | /* |
| 281 | * access() needs to use the real uid/gid, not the effective uid/gid. |
| 282 | * We do this by temporarily clearing all FS-related capabilities and |
| 283 | * switching the fsuid/fsgid around to the real ones. |
| 284 | */ |
Heiko Carstens | 6559eed8 | 2009-01-14 14:14:32 +0100 | [diff] [blame] | 285 | SYSCALL_DEFINE3(faccessat, int, dfd, const char __user *, filename, int, mode) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 286 | { |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 287 | const struct cred *old_cred; |
| 288 | struct cred *override_cred; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 289 | struct path path; |
Al Viro | 256984a | 2008-07-22 08:09:30 -0400 | [diff] [blame] | 290 | struct inode *inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 291 | int res; |
| 292 | |
| 293 | if (mode & ~S_IRWXO) /* where's F_OK, X_OK, W_OK, R_OK? */ |
| 294 | return -EINVAL; |
| 295 | |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 296 | override_cred = prepare_creds(); |
| 297 | if (!override_cred) |
| 298 | return -ENOMEM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 299 | |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 300 | override_cred->fsuid = override_cred->uid; |
| 301 | override_cred->fsgid = override_cred->gid; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 302 | |
Andrew G. Morgan | 086f731 | 2008-07-04 09:59:58 -0700 | [diff] [blame] | 303 | if (!issecure(SECURE_NO_SETUID_FIXUP)) { |
David Howells | 1cdcbec | 2008-11-14 10:39:14 +1100 | [diff] [blame] | 304 | /* Clear the capabilities if we switch to a non-root user */ |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 305 | if (override_cred->uid) |
| 306 | cap_clear(override_cred->cap_effective); |
Andrew G. Morgan | 086f731 | 2008-07-04 09:59:58 -0700 | [diff] [blame] | 307 | else |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 308 | override_cred->cap_effective = |
| 309 | override_cred->cap_permitted; |
Andrew G. Morgan | 086f731 | 2008-07-04 09:59:58 -0700 | [diff] [blame] | 310 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 311 | |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 312 | old_cred = override_creds(override_cred); |
| 313 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 314 | res = user_path_at(dfd, filename, LOOKUP_FOLLOW, &path); |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 315 | if (res) |
| 316 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 317 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 318 | inode = path.dentry->d_inode; |
Al Viro | 256984a | 2008-07-22 08:09:30 -0400 | [diff] [blame] | 319 | |
| 320 | if ((mode & MAY_EXEC) && S_ISREG(inode->i_mode)) { |
Al Viro | 3052447 | 2008-07-22 00:02:33 -0400 | [diff] [blame] | 321 | /* |
| 322 | * MAY_EXEC on regular files is denied if the fs is mounted |
| 323 | * with the "noexec" flag. |
| 324 | */ |
| 325 | res = -EACCES; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 326 | if (path.mnt->mnt_flags & MNT_NOEXEC) |
Al Viro | 3052447 | 2008-07-22 00:02:33 -0400 | [diff] [blame] | 327 | goto out_path_release; |
| 328 | } |
| 329 | |
Al Viro | 256984a | 2008-07-22 08:09:30 -0400 | [diff] [blame] | 330 | res = inode_permission(inode, mode | MAY_ACCESS); |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 331 | /* SuS v2 requires we report a read only fs too */ |
Al Viro | 256984a | 2008-07-22 08:09:30 -0400 | [diff] [blame] | 332 | if (res || !(mode & S_IWOTH) || special_file(inode->i_mode)) |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 333 | goto out_path_release; |
Dave Hansen | 2f676cb | 2008-02-15 14:37:55 -0800 | [diff] [blame] | 334 | /* |
| 335 | * This is a rare case where using __mnt_is_readonly() |
| 336 | * is OK without a mnt_want/drop_write() pair. Since |
| 337 | * no actual write to the fs is performed here, we do |
| 338 | * not need to telegraph to that to anyone. |
| 339 | * |
| 340 | * By doing this, we accept that this access is |
| 341 | * inherently racy and know that the fs may change |
| 342 | * state before we even see this result. |
| 343 | */ |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 344 | if (__mnt_is_readonly(path.mnt)) |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 345 | res = -EROFS; |
| 346 | |
| 347 | out_path_release: |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 348 | path_put(&path); |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 349 | out: |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 350 | revert_creds(old_cred); |
| 351 | put_cred(override_cred); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 352 | return res; |
| 353 | } |
| 354 | |
Heiko Carstens | ca013e9 | 2009-01-14 14:14:19 +0100 | [diff] [blame] | 355 | SYSCALL_DEFINE2(access, const char __user *, filename, int, mode) |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 356 | { |
| 357 | return sys_faccessat(AT_FDCWD, filename, mode); |
| 358 | } |
| 359 | |
Heiko Carstens | 3cdad42 | 2009-01-14 14:14:22 +0100 | [diff] [blame] | 360 | SYSCALL_DEFINE1(chdir, const char __user *, filename) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 361 | { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 362 | struct path path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 363 | int error; |
| 364 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 365 | error = user_path_dir(filename, &path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 366 | if (error) |
| 367 | goto out; |
| 368 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 369 | error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_ACCESS); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 370 | if (error) |
| 371 | goto dput_and_out; |
| 372 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 373 | set_fs_pwd(current->fs, &path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 374 | |
| 375 | dput_and_out: |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 376 | path_put(&path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 377 | out: |
| 378 | return error; |
| 379 | } |
| 380 | |
Heiko Carstens | 3cdad42 | 2009-01-14 14:14:22 +0100 | [diff] [blame] | 381 | SYSCALL_DEFINE1(fchdir, unsigned int, fd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 382 | { |
| 383 | struct file *file; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 384 | struct inode *inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 385 | int error; |
| 386 | |
| 387 | error = -EBADF; |
| 388 | file = fget(fd); |
| 389 | if (!file) |
| 390 | goto out; |
| 391 | |
Jan Blunck | ac748a0 | 2008-02-14 19:34:39 -0800 | [diff] [blame] | 392 | inode = file->f_path.dentry->d_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 393 | |
| 394 | error = -ENOTDIR; |
| 395 | if (!S_ISDIR(inode->i_mode)) |
| 396 | goto out_putf; |
| 397 | |
Al Viro | 256984a | 2008-07-22 08:09:30 -0400 | [diff] [blame] | 398 | error = inode_permission(inode, MAY_EXEC | MAY_ACCESS); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 399 | if (!error) |
Jan Blunck | ac748a0 | 2008-02-14 19:34:39 -0800 | [diff] [blame] | 400 | set_fs_pwd(current->fs, &file->f_path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 401 | out_putf: |
| 402 | fput(file); |
| 403 | out: |
| 404 | return error; |
| 405 | } |
| 406 | |
Heiko Carstens | 3480b25 | 2009-01-14 14:14:16 +0100 | [diff] [blame] | 407 | SYSCALL_DEFINE1(chroot, const char __user *, filename) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 408 | { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 409 | struct path path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 410 | int error; |
| 411 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 412 | error = user_path_dir(filename, &path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 413 | if (error) |
| 414 | goto out; |
| 415 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 416 | error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_ACCESS); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 417 | if (error) |
| 418 | goto dput_and_out; |
| 419 | |
| 420 | error = -EPERM; |
| 421 | if (!capable(CAP_SYS_CHROOT)) |
| 422 | goto dput_and_out; |
Tetsuo Handa | 8b8efb4 | 2009-10-04 21:49:48 +0900 | [diff] [blame] | 423 | error = security_path_chroot(&path); |
| 424 | if (error) |
| 425 | goto dput_and_out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 426 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 427 | set_fs_root(current->fs, &path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 428 | error = 0; |
| 429 | dput_and_out: |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 430 | path_put(&path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 431 | out: |
| 432 | return error; |
| 433 | } |
| 434 | |
Heiko Carstens | a26eab2 | 2009-01-14 14:14:17 +0100 | [diff] [blame] | 435 | SYSCALL_DEFINE2(fchmod, unsigned int, fd, mode_t, mode) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 436 | { |
| 437 | struct inode * inode; |
| 438 | struct dentry * dentry; |
| 439 | struct file * file; |
| 440 | int err = -EBADF; |
| 441 | struct iattr newattrs; |
| 442 | |
| 443 | file = fget(fd); |
| 444 | if (!file) |
| 445 | goto out; |
| 446 | |
Josef "Jeff" Sipek | 0f7fc9e | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 447 | dentry = file->f_path.dentry; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 448 | inode = dentry->d_inode; |
| 449 | |
Al Viro | 5a190ae | 2007-06-07 12:19:32 -0400 | [diff] [blame] | 450 | audit_inode(NULL, dentry); |
Amy Griffis | 73241cc | 2005-11-03 16:00:25 +0000 | [diff] [blame] | 451 | |
npiggin@suse.de | 96029c4 | 2009-04-26 20:25:55 +1000 | [diff] [blame] | 452 | err = mnt_want_write_file(file); |
Dave Hansen | 2af482a | 2008-02-15 14:37:50 -0800 | [diff] [blame] | 453 | if (err) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 454 | goto out_putf; |
Tetsuo Handa | fe542cf | 2009-11-22 11:49:55 +0900 | [diff] [blame] | 455 | mutex_lock(&inode->i_mutex); |
Tetsuo Handa | 89eda06 | 2009-10-04 21:49:47 +0900 | [diff] [blame] | 456 | err = security_path_chmod(dentry, file->f_vfsmnt, mode); |
| 457 | if (err) |
Tetsuo Handa | fe542cf | 2009-11-22 11:49:55 +0900 | [diff] [blame] | 458 | goto out_unlock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 459 | if (mode == (mode_t) -1) |
| 460 | mode = inode->i_mode; |
| 461 | newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO); |
| 462 | newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; |
| 463 | err = notify_change(dentry, &newattrs); |
Tetsuo Handa | fe542cf | 2009-11-22 11:49:55 +0900 | [diff] [blame] | 464 | out_unlock: |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 465 | mutex_unlock(&inode->i_mutex); |
Dave Hansen | 2af482a | 2008-02-15 14:37:50 -0800 | [diff] [blame] | 466 | mnt_drop_write(file->f_path.mnt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 467 | out_putf: |
| 468 | fput(file); |
| 469 | out: |
| 470 | return err; |
| 471 | } |
| 472 | |
Heiko Carstens | 6559eed8 | 2009-01-14 14:14:32 +0100 | [diff] [blame] | 473 | SYSCALL_DEFINE3(fchmodat, int, dfd, const char __user *, filename, mode_t, mode) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 474 | { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 475 | struct path path; |
| 476 | struct inode *inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 477 | int error; |
| 478 | struct iattr newattrs; |
| 479 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 480 | error = user_path_at(dfd, filename, LOOKUP_FOLLOW, &path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 481 | if (error) |
| 482 | goto out; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 483 | inode = path.dentry->d_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 484 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 485 | error = mnt_want_write(path.mnt); |
Dave Hansen | 2af482a | 2008-02-15 14:37:50 -0800 | [diff] [blame] | 486 | if (error) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 487 | goto dput_and_out; |
Tetsuo Handa | fe542cf | 2009-11-22 11:49:55 +0900 | [diff] [blame] | 488 | mutex_lock(&inode->i_mutex); |
Tetsuo Handa | 89eda06 | 2009-10-04 21:49:47 +0900 | [diff] [blame] | 489 | error = security_path_chmod(path.dentry, path.mnt, mode); |
| 490 | if (error) |
Tetsuo Handa | fe542cf | 2009-11-22 11:49:55 +0900 | [diff] [blame] | 491 | goto out_unlock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 492 | if (mode == (mode_t) -1) |
| 493 | mode = inode->i_mode; |
| 494 | newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO); |
| 495 | newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 496 | error = notify_change(path.dentry, &newattrs); |
Tetsuo Handa | fe542cf | 2009-11-22 11:49:55 +0900 | [diff] [blame] | 497 | out_unlock: |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 498 | mutex_unlock(&inode->i_mutex); |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 499 | mnt_drop_write(path.mnt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 500 | dput_and_out: |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 501 | path_put(&path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 502 | out: |
| 503 | return error; |
| 504 | } |
| 505 | |
Heiko Carstens | a26eab2 | 2009-01-14 14:14:17 +0100 | [diff] [blame] | 506 | SYSCALL_DEFINE2(chmod, const char __user *, filename, mode_t, mode) |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 507 | { |
| 508 | return sys_fchmodat(AT_FDCWD, filename, mode); |
| 509 | } |
| 510 | |
Tetsuo Handa | fe542cf | 2009-11-22 11:49:55 +0900 | [diff] [blame] | 511 | static int chown_common(struct path *path, uid_t user, gid_t group) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 512 | { |
Tetsuo Handa | fe542cf | 2009-11-22 11:49:55 +0900 | [diff] [blame] | 513 | struct inode *inode = path->dentry->d_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 514 | int error; |
| 515 | struct iattr newattrs; |
| 516 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 517 | newattrs.ia_valid = ATTR_CTIME; |
| 518 | if (user != (uid_t) -1) { |
| 519 | newattrs.ia_valid |= ATTR_UID; |
| 520 | newattrs.ia_uid = user; |
| 521 | } |
| 522 | if (group != (gid_t) -1) { |
| 523 | newattrs.ia_valid |= ATTR_GID; |
| 524 | newattrs.ia_gid = group; |
| 525 | } |
| 526 | if (!S_ISDIR(inode->i_mode)) |
Serge E. Hallyn | b537677 | 2007-10-16 23:31:36 -0700 | [diff] [blame] | 527 | newattrs.ia_valid |= |
| 528 | ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV; |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 529 | mutex_lock(&inode->i_mutex); |
Tetsuo Handa | fe542cf | 2009-11-22 11:49:55 +0900 | [diff] [blame] | 530 | error = security_path_chown(path, user, group); |
| 531 | if (!error) |
| 532 | error = notify_change(path->dentry, &newattrs); |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 533 | mutex_unlock(&inode->i_mutex); |
Miklos Szeredi | beb29e0 | 2008-07-01 15:01:29 +0200 | [diff] [blame] | 534 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 535 | return error; |
| 536 | } |
| 537 | |
Heiko Carstens | ca013e9 | 2009-01-14 14:14:19 +0100 | [diff] [blame] | 538 | SYSCALL_DEFINE3(chown, const char __user *, filename, uid_t, user, gid_t, group) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 539 | { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 540 | struct path path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 541 | int error; |
| 542 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 543 | error = user_path(filename, &path); |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 544 | if (error) |
| 545 | goto out; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 546 | error = mnt_want_write(path.mnt); |
Dave Hansen | 2af482a | 2008-02-15 14:37:50 -0800 | [diff] [blame] | 547 | if (error) |
| 548 | goto out_release; |
Tetsuo Handa | fe542cf | 2009-11-22 11:49:55 +0900 | [diff] [blame] | 549 | error = chown_common(&path, user, group); |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 550 | mnt_drop_write(path.mnt); |
Dave Hansen | 2af482a | 2008-02-15 14:37:50 -0800 | [diff] [blame] | 551 | out_release: |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 552 | path_put(&path); |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 553 | out: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 554 | return error; |
| 555 | } |
| 556 | |
Heiko Carstens | 6559eed8 | 2009-01-14 14:14:32 +0100 | [diff] [blame] | 557 | SYSCALL_DEFINE5(fchownat, int, dfd, const char __user *, filename, uid_t, user, |
| 558 | gid_t, group, int, flag) |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 559 | { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 560 | struct path path; |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 561 | int error = -EINVAL; |
| 562 | int follow; |
| 563 | |
| 564 | if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0) |
| 565 | goto out; |
| 566 | |
| 567 | follow = (flag & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 568 | error = user_path_at(dfd, filename, follow, &path); |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 569 | if (error) |
| 570 | goto out; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 571 | error = mnt_want_write(path.mnt); |
Dave Hansen | 2af482a | 2008-02-15 14:37:50 -0800 | [diff] [blame] | 572 | if (error) |
| 573 | goto out_release; |
Tetsuo Handa | fe542cf | 2009-11-22 11:49:55 +0900 | [diff] [blame] | 574 | error = chown_common(&path, user, group); |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 575 | mnt_drop_write(path.mnt); |
Dave Hansen | 2af482a | 2008-02-15 14:37:50 -0800 | [diff] [blame] | 576 | out_release: |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 577 | path_put(&path); |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 578 | out: |
| 579 | return error; |
| 580 | } |
| 581 | |
Heiko Carstens | ca013e9 | 2009-01-14 14:14:19 +0100 | [diff] [blame] | 582 | SYSCALL_DEFINE3(lchown, const char __user *, filename, uid_t, user, gid_t, group) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 583 | { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 584 | struct path path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 585 | int error; |
| 586 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 587 | error = user_lpath(filename, &path); |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 588 | if (error) |
| 589 | goto out; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 590 | error = mnt_want_write(path.mnt); |
Dave Hansen | 2af482a | 2008-02-15 14:37:50 -0800 | [diff] [blame] | 591 | if (error) |
| 592 | goto out_release; |
Tetsuo Handa | fe542cf | 2009-11-22 11:49:55 +0900 | [diff] [blame] | 593 | error = chown_common(&path, user, group); |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 594 | mnt_drop_write(path.mnt); |
Dave Hansen | 2af482a | 2008-02-15 14:37:50 -0800 | [diff] [blame] | 595 | out_release: |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 596 | path_put(&path); |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 597 | out: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 598 | return error; |
| 599 | } |
| 600 | |
Heiko Carstens | ca013e9 | 2009-01-14 14:14:19 +0100 | [diff] [blame] | 601 | SYSCALL_DEFINE3(fchown, unsigned int, fd, uid_t, user, gid_t, group) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 602 | { |
| 603 | struct file * file; |
| 604 | int error = -EBADF; |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 605 | struct dentry * dentry; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 606 | |
| 607 | file = fget(fd); |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 608 | if (!file) |
| 609 | goto out; |
| 610 | |
npiggin@suse.de | 96029c4 | 2009-04-26 20:25:55 +1000 | [diff] [blame] | 611 | error = mnt_want_write_file(file); |
Dave Hansen | 2af482a | 2008-02-15 14:37:50 -0800 | [diff] [blame] | 612 | if (error) |
| 613 | goto out_fput; |
Josef "Jeff" Sipek | 0f7fc9e | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 614 | dentry = file->f_path.dentry; |
Al Viro | 5a190ae | 2007-06-07 12:19:32 -0400 | [diff] [blame] | 615 | audit_inode(NULL, dentry); |
Tetsuo Handa | fe542cf | 2009-11-22 11:49:55 +0900 | [diff] [blame] | 616 | error = chown_common(&file->f_path, user, group); |
Dave Hansen | 2af482a | 2008-02-15 14:37:50 -0800 | [diff] [blame] | 617 | mnt_drop_write(file->f_path.mnt); |
| 618 | out_fput: |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 619 | fput(file); |
| 620 | out: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 621 | return error; |
| 622 | } |
| 623 | |
Dave Hansen | 4a3fd21 | 2008-02-15 14:37:48 -0800 | [diff] [blame] | 624 | /* |
| 625 | * You have to be very careful that these write |
| 626 | * counts get cleaned up in error cases and |
| 627 | * upon __fput(). This should probably never |
| 628 | * be called outside of __dentry_open(). |
| 629 | */ |
| 630 | static inline int __get_file_write_access(struct inode *inode, |
| 631 | struct vfsmount *mnt) |
| 632 | { |
| 633 | int error; |
| 634 | error = get_write_access(inode); |
| 635 | if (error) |
| 636 | return error; |
| 637 | /* |
| 638 | * Do not take mount writer counts on |
| 639 | * special files since no writes to |
| 640 | * the mount itself will occur. |
| 641 | */ |
| 642 | if (!special_file(inode->i_mode)) { |
| 643 | /* |
| 644 | * Balanced in __fput() |
| 645 | */ |
| 646 | error = mnt_want_write(mnt); |
| 647 | if (error) |
| 648 | put_write_access(inode); |
| 649 | } |
| 650 | return error; |
| 651 | } |
| 652 | |
Peter Staubach | a1a5b3d | 2005-09-13 01:25:12 -0700 | [diff] [blame] | 653 | static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt, |
Al Viro | 482928d | 2009-12-19 10:10:39 -0500 | [diff] [blame] | 654 | struct file *f, |
David Howells | 745ca24 | 2008-11-14 10:39:22 +1100 | [diff] [blame] | 655 | int (*open)(struct inode *, struct file *), |
| 656 | const struct cred *cred) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 657 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 658 | struct inode *inode; |
| 659 | int error; |
| 660 | |
Al Viro | 5300990 | 2009-12-19 10:15:07 -0500 | [diff] [blame] | 661 | f->f_mode = OPEN_FMODE(f->f_flags) | FMODE_LSEEK | |
Peter Staubach | a1a5b3d | 2005-09-13 01:25:12 -0700 | [diff] [blame] | 662 | FMODE_PREAD | FMODE_PWRITE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 663 | inode = dentry->d_inode; |
| 664 | if (f->f_mode & FMODE_WRITE) { |
Dave Hansen | 4a3fd21 | 2008-02-15 14:37:48 -0800 | [diff] [blame] | 665 | error = __get_file_write_access(inode, mnt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 666 | if (error) |
| 667 | goto cleanup_file; |
Dave Hansen | ad775f5 | 2008-02-15 14:38:01 -0800 | [diff] [blame] | 668 | if (!special_file(inode->i_mode)) |
| 669 | file_take_write(f); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 670 | } |
| 671 | |
| 672 | f->f_mapping = inode->i_mapping; |
Josef "Jeff" Sipek | 0f7fc9e | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 673 | f->f_path.dentry = dentry; |
| 674 | f->f_path.mnt = mnt; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 675 | f->f_pos = 0; |
| 676 | f->f_op = fops_get(inode->i_fop); |
| 677 | file_move(f, &inode->i_sb->s_files); |
| 678 | |
David Howells | 745ca24 | 2008-11-14 10:39:22 +1100 | [diff] [blame] | 679 | error = security_dentry_open(f, cred); |
Yuichi Nakamura | 788e7dd | 2007-09-14 09:27:07 +0900 | [diff] [blame] | 680 | if (error) |
| 681 | goto cleanup_all; |
| 682 | |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 683 | if (!open && f->f_op) |
| 684 | open = f->f_op->open; |
| 685 | if (open) { |
| 686 | error = open(inode, f); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 687 | if (error) |
| 688 | goto cleanup_all; |
| 689 | } |
Al Viro | b65a9cf | 2009-12-16 06:27:40 -0500 | [diff] [blame] | 690 | ima_counts_get(f); |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 691 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 692 | f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC); |
| 693 | |
| 694 | file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping); |
| 695 | |
| 696 | /* NB: we're sure to have correct a_ops only after f_op->open */ |
| 697 | if (f->f_flags & O_DIRECT) { |
Carsten Otte | ceffc07 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 698 | if (!f->f_mapping->a_ops || |
| 699 | ((!f->f_mapping->a_ops->direct_IO) && |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 700 | (!f->f_mapping->a_ops->get_xip_mem))) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 701 | fput(f); |
| 702 | f = ERR_PTR(-EINVAL); |
| 703 | } |
| 704 | } |
| 705 | |
| 706 | return f; |
| 707 | |
| 708 | cleanup_all: |
| 709 | fops_put(f->f_op); |
Dave Hansen | 4a3fd21 | 2008-02-15 14:37:48 -0800 | [diff] [blame] | 710 | if (f->f_mode & FMODE_WRITE) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 711 | put_write_access(inode); |
Dave Hansen | ad775f5 | 2008-02-15 14:38:01 -0800 | [diff] [blame] | 712 | if (!special_file(inode->i_mode)) { |
| 713 | /* |
| 714 | * We don't consider this a real |
| 715 | * mnt_want/drop_write() pair |
| 716 | * because it all happenend right |
| 717 | * here, so just reset the state. |
| 718 | */ |
| 719 | file_reset_write(f); |
Dave Hansen | 4a3fd21 | 2008-02-15 14:37:48 -0800 | [diff] [blame] | 720 | mnt_drop_write(mnt); |
Dave Hansen | ad775f5 | 2008-02-15 14:38:01 -0800 | [diff] [blame] | 721 | } |
Dave Hansen | 4a3fd21 | 2008-02-15 14:37:48 -0800 | [diff] [blame] | 722 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 723 | file_kill(f); |
Josef "Jeff" Sipek | 0f7fc9e | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 724 | f->f_path.dentry = NULL; |
| 725 | f->f_path.mnt = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 726 | cleanup_file: |
| 727 | put_filp(f); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 728 | dput(dentry); |
| 729 | mntput(mnt); |
| 730 | return ERR_PTR(error); |
| 731 | } |
| 732 | |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 733 | /** |
| 734 | * lookup_instantiate_filp - instantiates the open intent filp |
| 735 | * @nd: pointer to nameidata |
| 736 | * @dentry: pointer to dentry |
| 737 | * @open: open callback |
| 738 | * |
| 739 | * Helper for filesystems that want to use lookup open intents and pass back |
| 740 | * a fully instantiated struct file to the caller. |
| 741 | * This function is meant to be called from within a filesystem's |
| 742 | * lookup method. |
Oleg Drokin | 9a56c21 | 2006-03-25 03:07:02 -0800 | [diff] [blame] | 743 | * Beware of calling it for non-regular files! Those ->open methods might block |
| 744 | * (e.g. in fifo_open), leaving you with parent locked (and in case of fifo, |
| 745 | * leading to a deadlock, as nobody can open that fifo anymore, because |
| 746 | * 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] | 747 | * Note that in case of error, nd->intent.open.file is destroyed, but the |
| 748 | * path information remains valid. |
| 749 | * If the open callback is set to NULL, then the standard f_op->open() |
| 750 | * filesystem callback is substituted. |
| 751 | */ |
| 752 | struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry *dentry, |
| 753 | int (*open)(struct inode *, struct file *)) |
| 754 | { |
David Howells | 745ca24 | 2008-11-14 10:39:22 +1100 | [diff] [blame] | 755 | const struct cred *cred = current_cred(); |
| 756 | |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 757 | if (IS_ERR(nd->intent.open.file)) |
| 758 | goto out; |
| 759 | if (IS_ERR(dentry)) |
| 760 | goto out_err; |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 761 | nd->intent.open.file = __dentry_open(dget(dentry), mntget(nd->path.mnt), |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 762 | nd->intent.open.file, |
David Howells | 745ca24 | 2008-11-14 10:39:22 +1100 | [diff] [blame] | 763 | open, cred); |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 764 | out: |
| 765 | return nd->intent.open.file; |
| 766 | out_err: |
| 767 | release_open_intent(nd); |
| 768 | nd->intent.open.file = (struct file *)dentry; |
| 769 | goto out; |
| 770 | } |
| 771 | EXPORT_SYMBOL_GPL(lookup_instantiate_filp); |
| 772 | |
| 773 | /** |
| 774 | * nameidata_to_filp - convert a nameidata to an open filp. |
| 775 | * @nd: pointer to nameidata |
| 776 | * @flags: open flags |
| 777 | * |
| 778 | * Note that this function destroys the original nameidata |
| 779 | */ |
Al Viro | 482928d | 2009-12-19 10:10:39 -0500 | [diff] [blame] | 780 | struct file *nameidata_to_filp(struct nameidata *nd) |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 781 | { |
David Howells | 745ca24 | 2008-11-14 10:39:22 +1100 | [diff] [blame] | 782 | const struct cred *cred = current_cred(); |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 783 | struct file *filp; |
| 784 | |
| 785 | /* Pick up the filp from the open intent */ |
| 786 | filp = nd->intent.open.file; |
| 787 | /* Has the filesystem initialised the file for us? */ |
Josef "Jeff" Sipek | 0f7fc9e | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 788 | if (filp->f_path.dentry == NULL) |
Al Viro | 482928d | 2009-12-19 10:10:39 -0500 | [diff] [blame] | 789 | filp = __dentry_open(nd->path.dentry, nd->path.mnt, filp, |
David Howells | 745ca24 | 2008-11-14 10:39:22 +1100 | [diff] [blame] | 790 | NULL, cred); |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 791 | else |
Jan Blunck | 1d957f9 | 2008-02-14 19:34:35 -0800 | [diff] [blame] | 792 | path_put(&nd->path); |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 793 | return filp; |
| 794 | } |
| 795 | |
Peter Staubach | 6fdcc21 | 2005-11-07 00:59:42 -0800 | [diff] [blame] | 796 | /* |
| 797 | * dentry_open() will have done dput(dentry) and mntput(mnt) if it returns an |
| 798 | * error. |
| 799 | */ |
David Howells | 745ca24 | 2008-11-14 10:39:22 +1100 | [diff] [blame] | 800 | struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags, |
| 801 | const struct cred *cred) |
Peter Staubach | a1a5b3d | 2005-09-13 01:25:12 -0700 | [diff] [blame] | 802 | { |
| 803 | int error; |
| 804 | struct file *f; |
| 805 | |
David Howells | e0e8173 | 2009-09-02 09:13:40 +0100 | [diff] [blame] | 806 | validate_creds(cred); |
| 807 | |
Christoph Hellwig | 322ee5b | 2008-02-15 14:37:24 -0800 | [diff] [blame] | 808 | /* |
| 809 | * We must always pass in a valid mount pointer. Historically |
| 810 | * callers got away with not passing it, but we must enforce this at |
| 811 | * the earliest possible point now to avoid strange problems deep in the |
| 812 | * filesystem stack. |
| 813 | */ |
| 814 | if (!mnt) { |
| 815 | printk(KERN_WARNING "%s called with NULL vfsmount\n", __func__); |
| 816 | dump_stack(); |
| 817 | return ERR_PTR(-EINVAL); |
| 818 | } |
| 819 | |
Peter Staubach | a1a5b3d | 2005-09-13 01:25:12 -0700 | [diff] [blame] | 820 | error = -ENFILE; |
| 821 | f = get_empty_filp(); |
Peter Staubach | 6fdcc21 | 2005-11-07 00:59:42 -0800 | [diff] [blame] | 822 | if (f == NULL) { |
| 823 | dput(dentry); |
| 824 | mntput(mnt); |
Peter Staubach | a1a5b3d | 2005-09-13 01:25:12 -0700 | [diff] [blame] | 825 | return ERR_PTR(error); |
Peter Staubach | 6fdcc21 | 2005-11-07 00:59:42 -0800 | [diff] [blame] | 826 | } |
Peter Staubach | a1a5b3d | 2005-09-13 01:25:12 -0700 | [diff] [blame] | 827 | |
Al Viro | 482928d | 2009-12-19 10:10:39 -0500 | [diff] [blame] | 828 | f->f_flags = flags; |
| 829 | return __dentry_open(dentry, mnt, f, NULL, cred); |
Peter Staubach | a1a5b3d | 2005-09-13 01:25:12 -0700 | [diff] [blame] | 830 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 831 | EXPORT_SYMBOL(dentry_open); |
| 832 | |
Matt Mackall | b01ec0e | 2006-01-08 01:05:20 -0800 | [diff] [blame] | 833 | static void __put_unused_fd(struct files_struct *files, unsigned int fd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 834 | { |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 835 | struct fdtable *fdt = files_fdtable(files); |
| 836 | __FD_CLR(fd, fdt->open_fds); |
Eric Dumazet | 0c9e63f | 2006-03-23 03:00:12 -0800 | [diff] [blame] | 837 | if (fd < files->next_fd) |
| 838 | files->next_fd = fd; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 839 | } |
| 840 | |
Harvey Harrison | fc9b52c | 2008-02-08 04:19:52 -0800 | [diff] [blame] | 841 | void put_unused_fd(unsigned int fd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 842 | { |
| 843 | struct files_struct *files = current->files; |
| 844 | spin_lock(&files->file_lock); |
| 845 | __put_unused_fd(files, fd); |
| 846 | spin_unlock(&files->file_lock); |
| 847 | } |
| 848 | |
| 849 | EXPORT_SYMBOL(put_unused_fd); |
| 850 | |
| 851 | /* |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 852 | * Install a file pointer in the fd array. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 853 | * |
| 854 | * The VFS is full of places where we drop the files lock between |
| 855 | * setting the open_fds bitmap and installing the file in the file |
| 856 | * array. At any such point, we are vulnerable to a dup2() race |
| 857 | * installing a file in the array before us. We need to detect this and |
| 858 | * fput() the struct file we are about to overwrite in this case. |
| 859 | * |
| 860 | * It should never happen - if we allow dup2() do it, _really_ bad things |
| 861 | * will follow. |
| 862 | */ |
| 863 | |
Harvey Harrison | fc9b52c | 2008-02-08 04:19:52 -0800 | [diff] [blame] | 864 | void fd_install(unsigned int fd, struct file *file) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 865 | { |
| 866 | struct files_struct *files = current->files; |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 867 | struct fdtable *fdt; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 868 | spin_lock(&files->file_lock); |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 869 | fdt = files_fdtable(files); |
Dipankar Sarma | ab2af1f | 2005-09-09 13:04:13 -0700 | [diff] [blame] | 870 | BUG_ON(fdt->fd[fd] != NULL); |
| 871 | rcu_assign_pointer(fdt->fd[fd], file); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 872 | spin_unlock(&files->file_lock); |
| 873 | } |
| 874 | |
| 875 | EXPORT_SYMBOL(fd_install); |
| 876 | |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 877 | 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] | 878 | { |
Miklos Szeredi | e922efc | 2005-09-06 15:18:25 -0700 | [diff] [blame] | 879 | char *tmp = getname(filename); |
| 880 | int fd = PTR_ERR(tmp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 881 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 882 | if (!IS_ERR(tmp)) { |
Ulrich Drepper | f23513e | 2007-07-15 23:40:32 -0700 | [diff] [blame] | 883 | fd = get_unused_fd_flags(flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 884 | if (fd >= 0) { |
Al Viro | 6e8341a | 2009-04-06 11:16:22 -0400 | [diff] [blame] | 885 | struct file *f = do_filp_open(dfd, tmp, flags, mode, 0); |
Telemaque Ndizihiwe | fed2fc1 | 2005-06-23 00:10:33 -0700 | [diff] [blame] | 886 | if (IS_ERR(f)) { |
| 887 | put_unused_fd(fd); |
| 888 | fd = PTR_ERR(f); |
| 889 | } else { |
Josef "Jeff" Sipek | 0f7fc9e | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 890 | fsnotify_open(f->f_path.dentry); |
Telemaque Ndizihiwe | fed2fc1 | 2005-06-23 00:10:33 -0700 | [diff] [blame] | 891 | fd_install(fd, f); |
| 892 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 893 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 894 | putname(tmp); |
| 895 | } |
| 896 | return fd; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 897 | } |
Miklos Szeredi | e922efc | 2005-09-06 15:18:25 -0700 | [diff] [blame] | 898 | |
Heiko Carstens | ca013e9 | 2009-01-14 14:14:19 +0100 | [diff] [blame] | 899 | SYSCALL_DEFINE3(open, const char __user *, filename, int, flags, int, mode) |
Miklos Szeredi | e922efc | 2005-09-06 15:18:25 -0700 | [diff] [blame] | 900 | { |
Linus Torvalds | 385910f | 2006-04-18 13:22:59 -0700 | [diff] [blame] | 901 | long ret; |
| 902 | |
Miklos Szeredi | e922efc | 2005-09-06 15:18:25 -0700 | [diff] [blame] | 903 | if (force_o_largefile()) |
| 904 | flags |= O_LARGEFILE; |
| 905 | |
Linus Torvalds | 385910f | 2006-04-18 13:22:59 -0700 | [diff] [blame] | 906 | ret = do_sys_open(AT_FDCWD, filename, flags, mode); |
| 907 | /* avoid REGPARM breakage on x86: */ |
Roland McGrath | 54a0151 | 2008-04-10 15:37:38 -0700 | [diff] [blame] | 908 | asmlinkage_protect(3, ret, filename, flags, mode); |
Linus Torvalds | 385910f | 2006-04-18 13:22:59 -0700 | [diff] [blame] | 909 | return ret; |
Miklos Szeredi | e922efc | 2005-09-06 15:18:25 -0700 | [diff] [blame] | 910 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 911 | |
Heiko Carstens | 6559eed8 | 2009-01-14 14:14:32 +0100 | [diff] [blame] | 912 | SYSCALL_DEFINE4(openat, int, dfd, const char __user *, filename, int, flags, |
| 913 | int, mode) |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 914 | { |
Linus Torvalds | 385910f | 2006-04-18 13:22:59 -0700 | [diff] [blame] | 915 | long ret; |
| 916 | |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 917 | if (force_o_largefile()) |
| 918 | flags |= O_LARGEFILE; |
| 919 | |
Linus Torvalds | 385910f | 2006-04-18 13:22:59 -0700 | [diff] [blame] | 920 | ret = do_sys_open(dfd, filename, flags, mode); |
| 921 | /* avoid REGPARM breakage on x86: */ |
Roland McGrath | 54a0151 | 2008-04-10 15:37:38 -0700 | [diff] [blame] | 922 | asmlinkage_protect(4, ret, dfd, filename, flags, mode); |
Linus Torvalds | 385910f | 2006-04-18 13:22:59 -0700 | [diff] [blame] | 923 | return ret; |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 924 | } |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 925 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 926 | #ifndef __alpha__ |
| 927 | |
| 928 | /* |
| 929 | * For backward compatibility? Maybe this should be moved |
| 930 | * into arch/i386 instead? |
| 931 | */ |
Heiko Carstens | 002c897 | 2009-01-14 14:14:18 +0100 | [diff] [blame] | 932 | SYSCALL_DEFINE2(creat, const char __user *, pathname, int, mode) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 933 | { |
| 934 | return sys_open(pathname, O_CREAT | O_WRONLY | O_TRUNC, mode); |
| 935 | } |
| 936 | |
| 937 | #endif |
| 938 | |
| 939 | /* |
| 940 | * "id" is the POSIX thread ID. We use the |
| 941 | * files pointer for this.. |
| 942 | */ |
| 943 | int filp_close(struct file *filp, fl_owner_t id) |
| 944 | { |
Christoph Lameter | 45778ca | 2005-06-23 00:10:17 -0700 | [diff] [blame] | 945 | int retval = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 946 | |
| 947 | if (!file_count(filp)) { |
| 948 | printk(KERN_ERR "VFS: Close: file count is 0\n"); |
Christoph Lameter | 45778ca | 2005-06-23 00:10:17 -0700 | [diff] [blame] | 949 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 950 | } |
| 951 | |
Christoph Lameter | 45778ca | 2005-06-23 00:10:17 -0700 | [diff] [blame] | 952 | if (filp->f_op && filp->f_op->flush) |
Miklos Szeredi | 75e1fcc | 2006-06-23 02:05:12 -0700 | [diff] [blame] | 953 | retval = filp->f_op->flush(filp, id); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 954 | |
| 955 | dnotify_flush(filp, id); |
| 956 | locks_remove_posix(filp, id); |
| 957 | fput(filp); |
| 958 | return retval; |
| 959 | } |
| 960 | |
| 961 | EXPORT_SYMBOL(filp_close); |
| 962 | |
| 963 | /* |
| 964 | * Careful here! We test whether the file pointer is NULL before |
| 965 | * releasing the fd. This ensures that one clone task can't release |
| 966 | * an fd while another clone is opening it. |
| 967 | */ |
Heiko Carstens | ca013e9 | 2009-01-14 14:14:19 +0100 | [diff] [blame] | 968 | SYSCALL_DEFINE1(close, unsigned int, fd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 969 | { |
| 970 | struct file * filp; |
| 971 | struct files_struct *files = current->files; |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 972 | struct fdtable *fdt; |
Ernie Petrides | ee731f4 | 2006-09-29 02:00:13 -0700 | [diff] [blame] | 973 | int retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 974 | |
| 975 | spin_lock(&files->file_lock); |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 976 | fdt = files_fdtable(files); |
| 977 | if (fd >= fdt->max_fds) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 978 | goto out_unlock; |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 979 | filp = fdt->fd[fd]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 980 | if (!filp) |
| 981 | goto out_unlock; |
Dipankar Sarma | ab2af1f | 2005-09-09 13:04:13 -0700 | [diff] [blame] | 982 | rcu_assign_pointer(fdt->fd[fd], NULL); |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 983 | FD_CLR(fd, fdt->close_on_exec); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 984 | __put_unused_fd(files, fd); |
| 985 | spin_unlock(&files->file_lock); |
Ernie Petrides | ee731f4 | 2006-09-29 02:00:13 -0700 | [diff] [blame] | 986 | retval = filp_close(filp, files); |
| 987 | |
| 988 | /* can't restart close syscall because file table entry was cleared */ |
| 989 | if (unlikely(retval == -ERESTARTSYS || |
| 990 | retval == -ERESTARTNOINTR || |
| 991 | retval == -ERESTARTNOHAND || |
| 992 | retval == -ERESTART_RESTARTBLOCK)) |
| 993 | retval = -EINTR; |
| 994 | |
| 995 | return retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 996 | |
| 997 | out_unlock: |
| 998 | spin_unlock(&files->file_lock); |
| 999 | return -EBADF; |
| 1000 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1001 | EXPORT_SYMBOL(sys_close); |
| 1002 | |
| 1003 | /* |
| 1004 | * This routine simulates a hangup on the tty, to arrange that users |
| 1005 | * are given clean terminals at login time. |
| 1006 | */ |
Heiko Carstens | ca013e9 | 2009-01-14 14:14:19 +0100 | [diff] [blame] | 1007 | SYSCALL_DEFINE0(vhangup) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1008 | { |
| 1009 | if (capable(CAP_SYS_TTY_CONFIG)) { |
Alan Cox | 2cb5998 | 2008-10-13 10:40:30 +0100 | [diff] [blame] | 1010 | tty_vhangup_self(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1011 | return 0; |
| 1012 | } |
| 1013 | return -EPERM; |
| 1014 | } |
| 1015 | |
| 1016 | /* |
| 1017 | * Called when an inode is about to be open. |
| 1018 | * We use this to disallow opening large files on 32bit systems if |
| 1019 | * the caller didn't specify O_LARGEFILE. On 64bit systems we force |
| 1020 | * on this flag in sys_open. |
| 1021 | */ |
| 1022 | int generic_file_open(struct inode * inode, struct file * filp) |
| 1023 | { |
| 1024 | 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] | 1025 | return -EOVERFLOW; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1026 | return 0; |
| 1027 | } |
| 1028 | |
| 1029 | EXPORT_SYMBOL(generic_file_open); |
| 1030 | |
| 1031 | /* |
| 1032 | * This is used by subsystems that don't want seekable |
| 1033 | * file descriptors |
| 1034 | */ |
| 1035 | int nonseekable_open(struct inode *inode, struct file *filp) |
| 1036 | { |
| 1037 | filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE); |
| 1038 | return 0; |
| 1039 | } |
| 1040 | |
| 1041 | EXPORT_SYMBOL(nonseekable_open); |