Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/fs/fcntl.c |
| 3 | * |
| 4 | * Copyright (C) 1991, 1992 Linus Torvalds |
| 5 | */ |
| 6 | |
| 7 | #include <linux/syscalls.h> |
| 8 | #include <linux/init.h> |
| 9 | #include <linux/mm.h> |
| 10 | #include <linux/fs.h> |
| 11 | #include <linux/file.h> |
Al Viro | 9f3acc3 | 2008-04-24 07:44:08 -0400 | [diff] [blame] | 12 | #include <linux/fdtable.h> |
Randy Dunlap | 16f7e0f | 2006-01-11 12:17:46 -0800 | [diff] [blame] | 13 | #include <linux/capability.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 14 | #include <linux/dnotify.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 15 | #include <linux/slab.h> |
| 16 | #include <linux/module.h> |
| 17 | #include <linux/security.h> |
| 18 | #include <linux/ptrace.h> |
Jesper Juhl | 7ed20e1 | 2005-05-01 08:59:14 -0700 | [diff] [blame] | 19 | #include <linux/signal.h> |
Dipankar Sarma | ab2af1f | 2005-09-09 13:04:13 -0700 | [diff] [blame] | 20 | #include <linux/rcupdate.h> |
Pavel Emelyanov | b488893 | 2007-10-18 23:40:14 -0700 | [diff] [blame] | 21 | #include <linux/pid_namespace.h> |
Jonathan Corbet | 218d11a | 2008-12-05 16:12:48 -0700 | [diff] [blame] | 22 | #include <linux/smp_lock.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 23 | |
| 24 | #include <asm/poll.h> |
| 25 | #include <asm/siginfo.h> |
| 26 | #include <asm/uaccess.h> |
| 27 | |
Harvey Harrison | fc9b52c | 2008-02-08 04:19:52 -0800 | [diff] [blame] | 28 | void set_close_on_exec(unsigned int fd, int flag) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 29 | { |
| 30 | struct files_struct *files = current->files; |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 31 | struct fdtable *fdt; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | spin_lock(&files->file_lock); |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 33 | fdt = files_fdtable(files); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 34 | if (flag) |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 35 | FD_SET(fd, fdt->close_on_exec); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 36 | else |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 37 | FD_CLR(fd, fdt->close_on_exec); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 38 | spin_unlock(&files->file_lock); |
| 39 | } |
| 40 | |
Arjan van de Ven | 858119e | 2006-01-14 13:20:43 -0800 | [diff] [blame] | 41 | static int get_close_on_exec(unsigned int fd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 42 | { |
| 43 | struct files_struct *files = current->files; |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 44 | struct fdtable *fdt; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 45 | int res; |
Dipankar Sarma | b835996 | 2005-09-09 13:04:14 -0700 | [diff] [blame] | 46 | rcu_read_lock(); |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 47 | fdt = files_fdtable(files); |
| 48 | res = FD_ISSET(fd, fdt->close_on_exec); |
Dipankar Sarma | b835996 | 2005-09-09 13:04:14 -0700 | [diff] [blame] | 49 | rcu_read_unlock(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 50 | return res; |
| 51 | } |
| 52 | |
Heiko Carstens | a26eab2 | 2009-01-14 14:14:17 +0100 | [diff] [blame] | 53 | SYSCALL_DEFINE3(dup3, unsigned int, oldfd, unsigned int, newfd, int, flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 54 | { |
| 55 | int err = -EBADF; |
| 56 | struct file * file, *tofree; |
| 57 | struct files_struct * files = current->files; |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 58 | struct fdtable *fdt; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 59 | |
Ulrich Drepper | 336dd1f | 2008-07-23 21:29:29 -0700 | [diff] [blame] | 60 | if ((flags & ~O_CLOEXEC) != 0) |
| 61 | return -EINVAL; |
| 62 | |
Al Viro | 6c5d051 | 2008-07-26 13:38:19 -0400 | [diff] [blame] | 63 | if (unlikely(oldfd == newfd)) |
| 64 | return -EINVAL; |
| 65 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 66 | spin_lock(&files->file_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 67 | err = expand_files(files, newfd); |
Al Viro | 1b7e190 | 2008-07-30 06:18:03 -0400 | [diff] [blame] | 68 | file = fcheck(oldfd); |
| 69 | if (unlikely(!file)) |
| 70 | goto Ebadf; |
Al Viro | 4e1e018 | 2008-07-26 16:01:20 -0400 | [diff] [blame] | 71 | if (unlikely(err < 0)) { |
| 72 | if (err == -EMFILE) |
Al Viro | 1b7e190 | 2008-07-30 06:18:03 -0400 | [diff] [blame] | 73 | goto Ebadf; |
| 74 | goto out_unlock; |
Al Viro | 4e1e018 | 2008-07-26 16:01:20 -0400 | [diff] [blame] | 75 | } |
Al Viro | 1b7e190 | 2008-07-30 06:18:03 -0400 | [diff] [blame] | 76 | /* |
| 77 | * We need to detect attempts to do dup2() over allocated but still |
| 78 | * not finished descriptor. NB: OpenBSD avoids that at the price of |
| 79 | * extra work in their equivalent of fget() - they insert struct |
| 80 | * file immediately after grabbing descriptor, mark it larval if |
| 81 | * more work (e.g. actual opening) is needed and make sure that |
| 82 | * fget() treats larval files as absent. Potentially interesting, |
| 83 | * but while extra work in fget() is trivial, locking implications |
| 84 | * and amount of surgery on open()-related paths in VFS are not. |
| 85 | * FreeBSD fails with -EBADF in the same situation, NetBSD "solution" |
| 86 | * deadlocks in rather amusing ways, AFAICS. All of that is out of |
| 87 | * scope of POSIX or SUS, since neither considers shared descriptor |
| 88 | * tables and this condition does not arise without those. |
| 89 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 90 | err = -EBUSY; |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 91 | fdt = files_fdtable(files); |
| 92 | tofree = fdt->fd[newfd]; |
| 93 | if (!tofree && FD_ISSET(newfd, fdt->open_fds)) |
Al Viro | 1b7e190 | 2008-07-30 06:18:03 -0400 | [diff] [blame] | 94 | goto out_unlock; |
| 95 | get_file(file); |
Dipankar Sarma | ab2af1f | 2005-09-09 13:04:13 -0700 | [diff] [blame] | 96 | rcu_assign_pointer(fdt->fd[newfd], file); |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 97 | FD_SET(newfd, fdt->open_fds); |
Ulrich Drepper | 336dd1f | 2008-07-23 21:29:29 -0700 | [diff] [blame] | 98 | if (flags & O_CLOEXEC) |
| 99 | FD_SET(newfd, fdt->close_on_exec); |
| 100 | else |
| 101 | FD_CLR(newfd, fdt->close_on_exec); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 102 | spin_unlock(&files->file_lock); |
| 103 | |
| 104 | if (tofree) |
| 105 | filp_close(tofree, files); |
Al Viro | 1b7e190 | 2008-07-30 06:18:03 -0400 | [diff] [blame] | 106 | |
| 107 | return newfd; |
| 108 | |
| 109 | Ebadf: |
| 110 | err = -EBADF; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 111 | out_unlock: |
| 112 | spin_unlock(&files->file_lock); |
Al Viro | 1b7e190 | 2008-07-30 06:18:03 -0400 | [diff] [blame] | 113 | return err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 114 | } |
| 115 | |
Heiko Carstens | a26eab2 | 2009-01-14 14:14:17 +0100 | [diff] [blame] | 116 | SYSCALL_DEFINE2(dup2, unsigned int, oldfd, unsigned int, newfd) |
Ulrich Drepper | 336dd1f | 2008-07-23 21:29:29 -0700 | [diff] [blame] | 117 | { |
Al Viro | 6c5d051 | 2008-07-26 13:38:19 -0400 | [diff] [blame] | 118 | if (unlikely(newfd == oldfd)) { /* corner case */ |
| 119 | struct files_struct *files = current->files; |
| 120 | rcu_read_lock(); |
| 121 | if (!fcheck_files(files, oldfd)) |
| 122 | oldfd = -EBADF; |
| 123 | rcu_read_unlock(); |
| 124 | return oldfd; |
| 125 | } |
Ulrich Drepper | 336dd1f | 2008-07-23 21:29:29 -0700 | [diff] [blame] | 126 | return sys_dup3(oldfd, newfd, 0); |
| 127 | } |
| 128 | |
Heiko Carstens | a26eab2 | 2009-01-14 14:14:17 +0100 | [diff] [blame] | 129 | SYSCALL_DEFINE1(dup, unsigned int, fildes) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 130 | { |
| 131 | int ret = -EBADF; |
Al Viro | 1027abe | 2008-07-30 04:13:04 -0400 | [diff] [blame] | 132 | struct file *file = fget(fildes); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 133 | |
Al Viro | 1027abe | 2008-07-30 04:13:04 -0400 | [diff] [blame] | 134 | if (file) { |
| 135 | ret = get_unused_fd(); |
| 136 | if (ret >= 0) |
| 137 | fd_install(ret, file); |
| 138 | else |
| 139 | fput(file); |
| 140 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 141 | return ret; |
| 142 | } |
| 143 | |
Jonathan Corbet | 7639842 | 2009-02-01 14:26:59 -0700 | [diff] [blame] | 144 | #define SETFL_MASK (O_APPEND | O_NONBLOCK | O_NDELAY | O_DIRECT | O_NOATIME) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 145 | |
| 146 | static int setfl(int fd, struct file * filp, unsigned long arg) |
| 147 | { |
Josef "Jeff" Sipek | 0f7fc9e | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 148 | struct inode * inode = filp->f_path.dentry->d_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 149 | int error = 0; |
| 150 | |
dean gaudet | 7d95c8f | 2006-02-03 03:04:30 -0800 | [diff] [blame] | 151 | /* |
| 152 | * O_APPEND cannot be cleared if the file is marked as append-only |
| 153 | * and the file is open for write. |
| 154 | */ |
| 155 | if (((arg ^ filp->f_flags) & O_APPEND) && IS_APPEND(inode)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 156 | return -EPERM; |
| 157 | |
| 158 | /* O_NOATIME can only be set by the owner or superuser */ |
| 159 | if ((arg & O_NOATIME) && !(filp->f_flags & O_NOATIME)) |
Satyam Sharma | 3bd858a | 2007-07-17 15:00:08 +0530 | [diff] [blame] | 160 | if (!is_owner_or_cap(inode)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 161 | return -EPERM; |
| 162 | |
| 163 | /* required for strict SunOS emulation */ |
| 164 | if (O_NONBLOCK != O_NDELAY) |
| 165 | if (arg & O_NDELAY) |
| 166 | arg |= O_NONBLOCK; |
| 167 | |
| 168 | if (arg & O_DIRECT) { |
| 169 | if (!filp->f_mapping || !filp->f_mapping->a_ops || |
| 170 | !filp->f_mapping->a_ops->direct_IO) |
| 171 | return -EINVAL; |
| 172 | } |
| 173 | |
| 174 | if (filp->f_op && filp->f_op->check_flags) |
| 175 | error = filp->f_op->check_flags(arg); |
| 176 | if (error) |
| 177 | return error; |
| 178 | |
Jonathan Corbet | 218d11a | 2008-12-05 16:12:48 -0700 | [diff] [blame] | 179 | /* |
Jonathan Corbet | 7639842 | 2009-02-01 14:26:59 -0700 | [diff] [blame] | 180 | * ->fasync() is responsible for setting the FASYNC bit. |
Jonathan Corbet | 218d11a | 2008-12-05 16:12:48 -0700 | [diff] [blame] | 181 | */ |
Jonathan Corbet | 7639842 | 2009-02-01 14:26:59 -0700 | [diff] [blame] | 182 | if (((arg ^ filp->f_flags) & FASYNC) && filp->f_op && |
| 183 | filp->f_op->fasync) { |
| 184 | error = filp->f_op->fasync(fd, filp, (arg & FASYNC) != 0); |
| 185 | if (error < 0) |
| 186 | goto out; |
Jonathan Corbet | 60aa492 | 2009-02-01 14:52:56 -0700 | [diff] [blame^] | 187 | if (error > 0) |
| 188 | error = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 189 | } |
Jonathan Corbet | db1dd4d | 2009-02-06 15:25:24 -0700 | [diff] [blame] | 190 | spin_lock(&filp->f_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 191 | filp->f_flags = (arg & SETFL_MASK) | (filp->f_flags & ~SETFL_MASK); |
Jonathan Corbet | db1dd4d | 2009-02-06 15:25:24 -0700 | [diff] [blame] | 192 | spin_unlock(&filp->f_lock); |
Jonathan Corbet | 7639842 | 2009-02-01 14:26:59 -0700 | [diff] [blame] | 193 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 194 | out: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 195 | return error; |
| 196 | } |
| 197 | |
Eric W. Biederman | 609d7fa | 2006-10-02 02:17:15 -0700 | [diff] [blame] | 198 | static void f_modown(struct file *filp, struct pid *pid, enum pid_type type, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 199 | uid_t uid, uid_t euid, int force) |
| 200 | { |
| 201 | write_lock_irq(&filp->f_owner.lock); |
| 202 | if (force || !filp->f_owner.pid) { |
Eric W. Biederman | 609d7fa | 2006-10-02 02:17:15 -0700 | [diff] [blame] | 203 | put_pid(filp->f_owner.pid); |
| 204 | filp->f_owner.pid = get_pid(pid); |
| 205 | filp->f_owner.pid_type = type; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 206 | filp->f_owner.uid = uid; |
| 207 | filp->f_owner.euid = euid; |
| 208 | } |
| 209 | write_unlock_irq(&filp->f_owner.lock); |
| 210 | } |
| 211 | |
Eric W. Biederman | 609d7fa | 2006-10-02 02:17:15 -0700 | [diff] [blame] | 212 | int __f_setown(struct file *filp, struct pid *pid, enum pid_type type, |
| 213 | int force) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 214 | { |
David Howells | 86a264a | 2008-11-14 10:39:18 +1100 | [diff] [blame] | 215 | const struct cred *cred = current_cred(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 216 | int err; |
| 217 | |
| 218 | err = security_file_set_fowner(filp); |
| 219 | if (err) |
| 220 | return err; |
| 221 | |
David Howells | 86a264a | 2008-11-14 10:39:18 +1100 | [diff] [blame] | 222 | f_modown(filp, pid, type, cred->uid, cred->euid, force); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 223 | return 0; |
| 224 | } |
Eric W. Biederman | 609d7fa | 2006-10-02 02:17:15 -0700 | [diff] [blame] | 225 | EXPORT_SYMBOL(__f_setown); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 226 | |
Eric W. Biederman | 609d7fa | 2006-10-02 02:17:15 -0700 | [diff] [blame] | 227 | int f_setown(struct file *filp, unsigned long arg, int force) |
| 228 | { |
| 229 | enum pid_type type; |
| 230 | struct pid *pid; |
| 231 | int who = arg; |
| 232 | int result; |
| 233 | type = PIDTYPE_PID; |
| 234 | if (who < 0) { |
| 235 | type = PIDTYPE_PGID; |
| 236 | who = -who; |
| 237 | } |
| 238 | rcu_read_lock(); |
Pavel Emelyanov | b488893 | 2007-10-18 23:40:14 -0700 | [diff] [blame] | 239 | pid = find_vpid(who); |
Eric W. Biederman | 609d7fa | 2006-10-02 02:17:15 -0700 | [diff] [blame] | 240 | result = __f_setown(filp, pid, type, force); |
| 241 | rcu_read_unlock(); |
| 242 | return result; |
| 243 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 244 | EXPORT_SYMBOL(f_setown); |
| 245 | |
| 246 | void f_delown(struct file *filp) |
| 247 | { |
Eric W. Biederman | 609d7fa | 2006-10-02 02:17:15 -0700 | [diff] [blame] | 248 | f_modown(filp, NULL, PIDTYPE_PID, 0, 0, 1); |
| 249 | } |
| 250 | |
| 251 | pid_t f_getown(struct file *filp) |
| 252 | { |
| 253 | pid_t pid; |
Eric W. Biederman | 43fa1ad | 2006-10-02 02:17:27 -0700 | [diff] [blame] | 254 | read_lock(&filp->f_owner.lock); |
Pavel Emelyanov | 6c5f3e7 | 2008-02-08 04:19:20 -0800 | [diff] [blame] | 255 | pid = pid_vnr(filp->f_owner.pid); |
Eric W. Biederman | 609d7fa | 2006-10-02 02:17:15 -0700 | [diff] [blame] | 256 | if (filp->f_owner.pid_type == PIDTYPE_PGID) |
| 257 | pid = -pid; |
Eric W. Biederman | 43fa1ad | 2006-10-02 02:17:27 -0700 | [diff] [blame] | 258 | read_unlock(&filp->f_owner.lock); |
Eric W. Biederman | 609d7fa | 2006-10-02 02:17:15 -0700 | [diff] [blame] | 259 | return pid; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 260 | } |
| 261 | |
| 262 | static long do_fcntl(int fd, unsigned int cmd, unsigned long arg, |
| 263 | struct file *filp) |
| 264 | { |
| 265 | long err = -EINVAL; |
| 266 | |
| 267 | switch (cmd) { |
| 268 | case F_DUPFD: |
Ulrich Drepper | 22d2b35 | 2007-10-16 23:30:26 -0700 | [diff] [blame] | 269 | case F_DUPFD_CLOEXEC: |
Al Viro | 4e1e018 | 2008-07-26 16:01:20 -0400 | [diff] [blame] | 270 | if (arg >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur) |
| 271 | break; |
Al Viro | 1027abe | 2008-07-30 04:13:04 -0400 | [diff] [blame] | 272 | err = alloc_fd(arg, cmd == F_DUPFD_CLOEXEC ? O_CLOEXEC : 0); |
| 273 | if (err >= 0) { |
| 274 | get_file(filp); |
| 275 | fd_install(err, filp); |
| 276 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 277 | break; |
| 278 | case F_GETFD: |
| 279 | err = get_close_on_exec(fd) ? FD_CLOEXEC : 0; |
| 280 | break; |
| 281 | case F_SETFD: |
| 282 | err = 0; |
| 283 | set_close_on_exec(fd, arg & FD_CLOEXEC); |
| 284 | break; |
| 285 | case F_GETFL: |
| 286 | err = filp->f_flags; |
| 287 | break; |
| 288 | case F_SETFL: |
| 289 | err = setfl(fd, filp, arg); |
| 290 | break; |
| 291 | case F_GETLK: |
| 292 | err = fcntl_getlk(filp, (struct flock __user *) arg); |
| 293 | break; |
| 294 | case F_SETLK: |
| 295 | case F_SETLKW: |
Peter Staubach | c293621 | 2005-07-27 11:45:09 -0700 | [diff] [blame] | 296 | err = fcntl_setlk(fd, filp, cmd, (struct flock __user *) arg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 297 | break; |
| 298 | case F_GETOWN: |
| 299 | /* |
| 300 | * XXX If f_owner is a process group, the |
| 301 | * negative return value will get converted |
| 302 | * into an error. Oops. If we keep the |
| 303 | * current syscall conventions, the only way |
| 304 | * to fix this will be in libc. |
| 305 | */ |
Eric W. Biederman | 609d7fa | 2006-10-02 02:17:15 -0700 | [diff] [blame] | 306 | err = f_getown(filp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 307 | force_successful_syscall_return(); |
| 308 | break; |
| 309 | case F_SETOWN: |
| 310 | err = f_setown(filp, arg, 1); |
| 311 | break; |
| 312 | case F_GETSIG: |
| 313 | err = filp->f_owner.signum; |
| 314 | break; |
| 315 | case F_SETSIG: |
| 316 | /* arg == 0 restores default behaviour. */ |
Jesper Juhl | 7ed20e1 | 2005-05-01 08:59:14 -0700 | [diff] [blame] | 317 | if (!valid_signal(arg)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 318 | break; |
| 319 | } |
| 320 | err = 0; |
| 321 | filp->f_owner.signum = arg; |
| 322 | break; |
| 323 | case F_GETLEASE: |
| 324 | err = fcntl_getlease(filp); |
| 325 | break; |
| 326 | case F_SETLEASE: |
| 327 | err = fcntl_setlease(fd, filp, arg); |
| 328 | break; |
| 329 | case F_NOTIFY: |
| 330 | err = fcntl_dirnotify(fd, filp, arg); |
| 331 | break; |
| 332 | default: |
| 333 | break; |
| 334 | } |
| 335 | return err; |
| 336 | } |
| 337 | |
Heiko Carstens | a26eab2 | 2009-01-14 14:14:17 +0100 | [diff] [blame] | 338 | SYSCALL_DEFINE3(fcntl, unsigned int, fd, unsigned int, cmd, unsigned long, arg) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 339 | { |
| 340 | struct file *filp; |
| 341 | long err = -EBADF; |
| 342 | |
| 343 | filp = fget(fd); |
| 344 | if (!filp) |
| 345 | goto out; |
| 346 | |
| 347 | err = security_file_fcntl(filp, cmd, arg); |
| 348 | if (err) { |
| 349 | fput(filp); |
| 350 | return err; |
| 351 | } |
| 352 | |
| 353 | err = do_fcntl(fd, cmd, arg, filp); |
| 354 | |
| 355 | fput(filp); |
| 356 | out: |
| 357 | return err; |
| 358 | } |
| 359 | |
| 360 | #if BITS_PER_LONG == 32 |
Heiko Carstens | a26eab2 | 2009-01-14 14:14:17 +0100 | [diff] [blame] | 361 | SYSCALL_DEFINE3(fcntl64, unsigned int, fd, unsigned int, cmd, |
| 362 | unsigned long, arg) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 363 | { |
| 364 | struct file * filp; |
| 365 | long err; |
| 366 | |
| 367 | err = -EBADF; |
| 368 | filp = fget(fd); |
| 369 | if (!filp) |
| 370 | goto out; |
| 371 | |
| 372 | err = security_file_fcntl(filp, cmd, arg); |
| 373 | if (err) { |
| 374 | fput(filp); |
| 375 | return err; |
| 376 | } |
| 377 | err = -EBADF; |
| 378 | |
| 379 | switch (cmd) { |
| 380 | case F_GETLK64: |
| 381 | err = fcntl_getlk64(filp, (struct flock64 __user *) arg); |
| 382 | break; |
| 383 | case F_SETLK64: |
| 384 | case F_SETLKW64: |
Peter Staubach | c293621 | 2005-07-27 11:45:09 -0700 | [diff] [blame] | 385 | err = fcntl_setlk64(fd, filp, cmd, |
| 386 | (struct flock64 __user *) arg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 387 | break; |
| 388 | default: |
| 389 | err = do_fcntl(fd, cmd, arg, filp); |
| 390 | break; |
| 391 | } |
| 392 | fput(filp); |
| 393 | out: |
| 394 | return err; |
| 395 | } |
| 396 | #endif |
| 397 | |
| 398 | /* Table to convert sigio signal codes into poll band bitmaps */ |
| 399 | |
Eric Dumazet | fa3536c | 2006-03-26 01:37:24 -0800 | [diff] [blame] | 400 | static const long band_table[NSIGPOLL] = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 401 | POLLIN | POLLRDNORM, /* POLL_IN */ |
| 402 | POLLOUT | POLLWRNORM | POLLWRBAND, /* POLL_OUT */ |
| 403 | POLLIN | POLLRDNORM | POLLMSG, /* POLL_MSG */ |
| 404 | POLLERR, /* POLL_ERR */ |
| 405 | POLLPRI | POLLRDBAND, /* POLL_PRI */ |
| 406 | POLLHUP | POLLERR /* POLL_HUP */ |
| 407 | }; |
| 408 | |
| 409 | static inline int sigio_perm(struct task_struct *p, |
| 410 | struct fown_struct *fown, int sig) |
| 411 | { |
David Howells | c69e8d9 | 2008-11-14 10:39:19 +1100 | [diff] [blame] | 412 | const struct cred *cred; |
| 413 | int ret; |
| 414 | |
| 415 | rcu_read_lock(); |
| 416 | cred = __task_cred(p); |
| 417 | ret = ((fown->euid == 0 || |
| 418 | fown->euid == cred->suid || fown->euid == cred->uid || |
| 419 | fown->uid == cred->suid || fown->uid == cred->uid) && |
| 420 | !security_file_send_sigiotask(p, fown, sig)); |
| 421 | rcu_read_unlock(); |
| 422 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 423 | } |
| 424 | |
| 425 | static void send_sigio_to_task(struct task_struct *p, |
| 426 | struct fown_struct *fown, |
| 427 | int fd, |
| 428 | int reason) |
| 429 | { |
| 430 | if (!sigio_perm(p, fown, fown->signum)) |
| 431 | return; |
| 432 | |
| 433 | switch (fown->signum) { |
| 434 | siginfo_t si; |
| 435 | default: |
| 436 | /* Queue a rt signal with the appropriate fd as its |
| 437 | value. We use SI_SIGIO as the source, not |
| 438 | SI_KERNEL, since kernel signals always get |
| 439 | delivered even if we can't queue. Failure to |
| 440 | queue in this case _should_ be reported; we fall |
| 441 | back to SIGIO in that case. --sct */ |
| 442 | si.si_signo = fown->signum; |
| 443 | si.si_errno = 0; |
| 444 | si.si_code = reason; |
| 445 | /* Make sure we are called with one of the POLL_* |
| 446 | reasons, otherwise we could leak kernel stack into |
| 447 | userspace. */ |
Eric Sesterhenn | f6298aa | 2006-04-02 13:37:19 +0200 | [diff] [blame] | 448 | BUG_ON((reason & __SI_MASK) != __SI_POLL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 449 | if (reason - POLL_IN >= NSIGPOLL) |
| 450 | si.si_band = ~0L; |
| 451 | else |
| 452 | si.si_band = band_table[reason - POLL_IN]; |
| 453 | si.si_fd = fd; |
Oleg Nesterov | 850d6fb | 2006-01-08 01:03:29 -0800 | [diff] [blame] | 454 | if (!group_send_sig_info(fown->signum, &si, p)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 455 | break; |
| 456 | /* fall-through: fall back on the old plain SIGIO signal */ |
| 457 | case 0: |
Oleg Nesterov | 850d6fb | 2006-01-08 01:03:29 -0800 | [diff] [blame] | 458 | group_send_sig_info(SIGIO, SEND_SIG_PRIV, p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 459 | } |
| 460 | } |
| 461 | |
| 462 | void send_sigio(struct fown_struct *fown, int fd, int band) |
| 463 | { |
| 464 | struct task_struct *p; |
Eric W. Biederman | 609d7fa | 2006-10-02 02:17:15 -0700 | [diff] [blame] | 465 | enum pid_type type; |
| 466 | struct pid *pid; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 467 | |
| 468 | read_lock(&fown->lock); |
Eric W. Biederman | 609d7fa | 2006-10-02 02:17:15 -0700 | [diff] [blame] | 469 | type = fown->pid_type; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 470 | pid = fown->pid; |
| 471 | if (!pid) |
| 472 | goto out_unlock_fown; |
| 473 | |
| 474 | read_lock(&tasklist_lock); |
Eric W. Biederman | 609d7fa | 2006-10-02 02:17:15 -0700 | [diff] [blame] | 475 | do_each_pid_task(pid, type, p) { |
| 476 | send_sigio_to_task(p, fown, fd, band); |
| 477 | } while_each_pid_task(pid, type, p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 478 | read_unlock(&tasklist_lock); |
| 479 | out_unlock_fown: |
| 480 | read_unlock(&fown->lock); |
| 481 | } |
| 482 | |
| 483 | static void send_sigurg_to_task(struct task_struct *p, |
| 484 | struct fown_struct *fown) |
| 485 | { |
| 486 | if (sigio_perm(p, fown, SIGURG)) |
Oleg Nesterov | 850d6fb | 2006-01-08 01:03:29 -0800 | [diff] [blame] | 487 | group_send_sig_info(SIGURG, SEND_SIG_PRIV, p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 488 | } |
| 489 | |
| 490 | int send_sigurg(struct fown_struct *fown) |
| 491 | { |
| 492 | struct task_struct *p; |
Eric W. Biederman | 609d7fa | 2006-10-02 02:17:15 -0700 | [diff] [blame] | 493 | enum pid_type type; |
| 494 | struct pid *pid; |
| 495 | int ret = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 496 | |
| 497 | read_lock(&fown->lock); |
Eric W. Biederman | 609d7fa | 2006-10-02 02:17:15 -0700 | [diff] [blame] | 498 | type = fown->pid_type; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 499 | pid = fown->pid; |
| 500 | if (!pid) |
| 501 | goto out_unlock_fown; |
| 502 | |
| 503 | ret = 1; |
| 504 | |
| 505 | read_lock(&tasklist_lock); |
Eric W. Biederman | 609d7fa | 2006-10-02 02:17:15 -0700 | [diff] [blame] | 506 | do_each_pid_task(pid, type, p) { |
| 507 | send_sigurg_to_task(p, fown); |
| 508 | } while_each_pid_task(pid, type, p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 509 | read_unlock(&tasklist_lock); |
| 510 | out_unlock_fown: |
| 511 | read_unlock(&fown->lock); |
| 512 | return ret; |
| 513 | } |
| 514 | |
| 515 | static DEFINE_RWLOCK(fasync_lock); |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 516 | static struct kmem_cache *fasync_cache __read_mostly; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 517 | |
| 518 | /* |
Jonathan Corbet | 7639842 | 2009-02-01 14:26:59 -0700 | [diff] [blame] | 519 | * fasync_helper() is used by almost all character device drivers |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 520 | * to set up the fasync queue. It returns negative on error, 0 if it did |
| 521 | * no changes and positive if it added/deleted the entry. |
| 522 | */ |
| 523 | int fasync_helper(int fd, struct file * filp, int on, struct fasync_struct **fapp) |
| 524 | { |
| 525 | struct fasync_struct *fa, **fp; |
| 526 | struct fasync_struct *new = NULL; |
| 527 | int result = 0; |
| 528 | |
| 529 | if (on) { |
Christoph Lameter | e94b176 | 2006-12-06 20:33:17 -0800 | [diff] [blame] | 530 | new = kmem_cache_alloc(fasync_cache, GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 531 | if (!new) |
| 532 | return -ENOMEM; |
| 533 | } |
| 534 | write_lock_irq(&fasync_lock); |
| 535 | for (fp = fapp; (fa = *fp) != NULL; fp = &fa->fa_next) { |
| 536 | if (fa->fa_file == filp) { |
| 537 | if(on) { |
| 538 | fa->fa_fd = fd; |
| 539 | kmem_cache_free(fasync_cache, new); |
| 540 | } else { |
| 541 | *fp = fa->fa_next; |
| 542 | kmem_cache_free(fasync_cache, fa); |
| 543 | result = 1; |
| 544 | } |
| 545 | goto out; |
| 546 | } |
| 547 | } |
| 548 | |
| 549 | if (on) { |
| 550 | new->magic = FASYNC_MAGIC; |
| 551 | new->fa_file = filp; |
| 552 | new->fa_fd = fd; |
| 553 | new->fa_next = *fapp; |
| 554 | *fapp = new; |
| 555 | result = 1; |
| 556 | } |
| 557 | out: |
Jonathan Corbet | 7639842 | 2009-02-01 14:26:59 -0700 | [diff] [blame] | 558 | /* Fix up FASYNC bit while still holding fasync_lock */ |
| 559 | spin_lock(&filp->f_lock); |
| 560 | if (on) |
| 561 | filp->f_flags |= FASYNC; |
| 562 | else |
| 563 | filp->f_flags &= ~FASYNC; |
| 564 | spin_unlock(&filp->f_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 565 | write_unlock_irq(&fasync_lock); |
| 566 | return result; |
| 567 | } |
| 568 | |
| 569 | EXPORT_SYMBOL(fasync_helper); |
| 570 | |
| 571 | void __kill_fasync(struct fasync_struct *fa, int sig, int band) |
| 572 | { |
| 573 | while (fa) { |
| 574 | struct fown_struct * fown; |
| 575 | if (fa->magic != FASYNC_MAGIC) { |
| 576 | printk(KERN_ERR "kill_fasync: bad magic number in " |
| 577 | "fasync_struct!\n"); |
| 578 | return; |
| 579 | } |
| 580 | fown = &fa->fa_file->f_owner; |
| 581 | /* Don't send SIGURG to processes which have not set a |
| 582 | queued signum: SIGURG has its own default signalling |
| 583 | mechanism. */ |
| 584 | if (!(sig == SIGURG && fown->signum == 0)) |
| 585 | send_sigio(fown, fa->fa_fd, band); |
| 586 | fa = fa->fa_next; |
| 587 | } |
| 588 | } |
| 589 | |
| 590 | EXPORT_SYMBOL(__kill_fasync); |
| 591 | |
| 592 | void kill_fasync(struct fasync_struct **fp, int sig, int band) |
| 593 | { |
| 594 | /* First a quick test without locking: usually |
| 595 | * the list is empty. |
| 596 | */ |
| 597 | if (*fp) { |
| 598 | read_lock(&fasync_lock); |
| 599 | /* reread *fp after obtaining the lock */ |
| 600 | __kill_fasync(*fp, sig, band); |
| 601 | read_unlock(&fasync_lock); |
| 602 | } |
| 603 | } |
| 604 | EXPORT_SYMBOL(kill_fasync); |
| 605 | |
| 606 | static int __init fasync_init(void) |
| 607 | { |
| 608 | fasync_cache = kmem_cache_create("fasync_cache", |
Paul Mundt | 20c2df8 | 2007-07-20 10:11:58 +0900 | [diff] [blame] | 609 | sizeof(struct fasync_struct), 0, SLAB_PANIC, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 610 | return 0; |
| 611 | } |
| 612 | |
| 613 | module_init(fasync_init) |