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> |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 17 | #include <linux/pipe_fs_i.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 18 | #include <linux/security.h> |
| 19 | #include <linux/ptrace.h> |
Jesper Juhl | 7ed20e1 | 2005-05-01 08:59:14 -0700 | [diff] [blame] | 20 | #include <linux/signal.h> |
Dipankar Sarma | ab2af1f | 2005-09-09 13:04:13 -0700 | [diff] [blame] | 21 | #include <linux/rcupdate.h> |
Pavel Emelyanov | b488893 | 2007-10-18 23:40:14 -0700 | [diff] [blame] | 22 | #include <linux/pid_namespace.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; |
Jeff Mahoney | 2b79bc4 | 2009-05-11 14:25:34 -0400 | [diff] [blame] | 120 | int retval = oldfd; |
| 121 | |
Al Viro | 6c5d051 | 2008-07-26 13:38:19 -0400 | [diff] [blame] | 122 | rcu_read_lock(); |
| 123 | if (!fcheck_files(files, oldfd)) |
Jeff Mahoney | 2b79bc4 | 2009-05-11 14:25:34 -0400 | [diff] [blame] | 124 | retval = -EBADF; |
Al Viro | 6c5d051 | 2008-07-26 13:38:19 -0400 | [diff] [blame] | 125 | rcu_read_unlock(); |
Jeff Mahoney | 2b79bc4 | 2009-05-11 14:25:34 -0400 | [diff] [blame] | 126 | return retval; |
Al Viro | 6c5d051 | 2008-07-26 13:38:19 -0400 | [diff] [blame] | 127 | } |
Ulrich Drepper | 336dd1f | 2008-07-23 21:29:29 -0700 | [diff] [blame] | 128 | return sys_dup3(oldfd, newfd, 0); |
| 129 | } |
| 130 | |
Heiko Carstens | a26eab2 | 2009-01-14 14:14:17 +0100 | [diff] [blame] | 131 | SYSCALL_DEFINE1(dup, unsigned int, fildes) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 132 | { |
| 133 | int ret = -EBADF; |
Al Viro | 1abf0c7 | 2011-03-13 03:51:11 -0400 | [diff] [blame^] | 134 | struct file *file = fget_raw(fildes); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 135 | |
Al Viro | 1027abe | 2008-07-30 04:13:04 -0400 | [diff] [blame] | 136 | if (file) { |
| 137 | ret = get_unused_fd(); |
| 138 | if (ret >= 0) |
| 139 | fd_install(ret, file); |
| 140 | else |
| 141 | fput(file); |
| 142 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 143 | return ret; |
| 144 | } |
| 145 | |
Jonathan Corbet | 7639842 | 2009-02-01 14:26:59 -0700 | [diff] [blame] | 146 | #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] | 147 | |
| 148 | static int setfl(int fd, struct file * filp, unsigned long arg) |
| 149 | { |
Josef "Jeff" Sipek | 0f7fc9e | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 150 | struct inode * inode = filp->f_path.dentry->d_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 151 | int error = 0; |
| 152 | |
dean gaudet | 7d95c8f | 2006-02-03 03:04:30 -0800 | [diff] [blame] | 153 | /* |
| 154 | * O_APPEND cannot be cleared if the file is marked as append-only |
| 155 | * and the file is open for write. |
| 156 | */ |
| 157 | if (((arg ^ filp->f_flags) & O_APPEND) && IS_APPEND(inode)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 158 | return -EPERM; |
| 159 | |
| 160 | /* O_NOATIME can only be set by the owner or superuser */ |
| 161 | if ((arg & O_NOATIME) && !(filp->f_flags & O_NOATIME)) |
Satyam Sharma | 3bd858a | 2007-07-17 15:00:08 +0530 | [diff] [blame] | 162 | if (!is_owner_or_cap(inode)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 163 | return -EPERM; |
| 164 | |
| 165 | /* required for strict SunOS emulation */ |
| 166 | if (O_NONBLOCK != O_NDELAY) |
| 167 | if (arg & O_NDELAY) |
| 168 | arg |= O_NONBLOCK; |
| 169 | |
| 170 | if (arg & O_DIRECT) { |
| 171 | if (!filp->f_mapping || !filp->f_mapping->a_ops || |
| 172 | !filp->f_mapping->a_ops->direct_IO) |
| 173 | return -EINVAL; |
| 174 | } |
| 175 | |
| 176 | if (filp->f_op && filp->f_op->check_flags) |
| 177 | error = filp->f_op->check_flags(arg); |
| 178 | if (error) |
| 179 | return error; |
| 180 | |
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 | * ->fasync() is responsible for setting the FASYNC bit. |
Jonathan Corbet | 218d11a | 2008-12-05 16:12:48 -0700 | [diff] [blame] | 183 | */ |
Jonathan Corbet | 7639842 | 2009-02-01 14:26:59 -0700 | [diff] [blame] | 184 | if (((arg ^ filp->f_flags) & FASYNC) && filp->f_op && |
| 185 | filp->f_op->fasync) { |
| 186 | error = filp->f_op->fasync(fd, filp, (arg & FASYNC) != 0); |
| 187 | if (error < 0) |
| 188 | goto out; |
Jonathan Corbet | 60aa492 | 2009-02-01 14:52:56 -0700 | [diff] [blame] | 189 | if (error > 0) |
| 190 | error = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 191 | } |
Jonathan Corbet | db1dd4d | 2009-02-06 15:25:24 -0700 | [diff] [blame] | 192 | spin_lock(&filp->f_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 193 | filp->f_flags = (arg & SETFL_MASK) | (filp->f_flags & ~SETFL_MASK); |
Jonathan Corbet | db1dd4d | 2009-02-06 15:25:24 -0700 | [diff] [blame] | 194 | spin_unlock(&filp->f_lock); |
Jonathan Corbet | 7639842 | 2009-02-01 14:26:59 -0700 | [diff] [blame] | 195 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 196 | out: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 197 | return error; |
| 198 | } |
| 199 | |
Eric W. Biederman | 609d7fa | 2006-10-02 02:17:15 -0700 | [diff] [blame] | 200 | static void f_modown(struct file *filp, struct pid *pid, enum pid_type type, |
Oleg Nesterov | 2f38d70 | 2009-06-16 22:07:46 +0200 | [diff] [blame] | 201 | int force) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 202 | { |
Linus Torvalds | 80e1e82 | 2010-02-07 10:11:23 -0800 | [diff] [blame] | 203 | write_lock_irq(&filp->f_owner.lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 204 | if (force || !filp->f_owner.pid) { |
Eric W. Biederman | 609d7fa | 2006-10-02 02:17:15 -0700 | [diff] [blame] | 205 | put_pid(filp->f_owner.pid); |
| 206 | filp->f_owner.pid = get_pid(pid); |
| 207 | filp->f_owner.pid_type = type; |
Oleg Nesterov | 2f38d70 | 2009-06-16 22:07:46 +0200 | [diff] [blame] | 208 | |
| 209 | if (pid) { |
| 210 | const struct cred *cred = current_cred(); |
| 211 | filp->f_owner.uid = cred->uid; |
| 212 | filp->f_owner.euid = cred->euid; |
| 213 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 214 | } |
Linus Torvalds | 80e1e82 | 2010-02-07 10:11:23 -0800 | [diff] [blame] | 215 | write_unlock_irq(&filp->f_owner.lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 216 | } |
| 217 | |
Eric W. Biederman | 609d7fa | 2006-10-02 02:17:15 -0700 | [diff] [blame] | 218 | int __f_setown(struct file *filp, struct pid *pid, enum pid_type type, |
| 219 | int force) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 220 | { |
| 221 | int err; |
Oleg Nesterov | 2f38d70 | 2009-06-16 22:07:46 +0200 | [diff] [blame] | 222 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 223 | err = security_file_set_fowner(filp); |
| 224 | if (err) |
| 225 | return err; |
| 226 | |
Oleg Nesterov | 2f38d70 | 2009-06-16 22:07:46 +0200 | [diff] [blame] | 227 | f_modown(filp, pid, type, force); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 228 | return 0; |
| 229 | } |
Eric W. Biederman | 609d7fa | 2006-10-02 02:17:15 -0700 | [diff] [blame] | 230 | EXPORT_SYMBOL(__f_setown); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 231 | |
Eric W. Biederman | 609d7fa | 2006-10-02 02:17:15 -0700 | [diff] [blame] | 232 | int f_setown(struct file *filp, unsigned long arg, int force) |
| 233 | { |
| 234 | enum pid_type type; |
| 235 | struct pid *pid; |
| 236 | int who = arg; |
| 237 | int result; |
| 238 | type = PIDTYPE_PID; |
| 239 | if (who < 0) { |
| 240 | type = PIDTYPE_PGID; |
| 241 | who = -who; |
| 242 | } |
| 243 | rcu_read_lock(); |
Pavel Emelyanov | b488893 | 2007-10-18 23:40:14 -0700 | [diff] [blame] | 244 | pid = find_vpid(who); |
Eric W. Biederman | 609d7fa | 2006-10-02 02:17:15 -0700 | [diff] [blame] | 245 | result = __f_setown(filp, pid, type, force); |
| 246 | rcu_read_unlock(); |
| 247 | return result; |
| 248 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 249 | EXPORT_SYMBOL(f_setown); |
| 250 | |
| 251 | void f_delown(struct file *filp) |
| 252 | { |
Oleg Nesterov | 2f38d70 | 2009-06-16 22:07:46 +0200 | [diff] [blame] | 253 | f_modown(filp, NULL, PIDTYPE_PID, 1); |
Eric W. Biederman | 609d7fa | 2006-10-02 02:17:15 -0700 | [diff] [blame] | 254 | } |
| 255 | |
| 256 | pid_t f_getown(struct file *filp) |
| 257 | { |
| 258 | pid_t pid; |
Eric W. Biederman | 43fa1adb | 2006-10-02 02:17:27 -0700 | [diff] [blame] | 259 | read_lock(&filp->f_owner.lock); |
Pavel Emelyanov | 6c5f3e7 | 2008-02-08 04:19:20 -0800 | [diff] [blame] | 260 | pid = pid_vnr(filp->f_owner.pid); |
Eric W. Biederman | 609d7fa | 2006-10-02 02:17:15 -0700 | [diff] [blame] | 261 | if (filp->f_owner.pid_type == PIDTYPE_PGID) |
| 262 | pid = -pid; |
Eric W. Biederman | 43fa1adb | 2006-10-02 02:17:27 -0700 | [diff] [blame] | 263 | read_unlock(&filp->f_owner.lock); |
Eric W. Biederman | 609d7fa | 2006-10-02 02:17:15 -0700 | [diff] [blame] | 264 | return pid; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 265 | } |
| 266 | |
Peter Zijlstra | ba0a6c9 | 2009-09-23 15:57:03 -0700 | [diff] [blame] | 267 | static int f_setown_ex(struct file *filp, unsigned long arg) |
| 268 | { |
| 269 | struct f_owner_ex * __user owner_p = (void * __user)arg; |
| 270 | struct f_owner_ex owner; |
| 271 | struct pid *pid; |
| 272 | int type; |
| 273 | int ret; |
| 274 | |
| 275 | ret = copy_from_user(&owner, owner_p, sizeof(owner)); |
| 276 | if (ret) |
Dan Carpenter | 5b54470 | 2010-06-03 12:35:42 +0200 | [diff] [blame] | 277 | return -EFAULT; |
Peter Zijlstra | ba0a6c9 | 2009-09-23 15:57:03 -0700 | [diff] [blame] | 278 | |
| 279 | switch (owner.type) { |
| 280 | case F_OWNER_TID: |
| 281 | type = PIDTYPE_MAX; |
| 282 | break; |
| 283 | |
| 284 | case F_OWNER_PID: |
| 285 | type = PIDTYPE_PID; |
| 286 | break; |
| 287 | |
Peter Zijlstra | 978b405 | 2009-11-17 14:06:24 -0800 | [diff] [blame] | 288 | case F_OWNER_PGRP: |
Peter Zijlstra | ba0a6c9 | 2009-09-23 15:57:03 -0700 | [diff] [blame] | 289 | type = PIDTYPE_PGID; |
| 290 | break; |
| 291 | |
| 292 | default: |
| 293 | return -EINVAL; |
| 294 | } |
| 295 | |
| 296 | rcu_read_lock(); |
| 297 | pid = find_vpid(owner.pid); |
| 298 | if (owner.pid && !pid) |
| 299 | ret = -ESRCH; |
| 300 | else |
| 301 | ret = __f_setown(filp, pid, type, 1); |
| 302 | rcu_read_unlock(); |
| 303 | |
| 304 | return ret; |
| 305 | } |
| 306 | |
| 307 | static int f_getown_ex(struct file *filp, unsigned long arg) |
| 308 | { |
| 309 | struct f_owner_ex * __user owner_p = (void * __user)arg; |
| 310 | struct f_owner_ex owner; |
| 311 | int ret = 0; |
| 312 | |
| 313 | read_lock(&filp->f_owner.lock); |
| 314 | owner.pid = pid_vnr(filp->f_owner.pid); |
| 315 | switch (filp->f_owner.pid_type) { |
| 316 | case PIDTYPE_MAX: |
| 317 | owner.type = F_OWNER_TID; |
| 318 | break; |
| 319 | |
| 320 | case PIDTYPE_PID: |
| 321 | owner.type = F_OWNER_PID; |
| 322 | break; |
| 323 | |
| 324 | case PIDTYPE_PGID: |
Peter Zijlstra | 978b405 | 2009-11-17 14:06:24 -0800 | [diff] [blame] | 325 | owner.type = F_OWNER_PGRP; |
Peter Zijlstra | ba0a6c9 | 2009-09-23 15:57:03 -0700 | [diff] [blame] | 326 | break; |
| 327 | |
| 328 | default: |
| 329 | WARN_ON(1); |
| 330 | ret = -EINVAL; |
| 331 | break; |
| 332 | } |
| 333 | read_unlock(&filp->f_owner.lock); |
| 334 | |
Dan Carpenter | 5b54470 | 2010-06-03 12:35:42 +0200 | [diff] [blame] | 335 | if (!ret) { |
Peter Zijlstra | ba0a6c9 | 2009-09-23 15:57:03 -0700 | [diff] [blame] | 336 | ret = copy_to_user(owner_p, &owner, sizeof(owner)); |
Dan Carpenter | 5b54470 | 2010-06-03 12:35:42 +0200 | [diff] [blame] | 337 | if (ret) |
| 338 | ret = -EFAULT; |
| 339 | } |
Peter Zijlstra | ba0a6c9 | 2009-09-23 15:57:03 -0700 | [diff] [blame] | 340 | return ret; |
| 341 | } |
| 342 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 343 | static long do_fcntl(int fd, unsigned int cmd, unsigned long arg, |
| 344 | struct file *filp) |
| 345 | { |
| 346 | long err = -EINVAL; |
| 347 | |
| 348 | switch (cmd) { |
| 349 | case F_DUPFD: |
Ulrich Drepper | 22d2b35 | 2007-10-16 23:30:26 -0700 | [diff] [blame] | 350 | case F_DUPFD_CLOEXEC: |
Jiri Slaby | d554ed89 | 2010-03-05 13:42:42 -0800 | [diff] [blame] | 351 | if (arg >= rlimit(RLIMIT_NOFILE)) |
Al Viro | 4e1e018 | 2008-07-26 16:01:20 -0400 | [diff] [blame] | 352 | break; |
Al Viro | 1027abe | 2008-07-30 04:13:04 -0400 | [diff] [blame] | 353 | err = alloc_fd(arg, cmd == F_DUPFD_CLOEXEC ? O_CLOEXEC : 0); |
| 354 | if (err >= 0) { |
| 355 | get_file(filp); |
| 356 | fd_install(err, filp); |
| 357 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 358 | break; |
| 359 | case F_GETFD: |
| 360 | err = get_close_on_exec(fd) ? FD_CLOEXEC : 0; |
| 361 | break; |
| 362 | case F_SETFD: |
| 363 | err = 0; |
| 364 | set_close_on_exec(fd, arg & FD_CLOEXEC); |
| 365 | break; |
| 366 | case F_GETFL: |
| 367 | err = filp->f_flags; |
| 368 | break; |
| 369 | case F_SETFL: |
| 370 | err = setfl(fd, filp, arg); |
| 371 | break; |
| 372 | case F_GETLK: |
| 373 | err = fcntl_getlk(filp, (struct flock __user *) arg); |
| 374 | break; |
| 375 | case F_SETLK: |
| 376 | case F_SETLKW: |
Peter Staubach | c293621 | 2005-07-27 11:45:09 -0700 | [diff] [blame] | 377 | err = fcntl_setlk(fd, filp, cmd, (struct flock __user *) arg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 378 | break; |
| 379 | case F_GETOWN: |
| 380 | /* |
| 381 | * XXX If f_owner is a process group, the |
| 382 | * negative return value will get converted |
| 383 | * into an error. Oops. If we keep the |
| 384 | * current syscall conventions, the only way |
| 385 | * to fix this will be in libc. |
| 386 | */ |
Eric W. Biederman | 609d7fa | 2006-10-02 02:17:15 -0700 | [diff] [blame] | 387 | err = f_getown(filp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 388 | force_successful_syscall_return(); |
| 389 | break; |
| 390 | case F_SETOWN: |
| 391 | err = f_setown(filp, arg, 1); |
| 392 | break; |
Peter Zijlstra | ba0a6c9 | 2009-09-23 15:57:03 -0700 | [diff] [blame] | 393 | case F_GETOWN_EX: |
| 394 | err = f_getown_ex(filp, arg); |
| 395 | break; |
| 396 | case F_SETOWN_EX: |
| 397 | err = f_setown_ex(filp, arg); |
| 398 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 399 | case F_GETSIG: |
| 400 | err = filp->f_owner.signum; |
| 401 | break; |
| 402 | case F_SETSIG: |
| 403 | /* arg == 0 restores default behaviour. */ |
Jesper Juhl | 7ed20e1 | 2005-05-01 08:59:14 -0700 | [diff] [blame] | 404 | if (!valid_signal(arg)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 405 | break; |
| 406 | } |
| 407 | err = 0; |
| 408 | filp->f_owner.signum = arg; |
| 409 | break; |
| 410 | case F_GETLEASE: |
| 411 | err = fcntl_getlease(filp); |
| 412 | break; |
| 413 | case F_SETLEASE: |
| 414 | err = fcntl_setlease(fd, filp, arg); |
| 415 | break; |
| 416 | case F_NOTIFY: |
| 417 | err = fcntl_dirnotify(fd, filp, arg); |
| 418 | break; |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 419 | case F_SETPIPE_SZ: |
| 420 | case F_GETPIPE_SZ: |
| 421 | err = pipe_fcntl(filp, cmd, arg); |
| 422 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 423 | default: |
| 424 | break; |
| 425 | } |
| 426 | return err; |
| 427 | } |
| 428 | |
Al Viro | 1abf0c7 | 2011-03-13 03:51:11 -0400 | [diff] [blame^] | 429 | static int check_fcntl_cmd(unsigned cmd) |
| 430 | { |
| 431 | switch (cmd) { |
| 432 | case F_DUPFD: |
| 433 | case F_DUPFD_CLOEXEC: |
| 434 | case F_GETFD: |
| 435 | case F_SETFD: |
| 436 | case F_GETFL: |
| 437 | return 1; |
| 438 | } |
| 439 | return 0; |
| 440 | } |
| 441 | |
Heiko Carstens | a26eab2 | 2009-01-14 14:14:17 +0100 | [diff] [blame] | 442 | SYSCALL_DEFINE3(fcntl, unsigned int, fd, unsigned int, cmd, unsigned long, arg) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 443 | { |
| 444 | struct file *filp; |
| 445 | long err = -EBADF; |
| 446 | |
Al Viro | 1abf0c7 | 2011-03-13 03:51:11 -0400 | [diff] [blame^] | 447 | filp = fget_raw(fd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 448 | if (!filp) |
| 449 | goto out; |
| 450 | |
Al Viro | 1abf0c7 | 2011-03-13 03:51:11 -0400 | [diff] [blame^] | 451 | if (unlikely(filp->f_mode & FMODE_PATH)) { |
| 452 | if (!check_fcntl_cmd(cmd)) { |
| 453 | fput(filp); |
| 454 | goto out; |
| 455 | } |
| 456 | } |
| 457 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 458 | err = security_file_fcntl(filp, cmd, arg); |
| 459 | if (err) { |
| 460 | fput(filp); |
| 461 | return err; |
| 462 | } |
| 463 | |
| 464 | err = do_fcntl(fd, cmd, arg, filp); |
| 465 | |
| 466 | fput(filp); |
| 467 | out: |
| 468 | return err; |
| 469 | } |
| 470 | |
| 471 | #if BITS_PER_LONG == 32 |
Heiko Carstens | a26eab2 | 2009-01-14 14:14:17 +0100 | [diff] [blame] | 472 | SYSCALL_DEFINE3(fcntl64, unsigned int, fd, unsigned int, cmd, |
| 473 | unsigned long, arg) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 474 | { |
| 475 | struct file * filp; |
| 476 | long err; |
| 477 | |
| 478 | err = -EBADF; |
Al Viro | 1abf0c7 | 2011-03-13 03:51:11 -0400 | [diff] [blame^] | 479 | filp = fget_raw(fd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 480 | if (!filp) |
| 481 | goto out; |
| 482 | |
Al Viro | 1abf0c7 | 2011-03-13 03:51:11 -0400 | [diff] [blame^] | 483 | if (unlikely(filp->f_mode & FMODE_PATH)) { |
| 484 | if (!check_fcntl_cmd(cmd)) { |
| 485 | fput(filp); |
| 486 | goto out; |
| 487 | } |
| 488 | } |
| 489 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 490 | err = security_file_fcntl(filp, cmd, arg); |
| 491 | if (err) { |
| 492 | fput(filp); |
| 493 | return err; |
| 494 | } |
| 495 | err = -EBADF; |
| 496 | |
| 497 | switch (cmd) { |
| 498 | case F_GETLK64: |
| 499 | err = fcntl_getlk64(filp, (struct flock64 __user *) arg); |
| 500 | break; |
| 501 | case F_SETLK64: |
| 502 | case F_SETLKW64: |
Peter Staubach | c293621 | 2005-07-27 11:45:09 -0700 | [diff] [blame] | 503 | err = fcntl_setlk64(fd, filp, cmd, |
| 504 | (struct flock64 __user *) arg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 505 | break; |
| 506 | default: |
| 507 | err = do_fcntl(fd, cmd, arg, filp); |
| 508 | break; |
| 509 | } |
| 510 | fput(filp); |
| 511 | out: |
| 512 | return err; |
| 513 | } |
| 514 | #endif |
| 515 | |
| 516 | /* Table to convert sigio signal codes into poll band bitmaps */ |
| 517 | |
Eric Dumazet | fa3536c | 2006-03-26 01:37:24 -0800 | [diff] [blame] | 518 | static const long band_table[NSIGPOLL] = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 519 | POLLIN | POLLRDNORM, /* POLL_IN */ |
| 520 | POLLOUT | POLLWRNORM | POLLWRBAND, /* POLL_OUT */ |
| 521 | POLLIN | POLLRDNORM | POLLMSG, /* POLL_MSG */ |
| 522 | POLLERR, /* POLL_ERR */ |
| 523 | POLLPRI | POLLRDBAND, /* POLL_PRI */ |
| 524 | POLLHUP | POLLERR /* POLL_HUP */ |
| 525 | }; |
| 526 | |
| 527 | static inline int sigio_perm(struct task_struct *p, |
| 528 | struct fown_struct *fown, int sig) |
| 529 | { |
David Howells | c69e8d9 | 2008-11-14 10:39:19 +1100 | [diff] [blame] | 530 | const struct cred *cred; |
| 531 | int ret; |
| 532 | |
| 533 | rcu_read_lock(); |
| 534 | cred = __task_cred(p); |
| 535 | ret = ((fown->euid == 0 || |
| 536 | fown->euid == cred->suid || fown->euid == cred->uid || |
| 537 | fown->uid == cred->suid || fown->uid == cred->uid) && |
| 538 | !security_file_send_sigiotask(p, fown, sig)); |
| 539 | rcu_read_unlock(); |
| 540 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 541 | } |
| 542 | |
| 543 | static void send_sigio_to_task(struct task_struct *p, |
Oleg Nesterov | 8eeee4e | 2009-06-17 00:27:10 +0200 | [diff] [blame] | 544 | struct fown_struct *fown, |
Peter Zijlstra | ba0a6c9 | 2009-09-23 15:57:03 -0700 | [diff] [blame] | 545 | int fd, int reason, int group) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 546 | { |
Oleg Nesterov | 8eeee4e | 2009-06-17 00:27:10 +0200 | [diff] [blame] | 547 | /* |
| 548 | * F_SETSIG can change ->signum lockless in parallel, make |
| 549 | * sure we read it once and use the same value throughout. |
| 550 | */ |
| 551 | int signum = ACCESS_ONCE(fown->signum); |
| 552 | |
| 553 | if (!sigio_perm(p, fown, signum)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 554 | return; |
| 555 | |
Oleg Nesterov | 8eeee4e | 2009-06-17 00:27:10 +0200 | [diff] [blame] | 556 | switch (signum) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 557 | siginfo_t si; |
| 558 | default: |
| 559 | /* Queue a rt signal with the appropriate fd as its |
| 560 | value. We use SI_SIGIO as the source, not |
| 561 | SI_KERNEL, since kernel signals always get |
| 562 | delivered even if we can't queue. Failure to |
| 563 | queue in this case _should_ be reported; we fall |
| 564 | back to SIGIO in that case. --sct */ |
Oleg Nesterov | 8eeee4e | 2009-06-17 00:27:10 +0200 | [diff] [blame] | 565 | si.si_signo = signum; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 566 | si.si_errno = 0; |
| 567 | si.si_code = reason; |
| 568 | /* Make sure we are called with one of the POLL_* |
| 569 | reasons, otherwise we could leak kernel stack into |
| 570 | userspace. */ |
Eric Sesterhenn | f6298aa | 2006-04-02 13:37:19 +0200 | [diff] [blame] | 571 | BUG_ON((reason & __SI_MASK) != __SI_POLL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 572 | if (reason - POLL_IN >= NSIGPOLL) |
| 573 | si.si_band = ~0L; |
| 574 | else |
| 575 | si.si_band = band_table[reason - POLL_IN]; |
| 576 | si.si_fd = fd; |
Peter Zijlstra | ba0a6c9 | 2009-09-23 15:57:03 -0700 | [diff] [blame] | 577 | if (!do_send_sig_info(signum, &si, p, group)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 578 | break; |
| 579 | /* fall-through: fall back on the old plain SIGIO signal */ |
| 580 | case 0: |
Peter Zijlstra | ba0a6c9 | 2009-09-23 15:57:03 -0700 | [diff] [blame] | 581 | do_send_sig_info(SIGIO, SEND_SIG_PRIV, p, group); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 582 | } |
| 583 | } |
| 584 | |
| 585 | void send_sigio(struct fown_struct *fown, int fd, int band) |
| 586 | { |
| 587 | struct task_struct *p; |
Eric W. Biederman | 609d7fa | 2006-10-02 02:17:15 -0700 | [diff] [blame] | 588 | enum pid_type type; |
| 589 | struct pid *pid; |
Peter Zijlstra | ba0a6c9 | 2009-09-23 15:57:03 -0700 | [diff] [blame] | 590 | int group = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 591 | |
| 592 | read_lock(&fown->lock); |
Peter Zijlstra | ba0a6c9 | 2009-09-23 15:57:03 -0700 | [diff] [blame] | 593 | |
Eric W. Biederman | 609d7fa | 2006-10-02 02:17:15 -0700 | [diff] [blame] | 594 | type = fown->pid_type; |
Peter Zijlstra | ba0a6c9 | 2009-09-23 15:57:03 -0700 | [diff] [blame] | 595 | if (type == PIDTYPE_MAX) { |
| 596 | group = 0; |
| 597 | type = PIDTYPE_PID; |
| 598 | } |
| 599 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 600 | pid = fown->pid; |
| 601 | if (!pid) |
| 602 | goto out_unlock_fown; |
| 603 | |
| 604 | read_lock(&tasklist_lock); |
Eric W. Biederman | 609d7fa | 2006-10-02 02:17:15 -0700 | [diff] [blame] | 605 | do_each_pid_task(pid, type, p) { |
Peter Zijlstra | ba0a6c9 | 2009-09-23 15:57:03 -0700 | [diff] [blame] | 606 | send_sigio_to_task(p, fown, fd, band, group); |
Eric W. Biederman | 609d7fa | 2006-10-02 02:17:15 -0700 | [diff] [blame] | 607 | } while_each_pid_task(pid, type, p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 608 | read_unlock(&tasklist_lock); |
| 609 | out_unlock_fown: |
| 610 | read_unlock(&fown->lock); |
| 611 | } |
| 612 | |
| 613 | static void send_sigurg_to_task(struct task_struct *p, |
Peter Zijlstra | ba0a6c9 | 2009-09-23 15:57:03 -0700 | [diff] [blame] | 614 | struct fown_struct *fown, int group) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 615 | { |
| 616 | if (sigio_perm(p, fown, SIGURG)) |
Peter Zijlstra | ba0a6c9 | 2009-09-23 15:57:03 -0700 | [diff] [blame] | 617 | do_send_sig_info(SIGURG, SEND_SIG_PRIV, p, group); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 618 | } |
| 619 | |
| 620 | int send_sigurg(struct fown_struct *fown) |
| 621 | { |
| 622 | struct task_struct *p; |
Eric W. Biederman | 609d7fa | 2006-10-02 02:17:15 -0700 | [diff] [blame] | 623 | enum pid_type type; |
| 624 | struct pid *pid; |
Peter Zijlstra | ba0a6c9 | 2009-09-23 15:57:03 -0700 | [diff] [blame] | 625 | int group = 1; |
Eric W. Biederman | 609d7fa | 2006-10-02 02:17:15 -0700 | [diff] [blame] | 626 | int ret = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 627 | |
| 628 | read_lock(&fown->lock); |
Peter Zijlstra | ba0a6c9 | 2009-09-23 15:57:03 -0700 | [diff] [blame] | 629 | |
Eric W. Biederman | 609d7fa | 2006-10-02 02:17:15 -0700 | [diff] [blame] | 630 | type = fown->pid_type; |
Peter Zijlstra | ba0a6c9 | 2009-09-23 15:57:03 -0700 | [diff] [blame] | 631 | if (type == PIDTYPE_MAX) { |
| 632 | group = 0; |
| 633 | type = PIDTYPE_PID; |
| 634 | } |
| 635 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 636 | pid = fown->pid; |
| 637 | if (!pid) |
| 638 | goto out_unlock_fown; |
| 639 | |
| 640 | ret = 1; |
| 641 | |
| 642 | read_lock(&tasklist_lock); |
Eric W. Biederman | 609d7fa | 2006-10-02 02:17:15 -0700 | [diff] [blame] | 643 | do_each_pid_task(pid, type, p) { |
Peter Zijlstra | ba0a6c9 | 2009-09-23 15:57:03 -0700 | [diff] [blame] | 644 | send_sigurg_to_task(p, fown, group); |
Eric W. Biederman | 609d7fa | 2006-10-02 02:17:15 -0700 | [diff] [blame] | 645 | } while_each_pid_task(pid, type, p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 646 | read_unlock(&tasklist_lock); |
| 647 | out_unlock_fown: |
| 648 | read_unlock(&fown->lock); |
| 649 | return ret; |
| 650 | } |
| 651 | |
Eric Dumazet | 989a297 | 2010-04-14 09:55:35 +0000 | [diff] [blame] | 652 | static DEFINE_SPINLOCK(fasync_lock); |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 653 | static struct kmem_cache *fasync_cache __read_mostly; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 654 | |
Eric Dumazet | 989a297 | 2010-04-14 09:55:35 +0000 | [diff] [blame] | 655 | static void fasync_free_rcu(struct rcu_head *head) |
| 656 | { |
| 657 | kmem_cache_free(fasync_cache, |
| 658 | container_of(head, struct fasync_struct, fa_rcu)); |
| 659 | } |
| 660 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 661 | /* |
Linus Torvalds | 53281b6 | 2009-12-16 08:23:37 -0800 | [diff] [blame] | 662 | * Remove a fasync entry. If successfully removed, return |
| 663 | * positive and clear the FASYNC flag. If no entry exists, |
| 664 | * do nothing and return 0. |
| 665 | * |
| 666 | * NOTE! It is very important that the FASYNC flag always |
| 667 | * match the state "is the filp on a fasync list". |
| 668 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 669 | */ |
Linus Torvalds | f7347ce | 2010-10-27 12:38:12 -0400 | [diff] [blame] | 670 | int fasync_remove_entry(struct file *filp, struct fasync_struct **fapp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 671 | { |
| 672 | struct fasync_struct *fa, **fp; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 673 | int result = 0; |
| 674 | |
Jonathan Corbet | 4a6a449 | 2009-03-27 12:24:31 -0600 | [diff] [blame] | 675 | spin_lock(&filp->f_lock); |
Eric Dumazet | 989a297 | 2010-04-14 09:55:35 +0000 | [diff] [blame] | 676 | spin_lock(&fasync_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 677 | for (fp = fapp; (fa = *fp) != NULL; fp = &fa->fa_next) { |
Linus Torvalds | 53281b6 | 2009-12-16 08:23:37 -0800 | [diff] [blame] | 678 | if (fa->fa_file != filp) |
| 679 | continue; |
Eric Dumazet | 989a297 | 2010-04-14 09:55:35 +0000 | [diff] [blame] | 680 | |
| 681 | spin_lock_irq(&fa->fa_lock); |
| 682 | fa->fa_file = NULL; |
| 683 | spin_unlock_irq(&fa->fa_lock); |
| 684 | |
Linus Torvalds | 53281b6 | 2009-12-16 08:23:37 -0800 | [diff] [blame] | 685 | *fp = fa->fa_next; |
Eric Dumazet | 989a297 | 2010-04-14 09:55:35 +0000 | [diff] [blame] | 686 | call_rcu(&fa->fa_rcu, fasync_free_rcu); |
Jonathan Corbet | 7639842 | 2009-02-01 14:26:59 -0700 | [diff] [blame] | 687 | filp->f_flags &= ~FASYNC; |
Linus Torvalds | 53281b6 | 2009-12-16 08:23:37 -0800 | [diff] [blame] | 688 | result = 1; |
| 689 | break; |
| 690 | } |
Eric Dumazet | 989a297 | 2010-04-14 09:55:35 +0000 | [diff] [blame] | 691 | spin_unlock(&fasync_lock); |
Jonathan Corbet | 4a6a449 | 2009-03-27 12:24:31 -0600 | [diff] [blame] | 692 | spin_unlock(&filp->f_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 693 | return result; |
| 694 | } |
| 695 | |
Linus Torvalds | f7347ce | 2010-10-27 12:38:12 -0400 | [diff] [blame] | 696 | struct fasync_struct *fasync_alloc(void) |
Linus Torvalds | 53281b6 | 2009-12-16 08:23:37 -0800 | [diff] [blame] | 697 | { |
Linus Torvalds | f7347ce | 2010-10-27 12:38:12 -0400 | [diff] [blame] | 698 | return kmem_cache_alloc(fasync_cache, GFP_KERNEL); |
| 699 | } |
Linus Torvalds | 53281b6 | 2009-12-16 08:23:37 -0800 | [diff] [blame] | 700 | |
Linus Torvalds | f7347ce | 2010-10-27 12:38:12 -0400 | [diff] [blame] | 701 | /* |
| 702 | * NOTE! This can be used only for unused fasync entries: |
| 703 | * entries that actually got inserted on the fasync list |
| 704 | * need to be released by rcu - see fasync_remove_entry. |
| 705 | */ |
| 706 | void fasync_free(struct fasync_struct *new) |
| 707 | { |
| 708 | kmem_cache_free(fasync_cache, new); |
| 709 | } |
| 710 | |
| 711 | /* |
| 712 | * Insert a new entry into the fasync list. Return the pointer to the |
| 713 | * old one if we didn't use the new one. |
Linus Torvalds | 55f335a | 2010-10-27 18:17:02 -0700 | [diff] [blame] | 714 | * |
| 715 | * NOTE! It is very important that the FASYNC flag always |
| 716 | * match the state "is the filp on a fasync list". |
Linus Torvalds | f7347ce | 2010-10-27 12:38:12 -0400 | [diff] [blame] | 717 | */ |
| 718 | struct fasync_struct *fasync_insert_entry(int fd, struct file *filp, struct fasync_struct **fapp, struct fasync_struct *new) |
| 719 | { |
| 720 | struct fasync_struct *fa, **fp; |
Linus Torvalds | 53281b6 | 2009-12-16 08:23:37 -0800 | [diff] [blame] | 721 | |
| 722 | spin_lock(&filp->f_lock); |
Eric Dumazet | 989a297 | 2010-04-14 09:55:35 +0000 | [diff] [blame] | 723 | spin_lock(&fasync_lock); |
Linus Torvalds | 53281b6 | 2009-12-16 08:23:37 -0800 | [diff] [blame] | 724 | for (fp = fapp; (fa = *fp) != NULL; fp = &fa->fa_next) { |
| 725 | if (fa->fa_file != filp) |
| 726 | continue; |
Eric Dumazet | 989a297 | 2010-04-14 09:55:35 +0000 | [diff] [blame] | 727 | |
| 728 | spin_lock_irq(&fa->fa_lock); |
Linus Torvalds | 53281b6 | 2009-12-16 08:23:37 -0800 | [diff] [blame] | 729 | fa->fa_fd = fd; |
Eric Dumazet | 989a297 | 2010-04-14 09:55:35 +0000 | [diff] [blame] | 730 | spin_unlock_irq(&fa->fa_lock); |
Linus Torvalds | 53281b6 | 2009-12-16 08:23:37 -0800 | [diff] [blame] | 731 | goto out; |
| 732 | } |
| 733 | |
Eric Dumazet | 989a297 | 2010-04-14 09:55:35 +0000 | [diff] [blame] | 734 | spin_lock_init(&new->fa_lock); |
Linus Torvalds | 53281b6 | 2009-12-16 08:23:37 -0800 | [diff] [blame] | 735 | new->magic = FASYNC_MAGIC; |
| 736 | new->fa_file = filp; |
| 737 | new->fa_fd = fd; |
| 738 | new->fa_next = *fapp; |
Eric Dumazet | 989a297 | 2010-04-14 09:55:35 +0000 | [diff] [blame] | 739 | rcu_assign_pointer(*fapp, new); |
Linus Torvalds | 53281b6 | 2009-12-16 08:23:37 -0800 | [diff] [blame] | 740 | filp->f_flags |= FASYNC; |
| 741 | |
| 742 | out: |
Eric Dumazet | 989a297 | 2010-04-14 09:55:35 +0000 | [diff] [blame] | 743 | spin_unlock(&fasync_lock); |
Linus Torvalds | 53281b6 | 2009-12-16 08:23:37 -0800 | [diff] [blame] | 744 | spin_unlock(&filp->f_lock); |
Linus Torvalds | f7347ce | 2010-10-27 12:38:12 -0400 | [diff] [blame] | 745 | return fa; |
| 746 | } |
| 747 | |
| 748 | /* |
| 749 | * Add a fasync entry. Return negative on error, positive if |
| 750 | * added, and zero if did nothing but change an existing one. |
Linus Torvalds | f7347ce | 2010-10-27 12:38:12 -0400 | [diff] [blame] | 751 | */ |
| 752 | static int fasync_add_entry(int fd, struct file *filp, struct fasync_struct **fapp) |
| 753 | { |
| 754 | struct fasync_struct *new; |
| 755 | |
| 756 | new = fasync_alloc(); |
| 757 | if (!new) |
| 758 | return -ENOMEM; |
| 759 | |
| 760 | /* |
| 761 | * fasync_insert_entry() returns the old (update) entry if |
| 762 | * it existed. |
| 763 | * |
| 764 | * So free the (unused) new entry and return 0 to let the |
| 765 | * caller know that we didn't add any new fasync entries. |
| 766 | */ |
| 767 | if (fasync_insert_entry(fd, filp, fapp, new)) { |
| 768 | fasync_free(new); |
| 769 | return 0; |
| 770 | } |
| 771 | |
| 772 | return 1; |
Linus Torvalds | 53281b6 | 2009-12-16 08:23:37 -0800 | [diff] [blame] | 773 | } |
| 774 | |
| 775 | /* |
| 776 | * fasync_helper() is used by almost all character device drivers |
| 777 | * to set up the fasync queue, and for regular files by the file |
| 778 | * lease code. It returns negative on error, 0 if it did no changes |
| 779 | * and positive if it added/deleted the entry. |
| 780 | */ |
| 781 | int fasync_helper(int fd, struct file * filp, int on, struct fasync_struct **fapp) |
| 782 | { |
| 783 | if (!on) |
| 784 | return fasync_remove_entry(filp, fapp); |
| 785 | return fasync_add_entry(fd, filp, fapp); |
| 786 | } |
| 787 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 788 | EXPORT_SYMBOL(fasync_helper); |
| 789 | |
Eric Dumazet | 989a297 | 2010-04-14 09:55:35 +0000 | [diff] [blame] | 790 | /* |
| 791 | * rcu_read_lock() is held |
| 792 | */ |
| 793 | static void kill_fasync_rcu(struct fasync_struct *fa, int sig, int band) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 794 | { |
| 795 | while (fa) { |
Eric Dumazet | 989a297 | 2010-04-14 09:55:35 +0000 | [diff] [blame] | 796 | struct fown_struct *fown; |
Andrew Morton | f4985dc | 2010-06-29 15:05:42 -0700 | [diff] [blame] | 797 | unsigned long flags; |
| 798 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 799 | if (fa->magic != FASYNC_MAGIC) { |
| 800 | printk(KERN_ERR "kill_fasync: bad magic number in " |
| 801 | "fasync_struct!\n"); |
| 802 | return; |
| 803 | } |
Andrew Morton | f4985dc | 2010-06-29 15:05:42 -0700 | [diff] [blame] | 804 | spin_lock_irqsave(&fa->fa_lock, flags); |
Eric Dumazet | 989a297 | 2010-04-14 09:55:35 +0000 | [diff] [blame] | 805 | if (fa->fa_file) { |
| 806 | fown = &fa->fa_file->f_owner; |
| 807 | /* Don't send SIGURG to processes which have not set a |
| 808 | queued signum: SIGURG has its own default signalling |
| 809 | mechanism. */ |
| 810 | if (!(sig == SIGURG && fown->signum == 0)) |
| 811 | send_sigio(fown, fa->fa_fd, band); |
| 812 | } |
Andrew Morton | f4985dc | 2010-06-29 15:05:42 -0700 | [diff] [blame] | 813 | spin_unlock_irqrestore(&fa->fa_lock, flags); |
Eric Dumazet | 989a297 | 2010-04-14 09:55:35 +0000 | [diff] [blame] | 814 | fa = rcu_dereference(fa->fa_next); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 815 | } |
| 816 | } |
| 817 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 818 | void kill_fasync(struct fasync_struct **fp, int sig, int band) |
| 819 | { |
| 820 | /* First a quick test without locking: usually |
| 821 | * the list is empty. |
| 822 | */ |
| 823 | if (*fp) { |
Eric Dumazet | 989a297 | 2010-04-14 09:55:35 +0000 | [diff] [blame] | 824 | rcu_read_lock(); |
| 825 | kill_fasync_rcu(rcu_dereference(*fp), sig, band); |
| 826 | rcu_read_unlock(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 827 | } |
| 828 | } |
| 829 | EXPORT_SYMBOL(kill_fasync); |
| 830 | |
Wu Fengguang | 454eedb | 2010-08-10 18:01:29 -0700 | [diff] [blame] | 831 | static int __init fcntl_init(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 832 | { |
James Bottomley | 3ab04d5 | 2010-09-09 16:38:12 -0700 | [diff] [blame] | 833 | /* |
| 834 | * Please add new bits here to ensure allocation uniqueness. |
| 835 | * Exceptions: O_NONBLOCK is a two bit define on parisc; O_NDELAY |
| 836 | * is defined as O_NONBLOCK on some platforms and not on others. |
| 837 | */ |
Al Viro | 1abf0c7 | 2011-03-13 03:51:11 -0400 | [diff] [blame^] | 838 | BUILD_BUG_ON(19 - 1 /* for O_RDONLY being 0 */ != HWEIGHT32( |
Wu Fengguang | 454eedb | 2010-08-10 18:01:29 -0700 | [diff] [blame] | 839 | O_RDONLY | O_WRONLY | O_RDWR | |
| 840 | O_CREAT | O_EXCL | O_NOCTTY | |
James Bottomley | 3ab04d5 | 2010-09-09 16:38:12 -0700 | [diff] [blame] | 841 | O_TRUNC | O_APPEND | /* O_NONBLOCK | */ |
Wu Fengguang | 454eedb | 2010-08-10 18:01:29 -0700 | [diff] [blame] | 842 | __O_SYNC | O_DSYNC | FASYNC | |
| 843 | O_DIRECT | O_LARGEFILE | O_DIRECTORY | |
| 844 | O_NOFOLLOW | O_NOATIME | O_CLOEXEC | |
Al Viro | 1abf0c7 | 2011-03-13 03:51:11 -0400 | [diff] [blame^] | 845 | __FMODE_EXEC | O_PATH |
Wu Fengguang | 454eedb | 2010-08-10 18:01:29 -0700 | [diff] [blame] | 846 | )); |
| 847 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 848 | fasync_cache = kmem_cache_create("fasync_cache", |
Paul Mundt | 20c2df8 | 2007-07-20 10:11:58 +0900 | [diff] [blame] | 849 | sizeof(struct fasync_struct), 0, SLAB_PANIC, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 850 | return 0; |
| 851 | } |
| 852 | |
Wu Fengguang | 454eedb | 2010-08-10 18:01:29 -0700 | [diff] [blame] | 853 | module_init(fcntl_init) |