2 * Copyright (C) 1991, 1992 Linus Torvalds
6 * 'tty_io.c' gives an orthogonal feeling to tty's, be they consoles
7 * or rs-channels. It also implements echoing, cooked mode etc.
9 * Kill-line thanks to John T Kohl, who also corrected VMIN = VTIME = 0.
11 * Modified by Theodore Ts'o, 9/14/92, to dynamically allocate the
12 * tty_struct and tty_queue structures. Previously there was an array
13 * of 256 tty_struct's which was statically allocated, and the
14 * tty_queue structures were allocated at boot time. Both are now
15 * dynamically allocated only when the tty is open.
17 * Also restructured routines so that there is more of a separation
18 * between the high-level tty routines (tty_io.c and tty_ioctl.c) and
19 * the low-level tty routines (serial.c, pty.c, console.c). This
20 * makes for cleaner and more compact code. -TYT, 9/17/92
22 * Modified by Fred N. van Kempen, 01/29/93, to add line disciplines
23 * which can be dynamically activated and de-activated by the line
24 * discipline handling modules (like SLIP).
26 * NOTE: pay no attention to the line discipline code (yet); its
27 * interface is still subject to change in this version...
30 * Added functionality to the OPOST tty handling. No delays, but all
31 * other bits should be there.
32 * -- Nick Holloway <alfie@dcs.warwick.ac.uk>, 27th May 1993.
34 * Rewrote canonical mode and added more termios flags.
35 * -- julian@uhunix.uhcc.hawaii.edu (J. Cowley), 13Jan94
37 * Reorganized FASYNC support so mouse code can share it.
38 * -- ctm@ardi.com, 9Sep95
40 * New TIOCLINUX variants added.
41 * -- mj@k332.feld.cvut.cz, 19-Nov-95
43 * Restrict vt switching via ioctl()
44 * -- grif@cs.ucr.edu, 5-Dec-95
46 * Move console and virtual terminal code to more appropriate files,
47 * implement CONFIG_VT and generalize console device interface.
48 * -- Marko Kohtala <Marko.Kohtala@hut.fi>, March 97
50 * Rewrote tty_init_dev and tty_release_dev to eliminate races.
51 * -- Bill Hawes <whawes@star.net>, June 97
53 * Added devfs support.
54 * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 13-Jan-1998
56 * Added support for a Unix98-style ptmx device.
57 * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 14-Jan-1998
59 * Reduced memory usage for older ARM systems
60 * -- Russell King <rmk@arm.linux.org.uk>
62 * Move do_SAK() into process context. Less stack use in devfs functions.
63 * alloc_tty_struct() always uses kmalloc()
64 * -- Andrew Morton <andrewm@uow.edu.eu> 17Mar01
67 #include <linux/types.h>
68 #include <linux/major.h>
69 #include <linux/errno.h>
70 #include <linux/signal.h>
71 #include <linux/fcntl.h>
72 #include <linux/sched.h>
73 #include <linux/interrupt.h>
74 #include <linux/tty.h>
75 #include <linux/tty_driver.h>
76 #include <linux/tty_flip.h>
77 #include <linux/devpts_fs.h>
78 #include <linux/file.h>
79 #include <linux/fdtable.h>
80 #include <linux/console.h>
81 #include <linux/timer.h>
82 #include <linux/ctype.h>
85 #include <linux/string.h>
86 #include <linux/slab.h>
87 #include <linux/poll.h>
88 #include <linux/proc_fs.h>
89 #include <linux/init.h>
90 #include <linux/module.h>
91 #include <linux/device.h>
92 #include <linux/wait.h>
93 #include <linux/bitops.h>
94 #include <linux/delay.h>
95 #include <linux/seq_file.h>
96 #include <linux/serial.h>
97 #include <linux/ratelimit.h>
99 #include <linux/uaccess.h>
101 #include <linux/kbd_kern.h>
102 #include <linux/vt_kern.h>
103 #include <linux/selection.h>
105 #include <linux/kmod.h>
106 #include <linux/nsproxy.h>
108 #undef TTY_DEBUG_HANGUP
110 #define TTY_PARANOIA_CHECK 1
111 #define CHECK_TTY_COUNT 1
113 struct ktermios tty_std_termios
= { /* for the benefit of tty drivers */
114 .c_iflag
= ICRNL
| IXON
,
115 .c_oflag
= OPOST
| ONLCR
,
116 .c_cflag
= B38400
| CS8
| CREAD
| HUPCL
,
117 .c_lflag
= ISIG
| ICANON
| ECHO
| ECHOE
| ECHOK
|
118 ECHOCTL
| ECHOKE
| IEXTEN
,
124 EXPORT_SYMBOL(tty_std_termios
);
126 /* This list gets poked at by procfs and various bits of boot up code. This
127 could do with some rationalisation such as pulling the tty proc function
130 LIST_HEAD(tty_drivers
); /* linked list of tty drivers */
132 /* Mutex to protect creating and releasing a tty. This is shared with
133 vt.c for deeply disgusting hack reasons */
134 DEFINE_MUTEX(tty_mutex
);
135 EXPORT_SYMBOL(tty_mutex
);
137 /* Spinlock to protect the tty->tty_files list */
138 DEFINE_SPINLOCK(tty_files_lock
);
140 static ssize_t
tty_read(struct file
*, char __user
*, size_t, loff_t
*);
141 static ssize_t
tty_write(struct file
*, const char __user
*, size_t, loff_t
*);
142 ssize_t
redirected_tty_write(struct file
*, const char __user
*,
144 static unsigned int tty_poll(struct file
*, poll_table
*);
145 static int tty_open(struct inode
*, struct file
*);
146 long tty_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
);
148 static long tty_compat_ioctl(struct file
*file
, unsigned int cmd
,
151 #define tty_compat_ioctl NULL
153 static int __tty_fasync(int fd
, struct file
*filp
, int on
);
154 static int tty_fasync(int fd
, struct file
*filp
, int on
);
155 static void release_tty(struct tty_struct
*tty
, int idx
);
158 * free_tty_struct - free a disused tty
159 * @tty: tty struct to free
161 * Free the write buffers, tty queue and tty memory itself.
163 * Locking: none. Must be called after tty is definitely unused
166 void free_tty_struct(struct tty_struct
*tty
)
171 put_device(tty
->dev
);
172 kfree(tty
->write_buf
);
173 tty
->magic
= 0xDEADDEAD;
177 static inline struct tty_struct
*file_tty(struct file
*file
)
179 return ((struct tty_file_private
*)file
->private_data
)->tty
;
182 int tty_alloc_file(struct file
*file
)
184 struct tty_file_private
*priv
;
186 priv
= kmalloc(sizeof(*priv
), GFP_KERNEL
);
190 file
->private_data
= priv
;
195 /* Associate a new file with the tty structure */
196 void tty_add_file(struct tty_struct
*tty
, struct file
*file
)
198 struct tty_file_private
*priv
= file
->private_data
;
203 spin_lock(&tty_files_lock
);
204 list_add(&priv
->list
, &tty
->tty_files
);
205 spin_unlock(&tty_files_lock
);
209 * tty_free_file - free file->private_data
211 * This shall be used only for fail path handling when tty_add_file was not
214 void tty_free_file(struct file
*file
)
216 struct tty_file_private
*priv
= file
->private_data
;
218 file
->private_data
= NULL
;
222 /* Delete file from its tty */
223 static void tty_del_file(struct file
*file
)
225 struct tty_file_private
*priv
= file
->private_data
;
227 spin_lock(&tty_files_lock
);
228 list_del(&priv
->list
);
229 spin_unlock(&tty_files_lock
);
234 #define TTY_NUMBER(tty) ((tty)->index + (tty)->driver->name_base)
237 * tty_name - return tty naming
238 * @tty: tty structure
239 * @buf: buffer for output
241 * Convert a tty structure into a name. The name reflects the kernel
242 * naming policy and if udev is in use may not reflect user space
247 char *tty_name(struct tty_struct
*tty
, char *buf
)
249 if (!tty
) /* Hmm. NULL pointer. That's fun. */
250 strcpy(buf
, "NULL tty");
252 strcpy(buf
, tty
->name
);
256 EXPORT_SYMBOL(tty_name
);
258 int tty_paranoia_check(struct tty_struct
*tty
, struct inode
*inode
,
261 #ifdef TTY_PARANOIA_CHECK
264 "null TTY for (%d:%d) in %s\n",
265 imajor(inode
), iminor(inode
), routine
);
268 if (tty
->magic
!= TTY_MAGIC
) {
270 "bad magic number for tty struct (%d:%d) in %s\n",
271 imajor(inode
), iminor(inode
), routine
);
278 static int check_tty_count(struct tty_struct
*tty
, const char *routine
)
280 #ifdef CHECK_TTY_COUNT
284 spin_lock(&tty_files_lock
);
285 list_for_each(p
, &tty
->tty_files
) {
288 spin_unlock(&tty_files_lock
);
289 if (tty
->driver
->type
== TTY_DRIVER_TYPE_PTY
&&
290 tty
->driver
->subtype
== PTY_TYPE_SLAVE
&&
291 tty
->link
&& tty
->link
->count
)
293 if (tty
->count
!= count
) {
294 printk(KERN_WARNING
"Warning: dev (%s) tty->count(%d) "
295 "!= #fd's(%d) in %s\n",
296 tty
->name
, tty
->count
, count
, routine
);
304 * get_tty_driver - find device of a tty
305 * @dev_t: device identifier
306 * @index: returns the index of the tty
308 * This routine returns a tty driver structure, given a device number
309 * and also passes back the index number.
311 * Locking: caller must hold tty_mutex
314 static struct tty_driver
*get_tty_driver(dev_t device
, int *index
)
316 struct tty_driver
*p
;
318 list_for_each_entry(p
, &tty_drivers
, tty_drivers
) {
319 dev_t base
= MKDEV(p
->major
, p
->minor_start
);
320 if (device
< base
|| device
>= base
+ p
->num
)
322 *index
= device
- base
;
323 return tty_driver_kref_get(p
);
328 #ifdef CONFIG_CONSOLE_POLL
331 * tty_find_polling_driver - find device of a polled tty
332 * @name: name string to match
333 * @line: pointer to resulting tty line nr
335 * This routine returns a tty driver structure, given a name
336 * and the condition that the tty driver is capable of polled
339 struct tty_driver
*tty_find_polling_driver(char *name
, int *line
)
341 struct tty_driver
*p
, *res
= NULL
;
346 for (str
= name
; *str
; str
++)
347 if ((*str
>= '0' && *str
<= '9') || *str
== ',')
353 tty_line
= simple_strtoul(str
, &str
, 10);
355 mutex_lock(&tty_mutex
);
356 /* Search through the tty devices to look for a match */
357 list_for_each_entry(p
, &tty_drivers
, tty_drivers
) {
358 if (strncmp(name
, p
->name
, len
) != 0)
366 if (tty_line
>= 0 && tty_line
< p
->num
&& p
->ops
&&
367 p
->ops
->poll_init
&& !p
->ops
->poll_init(p
, tty_line
, stp
)) {
368 res
= tty_driver_kref_get(p
);
373 mutex_unlock(&tty_mutex
);
377 EXPORT_SYMBOL_GPL(tty_find_polling_driver
);
381 * tty_check_change - check for POSIX terminal changes
384 * If we try to write to, or set the state of, a terminal and we're
385 * not in the foreground, send a SIGTTOU. If the signal is blocked or
386 * ignored, go ahead and perform the operation. (POSIX 7.2)
391 int tty_check_change(struct tty_struct
*tty
)
396 if (current
->signal
->tty
!= tty
)
399 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
402 printk(KERN_WARNING
"tty_check_change: tty->pgrp == NULL!\n");
405 if (task_pgrp(current
) == tty
->pgrp
)
407 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
408 if (is_ignored(SIGTTOU
))
410 if (is_current_pgrp_orphaned()) {
414 kill_pgrp(task_pgrp(current
), SIGTTOU
, 1);
415 set_thread_flag(TIF_SIGPENDING
);
420 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
424 EXPORT_SYMBOL(tty_check_change
);
426 static ssize_t
hung_up_tty_read(struct file
*file
, char __user
*buf
,
427 size_t count
, loff_t
*ppos
)
432 static ssize_t
hung_up_tty_write(struct file
*file
, const char __user
*buf
,
433 size_t count
, loff_t
*ppos
)
438 /* No kernel lock held - none needed ;) */
439 static unsigned int hung_up_tty_poll(struct file
*filp
, poll_table
*wait
)
441 return POLLIN
| POLLOUT
| POLLERR
| POLLHUP
| POLLRDNORM
| POLLWRNORM
;
444 static long hung_up_tty_ioctl(struct file
*file
, unsigned int cmd
,
447 return cmd
== TIOCSPGRP
? -ENOTTY
: -EIO
;
450 static long hung_up_tty_compat_ioctl(struct file
*file
,
451 unsigned int cmd
, unsigned long arg
)
453 return cmd
== TIOCSPGRP
? -ENOTTY
: -EIO
;
456 static const struct file_operations tty_fops
= {
461 .unlocked_ioctl
= tty_ioctl
,
462 .compat_ioctl
= tty_compat_ioctl
,
464 .release
= tty_release
,
465 .fasync
= tty_fasync
,
468 static const struct file_operations console_fops
= {
471 .write
= redirected_tty_write
,
473 .unlocked_ioctl
= tty_ioctl
,
474 .compat_ioctl
= tty_compat_ioctl
,
476 .release
= tty_release
,
477 .fasync
= tty_fasync
,
480 static const struct file_operations hung_up_tty_fops
= {
482 .read
= hung_up_tty_read
,
483 .write
= hung_up_tty_write
,
484 .poll
= hung_up_tty_poll
,
485 .unlocked_ioctl
= hung_up_tty_ioctl
,
486 .compat_ioctl
= hung_up_tty_compat_ioctl
,
487 .release
= tty_release
,
490 static DEFINE_SPINLOCK(redirect_lock
);
491 static struct file
*redirect
;
494 void proc_clear_tty(struct task_struct
*p
)
497 struct tty_struct
*tty
;
498 spin_lock_irqsave(&p
->sighand
->siglock
, flags
);
499 tty
= p
->signal
->tty
;
500 p
->signal
->tty
= NULL
;
501 spin_unlock_irqrestore(&p
->sighand
->siglock
, flags
);
506 * proc_set_tty - set the controlling terminal
508 * Only callable by the session leader and only if it does not already have
509 * a controlling terminal.
511 * Caller must hold: tty_lock()
512 * a readlock on tasklist_lock
515 static void __proc_set_tty(struct tty_struct
*tty
)
519 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
521 * The session and fg pgrp references will be non-NULL if
522 * tiocsctty() is stealing the controlling tty
524 put_pid(tty
->session
);
526 tty
->pgrp
= get_pid(task_pgrp(current
));
527 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
528 tty
->session
= get_pid(task_session(current
));
529 if (current
->signal
->tty
) {
530 printk(KERN_DEBUG
"tty not NULL!!\n");
531 tty_kref_put(current
->signal
->tty
);
533 put_pid(current
->signal
->tty_old_pgrp
);
534 current
->signal
->tty
= tty_kref_get(tty
);
535 current
->signal
->tty_old_pgrp
= NULL
;
538 static void proc_set_tty(struct tty_struct
*tty
)
540 spin_lock_irq(¤t
->sighand
->siglock
);
542 spin_unlock_irq(¤t
->sighand
->siglock
);
545 struct tty_struct
*get_current_tty(void)
547 struct tty_struct
*tty
;
550 spin_lock_irqsave(¤t
->sighand
->siglock
, flags
);
551 tty
= tty_kref_get(current
->signal
->tty
);
552 spin_unlock_irqrestore(¤t
->sighand
->siglock
, flags
);
555 EXPORT_SYMBOL_GPL(get_current_tty
);
557 static void session_clear_tty(struct pid
*session
)
559 struct task_struct
*p
;
560 do_each_pid_task(session
, PIDTYPE_SID
, p
) {
562 } while_each_pid_task(session
, PIDTYPE_SID
, p
);
566 * tty_wakeup - request more data
569 * Internal and external helper for wakeups of tty. This function
570 * informs the line discipline if present that the driver is ready
571 * to receive more output data.
574 void tty_wakeup(struct tty_struct
*tty
)
576 struct tty_ldisc
*ld
;
578 if (test_bit(TTY_DO_WRITE_WAKEUP
, &tty
->flags
)) {
579 ld
= tty_ldisc_ref(tty
);
581 if (ld
->ops
->write_wakeup
)
582 ld
->ops
->write_wakeup(tty
);
586 wake_up_interruptible_poll(&tty
->write_wait
, POLLOUT
);
589 EXPORT_SYMBOL_GPL(tty_wakeup
);
592 * tty_signal_session_leader - sends SIGHUP to session leader
593 * @tty controlling tty
594 * @exit_session if non-zero, signal all foreground group processes
596 * Send SIGHUP and SIGCONT to the session leader and its process group.
597 * Optionally, signal all processes in the foreground process group.
599 * Returns the number of processes in the session with this tty
600 * as their controlling terminal. This value is used to drop
601 * tty references for those processes.
603 static int tty_signal_session_leader(struct tty_struct
*tty
, int exit_session
)
605 struct task_struct
*p
;
607 struct pid
*tty_pgrp
= NULL
;
609 read_lock(&tasklist_lock
);
611 do_each_pid_task(tty
->session
, PIDTYPE_SID
, p
) {
612 spin_lock_irq(&p
->sighand
->siglock
);
613 if (p
->signal
->tty
== tty
) {
614 p
->signal
->tty
= NULL
;
615 /* We defer the dereferences outside fo
619 if (!p
->signal
->leader
) {
620 spin_unlock_irq(&p
->sighand
->siglock
);
623 __group_send_sig_info(SIGHUP
, SEND_SIG_PRIV
, p
);
624 __group_send_sig_info(SIGCONT
, SEND_SIG_PRIV
, p
);
625 put_pid(p
->signal
->tty_old_pgrp
); /* A noop */
626 spin_lock(&tty
->ctrl_lock
);
627 tty_pgrp
= get_pid(tty
->pgrp
);
629 p
->signal
->tty_old_pgrp
= get_pid(tty
->pgrp
);
630 spin_unlock(&tty
->ctrl_lock
);
631 spin_unlock_irq(&p
->sighand
->siglock
);
632 } while_each_pid_task(tty
->session
, PIDTYPE_SID
, p
);
634 read_unlock(&tasklist_lock
);
638 kill_pgrp(tty_pgrp
, SIGHUP
, exit_session
);
646 * __tty_hangup - actual handler for hangup events
649 * This can be called by a "kworker" kernel thread. That is process
650 * synchronous but doesn't hold any locks, so we need to make sure we
651 * have the appropriate locks for what we're doing.
653 * The hangup event clears any pending redirections onto the hung up
654 * device. It ensures future writes will error and it does the needed
655 * line discipline hangup and signal delivery. The tty object itself
660 * redirect lock for undoing redirection
661 * file list lock for manipulating list of ttys
662 * tty_ldiscs_lock from called functions
663 * termios_rwsem resetting termios data
664 * tasklist_lock to walk task list for hangup event
665 * ->siglock to protect ->signal/->sighand
667 static void __tty_hangup(struct tty_struct
*tty
, int exit_session
)
669 struct file
*cons_filp
= NULL
;
670 struct file
*filp
, *f
= NULL
;
671 struct tty_file_private
*priv
;
672 int closecount
= 0, n
;
679 spin_lock(&redirect_lock
);
680 if (redirect
&& file_tty(redirect
) == tty
) {
684 spin_unlock(&redirect_lock
);
688 if (test_bit(TTY_HUPPED
, &tty
->flags
)) {
693 /* inuse_filps is protected by the single tty lock,
694 this really needs to change if we want to flush the
695 workqueue with the lock held */
696 check_tty_count(tty
, "tty_hangup");
698 spin_lock(&tty_files_lock
);
699 /* This breaks for file handles being sent over AF_UNIX sockets ? */
700 list_for_each_entry(priv
, &tty
->tty_files
, list
) {
702 if (filp
->f_op
->write
== redirected_tty_write
)
704 if (filp
->f_op
->write
!= tty_write
)
707 __tty_fasync(-1, filp
, 0); /* can't block */
708 filp
->f_op
= &hung_up_tty_fops
;
710 spin_unlock(&tty_files_lock
);
712 refs
= tty_signal_session_leader(tty
, exit_session
);
713 /* Account for the p->signal references we killed */
717 tty_ldisc_hangup(tty
);
719 spin_lock_irq(&tty
->ctrl_lock
);
720 clear_bit(TTY_THROTTLED
, &tty
->flags
);
721 clear_bit(TTY_DO_WRITE_WAKEUP
, &tty
->flags
);
722 put_pid(tty
->session
);
726 tty
->ctrl_status
= 0;
727 spin_unlock_irq(&tty
->ctrl_lock
);
730 * If one of the devices matches a console pointer, we
731 * cannot just call hangup() because that will cause
732 * tty->count and state->count to go out of sync.
733 * So we just call close() the right number of times.
737 for (n
= 0; n
< closecount
; n
++)
738 tty
->ops
->close(tty
, cons_filp
);
739 } else if (tty
->ops
->hangup
)
740 tty
->ops
->hangup(tty
);
742 * We don't want to have driver/ldisc interactions beyond
743 * the ones we did here. The driver layer expects no
744 * calls after ->hangup() from the ldisc side. However we
745 * can't yet guarantee all that.
747 set_bit(TTY_HUPPED
, &tty
->flags
);
754 static void do_tty_hangup(struct work_struct
*work
)
756 struct tty_struct
*tty
=
757 container_of(work
, struct tty_struct
, hangup_work
);
759 __tty_hangup(tty
, 0);
763 * tty_hangup - trigger a hangup event
764 * @tty: tty to hangup
766 * A carrier loss (virtual or otherwise) has occurred on this like
767 * schedule a hangup sequence to run after this event.
770 void tty_hangup(struct tty_struct
*tty
)
772 #ifdef TTY_DEBUG_HANGUP
774 printk(KERN_DEBUG
"%s hangup...\n", tty_name(tty
, buf
));
776 schedule_work(&tty
->hangup_work
);
779 EXPORT_SYMBOL(tty_hangup
);
782 * tty_vhangup - process vhangup
783 * @tty: tty to hangup
785 * The user has asked via system call for the terminal to be hung up.
786 * We do this synchronously so that when the syscall returns the process
787 * is complete. That guarantee is necessary for security reasons.
790 void tty_vhangup(struct tty_struct
*tty
)
792 #ifdef TTY_DEBUG_HANGUP
795 printk(KERN_DEBUG
"%s vhangup...\n", tty_name(tty
, buf
));
797 __tty_hangup(tty
, 0);
800 EXPORT_SYMBOL(tty_vhangup
);
804 * tty_vhangup_self - process vhangup for own ctty
806 * Perform a vhangup on the current controlling tty
809 void tty_vhangup_self(void)
811 struct tty_struct
*tty
;
813 tty
= get_current_tty();
821 * tty_vhangup_session - hangup session leader exit
822 * @tty: tty to hangup
824 * The session leader is exiting and hanging up its controlling terminal.
825 * Every process in the foreground process group is signalled SIGHUP.
827 * We do this synchronously so that when the syscall returns the process
828 * is complete. That guarantee is necessary for security reasons.
831 static void tty_vhangup_session(struct tty_struct
*tty
)
833 #ifdef TTY_DEBUG_HANGUP
836 printk(KERN_DEBUG
"%s vhangup session...\n", tty_name(tty
, buf
));
838 __tty_hangup(tty
, 1);
842 * tty_hung_up_p - was tty hung up
843 * @filp: file pointer of tty
845 * Return true if the tty has been subject to a vhangup or a carrier
849 int tty_hung_up_p(struct file
*filp
)
851 return (filp
->f_op
== &hung_up_tty_fops
);
854 EXPORT_SYMBOL(tty_hung_up_p
);
857 * disassociate_ctty - disconnect controlling tty
858 * @on_exit: true if exiting so need to "hang up" the session
860 * This function is typically called only by the session leader, when
861 * it wants to disassociate itself from its controlling tty.
863 * It performs the following functions:
864 * (1) Sends a SIGHUP and SIGCONT to the foreground process group
865 * (2) Clears the tty from being controlling the session
866 * (3) Clears the controlling tty for all processes in the
869 * The argument on_exit is set to 1 if called when a process is
870 * exiting; it is 0 if called by the ioctl TIOCNOTTY.
873 * BTM is taken for hysterical raisins, and held when
874 * called from no_tty().
875 * tty_mutex is taken to protect tty
876 * ->siglock is taken to protect ->signal/->sighand
877 * tasklist_lock is taken to walk process list for sessions
878 * ->siglock is taken to protect ->signal/->sighand
881 void disassociate_ctty(int on_exit
)
883 struct tty_struct
*tty
;
885 if (!current
->signal
->leader
)
888 tty
= get_current_tty();
890 if (on_exit
&& tty
->driver
->type
!= TTY_DRIVER_TYPE_PTY
) {
891 tty_vhangup_session(tty
);
893 struct pid
*tty_pgrp
= tty_get_pgrp(tty
);
895 kill_pgrp(tty_pgrp
, SIGHUP
, on_exit
);
897 kill_pgrp(tty_pgrp
, SIGCONT
, on_exit
);
903 } else if (on_exit
) {
904 struct pid
*old_pgrp
;
905 spin_lock_irq(¤t
->sighand
->siglock
);
906 old_pgrp
= current
->signal
->tty_old_pgrp
;
907 current
->signal
->tty_old_pgrp
= NULL
;
908 spin_unlock_irq(¤t
->sighand
->siglock
);
910 kill_pgrp(old_pgrp
, SIGHUP
, on_exit
);
911 kill_pgrp(old_pgrp
, SIGCONT
, on_exit
);
917 spin_lock_irq(¤t
->sighand
->siglock
);
918 put_pid(current
->signal
->tty_old_pgrp
);
919 current
->signal
->tty_old_pgrp
= NULL
;
921 tty
= tty_kref_get(current
->signal
->tty
);
924 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
925 put_pid(tty
->session
);
929 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
932 #ifdef TTY_DEBUG_HANGUP
933 printk(KERN_DEBUG
"error attempted to write to tty [0x%p]"
938 spin_unlock_irq(¤t
->sighand
->siglock
);
939 /* Now clear signal->tty under the lock */
940 read_lock(&tasklist_lock
);
941 session_clear_tty(task_session(current
));
942 read_unlock(&tasklist_lock
);
947 * no_tty - Ensure the current process does not have a controlling tty
951 /* FIXME: Review locking here. The tty_lock never covered any race
952 between a new association and proc_clear_tty but possible we need
953 to protect against this anyway */
954 struct task_struct
*tsk
= current
;
955 disassociate_ctty(0);
961 * stop_tty - propagate flow control
964 * Perform flow control to the driver. May be called
965 * on an already stopped device and will not re-call the driver
968 * This functionality is used by both the line disciplines for
969 * halting incoming flow and by the driver. It may therefore be
970 * called from any context, may be under the tty atomic_write_lock
977 void __stop_tty(struct tty_struct
*tty
)
983 (tty
->ops
->stop
)(tty
);
986 void stop_tty(struct tty_struct
*tty
)
990 spin_lock_irqsave(&tty
->flow_lock
, flags
);
992 spin_unlock_irqrestore(&tty
->flow_lock
, flags
);
994 EXPORT_SYMBOL(stop_tty
);
997 * start_tty - propagate flow control
1000 * Start a tty that has been stopped if at all possible. If this
1001 * tty was previous stopped and is now being started, the driver
1002 * start method is invoked and the line discipline woken.
1008 void __start_tty(struct tty_struct
*tty
)
1010 if (!tty
->stopped
|| tty
->flow_stopped
)
1013 if (tty
->ops
->start
)
1014 (tty
->ops
->start
)(tty
);
1018 void start_tty(struct tty_struct
*tty
)
1020 unsigned long flags
;
1022 spin_lock_irqsave(&tty
->flow_lock
, flags
);
1024 spin_unlock_irqrestore(&tty
->flow_lock
, flags
);
1026 EXPORT_SYMBOL(start_tty
);
1028 /* We limit tty time update visibility to every 8 seconds or so. */
1029 static void tty_update_time(struct timespec
*time
)
1031 unsigned long sec
= get_seconds() & ~7;
1032 if ((long)(sec
- time
->tv_sec
) > 0)
1037 * tty_read - read method for tty device files
1038 * @file: pointer to tty file
1040 * @count: size of user buffer
1043 * Perform the read system call function on this terminal device. Checks
1044 * for hung up devices before calling the line discipline method.
1047 * Locks the line discipline internally while needed. Multiple
1048 * read calls may be outstanding in parallel.
1051 static ssize_t
tty_read(struct file
*file
, char __user
*buf
, size_t count
,
1055 struct inode
*inode
= file_inode(file
);
1056 struct tty_struct
*tty
= file_tty(file
);
1057 struct tty_ldisc
*ld
;
1059 if (tty_paranoia_check(tty
, inode
, "tty_read"))
1061 if (!tty
|| (test_bit(TTY_IO_ERROR
, &tty
->flags
)))
1064 /* We want to wait for the line discipline to sort out in this
1066 ld
= tty_ldisc_ref_wait(tty
);
1068 i
= (ld
->ops
->read
)(tty
, file
, buf
, count
);
1071 tty_ldisc_deref(ld
);
1074 tty_update_time(&inode
->i_atime
);
1079 static void tty_write_unlock(struct tty_struct
*tty
)
1081 mutex_unlock(&tty
->atomic_write_lock
);
1082 wake_up_interruptible_poll(&tty
->write_wait
, POLLOUT
);
1085 static int tty_write_lock(struct tty_struct
*tty
, int ndelay
)
1087 if (!mutex_trylock(&tty
->atomic_write_lock
)) {
1090 if (mutex_lock_interruptible(&tty
->atomic_write_lock
))
1091 return -ERESTARTSYS
;
1097 * Split writes up in sane blocksizes to avoid
1098 * denial-of-service type attacks
1100 static inline ssize_t
do_tty_write(
1101 ssize_t (*write
)(struct tty_struct
*, struct file
*, const unsigned char *, size_t),
1102 struct tty_struct
*tty
,
1104 const char __user
*buf
,
1107 ssize_t ret
, written
= 0;
1110 ret
= tty_write_lock(tty
, file
->f_flags
& O_NDELAY
);
1115 * We chunk up writes into a temporary buffer. This
1116 * simplifies low-level drivers immensely, since they
1117 * don't have locking issues and user mode accesses.
1119 * But if TTY_NO_WRITE_SPLIT is set, we should use a
1122 * The default chunk-size is 2kB, because the NTTY
1123 * layer has problems with bigger chunks. It will
1124 * claim to be able to handle more characters than
1127 * FIXME: This can probably go away now except that 64K chunks
1128 * are too likely to fail unless switched to vmalloc...
1131 if (test_bit(TTY_NO_WRITE_SPLIT
, &tty
->flags
))
1136 /* write_buf/write_cnt is protected by the atomic_write_lock mutex */
1137 if (tty
->write_cnt
< chunk
) {
1138 unsigned char *buf_chunk
;
1143 buf_chunk
= kmalloc(chunk
, GFP_KERNEL
);
1148 kfree(tty
->write_buf
);
1149 tty
->write_cnt
= chunk
;
1150 tty
->write_buf
= buf_chunk
;
1153 /* Do the write .. */
1155 size_t size
= count
;
1159 if (copy_from_user(tty
->write_buf
, buf
, size
))
1161 ret
= write(tty
, file
, tty
->write_buf
, size
);
1170 if (signal_pending(current
))
1175 tty_update_time(&file_inode(file
)->i_mtime
);
1179 tty_write_unlock(tty
);
1184 * tty_write_message - write a message to a certain tty, not just the console.
1185 * @tty: the destination tty_struct
1186 * @msg: the message to write
1188 * This is used for messages that need to be redirected to a specific tty.
1189 * We don't put it into the syslog queue right now maybe in the future if
1192 * We must still hold the BTM and test the CLOSING flag for the moment.
1195 void tty_write_message(struct tty_struct
*tty
, char *msg
)
1198 mutex_lock(&tty
->atomic_write_lock
);
1200 if (tty
->ops
->write
&& !test_bit(TTY_CLOSING
, &tty
->flags
)) {
1202 tty
->ops
->write(tty
, msg
, strlen(msg
));
1205 tty_write_unlock(tty
);
1212 * tty_write - write method for tty device file
1213 * @file: tty file pointer
1214 * @buf: user data to write
1215 * @count: bytes to write
1218 * Write data to a tty device via the line discipline.
1221 * Locks the line discipline as required
1222 * Writes to the tty driver are serialized by the atomic_write_lock
1223 * and are then processed in chunks to the device. The line discipline
1224 * write method will not be invoked in parallel for each device.
1227 static ssize_t
tty_write(struct file
*file
, const char __user
*buf
,
1228 size_t count
, loff_t
*ppos
)
1230 struct tty_struct
*tty
= file_tty(file
);
1231 struct tty_ldisc
*ld
;
1234 if (tty_paranoia_check(tty
, file_inode(file
), "tty_write"))
1236 if (!tty
|| !tty
->ops
->write
||
1237 (test_bit(TTY_IO_ERROR
, &tty
->flags
)))
1239 /* Short term debug to catch buggy drivers */
1240 if (tty
->ops
->write_room
== NULL
)
1241 printk(KERN_ERR
"tty driver %s lacks a write_room method.\n",
1243 ld
= tty_ldisc_ref_wait(tty
);
1244 if (!ld
->ops
->write
)
1247 ret
= do_tty_write(ld
->ops
->write
, tty
, file
, buf
, count
);
1248 tty_ldisc_deref(ld
);
1252 ssize_t
redirected_tty_write(struct file
*file
, const char __user
*buf
,
1253 size_t count
, loff_t
*ppos
)
1255 struct file
*p
= NULL
;
1257 spin_lock(&redirect_lock
);
1259 p
= get_file(redirect
);
1260 spin_unlock(&redirect_lock
);
1264 res
= vfs_write(p
, buf
, count
, &p
->f_pos
);
1268 return tty_write(file
, buf
, count
, ppos
);
1272 * tty_send_xchar - send priority character
1274 * Send a high priority character to the tty even if stopped
1276 * Locking: none for xchar method, write ordering for write method.
1279 int tty_send_xchar(struct tty_struct
*tty
, char ch
)
1281 int was_stopped
= tty
->stopped
;
1283 if (tty
->ops
->send_xchar
) {
1284 tty
->ops
->send_xchar(tty
, ch
);
1288 if (tty_write_lock(tty
, 0) < 0)
1289 return -ERESTARTSYS
;
1293 tty
->ops
->write(tty
, &ch
, 1);
1296 tty_write_unlock(tty
);
1300 static char ptychar
[] = "pqrstuvwxyzabcde";
1303 * pty_line_name - generate name for a pty
1304 * @driver: the tty driver in use
1305 * @index: the minor number
1306 * @p: output buffer of at least 6 bytes
1308 * Generate a name from a driver reference and write it to the output
1313 static void pty_line_name(struct tty_driver
*driver
, int index
, char *p
)
1315 int i
= index
+ driver
->name_base
;
1316 /* ->name is initialized to "ttyp", but "tty" is expected */
1317 sprintf(p
, "%s%c%x",
1318 driver
->subtype
== PTY_TYPE_SLAVE
? "tty" : driver
->name
,
1319 ptychar
[i
>> 4 & 0xf], i
& 0xf);
1323 * tty_line_name - generate name for a tty
1324 * @driver: the tty driver in use
1325 * @index: the minor number
1326 * @p: output buffer of at least 7 bytes
1328 * Generate a name from a driver reference and write it to the output
1333 static ssize_t
tty_line_name(struct tty_driver
*driver
, int index
, char *p
)
1335 if (driver
->flags
& TTY_DRIVER_UNNUMBERED_NODE
)
1336 return sprintf(p
, "%s", driver
->name
);
1338 return sprintf(p
, "%s%d", driver
->name
,
1339 index
+ driver
->name_base
);
1343 * tty_driver_lookup_tty() - find an existing tty, if any
1344 * @driver: the driver for the tty
1345 * @idx: the minor number
1347 * Return the tty, if found or ERR_PTR() otherwise.
1349 * Locking: tty_mutex must be held. If tty is found, the mutex must
1350 * be held until the 'fast-open' is also done. Will change once we
1351 * have refcounting in the driver and per driver locking
1353 static struct tty_struct
*tty_driver_lookup_tty(struct tty_driver
*driver
,
1354 struct inode
*inode
, int idx
)
1356 if (driver
->ops
->lookup
)
1357 return driver
->ops
->lookup(driver
, inode
, idx
);
1359 return driver
->ttys
[idx
];
1363 * tty_init_termios - helper for termios setup
1364 * @tty: the tty to set up
1366 * Initialise the termios structures for this tty. Thus runs under
1367 * the tty_mutex currently so we can be relaxed about ordering.
1370 int tty_init_termios(struct tty_struct
*tty
)
1372 struct ktermios
*tp
;
1373 int idx
= tty
->index
;
1375 if (tty
->driver
->flags
& TTY_DRIVER_RESET_TERMIOS
)
1376 tty
->termios
= tty
->driver
->init_termios
;
1378 /* Check for lazy saved data */
1379 tp
= tty
->driver
->termios
[idx
];
1383 tty
->termios
= tty
->driver
->init_termios
;
1385 /* Compatibility until drivers always set this */
1386 tty
->termios
.c_ispeed
= tty_termios_input_baud_rate(&tty
->termios
);
1387 tty
->termios
.c_ospeed
= tty_termios_baud_rate(&tty
->termios
);
1390 EXPORT_SYMBOL_GPL(tty_init_termios
);
1392 int tty_standard_install(struct tty_driver
*driver
, struct tty_struct
*tty
)
1394 int ret
= tty_init_termios(tty
);
1398 tty_driver_kref_get(driver
);
1400 driver
->ttys
[tty
->index
] = tty
;
1403 EXPORT_SYMBOL_GPL(tty_standard_install
);
1406 * tty_driver_install_tty() - install a tty entry in the driver
1407 * @driver: the driver for the tty
1410 * Install a tty object into the driver tables. The tty->index field
1411 * will be set by the time this is called. This method is responsible
1412 * for ensuring any need additional structures are allocated and
1415 * Locking: tty_mutex for now
1417 static int tty_driver_install_tty(struct tty_driver
*driver
,
1418 struct tty_struct
*tty
)
1420 return driver
->ops
->install
? driver
->ops
->install(driver
, tty
) :
1421 tty_standard_install(driver
, tty
);
1425 * tty_driver_remove_tty() - remove a tty from the driver tables
1426 * @driver: the driver for the tty
1427 * @idx: the minor number
1429 * Remvoe a tty object from the driver tables. The tty->index field
1430 * will be set by the time this is called.
1432 * Locking: tty_mutex for now
1434 void tty_driver_remove_tty(struct tty_driver
*driver
, struct tty_struct
*tty
)
1436 if (driver
->ops
->remove
)
1437 driver
->ops
->remove(driver
, tty
);
1439 driver
->ttys
[tty
->index
] = NULL
;
1443 * tty_reopen() - fast re-open of an open tty
1444 * @tty - the tty to open
1446 * Return 0 on success, -errno on error.
1447 * Re-opens on master ptys are not allowed and return -EIO.
1449 * Locking: Caller must hold tty_lock
1451 static int tty_reopen(struct tty_struct
*tty
)
1453 struct tty_driver
*driver
= tty
->driver
;
1458 if (driver
->type
== TTY_DRIVER_TYPE_PTY
&&
1459 driver
->subtype
== PTY_TYPE_MASTER
)
1464 WARN_ON(!tty
->ldisc
);
1470 * tty_init_dev - initialise a tty device
1471 * @driver: tty driver we are opening a device on
1472 * @idx: device index
1473 * @ret_tty: returned tty structure
1475 * Prepare a tty device. This may not be a "new" clean device but
1476 * could also be an active device. The pty drivers require special
1477 * handling because of this.
1480 * The function is called under the tty_mutex, which
1481 * protects us from the tty struct or driver itself going away.
1483 * On exit the tty device has the line discipline attached and
1484 * a reference count of 1. If a pair was created for pty/tty use
1485 * and the other was a pty master then it too has a reference count of 1.
1487 * WSH 06/09/97: Rewritten to remove races and properly clean up after a
1488 * failed open. The new code protects the open with a mutex, so it's
1489 * really quite straightforward. The mutex locking can probably be
1490 * relaxed for the (most common) case of reopening a tty.
1493 struct tty_struct
*tty_init_dev(struct tty_driver
*driver
, int idx
)
1495 struct tty_struct
*tty
;
1499 * First time open is complex, especially for PTY devices.
1500 * This code guarantees that either everything succeeds and the
1501 * TTY is ready for operation, or else the table slots are vacated
1502 * and the allocated memory released. (Except that the termios
1503 * and locked termios may be retained.)
1506 if (!try_module_get(driver
->owner
))
1507 return ERR_PTR(-ENODEV
);
1509 tty
= alloc_tty_struct(driver
, idx
);
1512 goto err_module_put
;
1516 retval
= tty_driver_install_tty(driver
, tty
);
1518 goto err_deinit_tty
;
1521 tty
->port
= driver
->ports
[idx
];
1523 WARN_RATELIMIT(!tty
->port
,
1524 "%s: %s driver does not set tty->port. This will crash the kernel later. Fix the driver!\n",
1525 __func__
, tty
->driver
->name
);
1527 tty
->port
->itty
= tty
;
1530 * Structures all installed ... call the ldisc open routines.
1531 * If we fail here just call release_tty to clean up. No need
1532 * to decrement the use counts, as release_tty doesn't care.
1534 retval
= tty_ldisc_setup(tty
, tty
->link
);
1536 goto err_release_tty
;
1537 /* Return the tty locked so that it cannot vanish under the caller */
1542 deinitialize_tty_struct(tty
);
1543 free_tty_struct(tty
);
1545 module_put(driver
->owner
);
1546 return ERR_PTR(retval
);
1548 /* call the tty release_tty routine to clean out this slot */
1551 printk_ratelimited(KERN_INFO
"tty_init_dev: ldisc open failed, "
1552 "clearing slot %d\n", idx
);
1553 release_tty(tty
, idx
);
1554 return ERR_PTR(retval
);
1557 void tty_free_termios(struct tty_struct
*tty
)
1559 struct ktermios
*tp
;
1560 int idx
= tty
->index
;
1562 /* If the port is going to reset then it has no termios to save */
1563 if (tty
->driver
->flags
& TTY_DRIVER_RESET_TERMIOS
)
1566 /* Stash the termios data */
1567 tp
= tty
->driver
->termios
[idx
];
1569 tp
= kmalloc(sizeof(struct ktermios
), GFP_KERNEL
);
1571 pr_warn("tty: no memory to save termios state.\n");
1574 tty
->driver
->termios
[idx
] = tp
;
1578 EXPORT_SYMBOL(tty_free_termios
);
1581 * tty_flush_works - flush all works of a tty
1582 * @tty: tty device to flush works for
1584 * Sync flush all works belonging to @tty.
1586 static void tty_flush_works(struct tty_struct
*tty
)
1588 flush_work(&tty
->SAK_work
);
1589 flush_work(&tty
->hangup_work
);
1593 * release_one_tty - release tty structure memory
1594 * @kref: kref of tty we are obliterating
1596 * Releases memory associated with a tty structure, and clears out the
1597 * driver table slots. This function is called when a device is no longer
1598 * in use. It also gets called when setup of a device fails.
1601 * takes the file list lock internally when working on the list
1602 * of ttys that the driver keeps.
1604 * This method gets called from a work queue so that the driver private
1605 * cleanup ops can sleep (needed for USB at least)
1607 static void release_one_tty(struct work_struct
*work
)
1609 struct tty_struct
*tty
=
1610 container_of(work
, struct tty_struct
, hangup_work
);
1611 struct tty_driver
*driver
= tty
->driver
;
1612 struct module
*owner
= driver
->owner
;
1614 if (tty
->ops
->cleanup
)
1615 tty
->ops
->cleanup(tty
);
1618 tty_driver_kref_put(driver
);
1621 spin_lock(&tty_files_lock
);
1622 list_del_init(&tty
->tty_files
);
1623 spin_unlock(&tty_files_lock
);
1626 put_pid(tty
->session
);
1627 free_tty_struct(tty
);
1630 static void queue_release_one_tty(struct kref
*kref
)
1632 struct tty_struct
*tty
= container_of(kref
, struct tty_struct
, kref
);
1634 /* The hangup queue is now free so we can reuse it rather than
1635 waste a chunk of memory for each port */
1636 INIT_WORK(&tty
->hangup_work
, release_one_tty
);
1637 schedule_work(&tty
->hangup_work
);
1641 * tty_kref_put - release a tty kref
1644 * Release a reference to a tty device and if need be let the kref
1645 * layer destruct the object for us
1648 void tty_kref_put(struct tty_struct
*tty
)
1651 kref_put(&tty
->kref
, queue_release_one_tty
);
1653 EXPORT_SYMBOL(tty_kref_put
);
1656 * release_tty - release tty structure memory
1658 * Release both @tty and a possible linked partner (think pty pair),
1659 * and decrement the refcount of the backing module.
1663 * takes the file list lock internally when working on the list
1664 * of ttys that the driver keeps.
1667 static void release_tty(struct tty_struct
*tty
, int idx
)
1669 /* This should always be true but check for the moment */
1670 WARN_ON(tty
->index
!= idx
);
1671 WARN_ON(!mutex_is_locked(&tty_mutex
));
1672 if (tty
->ops
->shutdown
)
1673 tty
->ops
->shutdown(tty
);
1674 tty_free_termios(tty
);
1675 tty_driver_remove_tty(tty
->driver
, tty
);
1676 tty
->port
->itty
= NULL
;
1678 tty
->link
->port
->itty
= NULL
;
1679 cancel_work_sync(&tty
->port
->buf
.work
);
1682 tty_kref_put(tty
->link
);
1687 * tty_release_checks - check a tty before real release
1688 * @tty: tty to check
1689 * @o_tty: link of @tty (if any)
1690 * @idx: index of the tty
1692 * Performs some paranoid checking before true release of the @tty.
1693 * This is a no-op unless TTY_PARANOIA_CHECK is defined.
1695 static int tty_release_checks(struct tty_struct
*tty
, struct tty_struct
*o_tty
,
1698 #ifdef TTY_PARANOIA_CHECK
1699 if (idx
< 0 || idx
>= tty
->driver
->num
) {
1700 printk(KERN_DEBUG
"%s: bad idx when trying to free (%s)\n",
1701 __func__
, tty
->name
);
1705 /* not much to check for devpts */
1706 if (tty
->driver
->flags
& TTY_DRIVER_DEVPTS_MEM
)
1709 if (tty
!= tty
->driver
->ttys
[idx
]) {
1710 printk(KERN_DEBUG
"%s: driver.table[%d] not tty for (%s)\n",
1711 __func__
, idx
, tty
->name
);
1714 if (tty
->driver
->other
) {
1715 if (o_tty
!= tty
->driver
->other
->ttys
[idx
]) {
1716 printk(KERN_DEBUG
"%s: other->table[%d] not o_tty for (%s)\n",
1717 __func__
, idx
, tty
->name
);
1720 if (o_tty
->link
!= tty
) {
1721 printk(KERN_DEBUG
"%s: bad pty pointers\n", __func__
);
1730 * tty_release - vfs callback for close
1731 * @inode: inode of tty
1732 * @filp: file pointer for handle to tty
1734 * Called the last time each file handle is closed that references
1735 * this tty. There may however be several such references.
1738 * Takes bkl. See tty_release_dev
1740 * Even releasing the tty structures is a tricky business.. We have
1741 * to be very careful that the structures are all released at the
1742 * same time, as interrupts might otherwise get the wrong pointers.
1744 * WSH 09/09/97: rewritten to avoid some nasty race conditions that could
1745 * lead to double frees or releasing memory still in use.
1748 int tty_release(struct inode
*inode
, struct file
*filp
)
1750 struct tty_struct
*tty
= file_tty(filp
);
1751 struct tty_struct
*o_tty
;
1752 int pty_master
, tty_closing
, o_tty_closing
, do_sleep
;
1756 if (tty_paranoia_check(tty
, inode
, __func__
))
1760 check_tty_count(tty
, __func__
);
1762 __tty_fasync(-1, filp
, 0);
1765 pty_master
= (tty
->driver
->type
== TTY_DRIVER_TYPE_PTY
&&
1766 tty
->driver
->subtype
== PTY_TYPE_MASTER
);
1767 /* Review: parallel close */
1770 if (tty_release_checks(tty
, o_tty
, idx
)) {
1775 #ifdef TTY_DEBUG_HANGUP
1776 printk(KERN_DEBUG
"%s: %s (tty count=%d)...\n", __func__
,
1777 tty_name(tty
, buf
), tty
->count
);
1780 if (tty
->ops
->close
)
1781 tty
->ops
->close(tty
, filp
);
1785 * Sanity check: if tty->count is going to zero, there shouldn't be
1786 * any waiters on tty->read_wait or tty->write_wait. We test the
1787 * wait queues and kick everyone out _before_ actually starting to
1788 * close. This ensures that we won't block while releasing the tty
1791 * The test for the o_tty closing is necessary, since the master and
1792 * slave sides may close in any order. If the slave side closes out
1793 * first, its count will be one, since the master side holds an open.
1794 * Thus this test wouldn't be triggered at the time the slave closes,
1797 * Note that it's possible for the tty to be opened again while we're
1798 * flushing out waiters. By recalculating the closing flags before
1799 * each iteration we avoid any problems.
1802 /* Guard against races with tty->count changes elsewhere and
1803 opens on /dev/tty */
1805 mutex_lock(&tty_mutex
);
1806 tty_lock_pair(tty
, o_tty
);
1807 tty_closing
= tty
->count
<= 1;
1808 o_tty_closing
= o_tty
&&
1809 (o_tty
->count
<= (pty_master
? 1 : 0));
1813 if (waitqueue_active(&tty
->read_wait
)) {
1814 wake_up_poll(&tty
->read_wait
, POLLIN
);
1817 if (waitqueue_active(&tty
->write_wait
)) {
1818 wake_up_poll(&tty
->write_wait
, POLLOUT
);
1822 if (o_tty_closing
) {
1823 if (waitqueue_active(&o_tty
->read_wait
)) {
1824 wake_up_poll(&o_tty
->read_wait
, POLLIN
);
1827 if (waitqueue_active(&o_tty
->write_wait
)) {
1828 wake_up_poll(&o_tty
->write_wait
, POLLOUT
);
1835 printk(KERN_WARNING
"%s: %s: read/write wait queue active!\n",
1836 __func__
, tty_name(tty
, buf
));
1837 tty_unlock_pair(tty
, o_tty
);
1838 mutex_unlock(&tty_mutex
);
1843 * The closing flags are now consistent with the open counts on
1844 * both sides, and we've completed the last operation that could
1845 * block, so it's safe to proceed with closing.
1847 * We must *not* drop the tty_mutex until we ensure that a further
1848 * entry into tty_open can not pick up this tty.
1851 if (--o_tty
->count
< 0) {
1852 printk(KERN_WARNING
"%s: bad pty slave count (%d) for %s\n",
1853 __func__
, o_tty
->count
, tty_name(o_tty
, buf
));
1857 if (--tty
->count
< 0) {
1858 printk(KERN_WARNING
"%s: bad tty->count (%d) for %s\n",
1859 __func__
, tty
->count
, tty_name(tty
, buf
));
1864 * We've decremented tty->count, so we need to remove this file
1865 * descriptor off the tty->tty_files list; this serves two
1867 * - check_tty_count sees the correct number of file descriptors
1868 * associated with this tty.
1869 * - do_tty_hangup no longer sees this file descriptor as
1870 * something that needs to be handled for hangups.
1875 * Perform some housekeeping before deciding whether to return.
1877 * Set the TTY_CLOSING flag if this was the last open. In the
1878 * case of a pty we may have to wait around for the other side
1879 * to close, and TTY_CLOSING makes sure we can't be reopened.
1882 set_bit(TTY_CLOSING
, &tty
->flags
);
1884 set_bit(TTY_CLOSING
, &o_tty
->flags
);
1887 * If _either_ side is closing, make sure there aren't any
1888 * processes that still think tty or o_tty is their controlling
1891 if (tty_closing
|| o_tty_closing
) {
1892 read_lock(&tasklist_lock
);
1893 session_clear_tty(tty
->session
);
1895 session_clear_tty(o_tty
->session
);
1896 read_unlock(&tasklist_lock
);
1899 mutex_unlock(&tty_mutex
);
1900 tty_unlock_pair(tty
, o_tty
);
1901 /* At this point the TTY_CLOSING flag should ensure a dead tty
1902 cannot be re-opened by a racing opener */
1904 /* check whether both sides are closing ... */
1905 if (!tty_closing
|| (o_tty
&& !o_tty_closing
))
1908 #ifdef TTY_DEBUG_HANGUP
1909 printk(KERN_DEBUG
"%s: %s: final close\n", __func__
, tty_name(tty
, buf
));
1912 * Ask the line discipline code to release its structures
1914 tty_ldisc_release(tty
, o_tty
);
1916 /* Wait for pending work before tty destruction commmences */
1917 tty_flush_works(tty
);
1919 tty_flush_works(o_tty
);
1921 #ifdef TTY_DEBUG_HANGUP
1922 printk(KERN_DEBUG
"%s: %s: freeing structure...\n", __func__
, tty_name(tty
, buf
));
1925 * The release_tty function takes care of the details of clearing
1926 * the slots and preserving the termios structure. The tty_unlock_pair
1927 * should be safe as we keep a kref while the tty is locked (so the
1928 * unlock never unlocks a freed tty).
1930 mutex_lock(&tty_mutex
);
1931 release_tty(tty
, idx
);
1932 mutex_unlock(&tty_mutex
);
1938 * tty_open_current_tty - get locked tty of current task
1939 * @device: device number
1940 * @filp: file pointer to tty
1941 * @return: locked tty of the current task iff @device is /dev/tty
1943 * Performs a re-open of the current task's controlling tty.
1945 * We cannot return driver and index like for the other nodes because
1946 * devpts will not work then. It expects inodes to be from devpts FS.
1948 static struct tty_struct
*tty_open_current_tty(dev_t device
, struct file
*filp
)
1950 struct tty_struct
*tty
;
1953 if (device
!= MKDEV(TTYAUX_MAJOR
, 0))
1956 tty
= get_current_tty();
1958 return ERR_PTR(-ENXIO
);
1960 filp
->f_flags
|= O_NONBLOCK
; /* Don't let /dev/tty block */
1963 tty_kref_put(tty
); /* safe to drop the kref now */
1965 retval
= tty_reopen(tty
);
1968 tty
= ERR_PTR(retval
);
1974 * tty_lookup_driver - lookup a tty driver for a given device file
1975 * @device: device number
1976 * @filp: file pointer to tty
1977 * @noctty: set if the device should not become a controlling tty
1978 * @index: index for the device in the @return driver
1979 * @return: driver for this inode (with increased refcount)
1981 * If @return is not erroneous, the caller is responsible to decrement the
1982 * refcount by tty_driver_kref_put.
1984 * Locking: tty_mutex protects get_tty_driver
1986 static struct tty_driver
*tty_lookup_driver(dev_t device
, struct file
*filp
,
1987 int *noctty
, int *index
)
1989 struct tty_driver
*driver
;
1993 case MKDEV(TTY_MAJOR
, 0): {
1994 extern struct tty_driver
*console_driver
;
1995 driver
= tty_driver_kref_get(console_driver
);
1996 *index
= fg_console
;
2001 case MKDEV(TTYAUX_MAJOR
, 1): {
2002 struct tty_driver
*console_driver
= console_device(index
);
2003 if (console_driver
) {
2004 driver
= tty_driver_kref_get(console_driver
);
2006 /* Don't let /dev/console block */
2007 filp
->f_flags
|= O_NONBLOCK
;
2012 return ERR_PTR(-ENODEV
);
2015 driver
= get_tty_driver(device
, index
);
2017 return ERR_PTR(-ENODEV
);
2024 * tty_open - open a tty device
2025 * @inode: inode of device file
2026 * @filp: file pointer to tty
2028 * tty_open and tty_release keep up the tty count that contains the
2029 * number of opens done on a tty. We cannot use the inode-count, as
2030 * different inodes might point to the same tty.
2032 * Open-counting is needed for pty masters, as well as for keeping
2033 * track of serial lines: DTR is dropped when the last close happens.
2034 * (This is not done solely through tty->count, now. - Ted 1/27/92)
2036 * The termios state of a pty is reset on first open so that
2037 * settings don't persist across reuse.
2039 * Locking: tty_mutex protects tty, tty_lookup_driver and tty_init_dev.
2040 * tty->count should protect the rest.
2041 * ->siglock protects ->signal/->sighand
2043 * Note: the tty_unlock/lock cases without a ref are only safe due to
2047 static int tty_open(struct inode
*inode
, struct file
*filp
)
2049 struct tty_struct
*tty
;
2051 struct tty_driver
*driver
= NULL
;
2053 dev_t device
= inode
->i_rdev
;
2054 unsigned saved_flags
= filp
->f_flags
;
2056 nonseekable_open(inode
, filp
);
2059 retval
= tty_alloc_file(filp
);
2063 noctty
= filp
->f_flags
& O_NOCTTY
;
2067 tty
= tty_open_current_tty(device
, filp
);
2069 mutex_lock(&tty_mutex
);
2070 driver
= tty_lookup_driver(device
, filp
, &noctty
, &index
);
2071 if (IS_ERR(driver
)) {
2072 retval
= PTR_ERR(driver
);
2076 /* check whether we're reopening an existing tty */
2077 tty
= tty_driver_lookup_tty(driver
, inode
, index
);
2079 retval
= PTR_ERR(tty
);
2085 retval
= tty_reopen(tty
);
2088 tty
= ERR_PTR(retval
);
2090 } else /* Returns with the tty_lock held for now */
2091 tty
= tty_init_dev(driver
, index
);
2093 mutex_unlock(&tty_mutex
);
2094 tty_driver_kref_put(driver
);
2098 retval
= PTR_ERR(tty
);
2102 tty_add_file(tty
, filp
);
2104 check_tty_count(tty
, __func__
);
2105 if (tty
->driver
->type
== TTY_DRIVER_TYPE_PTY
&&
2106 tty
->driver
->subtype
== PTY_TYPE_MASTER
)
2108 #ifdef TTY_DEBUG_HANGUP
2109 printk(KERN_DEBUG
"%s: opening %s...\n", __func__
, tty
->name
);
2112 retval
= tty
->ops
->open(tty
, filp
);
2115 filp
->f_flags
= saved_flags
;
2117 if (!retval
&& test_bit(TTY_EXCLUSIVE
, &tty
->flags
) &&
2118 !capable(CAP_SYS_ADMIN
))
2122 #ifdef TTY_DEBUG_HANGUP
2123 printk(KERN_DEBUG
"%s: error %d in opening %s...\n", __func__
,
2126 tty_unlock(tty
); /* need to call tty_release without BTM */
2127 tty_release(inode
, filp
);
2128 if (retval
!= -ERESTARTSYS
)
2131 if (signal_pending(current
))
2136 * Need to reset f_op in case a hangup happened.
2138 if (filp
->f_op
== &hung_up_tty_fops
)
2139 filp
->f_op
= &tty_fops
;
2142 clear_bit(TTY_HUPPED
, &tty
->flags
);
2145 read_lock(&tasklist_lock
);
2146 spin_lock_irq(¤t
->sighand
->siglock
);
2148 current
->signal
->leader
&&
2149 !current
->signal
->tty
&&
2150 tty
->session
== NULL
)
2151 __proc_set_tty(tty
);
2152 spin_unlock_irq(¤t
->sighand
->siglock
);
2153 read_unlock(&tasklist_lock
);
2157 mutex_unlock(&tty_mutex
);
2158 /* after locks to avoid deadlock */
2159 if (!IS_ERR_OR_NULL(driver
))
2160 tty_driver_kref_put(driver
);
2162 tty_free_file(filp
);
2169 * tty_poll - check tty status
2170 * @filp: file being polled
2171 * @wait: poll wait structures to update
2173 * Call the line discipline polling method to obtain the poll
2174 * status of the device.
2176 * Locking: locks called line discipline but ldisc poll method
2177 * may be re-entered freely by other callers.
2180 static unsigned int tty_poll(struct file
*filp
, poll_table
*wait
)
2182 struct tty_struct
*tty
= file_tty(filp
);
2183 struct tty_ldisc
*ld
;
2186 if (tty_paranoia_check(tty
, file_inode(filp
), "tty_poll"))
2189 ld
= tty_ldisc_ref_wait(tty
);
2191 ret
= (ld
->ops
->poll
)(tty
, filp
, wait
);
2192 tty_ldisc_deref(ld
);
2196 static int __tty_fasync(int fd
, struct file
*filp
, int on
)
2198 struct tty_struct
*tty
= file_tty(filp
);
2199 struct tty_ldisc
*ldisc
;
2200 unsigned long flags
;
2203 if (tty_paranoia_check(tty
, file_inode(filp
), "tty_fasync"))
2206 retval
= fasync_helper(fd
, filp
, on
, &tty
->fasync
);
2210 ldisc
= tty_ldisc_ref(tty
);
2212 if (ldisc
->ops
->fasync
)
2213 ldisc
->ops
->fasync(tty
, on
);
2214 tty_ldisc_deref(ldisc
);
2221 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
2224 type
= PIDTYPE_PGID
;
2226 pid
= task_pid(current
);
2230 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
2231 __f_setown(filp
, pid
, type
, 0);
2239 static int tty_fasync(int fd
, struct file
*filp
, int on
)
2241 struct tty_struct
*tty
= file_tty(filp
);
2245 retval
= __tty_fasync(fd
, filp
, on
);
2252 * tiocsti - fake input character
2253 * @tty: tty to fake input into
2254 * @p: pointer to character
2256 * Fake input to a tty device. Does the necessary locking and
2259 * FIXME: does not honour flow control ??
2262 * Called functions take tty_ldiscs_lock
2263 * current->signal->tty check is safe without locks
2265 * FIXME: may race normal receive processing
2268 static int tiocsti(struct tty_struct
*tty
, char __user
*p
)
2271 struct tty_ldisc
*ld
;
2273 if ((current
->signal
->tty
!= tty
) && !capable(CAP_SYS_ADMIN
))
2275 if (get_user(ch
, p
))
2277 tty_audit_tiocsti(tty
, ch
);
2278 ld
= tty_ldisc_ref_wait(tty
);
2279 ld
->ops
->receive_buf(tty
, &ch
, &mbz
, 1);
2280 tty_ldisc_deref(ld
);
2285 * tiocgwinsz - implement window query ioctl
2287 * @arg: user buffer for result
2289 * Copies the kernel idea of the window size into the user buffer.
2291 * Locking: tty->winsize_mutex is taken to ensure the winsize data
2295 static int tiocgwinsz(struct tty_struct
*tty
, struct winsize __user
*arg
)
2299 mutex_lock(&tty
->winsize_mutex
);
2300 err
= copy_to_user(arg
, &tty
->winsize
, sizeof(*arg
));
2301 mutex_unlock(&tty
->winsize_mutex
);
2303 return err
? -EFAULT
: 0;
2307 * tty_do_resize - resize event
2308 * @tty: tty being resized
2309 * @rows: rows (character)
2310 * @cols: cols (character)
2312 * Update the termios variables and send the necessary signals to
2313 * peform a terminal resize correctly
2316 int tty_do_resize(struct tty_struct
*tty
, struct winsize
*ws
)
2321 mutex_lock(&tty
->winsize_mutex
);
2322 if (!memcmp(ws
, &tty
->winsize
, sizeof(*ws
)))
2325 /* Signal the foreground process group */
2326 pgrp
= tty_get_pgrp(tty
);
2328 kill_pgrp(pgrp
, SIGWINCH
, 1);
2333 mutex_unlock(&tty
->winsize_mutex
);
2336 EXPORT_SYMBOL(tty_do_resize
);
2339 * tiocswinsz - implement window size set ioctl
2340 * @tty; tty side of tty
2341 * @arg: user buffer for result
2343 * Copies the user idea of the window size to the kernel. Traditionally
2344 * this is just advisory information but for the Linux console it
2345 * actually has driver level meaning and triggers a VC resize.
2348 * Driver dependent. The default do_resize method takes the
2349 * tty termios mutex and ctrl_lock. The console takes its own lock
2350 * then calls into the default method.
2353 static int tiocswinsz(struct tty_struct
*tty
, struct winsize __user
*arg
)
2355 struct winsize tmp_ws
;
2356 if (copy_from_user(&tmp_ws
, arg
, sizeof(*arg
)))
2359 if (tty
->ops
->resize
)
2360 return tty
->ops
->resize(tty
, &tmp_ws
);
2362 return tty_do_resize(tty
, &tmp_ws
);
2366 * tioccons - allow admin to move logical console
2367 * @file: the file to become console
2369 * Allow the administrator to move the redirected console device
2371 * Locking: uses redirect_lock to guard the redirect information
2374 static int tioccons(struct file
*file
)
2376 if (!capable(CAP_SYS_ADMIN
))
2378 if (file
->f_op
->write
== redirected_tty_write
) {
2380 spin_lock(&redirect_lock
);
2383 spin_unlock(&redirect_lock
);
2388 spin_lock(&redirect_lock
);
2390 spin_unlock(&redirect_lock
);
2393 redirect
= get_file(file
);
2394 spin_unlock(&redirect_lock
);
2399 * fionbio - non blocking ioctl
2400 * @file: file to set blocking value
2401 * @p: user parameter
2403 * Historical tty interfaces had a blocking control ioctl before
2404 * the generic functionality existed. This piece of history is preserved
2405 * in the expected tty API of posix OS's.
2407 * Locking: none, the open file handle ensures it won't go away.
2410 static int fionbio(struct file
*file
, int __user
*p
)
2414 if (get_user(nonblock
, p
))
2417 spin_lock(&file
->f_lock
);
2419 file
->f_flags
|= O_NONBLOCK
;
2421 file
->f_flags
&= ~O_NONBLOCK
;
2422 spin_unlock(&file
->f_lock
);
2427 * tiocsctty - set controlling tty
2428 * @tty: tty structure
2429 * @arg: user argument
2431 * This ioctl is used to manage job control. It permits a session
2432 * leader to set this tty as the controlling tty for the session.
2435 * Takes tty_lock() to serialize proc_set_tty() for this tty
2436 * Takes tasklist_lock internally to walk sessions
2437 * Takes ->siglock() when updating signal->tty
2440 static int tiocsctty(struct tty_struct
*tty
, int arg
)
2445 read_lock(&tasklist_lock
);
2447 if (current
->signal
->leader
&& (task_session(current
) == tty
->session
))
2451 * The process must be a session leader and
2452 * not have a controlling tty already.
2454 if (!current
->signal
->leader
|| current
->signal
->tty
) {
2461 * This tty is already the controlling
2462 * tty for another session group!
2464 if (arg
== 1 && capable(CAP_SYS_ADMIN
)) {
2468 session_clear_tty(tty
->session
);
2476 read_unlock(&tasklist_lock
);
2482 * tty_get_pgrp - return a ref counted pgrp pid
2485 * Returns a refcounted instance of the pid struct for the process
2486 * group controlling the tty.
2489 struct pid
*tty_get_pgrp(struct tty_struct
*tty
)
2491 unsigned long flags
;
2494 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
2495 pgrp
= get_pid(tty
->pgrp
);
2496 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
2500 EXPORT_SYMBOL_GPL(tty_get_pgrp
);
2503 * This checks not only the pgrp, but falls back on the pid if no
2504 * satisfactory pgrp is found. I dunno - gdb doesn't work correctly
2507 * The caller must hold rcu lock or the tasklist lock.
2509 static struct pid
*session_of_pgrp(struct pid
*pgrp
)
2511 struct task_struct
*p
;
2512 struct pid
*sid
= NULL
;
2514 p
= pid_task(pgrp
, PIDTYPE_PGID
);
2516 p
= pid_task(pgrp
, PIDTYPE_PID
);
2518 sid
= task_session(p
);
2524 * tiocgpgrp - get process group
2525 * @tty: tty passed by user
2526 * @real_tty: tty side of the tty passed by the user if a pty else the tty
2529 * Obtain the process group of the tty. If there is no process group
2532 * Locking: none. Reference to current->signal->tty is safe.
2535 static int tiocgpgrp(struct tty_struct
*tty
, struct tty_struct
*real_tty
, pid_t __user
*p
)
2540 * (tty == real_tty) is a cheap way of
2541 * testing if the tty is NOT a master pty.
2543 if (tty
== real_tty
&& current
->signal
->tty
!= real_tty
)
2545 pid
= tty_get_pgrp(real_tty
);
2546 ret
= put_user(pid_vnr(pid
), p
);
2552 * tiocspgrp - attempt to set process group
2553 * @tty: tty passed by user
2554 * @real_tty: tty side device matching tty passed by user
2557 * Set the process group of the tty to the session passed. Only
2558 * permitted where the tty session is our session.
2560 * Locking: RCU, ctrl lock
2563 static int tiocspgrp(struct tty_struct
*tty
, struct tty_struct
*real_tty
, pid_t __user
*p
)
2567 int retval
= tty_check_change(real_tty
);
2568 unsigned long flags
;
2574 if (!current
->signal
->tty
||
2575 (current
->signal
->tty
!= real_tty
) ||
2576 (real_tty
->session
!= task_session(current
)))
2578 if (get_user(pgrp_nr
, p
))
2583 pgrp
= find_vpid(pgrp_nr
);
2588 if (session_of_pgrp(pgrp
) != task_session(current
))
2591 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
2592 put_pid(real_tty
->pgrp
);
2593 real_tty
->pgrp
= get_pid(pgrp
);
2594 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
2601 * tiocgsid - get session id
2602 * @tty: tty passed by user
2603 * @real_tty: tty side of the tty passed by the user if a pty else the tty
2604 * @p: pointer to returned session id
2606 * Obtain the session id of the tty. If there is no session
2609 * Locking: none. Reference to current->signal->tty is safe.
2612 static int tiocgsid(struct tty_struct
*tty
, struct tty_struct
*real_tty
, pid_t __user
*p
)
2615 * (tty == real_tty) is a cheap way of
2616 * testing if the tty is NOT a master pty.
2618 if (tty
== real_tty
&& current
->signal
->tty
!= real_tty
)
2620 if (!real_tty
->session
)
2622 return put_user(pid_vnr(real_tty
->session
), p
);
2626 * tiocsetd - set line discipline
2628 * @p: pointer to user data
2630 * Set the line discipline according to user request.
2632 * Locking: see tty_set_ldisc, this function is just a helper
2635 static int tiocsetd(struct tty_struct
*tty
, int __user
*p
)
2640 if (get_user(ldisc
, p
))
2643 ret
= tty_set_ldisc(tty
, ldisc
);
2649 * send_break - performed time break
2650 * @tty: device to break on
2651 * @duration: timeout in mS
2653 * Perform a timed break on hardware that lacks its own driver level
2654 * timed break functionality.
2657 * atomic_write_lock serializes
2661 static int send_break(struct tty_struct
*tty
, unsigned int duration
)
2665 if (tty
->ops
->break_ctl
== NULL
)
2668 if (tty
->driver
->flags
& TTY_DRIVER_HARDWARE_BREAK
)
2669 retval
= tty
->ops
->break_ctl(tty
, duration
);
2671 /* Do the work ourselves */
2672 if (tty_write_lock(tty
, 0) < 0)
2674 retval
= tty
->ops
->break_ctl(tty
, -1);
2677 if (!signal_pending(current
))
2678 msleep_interruptible(duration
);
2679 retval
= tty
->ops
->break_ctl(tty
, 0);
2681 tty_write_unlock(tty
);
2682 if (signal_pending(current
))
2689 * tty_tiocmget - get modem status
2691 * @file: user file pointer
2692 * @p: pointer to result
2694 * Obtain the modem status bits from the tty driver if the feature
2695 * is supported. Return -EINVAL if it is not available.
2697 * Locking: none (up to the driver)
2700 static int tty_tiocmget(struct tty_struct
*tty
, int __user
*p
)
2702 int retval
= -EINVAL
;
2704 if (tty
->ops
->tiocmget
) {
2705 retval
= tty
->ops
->tiocmget(tty
);
2708 retval
= put_user(retval
, p
);
2714 * tty_tiocmset - set modem status
2716 * @cmd: command - clear bits, set bits or set all
2717 * @p: pointer to desired bits
2719 * Set the modem status bits from the tty driver if the feature
2720 * is supported. Return -EINVAL if it is not available.
2722 * Locking: none (up to the driver)
2725 static int tty_tiocmset(struct tty_struct
*tty
, unsigned int cmd
,
2729 unsigned int set
, clear
, val
;
2731 if (tty
->ops
->tiocmset
== NULL
)
2734 retval
= get_user(val
, p
);
2750 set
&= TIOCM_DTR
|TIOCM_RTS
|TIOCM_OUT1
|TIOCM_OUT2
|TIOCM_LOOP
;
2751 clear
&= TIOCM_DTR
|TIOCM_RTS
|TIOCM_OUT1
|TIOCM_OUT2
|TIOCM_LOOP
;
2752 return tty
->ops
->tiocmset(tty
, set
, clear
);
2755 static int tty_tiocgicount(struct tty_struct
*tty
, void __user
*arg
)
2757 int retval
= -EINVAL
;
2758 struct serial_icounter_struct icount
;
2759 memset(&icount
, 0, sizeof(icount
));
2760 if (tty
->ops
->get_icount
)
2761 retval
= tty
->ops
->get_icount(tty
, &icount
);
2764 if (copy_to_user(arg
, &icount
, sizeof(icount
)))
2770 * if pty, return the slave side (real_tty)
2771 * otherwise, return self
2773 static struct tty_struct
*tty_pair_get_tty(struct tty_struct
*tty
)
2775 if (tty
->driver
->type
== TTY_DRIVER_TYPE_PTY
&&
2776 tty
->driver
->subtype
== PTY_TYPE_MASTER
)
2782 * Split this up, as gcc can choke on it otherwise..
2784 long tty_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
2786 struct tty_struct
*tty
= file_tty(file
);
2787 struct tty_struct
*real_tty
;
2788 void __user
*p
= (void __user
*)arg
;
2790 struct tty_ldisc
*ld
;
2792 if (tty_paranoia_check(tty
, file_inode(file
), "tty_ioctl"))
2795 real_tty
= tty_pair_get_tty(tty
);
2798 * Factor out some common prep work
2806 retval
= tty_check_change(tty
);
2809 if (cmd
!= TIOCCBRK
) {
2810 tty_wait_until_sent(tty
, 0);
2811 if (signal_pending(current
))
2822 return tiocsti(tty
, p
);
2824 return tiocgwinsz(real_tty
, p
);
2826 return tiocswinsz(real_tty
, p
);
2828 return real_tty
!= tty
? -EINVAL
: tioccons(file
);
2830 return fionbio(file
, p
);
2832 set_bit(TTY_EXCLUSIVE
, &tty
->flags
);
2835 clear_bit(TTY_EXCLUSIVE
, &tty
->flags
);
2839 int excl
= test_bit(TTY_EXCLUSIVE
, &tty
->flags
);
2840 return put_user(excl
, (int __user
*)p
);
2843 if (current
->signal
->tty
!= tty
)
2848 return tiocsctty(tty
, arg
);
2850 return tiocgpgrp(tty
, real_tty
, p
);
2852 return tiocspgrp(tty
, real_tty
, p
);
2854 return tiocgsid(tty
, real_tty
, p
);
2856 return put_user(tty
->ldisc
->ops
->num
, (int __user
*)p
);
2858 return tiocsetd(tty
, p
);
2860 if (!capable(CAP_SYS_ADMIN
))
2866 unsigned int ret
= new_encode_dev(tty_devnum(real_tty
));
2867 return put_user(ret
, (unsigned int __user
*)p
);
2872 case TIOCSBRK
: /* Turn break on, unconditionally */
2873 if (tty
->ops
->break_ctl
)
2874 return tty
->ops
->break_ctl(tty
, -1);
2876 case TIOCCBRK
: /* Turn break off, unconditionally */
2877 if (tty
->ops
->break_ctl
)
2878 return tty
->ops
->break_ctl(tty
, 0);
2880 case TCSBRK
: /* SVID version: non-zero arg --> no break */
2881 /* non-zero arg means wait for all output data
2882 * to be sent (performed above) but don't send break.
2883 * This is used by the tcdrain() termios function.
2886 return send_break(tty
, 250);
2888 case TCSBRKP
: /* support for POSIX tcsendbreak() */
2889 return send_break(tty
, arg
? arg
*100 : 250);
2892 return tty_tiocmget(tty
, p
);
2896 return tty_tiocmset(tty
, cmd
, p
);
2898 retval
= tty_tiocgicount(tty
, p
);
2899 /* For the moment allow fall through to the old method */
2900 if (retval
!= -EINVAL
)
2907 /* flush tty buffer and allow ldisc to process ioctl */
2908 tty_buffer_flush(tty
);
2913 if (tty
->ops
->ioctl
) {
2914 retval
= (tty
->ops
->ioctl
)(tty
, cmd
, arg
);
2915 if (retval
!= -ENOIOCTLCMD
)
2918 ld
= tty_ldisc_ref_wait(tty
);
2920 if (ld
->ops
->ioctl
) {
2921 retval
= ld
->ops
->ioctl(tty
, file
, cmd
, arg
);
2922 if (retval
== -ENOIOCTLCMD
)
2925 tty_ldisc_deref(ld
);
2929 #ifdef CONFIG_COMPAT
2930 static long tty_compat_ioctl(struct file
*file
, unsigned int cmd
,
2933 struct tty_struct
*tty
= file_tty(file
);
2934 struct tty_ldisc
*ld
;
2935 int retval
= -ENOIOCTLCMD
;
2937 if (tty_paranoia_check(tty
, file_inode(file
), "tty_ioctl"))
2940 if (tty
->ops
->compat_ioctl
) {
2941 retval
= (tty
->ops
->compat_ioctl
)(tty
, cmd
, arg
);
2942 if (retval
!= -ENOIOCTLCMD
)
2946 ld
= tty_ldisc_ref_wait(tty
);
2947 if (ld
->ops
->compat_ioctl
)
2948 retval
= ld
->ops
->compat_ioctl(tty
, file
, cmd
, arg
);
2950 retval
= n_tty_compat_ioctl_helper(tty
, file
, cmd
, arg
);
2951 tty_ldisc_deref(ld
);
2957 static int this_tty(const void *t
, struct file
*file
, unsigned fd
)
2959 if (likely(file
->f_op
->read
!= tty_read
))
2961 return file_tty(file
) != t
? 0 : fd
+ 1;
2965 * This implements the "Secure Attention Key" --- the idea is to
2966 * prevent trojan horses by killing all processes associated with this
2967 * tty when the user hits the "Secure Attention Key". Required for
2968 * super-paranoid applications --- see the Orange Book for more details.
2970 * This code could be nicer; ideally it should send a HUP, wait a few
2971 * seconds, then send a INT, and then a KILL signal. But you then
2972 * have to coordinate with the init process, since all processes associated
2973 * with the current tty must be dead before the new getty is allowed
2976 * Now, if it would be correct ;-/ The current code has a nasty hole -
2977 * it doesn't catch files in flight. We may send the descriptor to ourselves
2978 * via AF_UNIX socket, close it and later fetch from socket. FIXME.
2980 * Nasty bug: do_SAK is being called in interrupt context. This can
2981 * deadlock. We punt it up to process context. AKPM - 16Mar2001
2983 void __do_SAK(struct tty_struct
*tty
)
2988 struct task_struct
*g
, *p
;
2989 struct pid
*session
;
2994 session
= tty
->session
;
2996 tty_ldisc_flush(tty
);
2998 tty_driver_flush_buffer(tty
);
3000 read_lock(&tasklist_lock
);
3001 /* Kill the entire session */
3002 do_each_pid_task(session
, PIDTYPE_SID
, p
) {
3003 printk(KERN_NOTICE
"SAK: killed process %d"
3004 " (%s): task_session(p)==tty->session\n",
3005 task_pid_nr(p
), p
->comm
);
3006 send_sig(SIGKILL
, p
, 1);
3007 } while_each_pid_task(session
, PIDTYPE_SID
, p
);
3008 /* Now kill any processes that happen to have the
3011 do_each_thread(g
, p
) {
3012 if (p
->signal
->tty
== tty
) {
3013 printk(KERN_NOTICE
"SAK: killed process %d"
3014 " (%s): task_session(p)==tty->session\n",
3015 task_pid_nr(p
), p
->comm
);
3016 send_sig(SIGKILL
, p
, 1);
3020 i
= iterate_fd(p
->files
, 0, this_tty
, tty
);
3022 printk(KERN_NOTICE
"SAK: killed process %d"
3023 " (%s): fd#%d opened to the tty\n",
3024 task_pid_nr(p
), p
->comm
, i
- 1);
3025 force_sig(SIGKILL
, p
);
3028 } while_each_thread(g
, p
);
3029 read_unlock(&tasklist_lock
);
3033 static void do_SAK_work(struct work_struct
*work
)
3035 struct tty_struct
*tty
=
3036 container_of(work
, struct tty_struct
, SAK_work
);
3041 * The tq handling here is a little racy - tty->SAK_work may already be queued.
3042 * Fortunately we don't need to worry, because if ->SAK_work is already queued,
3043 * the values which we write to it will be identical to the values which it
3044 * already has. --akpm
3046 void do_SAK(struct tty_struct
*tty
)
3050 schedule_work(&tty
->SAK_work
);
3053 EXPORT_SYMBOL(do_SAK
);
3055 static int dev_match_devt(struct device
*dev
, const void *data
)
3057 const dev_t
*devt
= data
;
3058 return dev
->devt
== *devt
;
3061 /* Must put_device() after it's unused! */
3062 static struct device
*tty_get_device(struct tty_struct
*tty
)
3064 dev_t devt
= tty_devnum(tty
);
3065 return class_find_device(tty_class
, NULL
, &devt
, dev_match_devt
);
3072 * This subroutine allocates and initializes a tty structure.
3074 * Locking: none - tty in question is not exposed at this point
3077 struct tty_struct
*alloc_tty_struct(struct tty_driver
*driver
, int idx
)
3079 struct tty_struct
*tty
;
3081 tty
= kzalloc(sizeof(*tty
), GFP_KERNEL
);
3085 kref_init(&tty
->kref
);
3086 tty
->magic
= TTY_MAGIC
;
3087 tty_ldisc_init(tty
);
3088 tty
->session
= NULL
;
3090 mutex_init(&tty
->legacy_mutex
);
3091 mutex_init(&tty
->throttle_mutex
);
3092 init_rwsem(&tty
->termios_rwsem
);
3093 mutex_init(&tty
->winsize_mutex
);
3094 init_ldsem(&tty
->ldisc_sem
);
3095 init_waitqueue_head(&tty
->write_wait
);
3096 init_waitqueue_head(&tty
->read_wait
);
3097 INIT_WORK(&tty
->hangup_work
, do_tty_hangup
);
3098 mutex_init(&tty
->atomic_write_lock
);
3099 spin_lock_init(&tty
->ctrl_lock
);
3100 spin_lock_init(&tty
->flow_lock
);
3101 INIT_LIST_HEAD(&tty
->tty_files
);
3102 INIT_WORK(&tty
->SAK_work
, do_SAK_work
);
3104 tty
->driver
= driver
;
3105 tty
->ops
= driver
->ops
;
3107 tty_line_name(driver
, idx
, tty
->name
);
3108 tty
->dev
= tty_get_device(tty
);
3114 * deinitialize_tty_struct
3115 * @tty: tty to deinitialize
3117 * This subroutine deinitializes a tty structure that has been newly
3118 * allocated but tty_release cannot be called on that yet.
3120 * Locking: none - tty in question must not be exposed at this point
3122 void deinitialize_tty_struct(struct tty_struct
*tty
)
3124 tty_ldisc_deinit(tty
);
3128 * tty_put_char - write one character to a tty
3132 * Write one byte to the tty using the provided put_char method
3133 * if present. Returns the number of characters successfully output.
3135 * Note: the specific put_char operation in the driver layer may go
3136 * away soon. Don't call it directly, use this method
3139 int tty_put_char(struct tty_struct
*tty
, unsigned char ch
)
3141 if (tty
->ops
->put_char
)
3142 return tty
->ops
->put_char(tty
, ch
);
3143 return tty
->ops
->write(tty
, &ch
, 1);
3145 EXPORT_SYMBOL_GPL(tty_put_char
);
3147 struct class *tty_class
;
3149 static int tty_cdev_add(struct tty_driver
*driver
, dev_t dev
,
3150 unsigned int index
, unsigned int count
)
3152 /* init here, since reused cdevs cause crashes */
3153 cdev_init(&driver
->cdevs
[index
], &tty_fops
);
3154 driver
->cdevs
[index
].owner
= driver
->owner
;
3155 return cdev_add(&driver
->cdevs
[index
], dev
, count
);
3159 * tty_register_device - register a tty device
3160 * @driver: the tty driver that describes the tty device
3161 * @index: the index in the tty driver for this tty device
3162 * @device: a struct device that is associated with this tty device.
3163 * This field is optional, if there is no known struct device
3164 * for this tty device it can be set to NULL safely.
3166 * Returns a pointer to the struct device for this tty device
3167 * (or ERR_PTR(-EFOO) on error).
3169 * This call is required to be made to register an individual tty device
3170 * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If
3171 * that bit is not set, this function should not be called by a tty
3177 struct device
*tty_register_device(struct tty_driver
*driver
, unsigned index
,
3178 struct device
*device
)
3180 return tty_register_device_attr(driver
, index
, device
, NULL
, NULL
);
3182 EXPORT_SYMBOL(tty_register_device
);
3184 static void tty_device_create_release(struct device
*dev
)
3186 pr_debug("device: '%s': %s\n", dev_name(dev
), __func__
);
3191 * tty_register_device_attr - register a tty device
3192 * @driver: the tty driver that describes the tty device
3193 * @index: the index in the tty driver for this tty device
3194 * @device: a struct device that is associated with this tty device.
3195 * This field is optional, if there is no known struct device
3196 * for this tty device it can be set to NULL safely.
3197 * @drvdata: Driver data to be set to device.
3198 * @attr_grp: Attribute group to be set on device.
3200 * Returns a pointer to the struct device for this tty device
3201 * (or ERR_PTR(-EFOO) on error).
3203 * This call is required to be made to register an individual tty device
3204 * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If
3205 * that bit is not set, this function should not be called by a tty
3210 struct device
*tty_register_device_attr(struct tty_driver
*driver
,
3211 unsigned index
, struct device
*device
,
3213 const struct attribute_group
**attr_grp
)
3216 dev_t devt
= MKDEV(driver
->major
, driver
->minor_start
) + index
;
3217 struct device
*dev
= NULL
;
3218 int retval
= -ENODEV
;
3221 if (index
>= driver
->num
) {
3222 printk(KERN_ERR
"Attempt to register invalid tty line number "
3224 return ERR_PTR(-EINVAL
);
3227 if (driver
->type
== TTY_DRIVER_TYPE_PTY
)
3228 pty_line_name(driver
, index
, name
);
3230 tty_line_name(driver
, index
, name
);
3232 if (!(driver
->flags
& TTY_DRIVER_DYNAMIC_ALLOC
)) {
3233 retval
= tty_cdev_add(driver
, devt
, index
, 1);
3239 dev
= kzalloc(sizeof(*dev
), GFP_KERNEL
);
3246 dev
->class = tty_class
;
3247 dev
->parent
= device
;
3248 dev
->release
= tty_device_create_release
;
3249 dev_set_name(dev
, "%s", name
);
3250 dev
->groups
= attr_grp
;
3251 dev_set_drvdata(dev
, drvdata
);
3253 retval
= device_register(dev
);
3262 cdev_del(&driver
->cdevs
[index
]);
3263 return ERR_PTR(retval
);
3265 EXPORT_SYMBOL_GPL(tty_register_device_attr
);
3268 * tty_unregister_device - unregister a tty device
3269 * @driver: the tty driver that describes the tty device
3270 * @index: the index in the tty driver for this tty device
3272 * If a tty device is registered with a call to tty_register_device() then
3273 * this function must be called when the tty device is gone.
3278 void tty_unregister_device(struct tty_driver
*driver
, unsigned index
)
3280 device_destroy(tty_class
,
3281 MKDEV(driver
->major
, driver
->minor_start
) + index
);
3282 if (!(driver
->flags
& TTY_DRIVER_DYNAMIC_ALLOC
))
3283 cdev_del(&driver
->cdevs
[index
]);
3285 EXPORT_SYMBOL(tty_unregister_device
);
3288 * __tty_alloc_driver -- allocate tty driver
3289 * @lines: count of lines this driver can handle at most
3290 * @owner: module which is repsonsible for this driver
3291 * @flags: some of TTY_DRIVER_* flags, will be set in driver->flags
3293 * This should not be called directly, some of the provided macros should be
3294 * used instead. Use IS_ERR and friends on @retval.
3296 struct tty_driver
*__tty_alloc_driver(unsigned int lines
, struct module
*owner
,
3297 unsigned long flags
)
3299 struct tty_driver
*driver
;
3300 unsigned int cdevs
= 1;
3303 if (!lines
|| (flags
& TTY_DRIVER_UNNUMBERED_NODE
&& lines
> 1))
3304 return ERR_PTR(-EINVAL
);
3306 driver
= kzalloc(sizeof(struct tty_driver
), GFP_KERNEL
);
3308 return ERR_PTR(-ENOMEM
);
3310 kref_init(&driver
->kref
);
3311 driver
->magic
= TTY_DRIVER_MAGIC
;
3312 driver
->num
= lines
;
3313 driver
->owner
= owner
;
3314 driver
->flags
= flags
;
3316 if (!(flags
& TTY_DRIVER_DEVPTS_MEM
)) {
3317 driver
->ttys
= kcalloc(lines
, sizeof(*driver
->ttys
),
3319 driver
->termios
= kcalloc(lines
, sizeof(*driver
->termios
),
3321 if (!driver
->ttys
|| !driver
->termios
) {
3327 if (!(flags
& TTY_DRIVER_DYNAMIC_ALLOC
)) {
3328 driver
->ports
= kcalloc(lines
, sizeof(*driver
->ports
),
3330 if (!driver
->ports
) {
3337 driver
->cdevs
= kcalloc(cdevs
, sizeof(*driver
->cdevs
), GFP_KERNEL
);
3338 if (!driver
->cdevs
) {
3345 kfree(driver
->ports
);
3346 kfree(driver
->ttys
);
3347 kfree(driver
->termios
);
3349 return ERR_PTR(err
);
3351 EXPORT_SYMBOL(__tty_alloc_driver
);
3353 static void destruct_tty_driver(struct kref
*kref
)
3355 struct tty_driver
*driver
= container_of(kref
, struct tty_driver
, kref
);
3357 struct ktermios
*tp
;
3359 if (driver
->flags
& TTY_DRIVER_INSTALLED
) {
3361 * Free the termios and termios_locked structures because
3362 * we don't want to get memory leaks when modular tty
3363 * drivers are removed from the kernel.
3365 for (i
= 0; i
< driver
->num
; i
++) {
3366 tp
= driver
->termios
[i
];
3368 driver
->termios
[i
] = NULL
;
3371 if (!(driver
->flags
& TTY_DRIVER_DYNAMIC_DEV
))
3372 tty_unregister_device(driver
, i
);
3374 proc_tty_unregister_driver(driver
);
3375 if (driver
->flags
& TTY_DRIVER_DYNAMIC_ALLOC
)
3376 cdev_del(&driver
->cdevs
[0]);
3378 kfree(driver
->cdevs
);
3379 kfree(driver
->ports
);
3380 kfree(driver
->termios
);
3381 kfree(driver
->ttys
);
3385 void tty_driver_kref_put(struct tty_driver
*driver
)
3387 kref_put(&driver
->kref
, destruct_tty_driver
);
3389 EXPORT_SYMBOL(tty_driver_kref_put
);
3391 void tty_set_operations(struct tty_driver
*driver
,
3392 const struct tty_operations
*op
)
3396 EXPORT_SYMBOL(tty_set_operations
);
3398 void put_tty_driver(struct tty_driver
*d
)
3400 tty_driver_kref_put(d
);
3402 EXPORT_SYMBOL(put_tty_driver
);
3405 * Called by a tty driver to register itself.
3407 int tty_register_driver(struct tty_driver
*driver
)
3414 if (!driver
->major
) {
3415 error
= alloc_chrdev_region(&dev
, driver
->minor_start
,
3416 driver
->num
, driver
->name
);
3418 driver
->major
= MAJOR(dev
);
3419 driver
->minor_start
= MINOR(dev
);
3422 dev
= MKDEV(driver
->major
, driver
->minor_start
);
3423 error
= register_chrdev_region(dev
, driver
->num
, driver
->name
);
3428 if (driver
->flags
& TTY_DRIVER_DYNAMIC_ALLOC
) {
3429 error
= tty_cdev_add(driver
, dev
, 0, driver
->num
);
3431 goto err_unreg_char
;
3434 mutex_lock(&tty_mutex
);
3435 list_add(&driver
->tty_drivers
, &tty_drivers
);
3436 mutex_unlock(&tty_mutex
);
3438 if (!(driver
->flags
& TTY_DRIVER_DYNAMIC_DEV
)) {
3439 for (i
= 0; i
< driver
->num
; i
++) {
3440 d
= tty_register_device(driver
, i
, NULL
);
3443 goto err_unreg_devs
;
3447 proc_tty_register_driver(driver
);
3448 driver
->flags
|= TTY_DRIVER_INSTALLED
;
3452 for (i
--; i
>= 0; i
--)
3453 tty_unregister_device(driver
, i
);
3455 mutex_lock(&tty_mutex
);
3456 list_del(&driver
->tty_drivers
);
3457 mutex_unlock(&tty_mutex
);
3460 unregister_chrdev_region(dev
, driver
->num
);
3464 EXPORT_SYMBOL(tty_register_driver
);
3467 * Called by a tty driver to unregister itself.
3469 int tty_unregister_driver(struct tty_driver
*driver
)
3473 if (driver
->refcount
)
3476 unregister_chrdev_region(MKDEV(driver
->major
, driver
->minor_start
),
3478 mutex_lock(&tty_mutex
);
3479 list_del(&driver
->tty_drivers
);
3480 mutex_unlock(&tty_mutex
);
3484 EXPORT_SYMBOL(tty_unregister_driver
);
3486 dev_t
tty_devnum(struct tty_struct
*tty
)
3488 return MKDEV(tty
->driver
->major
, tty
->driver
->minor_start
) + tty
->index
;
3490 EXPORT_SYMBOL(tty_devnum
);
3492 void tty_default_fops(struct file_operations
*fops
)
3498 * Initialize the console device. This is called *early*, so
3499 * we can't necessarily depend on lots of kernel help here.
3500 * Just do some early initializations, and do the complex setup
3503 void __init
console_init(void)
3507 /* Setup the default TTY line discipline. */
3511 * set up the console device so that later boot sequences can
3512 * inform about problems etc..
3514 call
= __con_initcall_start
;
3515 while (call
< __con_initcall_end
) {
3521 static char *tty_devnode(struct device
*dev
, umode_t
*mode
)
3525 if (dev
->devt
== MKDEV(TTYAUX_MAJOR
, 0) ||
3526 dev
->devt
== MKDEV(TTYAUX_MAJOR
, 2))
3531 static int __init
tty_class_init(void)
3533 tty_class
= class_create(THIS_MODULE
, "tty");
3534 if (IS_ERR(tty_class
))
3535 return PTR_ERR(tty_class
);
3536 tty_class
->devnode
= tty_devnode
;
3540 postcore_initcall(tty_class_init
);
3542 /* 3/2004 jmc: why do these devices exist? */
3543 static struct cdev tty_cdev
, console_cdev
;
3545 static ssize_t
show_cons_active(struct device
*dev
,
3546 struct device_attribute
*attr
, char *buf
)
3548 struct console
*cs
[16];
3554 for_each_console(c
) {
3559 if ((c
->flags
& CON_ENABLED
) == 0)
3562 if (i
>= ARRAY_SIZE(cs
))
3566 int index
= cs
[i
]->index
;
3567 struct tty_driver
*drv
= cs
[i
]->device(cs
[i
], &index
);
3569 /* don't resolve tty0 as some programs depend on it */
3570 if (drv
&& (cs
[i
]->index
> 0 || drv
->major
!= TTY_MAJOR
))
3571 count
+= tty_line_name(drv
, index
, buf
+ count
);
3573 count
+= sprintf(buf
+ count
, "%s%d",
3574 cs
[i
]->name
, cs
[i
]->index
);
3576 count
+= sprintf(buf
+ count
, "%c", i
? ' ':'\n');
3582 static DEVICE_ATTR(active
, S_IRUGO
, show_cons_active
, NULL
);
3584 static struct device
*consdev
;
3586 void console_sysfs_notify(void)
3589 sysfs_notify(&consdev
->kobj
, NULL
, "active");
3593 * Ok, now we can initialize the rest of the tty devices and can count
3594 * on memory allocations, interrupts etc..
3596 int __init
tty_init(void)
3598 cdev_init(&tty_cdev
, &tty_fops
);
3599 if (cdev_add(&tty_cdev
, MKDEV(TTYAUX_MAJOR
, 0), 1) ||
3600 register_chrdev_region(MKDEV(TTYAUX_MAJOR
, 0), 1, "/dev/tty") < 0)
3601 panic("Couldn't register /dev/tty driver\n");
3602 device_create(tty_class
, NULL
, MKDEV(TTYAUX_MAJOR
, 0), NULL
, "tty");
3604 cdev_init(&console_cdev
, &console_fops
);
3605 if (cdev_add(&console_cdev
, MKDEV(TTYAUX_MAJOR
, 1), 1) ||
3606 register_chrdev_region(MKDEV(TTYAUX_MAJOR
, 1), 1, "/dev/console") < 0)
3607 panic("Couldn't register /dev/console driver\n");
3608 consdev
= device_create(tty_class
, NULL
, MKDEV(TTYAUX_MAJOR
, 1), NULL
,
3610 if (IS_ERR(consdev
))
3613 WARN_ON(device_create_file(consdev
, &dev_attr_active
) < 0);
3616 vty_init(&console_fops
);