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
109 #ifdef TTY_DEBUG_HANGUP
110 # define tty_debug_hangup(tty, f, args...) tty_debug(tty, f, ##args)
112 # define tty_debug_hangup(tty, f, args...) do { } while (0)
115 #define TTY_PARANOIA_CHECK 1
116 #define CHECK_TTY_COUNT 1
118 struct ktermios tty_std_termios
= { /* for the benefit of tty drivers */
119 .c_iflag
= ICRNL
| IXON
,
120 .c_oflag
= OPOST
| ONLCR
,
121 .c_cflag
= B38400
| CS8
| CREAD
| HUPCL
,
122 .c_lflag
= ISIG
| ICANON
| ECHO
| ECHOE
| ECHOK
|
123 ECHOCTL
| ECHOKE
| IEXTEN
,
129 EXPORT_SYMBOL(tty_std_termios
);
131 /* This list gets poked at by procfs and various bits of boot up code. This
132 could do with some rationalisation such as pulling the tty proc function
135 LIST_HEAD(tty_drivers
); /* linked list of tty drivers */
137 /* Mutex to protect creating and releasing a tty. This is shared with
138 vt.c for deeply disgusting hack reasons */
139 DEFINE_MUTEX(tty_mutex
);
140 EXPORT_SYMBOL(tty_mutex
);
142 /* Spinlock to protect the tty->tty_files list */
143 DEFINE_SPINLOCK(tty_files_lock
);
145 static ssize_t
tty_read(struct file
*, char __user
*, size_t, loff_t
*);
146 static ssize_t
tty_write(struct file
*, const char __user
*, size_t, loff_t
*);
147 ssize_t
redirected_tty_write(struct file
*, const char __user
*,
149 static unsigned int tty_poll(struct file
*, poll_table
*);
150 static int tty_open(struct inode
*, struct file
*);
151 long tty_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
);
153 static long tty_compat_ioctl(struct file
*file
, unsigned int cmd
,
156 #define tty_compat_ioctl NULL
158 static int __tty_fasync(int fd
, struct file
*filp
, int on
);
159 static int tty_fasync(int fd
, struct file
*filp
, int on
);
160 static void release_tty(struct tty_struct
*tty
, int idx
);
163 * free_tty_struct - free a disused tty
164 * @tty: tty struct to free
166 * Free the write buffers, tty queue and tty memory itself.
168 * Locking: none. Must be called after tty is definitely unused
171 void free_tty_struct(struct tty_struct
*tty
)
175 put_device(tty
->dev
);
176 kfree(tty
->write_buf
);
177 tty
->magic
= 0xDEADDEAD;
181 static inline struct tty_struct
*file_tty(struct file
*file
)
183 return ((struct tty_file_private
*)file
->private_data
)->tty
;
186 int tty_alloc_file(struct file
*file
)
188 struct tty_file_private
*priv
;
190 priv
= kmalloc(sizeof(*priv
), GFP_KERNEL
);
194 file
->private_data
= priv
;
199 /* Associate a new file with the tty structure */
200 void tty_add_file(struct tty_struct
*tty
, struct file
*file
)
202 struct tty_file_private
*priv
= file
->private_data
;
207 spin_lock(&tty_files_lock
);
208 list_add(&priv
->list
, &tty
->tty_files
);
209 spin_unlock(&tty_files_lock
);
213 * tty_free_file - free file->private_data
215 * This shall be used only for fail path handling when tty_add_file was not
218 void tty_free_file(struct file
*file
)
220 struct tty_file_private
*priv
= file
->private_data
;
222 file
->private_data
= NULL
;
226 /* Delete file from its tty */
227 static void tty_del_file(struct file
*file
)
229 struct tty_file_private
*priv
= file
->private_data
;
231 spin_lock(&tty_files_lock
);
232 list_del(&priv
->list
);
233 spin_unlock(&tty_files_lock
);
238 #define TTY_NUMBER(tty) ((tty)->index + (tty)->driver->name_base)
241 * tty_name - return tty naming
242 * @tty: tty structure
244 * Convert a tty structure into a name. The name reflects the kernel
245 * naming policy and if udev is in use may not reflect user space
250 const char *tty_name(const struct tty_struct
*tty
)
252 if (!tty
) /* Hmm. NULL pointer. That's fun. */
257 EXPORT_SYMBOL(tty_name
);
259 int tty_paranoia_check(struct tty_struct
*tty
, struct inode
*inode
,
262 #ifdef TTY_PARANOIA_CHECK
265 "null TTY for (%d:%d) in %s\n",
266 imajor(inode
), iminor(inode
), routine
);
269 if (tty
->magic
!= TTY_MAGIC
) {
271 "bad magic number for tty struct (%d:%d) in %s\n",
272 imajor(inode
), iminor(inode
), routine
);
279 /* Caller must hold tty_lock */
280 static int check_tty_count(struct tty_struct
*tty
, const char *routine
)
282 #ifdef CHECK_TTY_COUNT
286 spin_lock(&tty_files_lock
);
287 list_for_each(p
, &tty
->tty_files
) {
290 spin_unlock(&tty_files_lock
);
291 if (tty
->driver
->type
== TTY_DRIVER_TYPE_PTY
&&
292 tty
->driver
->subtype
== PTY_TYPE_SLAVE
&&
293 tty
->link
&& tty
->link
->count
)
295 if (tty
->count
!= count
) {
296 printk(KERN_WARNING
"Warning: dev (%s) tty->count(%d) "
297 "!= #fd's(%d) in %s\n",
298 tty
->name
, tty
->count
, count
, routine
);
306 * get_tty_driver - find device of a tty
307 * @dev_t: device identifier
308 * @index: returns the index of the tty
310 * This routine returns a tty driver structure, given a device number
311 * and also passes back the index number.
313 * Locking: caller must hold tty_mutex
316 static struct tty_driver
*get_tty_driver(dev_t device
, int *index
)
318 struct tty_driver
*p
;
320 list_for_each_entry(p
, &tty_drivers
, tty_drivers
) {
321 dev_t base
= MKDEV(p
->major
, p
->minor_start
);
322 if (device
< base
|| device
>= base
+ p
->num
)
324 *index
= device
- base
;
325 return tty_driver_kref_get(p
);
330 #ifdef CONFIG_CONSOLE_POLL
333 * tty_find_polling_driver - find device of a polled tty
334 * @name: name string to match
335 * @line: pointer to resulting tty line nr
337 * This routine returns a tty driver structure, given a name
338 * and the condition that the tty driver is capable of polled
341 struct tty_driver
*tty_find_polling_driver(char *name
, int *line
)
343 struct tty_driver
*p
, *res
= NULL
;
348 for (str
= name
; *str
; str
++)
349 if ((*str
>= '0' && *str
<= '9') || *str
== ',')
355 tty_line
= simple_strtoul(str
, &str
, 10);
357 mutex_lock(&tty_mutex
);
358 /* Search through the tty devices to look for a match */
359 list_for_each_entry(p
, &tty_drivers
, tty_drivers
) {
360 if (strncmp(name
, p
->name
, len
) != 0)
368 if (tty_line
>= 0 && tty_line
< p
->num
&& p
->ops
&&
369 p
->ops
->poll_init
&& !p
->ops
->poll_init(p
, tty_line
, stp
)) {
370 res
= tty_driver_kref_get(p
);
375 mutex_unlock(&tty_mutex
);
379 EXPORT_SYMBOL_GPL(tty_find_polling_driver
);
383 * tty_check_change - check for POSIX terminal changes
386 * If we try to write to, or set the state of, a terminal and we're
387 * not in the foreground, send a SIGTTOU. If the signal is blocked or
388 * ignored, go ahead and perform the operation. (POSIX 7.2)
393 int tty_check_change(struct tty_struct
*tty
)
399 if (current
->signal
->tty
!= tty
)
403 pgrp
= task_pgrp(current
);
405 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
408 printk(KERN_WARNING
"tty_check_change: tty->pgrp == NULL!\n");
411 if (pgrp
== tty
->pgrp
)
413 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
415 if (is_ignored(SIGTTOU
))
417 if (is_current_pgrp_orphaned()) {
421 kill_pgrp(pgrp
, SIGTTOU
, 1);
423 set_thread_flag(TIF_SIGPENDING
);
427 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
433 EXPORT_SYMBOL(tty_check_change
);
435 static ssize_t
hung_up_tty_read(struct file
*file
, char __user
*buf
,
436 size_t count
, loff_t
*ppos
)
441 static ssize_t
hung_up_tty_write(struct file
*file
, const char __user
*buf
,
442 size_t count
, loff_t
*ppos
)
447 /* No kernel lock held - none needed ;) */
448 static unsigned int hung_up_tty_poll(struct file
*filp
, poll_table
*wait
)
450 return POLLIN
| POLLOUT
| POLLERR
| POLLHUP
| POLLRDNORM
| POLLWRNORM
;
453 static long hung_up_tty_ioctl(struct file
*file
, unsigned int cmd
,
456 return cmd
== TIOCSPGRP
? -ENOTTY
: -EIO
;
459 static long hung_up_tty_compat_ioctl(struct file
*file
,
460 unsigned int cmd
, unsigned long arg
)
462 return cmd
== TIOCSPGRP
? -ENOTTY
: -EIO
;
465 static const struct file_operations tty_fops
= {
470 .unlocked_ioctl
= tty_ioctl
,
471 .compat_ioctl
= tty_compat_ioctl
,
473 .release
= tty_release
,
474 .fasync
= tty_fasync
,
477 static const struct file_operations console_fops
= {
480 .write
= redirected_tty_write
,
482 .unlocked_ioctl
= tty_ioctl
,
483 .compat_ioctl
= tty_compat_ioctl
,
485 .release
= tty_release
,
486 .fasync
= tty_fasync
,
489 static const struct file_operations hung_up_tty_fops
= {
491 .read
= hung_up_tty_read
,
492 .write
= hung_up_tty_write
,
493 .poll
= hung_up_tty_poll
,
494 .unlocked_ioctl
= hung_up_tty_ioctl
,
495 .compat_ioctl
= hung_up_tty_compat_ioctl
,
496 .release
= tty_release
,
499 static DEFINE_SPINLOCK(redirect_lock
);
500 static struct file
*redirect
;
503 void proc_clear_tty(struct task_struct
*p
)
506 struct tty_struct
*tty
;
507 spin_lock_irqsave(&p
->sighand
->siglock
, flags
);
508 tty
= p
->signal
->tty
;
509 p
->signal
->tty
= NULL
;
510 spin_unlock_irqrestore(&p
->sighand
->siglock
, flags
);
515 * proc_set_tty - set the controlling terminal
517 * Only callable by the session leader and only if it does not already have
518 * a controlling terminal.
520 * Caller must hold: tty_lock()
521 * a readlock on tasklist_lock
524 static void __proc_set_tty(struct tty_struct
*tty
)
528 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
530 * The session and fg pgrp references will be non-NULL if
531 * tiocsctty() is stealing the controlling tty
533 put_pid(tty
->session
);
535 tty
->pgrp
= get_pid(task_pgrp(current
));
536 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
537 tty
->session
= get_pid(task_session(current
));
538 if (current
->signal
->tty
) {
539 tty_debug(tty
, "current tty %s not NULL!!\n",
540 current
->signal
->tty
->name
);
541 tty_kref_put(current
->signal
->tty
);
543 put_pid(current
->signal
->tty_old_pgrp
);
544 current
->signal
->tty
= tty_kref_get(tty
);
545 current
->signal
->tty_old_pgrp
= NULL
;
548 static void proc_set_tty(struct tty_struct
*tty
)
550 spin_lock_irq(¤t
->sighand
->siglock
);
552 spin_unlock_irq(¤t
->sighand
->siglock
);
555 struct tty_struct
*get_current_tty(void)
557 struct tty_struct
*tty
;
560 spin_lock_irqsave(¤t
->sighand
->siglock
, flags
);
561 tty
= tty_kref_get(current
->signal
->tty
);
562 spin_unlock_irqrestore(¤t
->sighand
->siglock
, flags
);
565 EXPORT_SYMBOL_GPL(get_current_tty
);
567 static void session_clear_tty(struct pid
*session
)
569 struct task_struct
*p
;
570 do_each_pid_task(session
, PIDTYPE_SID
, p
) {
572 } while_each_pid_task(session
, PIDTYPE_SID
, p
);
576 * tty_wakeup - request more data
579 * Internal and external helper for wakeups of tty. This function
580 * informs the line discipline if present that the driver is ready
581 * to receive more output data.
584 void tty_wakeup(struct tty_struct
*tty
)
586 struct tty_ldisc
*ld
;
588 if (test_bit(TTY_DO_WRITE_WAKEUP
, &tty
->flags
)) {
589 ld
= tty_ldisc_ref(tty
);
591 if (ld
->ops
->write_wakeup
)
592 ld
->ops
->write_wakeup(tty
);
596 wake_up_interruptible_poll(&tty
->write_wait
, POLLOUT
);
599 EXPORT_SYMBOL_GPL(tty_wakeup
);
602 * tty_signal_session_leader - sends SIGHUP to session leader
603 * @tty controlling tty
604 * @exit_session if non-zero, signal all foreground group processes
606 * Send SIGHUP and SIGCONT to the session leader and its process group.
607 * Optionally, signal all processes in the foreground process group.
609 * Returns the number of processes in the session with this tty
610 * as their controlling terminal. This value is used to drop
611 * tty references for those processes.
613 static int tty_signal_session_leader(struct tty_struct
*tty
, int exit_session
)
615 struct task_struct
*p
;
617 struct pid
*tty_pgrp
= NULL
;
619 read_lock(&tasklist_lock
);
621 do_each_pid_task(tty
->session
, PIDTYPE_SID
, p
) {
622 spin_lock_irq(&p
->sighand
->siglock
);
623 if (p
->signal
->tty
== tty
) {
624 p
->signal
->tty
= NULL
;
625 /* We defer the dereferences outside fo
629 if (!p
->signal
->leader
) {
630 spin_unlock_irq(&p
->sighand
->siglock
);
633 __group_send_sig_info(SIGHUP
, SEND_SIG_PRIV
, p
);
634 __group_send_sig_info(SIGCONT
, SEND_SIG_PRIV
, p
);
635 put_pid(p
->signal
->tty_old_pgrp
); /* A noop */
636 spin_lock(&tty
->ctrl_lock
);
637 tty_pgrp
= get_pid(tty
->pgrp
);
639 p
->signal
->tty_old_pgrp
= get_pid(tty
->pgrp
);
640 spin_unlock(&tty
->ctrl_lock
);
641 spin_unlock_irq(&p
->sighand
->siglock
);
642 } while_each_pid_task(tty
->session
, PIDTYPE_SID
, p
);
644 read_unlock(&tasklist_lock
);
648 kill_pgrp(tty_pgrp
, SIGHUP
, exit_session
);
656 * __tty_hangup - actual handler for hangup events
659 * This can be called by a "kworker" kernel thread. That is process
660 * synchronous but doesn't hold any locks, so we need to make sure we
661 * have the appropriate locks for what we're doing.
663 * The hangup event clears any pending redirections onto the hung up
664 * device. It ensures future writes will error and it does the needed
665 * line discipline hangup and signal delivery. The tty object itself
670 * redirect lock for undoing redirection
671 * file list lock for manipulating list of ttys
672 * tty_ldiscs_lock from called functions
673 * termios_rwsem resetting termios data
674 * tasklist_lock to walk task list for hangup event
675 * ->siglock to protect ->signal/->sighand
677 static void __tty_hangup(struct tty_struct
*tty
, int exit_session
)
679 struct file
*cons_filp
= NULL
;
680 struct file
*filp
, *f
= NULL
;
681 struct tty_file_private
*priv
;
682 int closecount
= 0, n
;
689 spin_lock(&redirect_lock
);
690 if (redirect
&& file_tty(redirect
) == tty
) {
694 spin_unlock(&redirect_lock
);
698 if (test_bit(TTY_HUPPED
, &tty
->flags
)) {
703 /* inuse_filps is protected by the single tty lock,
704 this really needs to change if we want to flush the
705 workqueue with the lock held */
706 check_tty_count(tty
, "tty_hangup");
708 spin_lock(&tty_files_lock
);
709 /* This breaks for file handles being sent over AF_UNIX sockets ? */
710 list_for_each_entry(priv
, &tty
->tty_files
, list
) {
712 if (filp
->f_op
->write
== redirected_tty_write
)
714 if (filp
->f_op
->write
!= tty_write
)
717 __tty_fasync(-1, filp
, 0); /* can't block */
718 filp
->f_op
= &hung_up_tty_fops
;
720 spin_unlock(&tty_files_lock
);
722 refs
= tty_signal_session_leader(tty
, exit_session
);
723 /* Account for the p->signal references we killed */
727 tty_ldisc_hangup(tty
);
729 spin_lock_irq(&tty
->ctrl_lock
);
730 clear_bit(TTY_THROTTLED
, &tty
->flags
);
731 clear_bit(TTY_DO_WRITE_WAKEUP
, &tty
->flags
);
732 put_pid(tty
->session
);
736 tty
->ctrl_status
= 0;
737 spin_unlock_irq(&tty
->ctrl_lock
);
740 * If one of the devices matches a console pointer, we
741 * cannot just call hangup() because that will cause
742 * tty->count and state->count to go out of sync.
743 * So we just call close() the right number of times.
747 for (n
= 0; n
< closecount
; n
++)
748 tty
->ops
->close(tty
, cons_filp
);
749 } else if (tty
->ops
->hangup
)
750 tty
->ops
->hangup(tty
);
752 * We don't want to have driver/ldisc interactions beyond
753 * the ones we did here. The driver layer expects no
754 * calls after ->hangup() from the ldisc side. However we
755 * can't yet guarantee all that.
757 set_bit(TTY_HUPPED
, &tty
->flags
);
764 static void do_tty_hangup(struct work_struct
*work
)
766 struct tty_struct
*tty
=
767 container_of(work
, struct tty_struct
, hangup_work
);
769 __tty_hangup(tty
, 0);
773 * tty_hangup - trigger a hangup event
774 * @tty: tty to hangup
776 * A carrier loss (virtual or otherwise) has occurred on this like
777 * schedule a hangup sequence to run after this event.
780 void tty_hangup(struct tty_struct
*tty
)
782 tty_debug_hangup(tty
, "\n");
783 schedule_work(&tty
->hangup_work
);
786 EXPORT_SYMBOL(tty_hangup
);
789 * tty_vhangup - process vhangup
790 * @tty: tty to hangup
792 * The user has asked via system call for the terminal to be hung up.
793 * We do this synchronously so that when the syscall returns the process
794 * is complete. That guarantee is necessary for security reasons.
797 void tty_vhangup(struct tty_struct
*tty
)
799 tty_debug_hangup(tty
, "\n");
800 __tty_hangup(tty
, 0);
803 EXPORT_SYMBOL(tty_vhangup
);
807 * tty_vhangup_self - process vhangup for own ctty
809 * Perform a vhangup on the current controlling tty
812 void tty_vhangup_self(void)
814 struct tty_struct
*tty
;
816 tty
= get_current_tty();
824 * tty_vhangup_session - hangup session leader exit
825 * @tty: tty to hangup
827 * The session leader is exiting and hanging up its controlling terminal.
828 * Every process in the foreground process group is signalled SIGHUP.
830 * We do this synchronously so that when the syscall returns the process
831 * is complete. That guarantee is necessary for security reasons.
834 static void tty_vhangup_session(struct tty_struct
*tty
)
836 tty_debug_hangup(tty
, "\n");
837 __tty_hangup(tty
, 1);
841 * tty_hung_up_p - was tty hung up
842 * @filp: file pointer of tty
844 * Return true if the tty has been subject to a vhangup or a carrier
848 int tty_hung_up_p(struct file
*filp
)
850 return (filp
->f_op
== &hung_up_tty_fops
);
853 EXPORT_SYMBOL(tty_hung_up_p
);
856 * disassociate_ctty - disconnect controlling tty
857 * @on_exit: true if exiting so need to "hang up" the session
859 * This function is typically called only by the session leader, when
860 * it wants to disassociate itself from its controlling tty.
862 * It performs the following functions:
863 * (1) Sends a SIGHUP and SIGCONT to the foreground process group
864 * (2) Clears the tty from being controlling the session
865 * (3) Clears the controlling tty for all processes in the
868 * The argument on_exit is set to 1 if called when a process is
869 * exiting; it is 0 if called by the ioctl TIOCNOTTY.
872 * BTM is taken for hysterical raisins, and held when
873 * called from no_tty().
874 * tty_mutex is taken to protect tty
875 * ->siglock is taken to protect ->signal/->sighand
876 * tasklist_lock is taken to walk process list for sessions
877 * ->siglock is taken to protect ->signal/->sighand
880 void disassociate_ctty(int on_exit
)
882 struct tty_struct
*tty
;
884 if (!current
->signal
->leader
)
887 tty
= get_current_tty();
889 if (on_exit
&& tty
->driver
->type
!= TTY_DRIVER_TYPE_PTY
) {
890 tty_vhangup_session(tty
);
892 struct pid
*tty_pgrp
= tty_get_pgrp(tty
);
894 kill_pgrp(tty_pgrp
, SIGHUP
, on_exit
);
896 kill_pgrp(tty_pgrp
, SIGCONT
, on_exit
);
902 } else if (on_exit
) {
903 struct pid
*old_pgrp
;
904 spin_lock_irq(¤t
->sighand
->siglock
);
905 old_pgrp
= current
->signal
->tty_old_pgrp
;
906 current
->signal
->tty_old_pgrp
= NULL
;
907 spin_unlock_irq(¤t
->sighand
->siglock
);
909 kill_pgrp(old_pgrp
, SIGHUP
, on_exit
);
910 kill_pgrp(old_pgrp
, SIGCONT
, on_exit
);
916 spin_lock_irq(¤t
->sighand
->siglock
);
917 put_pid(current
->signal
->tty_old_pgrp
);
918 current
->signal
->tty_old_pgrp
= NULL
;
920 tty
= tty_kref_get(current
->signal
->tty
);
923 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
924 put_pid(tty
->session
);
928 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
931 tty_debug_hangup(tty
, "no current tty\n");
933 spin_unlock_irq(¤t
->sighand
->siglock
);
934 /* Now clear signal->tty under the lock */
935 read_lock(&tasklist_lock
);
936 session_clear_tty(task_session(current
));
937 read_unlock(&tasklist_lock
);
942 * no_tty - Ensure the current process does not have a controlling tty
946 /* FIXME: Review locking here. The tty_lock never covered any race
947 between a new association and proc_clear_tty but possible we need
948 to protect against this anyway */
949 struct task_struct
*tsk
= current
;
950 disassociate_ctty(0);
956 * stop_tty - propagate flow control
959 * Perform flow control to the driver. May be called
960 * on an already stopped device and will not re-call the driver
963 * This functionality is used by both the line disciplines for
964 * halting incoming flow and by the driver. It may therefore be
965 * called from any context, may be under the tty atomic_write_lock
972 void __stop_tty(struct tty_struct
*tty
)
981 void stop_tty(struct tty_struct
*tty
)
985 spin_lock_irqsave(&tty
->flow_lock
, flags
);
987 spin_unlock_irqrestore(&tty
->flow_lock
, flags
);
989 EXPORT_SYMBOL(stop_tty
);
992 * start_tty - propagate flow control
995 * Start a tty that has been stopped if at all possible. If this
996 * tty was previous stopped and is now being started, the driver
997 * start method is invoked and the line discipline woken.
1003 void __start_tty(struct tty_struct
*tty
)
1005 if (!tty
->stopped
|| tty
->flow_stopped
)
1008 if (tty
->ops
->start
)
1009 tty
->ops
->start(tty
);
1013 void start_tty(struct tty_struct
*tty
)
1015 unsigned long flags
;
1017 spin_lock_irqsave(&tty
->flow_lock
, flags
);
1019 spin_unlock_irqrestore(&tty
->flow_lock
, flags
);
1021 EXPORT_SYMBOL(start_tty
);
1023 static void tty_update_time(struct timespec
*time
)
1025 unsigned long sec
= get_seconds();
1028 * We only care if the two values differ in anything other than the
1029 * lower three bits (i.e every 8 seconds). If so, then we can update
1030 * the time of the tty device, otherwise it could be construded as a
1031 * security leak to let userspace know the exact timing of the tty.
1033 if ((sec
^ time
->tv_sec
) & ~7)
1038 * tty_read - read method for tty device files
1039 * @file: pointer to tty file
1041 * @count: size of user buffer
1044 * Perform the read system call function on this terminal device. Checks
1045 * for hung up devices before calling the line discipline method.
1048 * Locks the line discipline internally while needed. Multiple
1049 * read calls may be outstanding in parallel.
1052 static ssize_t
tty_read(struct file
*file
, char __user
*buf
, size_t count
,
1056 struct inode
*inode
= file_inode(file
);
1057 struct tty_struct
*tty
= file_tty(file
);
1058 struct tty_ldisc
*ld
;
1060 if (tty_paranoia_check(tty
, inode
, "tty_read"))
1062 if (!tty
|| (test_bit(TTY_IO_ERROR
, &tty
->flags
)))
1065 /* We want to wait for the line discipline to sort out in this
1067 ld
= tty_ldisc_ref_wait(tty
);
1069 i
= ld
->ops
->read(tty
, file
, buf
, count
);
1072 tty_ldisc_deref(ld
);
1075 tty_update_time(&inode
->i_atime
);
1080 static void tty_write_unlock(struct tty_struct
*tty
)
1082 mutex_unlock(&tty
->atomic_write_lock
);
1083 wake_up_interruptible_poll(&tty
->write_wait
, POLLOUT
);
1086 static int tty_write_lock(struct tty_struct
*tty
, int ndelay
)
1088 if (!mutex_trylock(&tty
->atomic_write_lock
)) {
1091 if (mutex_lock_interruptible(&tty
->atomic_write_lock
))
1092 return -ERESTARTSYS
;
1098 * Split writes up in sane blocksizes to avoid
1099 * denial-of-service type attacks
1101 static inline ssize_t
do_tty_write(
1102 ssize_t (*write
)(struct tty_struct
*, struct file
*, const unsigned char *, size_t),
1103 struct tty_struct
*tty
,
1105 const char __user
*buf
,
1108 ssize_t ret
, written
= 0;
1111 ret
= tty_write_lock(tty
, file
->f_flags
& O_NDELAY
);
1116 * We chunk up writes into a temporary buffer. This
1117 * simplifies low-level drivers immensely, since they
1118 * don't have locking issues and user mode accesses.
1120 * But if TTY_NO_WRITE_SPLIT is set, we should use a
1123 * The default chunk-size is 2kB, because the NTTY
1124 * layer has problems with bigger chunks. It will
1125 * claim to be able to handle more characters than
1128 * FIXME: This can probably go away now except that 64K chunks
1129 * are too likely to fail unless switched to vmalloc...
1132 if (test_bit(TTY_NO_WRITE_SPLIT
, &tty
->flags
))
1137 /* write_buf/write_cnt is protected by the atomic_write_lock mutex */
1138 if (tty
->write_cnt
< chunk
) {
1139 unsigned char *buf_chunk
;
1144 buf_chunk
= kmalloc(chunk
, GFP_KERNEL
);
1149 kfree(tty
->write_buf
);
1150 tty
->write_cnt
= chunk
;
1151 tty
->write_buf
= buf_chunk
;
1154 /* Do the write .. */
1156 size_t size
= count
;
1160 if (copy_from_user(tty
->write_buf
, buf
, size
))
1162 ret
= write(tty
, file
, tty
->write_buf
, size
);
1171 if (signal_pending(current
))
1176 tty_update_time(&file_inode(file
)->i_mtime
);
1180 tty_write_unlock(tty
);
1185 * tty_write_message - write a message to a certain tty, not just the console.
1186 * @tty: the destination tty_struct
1187 * @msg: the message to write
1189 * This is used for messages that need to be redirected to a specific tty.
1190 * We don't put it into the syslog queue right now maybe in the future if
1193 * We must still hold the BTM and test the CLOSING flag for the moment.
1196 void tty_write_message(struct tty_struct
*tty
, char *msg
)
1199 mutex_lock(&tty
->atomic_write_lock
);
1201 if (tty
->ops
->write
&& tty
->count
> 0) {
1203 tty
->ops
->write(tty
, msg
, strlen(msg
));
1206 tty_write_unlock(tty
);
1213 * tty_write - write method for tty device file
1214 * @file: tty file pointer
1215 * @buf: user data to write
1216 * @count: bytes to write
1219 * Write data to a tty device via the line discipline.
1222 * Locks the line discipline as required
1223 * Writes to the tty driver are serialized by the atomic_write_lock
1224 * and are then processed in chunks to the device. The line discipline
1225 * write method will not be invoked in parallel for each device.
1228 static ssize_t
tty_write(struct file
*file
, const char __user
*buf
,
1229 size_t count
, loff_t
*ppos
)
1231 struct tty_struct
*tty
= file_tty(file
);
1232 struct tty_ldisc
*ld
;
1235 if (tty_paranoia_check(tty
, file_inode(file
), "tty_write"))
1237 if (!tty
|| !tty
->ops
->write
||
1238 (test_bit(TTY_IO_ERROR
, &tty
->flags
)))
1240 /* Short term debug to catch buggy drivers */
1241 if (tty
->ops
->write_room
== NULL
)
1242 printk(KERN_ERR
"tty driver %s lacks a write_room method.\n",
1244 ld
= tty_ldisc_ref_wait(tty
);
1245 if (!ld
->ops
->write
)
1248 ret
= do_tty_write(ld
->ops
->write
, tty
, file
, buf
, count
);
1249 tty_ldisc_deref(ld
);
1253 ssize_t
redirected_tty_write(struct file
*file
, const char __user
*buf
,
1254 size_t count
, loff_t
*ppos
)
1256 struct file
*p
= NULL
;
1258 spin_lock(&redirect_lock
);
1260 p
= get_file(redirect
);
1261 spin_unlock(&redirect_lock
);
1265 res
= vfs_write(p
, buf
, count
, &p
->f_pos
);
1269 return tty_write(file
, buf
, count
, ppos
);
1273 * tty_send_xchar - send priority character
1275 * Send a high priority character to the tty even if stopped
1277 * Locking: none for xchar method, write ordering for write method.
1280 int tty_send_xchar(struct tty_struct
*tty
, char ch
)
1282 int was_stopped
= tty
->stopped
;
1284 if (tty
->ops
->send_xchar
) {
1285 tty
->ops
->send_xchar(tty
, ch
);
1289 if (tty_write_lock(tty
, 0) < 0)
1290 return -ERESTARTSYS
;
1294 tty
->ops
->write(tty
, &ch
, 1);
1297 tty_write_unlock(tty
);
1301 static char ptychar
[] = "pqrstuvwxyzabcde";
1304 * pty_line_name - generate name for a pty
1305 * @driver: the tty driver in use
1306 * @index: the minor number
1307 * @p: output buffer of at least 6 bytes
1309 * Generate a name from a driver reference and write it to the output
1314 static void pty_line_name(struct tty_driver
*driver
, int index
, char *p
)
1316 int i
= index
+ driver
->name_base
;
1317 /* ->name is initialized to "ttyp", but "tty" is expected */
1318 sprintf(p
, "%s%c%x",
1319 driver
->subtype
== PTY_TYPE_SLAVE
? "tty" : driver
->name
,
1320 ptychar
[i
>> 4 & 0xf], i
& 0xf);
1324 * tty_line_name - generate name for a tty
1325 * @driver: the tty driver in use
1326 * @index: the minor number
1327 * @p: output buffer of at least 7 bytes
1329 * Generate a name from a driver reference and write it to the output
1334 static ssize_t
tty_line_name(struct tty_driver
*driver
, int index
, char *p
)
1336 if (driver
->flags
& TTY_DRIVER_UNNUMBERED_NODE
)
1337 return sprintf(p
, "%s", driver
->name
);
1339 return sprintf(p
, "%s%d", driver
->name
,
1340 index
+ driver
->name_base
);
1344 * tty_driver_lookup_tty() - find an existing tty, if any
1345 * @driver: the driver for the tty
1346 * @idx: the minor number
1348 * Return the tty, if found. If not found, return NULL or ERR_PTR() if the
1349 * driver lookup() method returns an error.
1351 * Locking: tty_mutex must be held. If the tty is found, bump the tty kref.
1353 static struct tty_struct
*tty_driver_lookup_tty(struct tty_driver
*driver
,
1354 struct inode
*inode
, int idx
)
1356 struct tty_struct
*tty
;
1358 if (driver
->ops
->lookup
)
1359 tty
= driver
->ops
->lookup(driver
, inode
, idx
);
1361 tty
= driver
->ttys
[idx
];
1369 * tty_init_termios - helper for termios setup
1370 * @tty: the tty to set up
1372 * Initialise the termios structures for this tty. Thus runs under
1373 * the tty_mutex currently so we can be relaxed about ordering.
1376 int tty_init_termios(struct tty_struct
*tty
)
1378 struct ktermios
*tp
;
1379 int idx
= tty
->index
;
1381 if (tty
->driver
->flags
& TTY_DRIVER_RESET_TERMIOS
)
1382 tty
->termios
= tty
->driver
->init_termios
;
1384 /* Check for lazy saved data */
1385 tp
= tty
->driver
->termios
[idx
];
1389 tty
->termios
= tty
->driver
->init_termios
;
1391 /* Compatibility until drivers always set this */
1392 tty
->termios
.c_ispeed
= tty_termios_input_baud_rate(&tty
->termios
);
1393 tty
->termios
.c_ospeed
= tty_termios_baud_rate(&tty
->termios
);
1396 EXPORT_SYMBOL_GPL(tty_init_termios
);
1398 int tty_standard_install(struct tty_driver
*driver
, struct tty_struct
*tty
)
1400 int ret
= tty_init_termios(tty
);
1404 tty_driver_kref_get(driver
);
1406 driver
->ttys
[tty
->index
] = tty
;
1409 EXPORT_SYMBOL_GPL(tty_standard_install
);
1412 * tty_driver_install_tty() - install a tty entry in the driver
1413 * @driver: the driver for the tty
1416 * Install a tty object into the driver tables. The tty->index field
1417 * will be set by the time this is called. This method is responsible
1418 * for ensuring any need additional structures are allocated and
1421 * Locking: tty_mutex for now
1423 static int tty_driver_install_tty(struct tty_driver
*driver
,
1424 struct tty_struct
*tty
)
1426 return driver
->ops
->install
? driver
->ops
->install(driver
, tty
) :
1427 tty_standard_install(driver
, tty
);
1431 * tty_driver_remove_tty() - remove a tty from the driver tables
1432 * @driver: the driver for the tty
1433 * @idx: the minor number
1435 * Remvoe a tty object from the driver tables. The tty->index field
1436 * will be set by the time this is called.
1438 * Locking: tty_mutex for now
1440 void tty_driver_remove_tty(struct tty_driver
*driver
, struct tty_struct
*tty
)
1442 if (driver
->ops
->remove
)
1443 driver
->ops
->remove(driver
, tty
);
1445 driver
->ttys
[tty
->index
] = NULL
;
1449 * tty_reopen() - fast re-open of an open tty
1450 * @tty - the tty to open
1452 * Return 0 on success, -errno on error.
1453 * Re-opens on master ptys are not allowed and return -EIO.
1455 * Locking: Caller must hold tty_lock
1457 static int tty_reopen(struct tty_struct
*tty
)
1459 struct tty_driver
*driver
= tty
->driver
;
1464 if (driver
->type
== TTY_DRIVER_TYPE_PTY
&&
1465 driver
->subtype
== PTY_TYPE_MASTER
)
1468 if (test_bit(TTY_EXCLUSIVE
, &tty
->flags
) && !capable(CAP_SYS_ADMIN
))
1473 WARN_ON(!tty
->ldisc
);
1479 * tty_init_dev - initialise a tty device
1480 * @driver: tty driver we are opening a device on
1481 * @idx: device index
1482 * @ret_tty: returned tty structure
1484 * Prepare a tty device. This may not be a "new" clean device but
1485 * could also be an active device. The pty drivers require special
1486 * handling because of this.
1489 * The function is called under the tty_mutex, which
1490 * protects us from the tty struct or driver itself going away.
1492 * On exit the tty device has the line discipline attached and
1493 * a reference count of 1. If a pair was created for pty/tty use
1494 * and the other was a pty master then it too has a reference count of 1.
1496 * WSH 06/09/97: Rewritten to remove races and properly clean up after a
1497 * failed open. The new code protects the open with a mutex, so it's
1498 * really quite straightforward. The mutex locking can probably be
1499 * relaxed for the (most common) case of reopening a tty.
1502 struct tty_struct
*tty_init_dev(struct tty_driver
*driver
, int idx
)
1504 struct tty_struct
*tty
;
1508 * First time open is complex, especially for PTY devices.
1509 * This code guarantees that either everything succeeds and the
1510 * TTY is ready for operation, or else the table slots are vacated
1511 * and the allocated memory released. (Except that the termios
1512 * and locked termios may be retained.)
1515 if (!try_module_get(driver
->owner
))
1516 return ERR_PTR(-ENODEV
);
1518 tty
= alloc_tty_struct(driver
, idx
);
1521 goto err_module_put
;
1525 retval
= tty_driver_install_tty(driver
, tty
);
1527 goto err_deinit_tty
;
1530 tty
->port
= driver
->ports
[idx
];
1532 WARN_RATELIMIT(!tty
->port
,
1533 "%s: %s driver does not set tty->port. This will crash the kernel later. Fix the driver!\n",
1534 __func__
, tty
->driver
->name
);
1536 tty
->port
->itty
= tty
;
1539 * Structures all installed ... call the ldisc open routines.
1540 * If we fail here just call release_tty to clean up. No need
1541 * to decrement the use counts, as release_tty doesn't care.
1543 retval
= tty_ldisc_setup(tty
, tty
->link
);
1545 goto err_release_tty
;
1546 /* Return the tty locked so that it cannot vanish under the caller */
1551 deinitialize_tty_struct(tty
);
1552 free_tty_struct(tty
);
1554 module_put(driver
->owner
);
1555 return ERR_PTR(retval
);
1557 /* call the tty release_tty routine to clean out this slot */
1560 printk_ratelimited(KERN_INFO
"tty_init_dev: ldisc open failed, "
1561 "clearing slot %d\n", idx
);
1562 release_tty(tty
, idx
);
1563 return ERR_PTR(retval
);
1566 void tty_free_termios(struct tty_struct
*tty
)
1568 struct ktermios
*tp
;
1569 int idx
= tty
->index
;
1571 /* If the port is going to reset then it has no termios to save */
1572 if (tty
->driver
->flags
& TTY_DRIVER_RESET_TERMIOS
)
1575 /* Stash the termios data */
1576 tp
= tty
->driver
->termios
[idx
];
1578 tp
= kmalloc(sizeof(struct ktermios
), GFP_KERNEL
);
1580 pr_warn("tty: no memory to save termios state.\n");
1583 tty
->driver
->termios
[idx
] = tp
;
1587 EXPORT_SYMBOL(tty_free_termios
);
1590 * tty_flush_works - flush all works of a tty/pty pair
1591 * @tty: tty device to flush works for (or either end of a pty pair)
1593 * Sync flush all works belonging to @tty (and the 'other' tty).
1595 static void tty_flush_works(struct tty_struct
*tty
)
1597 flush_work(&tty
->SAK_work
);
1598 flush_work(&tty
->hangup_work
);
1600 flush_work(&tty
->link
->SAK_work
);
1601 flush_work(&tty
->link
->hangup_work
);
1606 * release_one_tty - release tty structure memory
1607 * @kref: kref of tty we are obliterating
1609 * Releases memory associated with a tty structure, and clears out the
1610 * driver table slots. This function is called when a device is no longer
1611 * in use. It also gets called when setup of a device fails.
1614 * takes the file list lock internally when working on the list
1615 * of ttys that the driver keeps.
1617 * This method gets called from a work queue so that the driver private
1618 * cleanup ops can sleep (needed for USB at least)
1620 static void release_one_tty(struct work_struct
*work
)
1622 struct tty_struct
*tty
=
1623 container_of(work
, struct tty_struct
, hangup_work
);
1624 struct tty_driver
*driver
= tty
->driver
;
1625 struct module
*owner
= driver
->owner
;
1627 if (tty
->ops
->cleanup
)
1628 tty
->ops
->cleanup(tty
);
1631 tty_driver_kref_put(driver
);
1634 spin_lock(&tty_files_lock
);
1635 list_del_init(&tty
->tty_files
);
1636 spin_unlock(&tty_files_lock
);
1639 put_pid(tty
->session
);
1640 free_tty_struct(tty
);
1643 static void queue_release_one_tty(struct kref
*kref
)
1645 struct tty_struct
*tty
= container_of(kref
, struct tty_struct
, kref
);
1647 /* The hangup queue is now free so we can reuse it rather than
1648 waste a chunk of memory for each port */
1649 INIT_WORK(&tty
->hangup_work
, release_one_tty
);
1650 schedule_work(&tty
->hangup_work
);
1654 * tty_kref_put - release a tty kref
1657 * Release a reference to a tty device and if need be let the kref
1658 * layer destruct the object for us
1661 void tty_kref_put(struct tty_struct
*tty
)
1664 kref_put(&tty
->kref
, queue_release_one_tty
);
1666 EXPORT_SYMBOL(tty_kref_put
);
1669 * release_tty - release tty structure memory
1671 * Release both @tty and a possible linked partner (think pty pair),
1672 * and decrement the refcount of the backing module.
1676 * takes the file list lock internally when working on the list
1677 * of ttys that the driver keeps.
1680 static void release_tty(struct tty_struct
*tty
, int idx
)
1682 /* This should always be true but check for the moment */
1683 WARN_ON(tty
->index
!= idx
);
1684 WARN_ON(!mutex_is_locked(&tty_mutex
));
1685 if (tty
->ops
->shutdown
)
1686 tty
->ops
->shutdown(tty
);
1687 tty_free_termios(tty
);
1688 tty_driver_remove_tty(tty
->driver
, tty
);
1689 tty
->port
->itty
= NULL
;
1691 tty
->link
->port
->itty
= NULL
;
1692 cancel_work_sync(&tty
->port
->buf
.work
);
1694 tty_kref_put(tty
->link
);
1699 * tty_release_checks - check a tty before real release
1700 * @tty: tty to check
1701 * @o_tty: link of @tty (if any)
1702 * @idx: index of the tty
1704 * Performs some paranoid checking before true release of the @tty.
1705 * This is a no-op unless TTY_PARANOIA_CHECK is defined.
1707 static int tty_release_checks(struct tty_struct
*tty
, int idx
)
1709 #ifdef TTY_PARANOIA_CHECK
1710 if (idx
< 0 || idx
>= tty
->driver
->num
) {
1711 tty_debug(tty
, "bad idx %d\n", idx
);
1715 /* not much to check for devpts */
1716 if (tty
->driver
->flags
& TTY_DRIVER_DEVPTS_MEM
)
1719 if (tty
!= tty
->driver
->ttys
[idx
]) {
1720 tty_debug(tty
, "bad driver table[%d] = %p\n",
1721 idx
, tty
->driver
->ttys
[idx
]);
1724 if (tty
->driver
->other
) {
1725 struct tty_struct
*o_tty
= tty
->link
;
1727 if (o_tty
!= tty
->driver
->other
->ttys
[idx
]) {
1728 tty_debug(tty
, "bad other table[%d] = %p\n",
1729 idx
, tty
->driver
->other
->ttys
[idx
]);
1732 if (o_tty
->link
!= tty
) {
1733 tty_debug(tty
, "bad link = %p\n", o_tty
->link
);
1742 * tty_release - vfs callback for close
1743 * @inode: inode of tty
1744 * @filp: file pointer for handle to tty
1746 * Called the last time each file handle is closed that references
1747 * this tty. There may however be several such references.
1750 * Takes bkl. See tty_release_dev
1752 * Even releasing the tty structures is a tricky business.. We have
1753 * to be very careful that the structures are all released at the
1754 * same time, as interrupts might otherwise get the wrong pointers.
1756 * WSH 09/09/97: rewritten to avoid some nasty race conditions that could
1757 * lead to double frees or releasing memory still in use.
1760 int tty_release(struct inode
*inode
, struct file
*filp
)
1762 struct tty_struct
*tty
= file_tty(filp
);
1763 struct tty_struct
*o_tty
= NULL
;
1764 int do_sleep
, final
;
1769 if (tty_paranoia_check(tty
, inode
, __func__
))
1773 check_tty_count(tty
, __func__
);
1775 __tty_fasync(-1, filp
, 0);
1778 if (tty
->driver
->type
== TTY_DRIVER_TYPE_PTY
&&
1779 tty
->driver
->subtype
== PTY_TYPE_MASTER
)
1782 if (tty_release_checks(tty
, idx
)) {
1787 tty_debug_hangup(tty
, "(tty count=%d)...\n", tty
->count
);
1789 if (tty
->ops
->close
)
1790 tty
->ops
->close(tty
, filp
);
1792 /* If tty is pty master, lock the slave pty (stable lock order) */
1793 tty_lock_slave(o_tty
);
1796 * Sanity check: if tty->count is going to zero, there shouldn't be
1797 * any waiters on tty->read_wait or tty->write_wait. We test the
1798 * wait queues and kick everyone out _before_ actually starting to
1799 * close. This ensures that we won't block while releasing the tty
1802 * The test for the o_tty closing is necessary, since the master and
1803 * slave sides may close in any order. If the slave side closes out
1804 * first, its count will be one, since the master side holds an open.
1805 * Thus this test wouldn't be triggered at the time the slave closed,
1811 if (tty
->count
<= 1) {
1812 if (waitqueue_active(&tty
->read_wait
)) {
1813 wake_up_poll(&tty
->read_wait
, POLLIN
);
1816 if (waitqueue_active(&tty
->write_wait
)) {
1817 wake_up_poll(&tty
->write_wait
, POLLOUT
);
1821 if (o_tty
&& o_tty
->count
<= 1) {
1822 if (waitqueue_active(&o_tty
->read_wait
)) {
1823 wake_up_poll(&o_tty
->read_wait
, POLLIN
);
1826 if (waitqueue_active(&o_tty
->write_wait
)) {
1827 wake_up_poll(&o_tty
->write_wait
, POLLOUT
);
1836 printk(KERN_WARNING
"%s: %s: read/write wait queue active!\n",
1837 __func__
, tty_name(tty
));
1839 schedule_timeout_killable(timeout
);
1840 if (timeout
< 120 * HZ
)
1841 timeout
= 2 * timeout
+ 1;
1843 timeout
= MAX_SCHEDULE_TIMEOUT
;
1847 if (--o_tty
->count
< 0) {
1848 printk(KERN_WARNING
"%s: bad pty slave count (%d) for %s\n",
1849 __func__
, o_tty
->count
, tty_name(o_tty
));
1853 if (--tty
->count
< 0) {
1854 printk(KERN_WARNING
"%s: bad tty->count (%d) for %s\n",
1855 __func__
, tty
->count
, tty_name(tty
));
1860 * We've decremented tty->count, so we need to remove this file
1861 * descriptor off the tty->tty_files list; this serves two
1863 * - check_tty_count sees the correct number of file descriptors
1864 * associated with this tty.
1865 * - do_tty_hangup no longer sees this file descriptor as
1866 * something that needs to be handled for hangups.
1871 * Perform some housekeeping before deciding whether to return.
1873 * If _either_ side is closing, make sure there aren't any
1874 * processes that still think tty or o_tty is their controlling
1878 read_lock(&tasklist_lock
);
1879 session_clear_tty(tty
->session
);
1881 session_clear_tty(o_tty
->session
);
1882 read_unlock(&tasklist_lock
);
1885 /* check whether both sides are closing ... */
1886 final
= !tty
->count
&& !(o_tty
&& o_tty
->count
);
1888 tty_unlock_slave(o_tty
);
1891 /* At this point, the tty->count == 0 should ensure a dead tty
1892 cannot be re-opened by a racing opener */
1897 tty_debug_hangup(tty
, "final close\n");
1899 * Ask the line discipline code to release its structures
1901 tty_ldisc_release(tty
);
1903 /* Wait for pending work before tty destruction commmences */
1904 tty_flush_works(tty
);
1906 tty_debug_hangup(tty
, "freeing structure...\n");
1908 * The release_tty function takes care of the details of clearing
1909 * the slots and preserving the termios structure. The tty_unlock_pair
1910 * should be safe as we keep a kref while the tty is locked (so the
1911 * unlock never unlocks a freed tty).
1913 mutex_lock(&tty_mutex
);
1914 release_tty(tty
, idx
);
1915 mutex_unlock(&tty_mutex
);
1921 * tty_open_current_tty - get locked tty of current task
1922 * @device: device number
1923 * @filp: file pointer to tty
1924 * @return: locked tty of the current task iff @device is /dev/tty
1926 * Performs a re-open of the current task's controlling tty.
1928 * We cannot return driver and index like for the other nodes because
1929 * devpts will not work then. It expects inodes to be from devpts FS.
1931 static struct tty_struct
*tty_open_current_tty(dev_t device
, struct file
*filp
)
1933 struct tty_struct
*tty
;
1936 if (device
!= MKDEV(TTYAUX_MAJOR
, 0))
1939 tty
= get_current_tty();
1941 return ERR_PTR(-ENXIO
);
1943 filp
->f_flags
|= O_NONBLOCK
; /* Don't let /dev/tty block */
1946 tty_kref_put(tty
); /* safe to drop the kref now */
1948 retval
= tty_reopen(tty
);
1951 tty
= ERR_PTR(retval
);
1957 * tty_lookup_driver - lookup a tty driver for a given device file
1958 * @device: device number
1959 * @filp: file pointer to tty
1960 * @noctty: set if the device should not become a controlling tty
1961 * @index: index for the device in the @return driver
1962 * @return: driver for this inode (with increased refcount)
1964 * If @return is not erroneous, the caller is responsible to decrement the
1965 * refcount by tty_driver_kref_put.
1967 * Locking: tty_mutex protects get_tty_driver
1969 static struct tty_driver
*tty_lookup_driver(dev_t device
, struct file
*filp
,
1970 int *noctty
, int *index
)
1972 struct tty_driver
*driver
;
1976 case MKDEV(TTY_MAJOR
, 0): {
1977 extern struct tty_driver
*console_driver
;
1978 driver
= tty_driver_kref_get(console_driver
);
1979 *index
= fg_console
;
1984 case MKDEV(TTYAUX_MAJOR
, 1): {
1985 struct tty_driver
*console_driver
= console_device(index
);
1986 if (console_driver
) {
1987 driver
= tty_driver_kref_get(console_driver
);
1989 /* Don't let /dev/console block */
1990 filp
->f_flags
|= O_NONBLOCK
;
1995 return ERR_PTR(-ENODEV
);
1998 driver
= get_tty_driver(device
, index
);
2000 return ERR_PTR(-ENODEV
);
2007 * tty_open - open a tty device
2008 * @inode: inode of device file
2009 * @filp: file pointer to tty
2011 * tty_open and tty_release keep up the tty count that contains the
2012 * number of opens done on a tty. We cannot use the inode-count, as
2013 * different inodes might point to the same tty.
2015 * Open-counting is needed for pty masters, as well as for keeping
2016 * track of serial lines: DTR is dropped when the last close happens.
2017 * (This is not done solely through tty->count, now. - Ted 1/27/92)
2019 * The termios state of a pty is reset on first open so that
2020 * settings don't persist across reuse.
2022 * Locking: tty_mutex protects tty, tty_lookup_driver and tty_init_dev.
2023 * tty->count should protect the rest.
2024 * ->siglock protects ->signal/->sighand
2026 * Note: the tty_unlock/lock cases without a ref are only safe due to
2030 static int tty_open(struct inode
*inode
, struct file
*filp
)
2032 struct tty_struct
*tty
;
2034 struct tty_driver
*driver
= NULL
;
2036 dev_t device
= inode
->i_rdev
;
2037 unsigned saved_flags
= filp
->f_flags
;
2039 nonseekable_open(inode
, filp
);
2042 retval
= tty_alloc_file(filp
);
2046 noctty
= filp
->f_flags
& O_NOCTTY
;
2050 tty
= tty_open_current_tty(device
, filp
);
2052 mutex_lock(&tty_mutex
);
2053 driver
= tty_lookup_driver(device
, filp
, &noctty
, &index
);
2054 if (IS_ERR(driver
)) {
2055 retval
= PTR_ERR(driver
);
2059 /* check whether we're reopening an existing tty */
2060 tty
= tty_driver_lookup_tty(driver
, inode
, index
);
2062 retval
= PTR_ERR(tty
);
2067 mutex_unlock(&tty_mutex
);
2069 /* safe to drop the kref from tty_driver_lookup_tty() */
2071 retval
= tty_reopen(tty
);
2074 tty
= ERR_PTR(retval
);
2076 } else { /* Returns with the tty_lock held for now */
2077 tty
= tty_init_dev(driver
, index
);
2078 mutex_unlock(&tty_mutex
);
2081 tty_driver_kref_put(driver
);
2085 retval
= PTR_ERR(tty
);
2089 tty_add_file(tty
, filp
);
2091 check_tty_count(tty
, __func__
);
2092 if (tty
->driver
->type
== TTY_DRIVER_TYPE_PTY
&&
2093 tty
->driver
->subtype
== PTY_TYPE_MASTER
)
2096 tty_debug_hangup(tty
, "(tty count=%d)\n", tty
->count
);
2099 retval
= tty
->ops
->open(tty
, filp
);
2102 filp
->f_flags
= saved_flags
;
2105 tty_debug_hangup(tty
, "error %d, releasing...\n", retval
);
2107 tty_unlock(tty
); /* need to call tty_release without BTM */
2108 tty_release(inode
, filp
);
2109 if (retval
!= -ERESTARTSYS
)
2112 if (signal_pending(current
))
2117 * Need to reset f_op in case a hangup happened.
2119 if (tty_hung_up_p(filp
))
2120 filp
->f_op
= &tty_fops
;
2123 clear_bit(TTY_HUPPED
, &tty
->flags
);
2126 read_lock(&tasklist_lock
);
2127 spin_lock_irq(¤t
->sighand
->siglock
);
2129 current
->signal
->leader
&&
2130 !current
->signal
->tty
&&
2131 tty
->session
== NULL
)
2132 __proc_set_tty(tty
);
2133 spin_unlock_irq(¤t
->sighand
->siglock
);
2134 read_unlock(&tasklist_lock
);
2138 mutex_unlock(&tty_mutex
);
2139 /* after locks to avoid deadlock */
2140 if (!IS_ERR_OR_NULL(driver
))
2141 tty_driver_kref_put(driver
);
2143 tty_free_file(filp
);
2150 * tty_poll - check tty status
2151 * @filp: file being polled
2152 * @wait: poll wait structures to update
2154 * Call the line discipline polling method to obtain the poll
2155 * status of the device.
2157 * Locking: locks called line discipline but ldisc poll method
2158 * may be re-entered freely by other callers.
2161 static unsigned int tty_poll(struct file
*filp
, poll_table
*wait
)
2163 struct tty_struct
*tty
= file_tty(filp
);
2164 struct tty_ldisc
*ld
;
2167 if (tty_paranoia_check(tty
, file_inode(filp
), "tty_poll"))
2170 ld
= tty_ldisc_ref_wait(tty
);
2172 ret
= ld
->ops
->poll(tty
, filp
, wait
);
2173 tty_ldisc_deref(ld
);
2177 static int __tty_fasync(int fd
, struct file
*filp
, int on
)
2179 struct tty_struct
*tty
= file_tty(filp
);
2180 struct tty_ldisc
*ldisc
;
2181 unsigned long flags
;
2184 if (tty_paranoia_check(tty
, file_inode(filp
), "tty_fasync"))
2187 retval
= fasync_helper(fd
, filp
, on
, &tty
->fasync
);
2191 ldisc
= tty_ldisc_ref(tty
);
2193 if (ldisc
->ops
->fasync
)
2194 ldisc
->ops
->fasync(tty
, on
);
2195 tty_ldisc_deref(ldisc
);
2202 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
2205 type
= PIDTYPE_PGID
;
2207 pid
= task_pid(current
);
2211 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
2212 __f_setown(filp
, pid
, type
, 0);
2220 static int tty_fasync(int fd
, struct file
*filp
, int on
)
2222 struct tty_struct
*tty
= file_tty(filp
);
2226 retval
= __tty_fasync(fd
, filp
, on
);
2233 * tiocsti - fake input character
2234 * @tty: tty to fake input into
2235 * @p: pointer to character
2237 * Fake input to a tty device. Does the necessary locking and
2240 * FIXME: does not honour flow control ??
2243 * Called functions take tty_ldiscs_lock
2244 * current->signal->tty check is safe without locks
2246 * FIXME: may race normal receive processing
2249 static int tiocsti(struct tty_struct
*tty
, char __user
*p
)
2252 struct tty_ldisc
*ld
;
2254 if ((current
->signal
->tty
!= tty
) && !capable(CAP_SYS_ADMIN
))
2256 if (get_user(ch
, p
))
2258 tty_audit_tiocsti(tty
, ch
);
2259 ld
= tty_ldisc_ref_wait(tty
);
2260 ld
->ops
->receive_buf(tty
, &ch
, &mbz
, 1);
2261 tty_ldisc_deref(ld
);
2266 * tiocgwinsz - implement window query ioctl
2268 * @arg: user buffer for result
2270 * Copies the kernel idea of the window size into the user buffer.
2272 * Locking: tty->winsize_mutex is taken to ensure the winsize data
2276 static int tiocgwinsz(struct tty_struct
*tty
, struct winsize __user
*arg
)
2280 mutex_lock(&tty
->winsize_mutex
);
2281 err
= copy_to_user(arg
, &tty
->winsize
, sizeof(*arg
));
2282 mutex_unlock(&tty
->winsize_mutex
);
2284 return err
? -EFAULT
: 0;
2288 * tty_do_resize - resize event
2289 * @tty: tty being resized
2290 * @rows: rows (character)
2291 * @cols: cols (character)
2293 * Update the termios variables and send the necessary signals to
2294 * peform a terminal resize correctly
2297 int tty_do_resize(struct tty_struct
*tty
, struct winsize
*ws
)
2302 mutex_lock(&tty
->winsize_mutex
);
2303 if (!memcmp(ws
, &tty
->winsize
, sizeof(*ws
)))
2306 /* Signal the foreground process group */
2307 pgrp
= tty_get_pgrp(tty
);
2309 kill_pgrp(pgrp
, SIGWINCH
, 1);
2314 mutex_unlock(&tty
->winsize_mutex
);
2317 EXPORT_SYMBOL(tty_do_resize
);
2320 * tiocswinsz - implement window size set ioctl
2321 * @tty; tty side of tty
2322 * @arg: user buffer for result
2324 * Copies the user idea of the window size to the kernel. Traditionally
2325 * this is just advisory information but for the Linux console it
2326 * actually has driver level meaning and triggers a VC resize.
2329 * Driver dependent. The default do_resize method takes the
2330 * tty termios mutex and ctrl_lock. The console takes its own lock
2331 * then calls into the default method.
2334 static int tiocswinsz(struct tty_struct
*tty
, struct winsize __user
*arg
)
2336 struct winsize tmp_ws
;
2337 if (copy_from_user(&tmp_ws
, arg
, sizeof(*arg
)))
2340 if (tty
->ops
->resize
)
2341 return tty
->ops
->resize(tty
, &tmp_ws
);
2343 return tty_do_resize(tty
, &tmp_ws
);
2347 * tioccons - allow admin to move logical console
2348 * @file: the file to become console
2350 * Allow the administrator to move the redirected console device
2352 * Locking: uses redirect_lock to guard the redirect information
2355 static int tioccons(struct file
*file
)
2357 if (!capable(CAP_SYS_ADMIN
))
2359 if (file
->f_op
->write
== redirected_tty_write
) {
2361 spin_lock(&redirect_lock
);
2364 spin_unlock(&redirect_lock
);
2369 spin_lock(&redirect_lock
);
2371 spin_unlock(&redirect_lock
);
2374 redirect
= get_file(file
);
2375 spin_unlock(&redirect_lock
);
2380 * fionbio - non blocking ioctl
2381 * @file: file to set blocking value
2382 * @p: user parameter
2384 * Historical tty interfaces had a blocking control ioctl before
2385 * the generic functionality existed. This piece of history is preserved
2386 * in the expected tty API of posix OS's.
2388 * Locking: none, the open file handle ensures it won't go away.
2391 static int fionbio(struct file
*file
, int __user
*p
)
2395 if (get_user(nonblock
, p
))
2398 spin_lock(&file
->f_lock
);
2400 file
->f_flags
|= O_NONBLOCK
;
2402 file
->f_flags
&= ~O_NONBLOCK
;
2403 spin_unlock(&file
->f_lock
);
2408 * tiocsctty - set controlling tty
2409 * @tty: tty structure
2410 * @arg: user argument
2412 * This ioctl is used to manage job control. It permits a session
2413 * leader to set this tty as the controlling tty for the session.
2416 * Takes tty_lock() to serialize proc_set_tty() for this tty
2417 * Takes tasklist_lock internally to walk sessions
2418 * Takes ->siglock() when updating signal->tty
2421 static int tiocsctty(struct tty_struct
*tty
, int arg
)
2426 read_lock(&tasklist_lock
);
2428 if (current
->signal
->leader
&& (task_session(current
) == tty
->session
))
2432 * The process must be a session leader and
2433 * not have a controlling tty already.
2435 if (!current
->signal
->leader
|| current
->signal
->tty
) {
2442 * This tty is already the controlling
2443 * tty for another session group!
2445 if (arg
== 1 && capable(CAP_SYS_ADMIN
)) {
2449 session_clear_tty(tty
->session
);
2457 read_unlock(&tasklist_lock
);
2463 * tty_get_pgrp - return a ref counted pgrp pid
2466 * Returns a refcounted instance of the pid struct for the process
2467 * group controlling the tty.
2470 struct pid
*tty_get_pgrp(struct tty_struct
*tty
)
2472 unsigned long flags
;
2475 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
2476 pgrp
= get_pid(tty
->pgrp
);
2477 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
2481 EXPORT_SYMBOL_GPL(tty_get_pgrp
);
2484 * This checks not only the pgrp, but falls back on the pid if no
2485 * satisfactory pgrp is found. I dunno - gdb doesn't work correctly
2488 * The caller must hold rcu lock or the tasklist lock.
2490 static struct pid
*session_of_pgrp(struct pid
*pgrp
)
2492 struct task_struct
*p
;
2493 struct pid
*sid
= NULL
;
2495 p
= pid_task(pgrp
, PIDTYPE_PGID
);
2497 p
= pid_task(pgrp
, PIDTYPE_PID
);
2499 sid
= task_session(p
);
2505 * tiocgpgrp - get process group
2506 * @tty: tty passed by user
2507 * @real_tty: tty side of the tty passed by the user if a pty else the tty
2510 * Obtain the process group of the tty. If there is no process group
2513 * Locking: none. Reference to current->signal->tty is safe.
2516 static int tiocgpgrp(struct tty_struct
*tty
, struct tty_struct
*real_tty
, pid_t __user
*p
)
2521 * (tty == real_tty) is a cheap way of
2522 * testing if the tty is NOT a master pty.
2524 if (tty
== real_tty
&& current
->signal
->tty
!= real_tty
)
2526 pid
= tty_get_pgrp(real_tty
);
2527 ret
= put_user(pid_vnr(pid
), p
);
2533 * tiocspgrp - attempt to set process group
2534 * @tty: tty passed by user
2535 * @real_tty: tty side device matching tty passed by user
2538 * Set the process group of the tty to the session passed. Only
2539 * permitted where the tty session is our session.
2541 * Locking: RCU, ctrl lock
2544 static int tiocspgrp(struct tty_struct
*tty
, struct tty_struct
*real_tty
, pid_t __user
*p
)
2548 int retval
= tty_check_change(real_tty
);
2549 unsigned long flags
;
2555 if (!current
->signal
->tty
||
2556 (current
->signal
->tty
!= real_tty
) ||
2557 (real_tty
->session
!= task_session(current
)))
2559 if (get_user(pgrp_nr
, p
))
2564 pgrp
= find_vpid(pgrp_nr
);
2569 if (session_of_pgrp(pgrp
) != task_session(current
))
2572 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
2573 put_pid(real_tty
->pgrp
);
2574 real_tty
->pgrp
= get_pid(pgrp
);
2575 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
2582 * tiocgsid - get session id
2583 * @tty: tty passed by user
2584 * @real_tty: tty side of the tty passed by the user if a pty else the tty
2585 * @p: pointer to returned session id
2587 * Obtain the session id of the tty. If there is no session
2590 * Locking: none. Reference to current->signal->tty is safe.
2593 static int tiocgsid(struct tty_struct
*tty
, struct tty_struct
*real_tty
, pid_t __user
*p
)
2596 * (tty == real_tty) is a cheap way of
2597 * testing if the tty is NOT a master pty.
2599 if (tty
== real_tty
&& current
->signal
->tty
!= real_tty
)
2601 if (!real_tty
->session
)
2603 return put_user(pid_vnr(real_tty
->session
), p
);
2607 * tiocsetd - set line discipline
2609 * @p: pointer to user data
2611 * Set the line discipline according to user request.
2613 * Locking: see tty_set_ldisc, this function is just a helper
2616 static int tiocsetd(struct tty_struct
*tty
, int __user
*p
)
2621 if (get_user(ldisc
, p
))
2624 ret
= tty_set_ldisc(tty
, ldisc
);
2630 * send_break - performed time break
2631 * @tty: device to break on
2632 * @duration: timeout in mS
2634 * Perform a timed break on hardware that lacks its own driver level
2635 * timed break functionality.
2638 * atomic_write_lock serializes
2642 static int send_break(struct tty_struct
*tty
, unsigned int duration
)
2646 if (tty
->ops
->break_ctl
== NULL
)
2649 if (tty
->driver
->flags
& TTY_DRIVER_HARDWARE_BREAK
)
2650 retval
= tty
->ops
->break_ctl(tty
, duration
);
2652 /* Do the work ourselves */
2653 if (tty_write_lock(tty
, 0) < 0)
2655 retval
= tty
->ops
->break_ctl(tty
, -1);
2658 if (!signal_pending(current
))
2659 msleep_interruptible(duration
);
2660 retval
= tty
->ops
->break_ctl(tty
, 0);
2662 tty_write_unlock(tty
);
2663 if (signal_pending(current
))
2670 * tty_tiocmget - get modem status
2672 * @file: user file pointer
2673 * @p: pointer to result
2675 * Obtain the modem status bits from the tty driver if the feature
2676 * is supported. Return -EINVAL if it is not available.
2678 * Locking: none (up to the driver)
2681 static int tty_tiocmget(struct tty_struct
*tty
, int __user
*p
)
2683 int retval
= -EINVAL
;
2685 if (tty
->ops
->tiocmget
) {
2686 retval
= tty
->ops
->tiocmget(tty
);
2689 retval
= put_user(retval
, p
);
2695 * tty_tiocmset - set modem status
2697 * @cmd: command - clear bits, set bits or set all
2698 * @p: pointer to desired bits
2700 * Set the modem status bits from the tty driver if the feature
2701 * is supported. Return -EINVAL if it is not available.
2703 * Locking: none (up to the driver)
2706 static int tty_tiocmset(struct tty_struct
*tty
, unsigned int cmd
,
2710 unsigned int set
, clear
, val
;
2712 if (tty
->ops
->tiocmset
== NULL
)
2715 retval
= get_user(val
, p
);
2731 set
&= TIOCM_DTR
|TIOCM_RTS
|TIOCM_OUT1
|TIOCM_OUT2
|TIOCM_LOOP
;
2732 clear
&= TIOCM_DTR
|TIOCM_RTS
|TIOCM_OUT1
|TIOCM_OUT2
|TIOCM_LOOP
;
2733 return tty
->ops
->tiocmset(tty
, set
, clear
);
2736 static int tty_tiocgicount(struct tty_struct
*tty
, void __user
*arg
)
2738 int retval
= -EINVAL
;
2739 struct serial_icounter_struct icount
;
2740 memset(&icount
, 0, sizeof(icount
));
2741 if (tty
->ops
->get_icount
)
2742 retval
= tty
->ops
->get_icount(tty
, &icount
);
2745 if (copy_to_user(arg
, &icount
, sizeof(icount
)))
2750 static void tty_warn_deprecated_flags(struct serial_struct __user
*ss
)
2752 static DEFINE_RATELIMIT_STATE(depr_flags
,
2753 DEFAULT_RATELIMIT_INTERVAL
,
2754 DEFAULT_RATELIMIT_BURST
);
2755 char comm
[TASK_COMM_LEN
];
2758 if (get_user(flags
, &ss
->flags
))
2761 flags
&= ASYNC_DEPRECATED
;
2763 if (flags
&& __ratelimit(&depr_flags
))
2764 pr_warning("%s: '%s' is using deprecated serial flags (with no effect): %.8x\n",
2765 __func__
, get_task_comm(comm
, current
), flags
);
2769 * if pty, return the slave side (real_tty)
2770 * otherwise, return self
2772 static struct tty_struct
*tty_pair_get_tty(struct tty_struct
*tty
)
2774 if (tty
->driver
->type
== TTY_DRIVER_TYPE_PTY
&&
2775 tty
->driver
->subtype
== PTY_TYPE_MASTER
)
2781 * Split this up, as gcc can choke on it otherwise..
2783 long tty_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
2785 struct tty_struct
*tty
= file_tty(file
);
2786 struct tty_struct
*real_tty
;
2787 void __user
*p
= (void __user
*)arg
;
2789 struct tty_ldisc
*ld
;
2791 if (tty_paranoia_check(tty
, file_inode(file
), "tty_ioctl"))
2794 real_tty
= tty_pair_get_tty(tty
);
2797 * Factor out some common prep work
2805 retval
= tty_check_change(tty
);
2808 if (cmd
!= TIOCCBRK
) {
2809 tty_wait_until_sent(tty
, 0);
2810 if (signal_pending(current
))
2821 return tiocsti(tty
, p
);
2823 return tiocgwinsz(real_tty
, p
);
2825 return tiocswinsz(real_tty
, p
);
2827 return real_tty
!= tty
? -EINVAL
: tioccons(file
);
2829 return fionbio(file
, p
);
2831 set_bit(TTY_EXCLUSIVE
, &tty
->flags
);
2834 clear_bit(TTY_EXCLUSIVE
, &tty
->flags
);
2838 int excl
= test_bit(TTY_EXCLUSIVE
, &tty
->flags
);
2839 return put_user(excl
, (int __user
*)p
);
2842 if (current
->signal
->tty
!= tty
)
2847 return tiocsctty(tty
, arg
);
2849 return tiocgpgrp(tty
, real_tty
, p
);
2851 return tiocspgrp(tty
, real_tty
, p
);
2853 return tiocgsid(tty
, real_tty
, p
);
2855 return put_user(tty
->ldisc
->ops
->num
, (int __user
*)p
);
2857 return tiocsetd(tty
, p
);
2859 if (!capable(CAP_SYS_ADMIN
))
2865 unsigned int ret
= new_encode_dev(tty_devnum(real_tty
));
2866 return put_user(ret
, (unsigned int __user
*)p
);
2871 case TIOCSBRK
: /* Turn break on, unconditionally */
2872 if (tty
->ops
->break_ctl
)
2873 return tty
->ops
->break_ctl(tty
, -1);
2875 case TIOCCBRK
: /* Turn break off, unconditionally */
2876 if (tty
->ops
->break_ctl
)
2877 return tty
->ops
->break_ctl(tty
, 0);
2879 case TCSBRK
: /* SVID version: non-zero arg --> no break */
2880 /* non-zero arg means wait for all output data
2881 * to be sent (performed above) but don't send break.
2882 * This is used by the tcdrain() termios function.
2885 return send_break(tty
, 250);
2887 case TCSBRKP
: /* support for POSIX tcsendbreak() */
2888 return send_break(tty
, arg
? arg
*100 : 250);
2891 return tty_tiocmget(tty
, p
);
2895 return tty_tiocmset(tty
, cmd
, p
);
2897 retval
= tty_tiocgicount(tty
, p
);
2898 /* For the moment allow fall through to the old method */
2899 if (retval
!= -EINVAL
)
2906 /* flush tty buffer and allow ldisc to process ioctl */
2907 tty_buffer_flush(tty
, NULL
);
2912 tty_warn_deprecated_flags(p
);
2915 if (tty
->ops
->ioctl
) {
2916 retval
= tty
->ops
->ioctl(tty
, cmd
, arg
);
2917 if (retval
!= -ENOIOCTLCMD
)
2920 ld
= tty_ldisc_ref_wait(tty
);
2922 if (ld
->ops
->ioctl
) {
2923 retval
= ld
->ops
->ioctl(tty
, file
, cmd
, arg
);
2924 if (retval
== -ENOIOCTLCMD
)
2927 tty_ldisc_deref(ld
);
2931 #ifdef CONFIG_COMPAT
2932 static long tty_compat_ioctl(struct file
*file
, unsigned int cmd
,
2935 struct tty_struct
*tty
= file_tty(file
);
2936 struct tty_ldisc
*ld
;
2937 int retval
= -ENOIOCTLCMD
;
2939 if (tty_paranoia_check(tty
, file_inode(file
), "tty_ioctl"))
2942 if (tty
->ops
->compat_ioctl
) {
2943 retval
= tty
->ops
->compat_ioctl(tty
, cmd
, arg
);
2944 if (retval
!= -ENOIOCTLCMD
)
2948 ld
= tty_ldisc_ref_wait(tty
);
2949 if (ld
->ops
->compat_ioctl
)
2950 retval
= ld
->ops
->compat_ioctl(tty
, file
, cmd
, arg
);
2952 retval
= n_tty_compat_ioctl_helper(tty
, file
, cmd
, arg
);
2953 tty_ldisc_deref(ld
);
2959 static int this_tty(const void *t
, struct file
*file
, unsigned fd
)
2961 if (likely(file
->f_op
->read
!= tty_read
))
2963 return file_tty(file
) != t
? 0 : fd
+ 1;
2967 * This implements the "Secure Attention Key" --- the idea is to
2968 * prevent trojan horses by killing all processes associated with this
2969 * tty when the user hits the "Secure Attention Key". Required for
2970 * super-paranoid applications --- see the Orange Book for more details.
2972 * This code could be nicer; ideally it should send a HUP, wait a few
2973 * seconds, then send a INT, and then a KILL signal. But you then
2974 * have to coordinate with the init process, since all processes associated
2975 * with the current tty must be dead before the new getty is allowed
2978 * Now, if it would be correct ;-/ The current code has a nasty hole -
2979 * it doesn't catch files in flight. We may send the descriptor to ourselves
2980 * via AF_UNIX socket, close it and later fetch from socket. FIXME.
2982 * Nasty bug: do_SAK is being called in interrupt context. This can
2983 * deadlock. We punt it up to process context. AKPM - 16Mar2001
2985 void __do_SAK(struct tty_struct
*tty
)
2990 struct task_struct
*g
, *p
;
2991 struct pid
*session
;
2996 session
= tty
->session
;
2998 tty_ldisc_flush(tty
);
3000 tty_driver_flush_buffer(tty
);
3002 read_lock(&tasklist_lock
);
3003 /* Kill the entire session */
3004 do_each_pid_task(session
, PIDTYPE_SID
, p
) {
3005 printk(KERN_NOTICE
"SAK: killed process %d"
3006 " (%s): task_session(p)==tty->session\n",
3007 task_pid_nr(p
), p
->comm
);
3008 send_sig(SIGKILL
, p
, 1);
3009 } while_each_pid_task(session
, PIDTYPE_SID
, p
);
3010 /* Now kill any processes that happen to have the
3013 do_each_thread(g
, p
) {
3014 if (p
->signal
->tty
== tty
) {
3015 printk(KERN_NOTICE
"SAK: killed process %d"
3016 " (%s): task_session(p)==tty->session\n",
3017 task_pid_nr(p
), p
->comm
);
3018 send_sig(SIGKILL
, p
, 1);
3022 i
= iterate_fd(p
->files
, 0, this_tty
, tty
);
3024 printk(KERN_NOTICE
"SAK: killed process %d"
3025 " (%s): fd#%d opened to the tty\n",
3026 task_pid_nr(p
), p
->comm
, i
- 1);
3027 force_sig(SIGKILL
, p
);
3030 } while_each_thread(g
, p
);
3031 read_unlock(&tasklist_lock
);
3035 static void do_SAK_work(struct work_struct
*work
)
3037 struct tty_struct
*tty
=
3038 container_of(work
, struct tty_struct
, SAK_work
);
3043 * The tq handling here is a little racy - tty->SAK_work may already be queued.
3044 * Fortunately we don't need to worry, because if ->SAK_work is already queued,
3045 * the values which we write to it will be identical to the values which it
3046 * already has. --akpm
3048 void do_SAK(struct tty_struct
*tty
)
3052 schedule_work(&tty
->SAK_work
);
3055 EXPORT_SYMBOL(do_SAK
);
3057 static int dev_match_devt(struct device
*dev
, const void *data
)
3059 const dev_t
*devt
= data
;
3060 return dev
->devt
== *devt
;
3063 /* Must put_device() after it's unused! */
3064 static struct device
*tty_get_device(struct tty_struct
*tty
)
3066 dev_t devt
= tty_devnum(tty
);
3067 return class_find_device(tty_class
, NULL
, &devt
, dev_match_devt
);
3074 * This subroutine allocates and initializes a tty structure.
3076 * Locking: none - tty in question is not exposed at this point
3079 struct tty_struct
*alloc_tty_struct(struct tty_driver
*driver
, int idx
)
3081 struct tty_struct
*tty
;
3083 tty
= kzalloc(sizeof(*tty
), GFP_KERNEL
);
3087 kref_init(&tty
->kref
);
3088 tty
->magic
= TTY_MAGIC
;
3089 tty_ldisc_init(tty
);
3090 tty
->session
= NULL
;
3092 mutex_init(&tty
->legacy_mutex
);
3093 mutex_init(&tty
->throttle_mutex
);
3094 init_rwsem(&tty
->termios_rwsem
);
3095 mutex_init(&tty
->winsize_mutex
);
3096 init_ldsem(&tty
->ldisc_sem
);
3097 init_waitqueue_head(&tty
->write_wait
);
3098 init_waitqueue_head(&tty
->read_wait
);
3099 INIT_WORK(&tty
->hangup_work
, do_tty_hangup
);
3100 mutex_init(&tty
->atomic_write_lock
);
3101 spin_lock_init(&tty
->ctrl_lock
);
3102 spin_lock_init(&tty
->flow_lock
);
3103 INIT_LIST_HEAD(&tty
->tty_files
);
3104 INIT_WORK(&tty
->SAK_work
, do_SAK_work
);
3106 tty
->driver
= driver
;
3107 tty
->ops
= driver
->ops
;
3109 tty_line_name(driver
, idx
, tty
->name
);
3110 tty
->dev
= tty_get_device(tty
);
3116 * deinitialize_tty_struct
3117 * @tty: tty to deinitialize
3119 * This subroutine deinitializes a tty structure that has been newly
3120 * allocated but tty_release cannot be called on that yet.
3122 * Locking: none - tty in question must not be exposed at this point
3124 void deinitialize_tty_struct(struct tty_struct
*tty
)
3126 tty_ldisc_deinit(tty
);
3130 * tty_put_char - write one character to a tty
3134 * Write one byte to the tty using the provided put_char method
3135 * if present. Returns the number of characters successfully output.
3137 * Note: the specific put_char operation in the driver layer may go
3138 * away soon. Don't call it directly, use this method
3141 int tty_put_char(struct tty_struct
*tty
, unsigned char ch
)
3143 if (tty
->ops
->put_char
)
3144 return tty
->ops
->put_char(tty
, ch
);
3145 return tty
->ops
->write(tty
, &ch
, 1);
3147 EXPORT_SYMBOL_GPL(tty_put_char
);
3149 struct class *tty_class
;
3151 static int tty_cdev_add(struct tty_driver
*driver
, dev_t dev
,
3152 unsigned int index
, unsigned int count
)
3154 /* init here, since reused cdevs cause crashes */
3155 cdev_init(&driver
->cdevs
[index
], &tty_fops
);
3156 driver
->cdevs
[index
].owner
= driver
->owner
;
3157 return cdev_add(&driver
->cdevs
[index
], dev
, count
);
3161 * tty_register_device - register a tty device
3162 * @driver: the tty driver that describes the tty device
3163 * @index: the index in the tty driver for this tty device
3164 * @device: a struct device that is associated with this tty device.
3165 * This field is optional, if there is no known struct device
3166 * for this tty device it can be set to NULL safely.
3168 * Returns a pointer to the struct device for this tty device
3169 * (or ERR_PTR(-EFOO) on error).
3171 * This call is required to be made to register an individual tty device
3172 * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If
3173 * that bit is not set, this function should not be called by a tty
3179 struct device
*tty_register_device(struct tty_driver
*driver
, unsigned index
,
3180 struct device
*device
)
3182 return tty_register_device_attr(driver
, index
, device
, NULL
, NULL
);
3184 EXPORT_SYMBOL(tty_register_device
);
3186 static void tty_device_create_release(struct device
*dev
)
3188 pr_debug("device: '%s': %s\n", dev_name(dev
), __func__
);
3193 * tty_register_device_attr - register a tty device
3194 * @driver: the tty driver that describes the tty device
3195 * @index: the index in the tty driver for this tty device
3196 * @device: a struct device that is associated with this tty device.
3197 * This field is optional, if there is no known struct device
3198 * for this tty device it can be set to NULL safely.
3199 * @drvdata: Driver data to be set to device.
3200 * @attr_grp: Attribute group to be set on device.
3202 * Returns a pointer to the struct device for this tty device
3203 * (or ERR_PTR(-EFOO) on error).
3205 * This call is required to be made to register an individual tty device
3206 * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If
3207 * that bit is not set, this function should not be called by a tty
3212 struct device
*tty_register_device_attr(struct tty_driver
*driver
,
3213 unsigned index
, struct device
*device
,
3215 const struct attribute_group
**attr_grp
)
3218 dev_t devt
= MKDEV(driver
->major
, driver
->minor_start
) + index
;
3219 struct device
*dev
= NULL
;
3220 int retval
= -ENODEV
;
3223 if (index
>= driver
->num
) {
3224 printk(KERN_ERR
"Attempt to register invalid tty line number "
3226 return ERR_PTR(-EINVAL
);
3229 if (driver
->type
== TTY_DRIVER_TYPE_PTY
)
3230 pty_line_name(driver
, index
, name
);
3232 tty_line_name(driver
, index
, name
);
3234 if (!(driver
->flags
& TTY_DRIVER_DYNAMIC_ALLOC
)) {
3235 retval
= tty_cdev_add(driver
, devt
, index
, 1);
3241 dev
= kzalloc(sizeof(*dev
), GFP_KERNEL
);
3248 dev
->class = tty_class
;
3249 dev
->parent
= device
;
3250 dev
->release
= tty_device_create_release
;
3251 dev_set_name(dev
, "%s", name
);
3252 dev
->groups
= attr_grp
;
3253 dev_set_drvdata(dev
, drvdata
);
3255 retval
= device_register(dev
);
3264 cdev_del(&driver
->cdevs
[index
]);
3265 return ERR_PTR(retval
);
3267 EXPORT_SYMBOL_GPL(tty_register_device_attr
);
3270 * tty_unregister_device - unregister a tty device
3271 * @driver: the tty driver that describes the tty device
3272 * @index: the index in the tty driver for this tty device
3274 * If a tty device is registered with a call to tty_register_device() then
3275 * this function must be called when the tty device is gone.
3280 void tty_unregister_device(struct tty_driver
*driver
, unsigned index
)
3282 device_destroy(tty_class
,
3283 MKDEV(driver
->major
, driver
->minor_start
) + index
);
3284 if (!(driver
->flags
& TTY_DRIVER_DYNAMIC_ALLOC
))
3285 cdev_del(&driver
->cdevs
[index
]);
3287 EXPORT_SYMBOL(tty_unregister_device
);
3290 * __tty_alloc_driver -- allocate tty driver
3291 * @lines: count of lines this driver can handle at most
3292 * @owner: module which is repsonsible for this driver
3293 * @flags: some of TTY_DRIVER_* flags, will be set in driver->flags
3295 * This should not be called directly, some of the provided macros should be
3296 * used instead. Use IS_ERR and friends on @retval.
3298 struct tty_driver
*__tty_alloc_driver(unsigned int lines
, struct module
*owner
,
3299 unsigned long flags
)
3301 struct tty_driver
*driver
;
3302 unsigned int cdevs
= 1;
3305 if (!lines
|| (flags
& TTY_DRIVER_UNNUMBERED_NODE
&& lines
> 1))
3306 return ERR_PTR(-EINVAL
);
3308 driver
= kzalloc(sizeof(struct tty_driver
), GFP_KERNEL
);
3310 return ERR_PTR(-ENOMEM
);
3312 kref_init(&driver
->kref
);
3313 driver
->magic
= TTY_DRIVER_MAGIC
;
3314 driver
->num
= lines
;
3315 driver
->owner
= owner
;
3316 driver
->flags
= flags
;
3318 if (!(flags
& TTY_DRIVER_DEVPTS_MEM
)) {
3319 driver
->ttys
= kcalloc(lines
, sizeof(*driver
->ttys
),
3321 driver
->termios
= kcalloc(lines
, sizeof(*driver
->termios
),
3323 if (!driver
->ttys
|| !driver
->termios
) {
3329 if (!(flags
& TTY_DRIVER_DYNAMIC_ALLOC
)) {
3330 driver
->ports
= kcalloc(lines
, sizeof(*driver
->ports
),
3332 if (!driver
->ports
) {
3339 driver
->cdevs
= kcalloc(cdevs
, sizeof(*driver
->cdevs
), GFP_KERNEL
);
3340 if (!driver
->cdevs
) {
3347 kfree(driver
->ports
);
3348 kfree(driver
->ttys
);
3349 kfree(driver
->termios
);
3351 return ERR_PTR(err
);
3353 EXPORT_SYMBOL(__tty_alloc_driver
);
3355 static void destruct_tty_driver(struct kref
*kref
)
3357 struct tty_driver
*driver
= container_of(kref
, struct tty_driver
, kref
);
3359 struct ktermios
*tp
;
3361 if (driver
->flags
& TTY_DRIVER_INSTALLED
) {
3363 * Free the termios and termios_locked structures because
3364 * we don't want to get memory leaks when modular tty
3365 * drivers are removed from the kernel.
3367 for (i
= 0; i
< driver
->num
; i
++) {
3368 tp
= driver
->termios
[i
];
3370 driver
->termios
[i
] = NULL
;
3373 if (!(driver
->flags
& TTY_DRIVER_DYNAMIC_DEV
))
3374 tty_unregister_device(driver
, i
);
3376 proc_tty_unregister_driver(driver
);
3377 if (driver
->flags
& TTY_DRIVER_DYNAMIC_ALLOC
)
3378 cdev_del(&driver
->cdevs
[0]);
3380 kfree(driver
->cdevs
);
3381 kfree(driver
->ports
);
3382 kfree(driver
->termios
);
3383 kfree(driver
->ttys
);
3387 void tty_driver_kref_put(struct tty_driver
*driver
)
3389 kref_put(&driver
->kref
, destruct_tty_driver
);
3391 EXPORT_SYMBOL(tty_driver_kref_put
);
3393 void tty_set_operations(struct tty_driver
*driver
,
3394 const struct tty_operations
*op
)
3398 EXPORT_SYMBOL(tty_set_operations
);
3400 void put_tty_driver(struct tty_driver
*d
)
3402 tty_driver_kref_put(d
);
3404 EXPORT_SYMBOL(put_tty_driver
);
3407 * Called by a tty driver to register itself.
3409 int tty_register_driver(struct tty_driver
*driver
)
3416 if (!driver
->major
) {
3417 error
= alloc_chrdev_region(&dev
, driver
->minor_start
,
3418 driver
->num
, driver
->name
);
3420 driver
->major
= MAJOR(dev
);
3421 driver
->minor_start
= MINOR(dev
);
3424 dev
= MKDEV(driver
->major
, driver
->minor_start
);
3425 error
= register_chrdev_region(dev
, driver
->num
, driver
->name
);
3430 if (driver
->flags
& TTY_DRIVER_DYNAMIC_ALLOC
) {
3431 error
= tty_cdev_add(driver
, dev
, 0, driver
->num
);
3433 goto err_unreg_char
;
3436 mutex_lock(&tty_mutex
);
3437 list_add(&driver
->tty_drivers
, &tty_drivers
);
3438 mutex_unlock(&tty_mutex
);
3440 if (!(driver
->flags
& TTY_DRIVER_DYNAMIC_DEV
)) {
3441 for (i
= 0; i
< driver
->num
; i
++) {
3442 d
= tty_register_device(driver
, i
, NULL
);
3445 goto err_unreg_devs
;
3449 proc_tty_register_driver(driver
);
3450 driver
->flags
|= TTY_DRIVER_INSTALLED
;
3454 for (i
--; i
>= 0; i
--)
3455 tty_unregister_device(driver
, i
);
3457 mutex_lock(&tty_mutex
);
3458 list_del(&driver
->tty_drivers
);
3459 mutex_unlock(&tty_mutex
);
3462 unregister_chrdev_region(dev
, driver
->num
);
3466 EXPORT_SYMBOL(tty_register_driver
);
3469 * Called by a tty driver to unregister itself.
3471 int tty_unregister_driver(struct tty_driver
*driver
)
3475 if (driver
->refcount
)
3478 unregister_chrdev_region(MKDEV(driver
->major
, driver
->minor_start
),
3480 mutex_lock(&tty_mutex
);
3481 list_del(&driver
->tty_drivers
);
3482 mutex_unlock(&tty_mutex
);
3486 EXPORT_SYMBOL(tty_unregister_driver
);
3488 dev_t
tty_devnum(struct tty_struct
*tty
)
3490 return MKDEV(tty
->driver
->major
, tty
->driver
->minor_start
) + tty
->index
;
3492 EXPORT_SYMBOL(tty_devnum
);
3494 void tty_default_fops(struct file_operations
*fops
)
3500 * Initialize the console device. This is called *early*, so
3501 * we can't necessarily depend on lots of kernel help here.
3502 * Just do some early initializations, and do the complex setup
3505 void __init
console_init(void)
3509 /* Setup the default TTY line discipline. */
3513 * set up the console device so that later boot sequences can
3514 * inform about problems etc..
3516 call
= __con_initcall_start
;
3517 while (call
< __con_initcall_end
) {
3523 static char *tty_devnode(struct device
*dev
, umode_t
*mode
)
3527 if (dev
->devt
== MKDEV(TTYAUX_MAJOR
, 0) ||
3528 dev
->devt
== MKDEV(TTYAUX_MAJOR
, 2))
3533 static int __init
tty_class_init(void)
3535 tty_class
= class_create(THIS_MODULE
, "tty");
3536 if (IS_ERR(tty_class
))
3537 return PTR_ERR(tty_class
);
3538 tty_class
->devnode
= tty_devnode
;
3542 postcore_initcall(tty_class_init
);
3544 /* 3/2004 jmc: why do these devices exist? */
3545 static struct cdev tty_cdev
, console_cdev
;
3547 static ssize_t
show_cons_active(struct device
*dev
,
3548 struct device_attribute
*attr
, char *buf
)
3550 struct console
*cs
[16];
3556 for_each_console(c
) {
3561 if ((c
->flags
& CON_ENABLED
) == 0)
3564 if (i
>= ARRAY_SIZE(cs
))
3568 int index
= cs
[i
]->index
;
3569 struct tty_driver
*drv
= cs
[i
]->device(cs
[i
], &index
);
3571 /* don't resolve tty0 as some programs depend on it */
3572 if (drv
&& (cs
[i
]->index
> 0 || drv
->major
!= TTY_MAJOR
))
3573 count
+= tty_line_name(drv
, index
, buf
+ count
);
3575 count
+= sprintf(buf
+ count
, "%s%d",
3576 cs
[i
]->name
, cs
[i
]->index
);
3578 count
+= sprintf(buf
+ count
, "%c", i
? ' ':'\n');
3584 static DEVICE_ATTR(active
, S_IRUGO
, show_cons_active
, NULL
);
3586 static struct attribute
*cons_dev_attrs
[] = {
3587 &dev_attr_active
.attr
,
3591 ATTRIBUTE_GROUPS(cons_dev
);
3593 static struct device
*consdev
;
3595 void console_sysfs_notify(void)
3598 sysfs_notify(&consdev
->kobj
, NULL
, "active");
3602 * Ok, now we can initialize the rest of the tty devices and can count
3603 * on memory allocations, interrupts etc..
3605 int __init
tty_init(void)
3607 cdev_init(&tty_cdev
, &tty_fops
);
3608 if (cdev_add(&tty_cdev
, MKDEV(TTYAUX_MAJOR
, 0), 1) ||
3609 register_chrdev_region(MKDEV(TTYAUX_MAJOR
, 0), 1, "/dev/tty") < 0)
3610 panic("Couldn't register /dev/tty driver\n");
3611 device_create(tty_class
, NULL
, MKDEV(TTYAUX_MAJOR
, 0), NULL
, "tty");
3613 cdev_init(&console_cdev
, &console_fops
);
3614 if (cdev_add(&console_cdev
, MKDEV(TTYAUX_MAJOR
, 1), 1) ||
3615 register_chrdev_region(MKDEV(TTYAUX_MAJOR
, 1), 1, "/dev/console") < 0)
3616 panic("Couldn't register /dev/console driver\n");
3617 consdev
= device_create_with_groups(tty_class
, NULL
,
3618 MKDEV(TTYAUX_MAJOR
, 1), NULL
,
3619 cons_dev_groups
, "console");
3620 if (IS_ERR(consdev
))
3624 vty_init(&console_fops
);