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: a readlock on tasklist_lock
514 static void __proc_set_tty(struct tty_struct
*tty
)
518 /* We should not have a session or pgrp to put here but.... */
519 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
520 put_pid(tty
->session
);
522 tty
->pgrp
= get_pid(task_pgrp(current
));
523 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
524 tty
->session
= get_pid(task_session(current
));
525 if (current
->signal
->tty
) {
526 printk(KERN_DEBUG
"tty not NULL!!\n");
527 tty_kref_put(current
->signal
->tty
);
529 put_pid(current
->signal
->tty_old_pgrp
);
530 current
->signal
->tty
= tty_kref_get(tty
);
531 current
->signal
->tty_old_pgrp
= NULL
;
534 static void proc_set_tty(struct tty_struct
*tty
)
536 spin_lock_irq(¤t
->sighand
->siglock
);
538 spin_unlock_irq(¤t
->sighand
->siglock
);
541 struct tty_struct
*get_current_tty(void)
543 struct tty_struct
*tty
;
546 spin_lock_irqsave(¤t
->sighand
->siglock
, flags
);
547 tty
= tty_kref_get(current
->signal
->tty
);
548 spin_unlock_irqrestore(¤t
->sighand
->siglock
, flags
);
551 EXPORT_SYMBOL_GPL(get_current_tty
);
553 static void session_clear_tty(struct pid
*session
)
555 struct task_struct
*p
;
556 do_each_pid_task(session
, PIDTYPE_SID
, p
) {
558 } while_each_pid_task(session
, PIDTYPE_SID
, p
);
562 * tty_wakeup - request more data
565 * Internal and external helper for wakeups of tty. This function
566 * informs the line discipline if present that the driver is ready
567 * to receive more output data.
570 void tty_wakeup(struct tty_struct
*tty
)
572 struct tty_ldisc
*ld
;
574 if (test_bit(TTY_DO_WRITE_WAKEUP
, &tty
->flags
)) {
575 ld
= tty_ldisc_ref(tty
);
577 if (ld
->ops
->write_wakeup
)
578 ld
->ops
->write_wakeup(tty
);
582 wake_up_interruptible_poll(&tty
->write_wait
, POLLOUT
);
585 EXPORT_SYMBOL_GPL(tty_wakeup
);
588 * tty_signal_session_leader - sends SIGHUP to session leader
589 * @tty controlling tty
590 * @exit_session if non-zero, signal all foreground group processes
592 * Send SIGHUP and SIGCONT to the session leader and its process group.
593 * Optionally, signal all processes in the foreground process group.
595 * Returns the number of processes in the session with this tty
596 * as their controlling terminal. This value is used to drop
597 * tty references for those processes.
599 static int tty_signal_session_leader(struct tty_struct
*tty
, int exit_session
)
601 struct task_struct
*p
;
603 struct pid
*tty_pgrp
= NULL
;
605 read_lock(&tasklist_lock
);
607 do_each_pid_task(tty
->session
, PIDTYPE_SID
, p
) {
608 spin_lock_irq(&p
->sighand
->siglock
);
609 if (p
->signal
->tty
== tty
) {
610 p
->signal
->tty
= NULL
;
611 /* We defer the dereferences outside fo
615 if (!p
->signal
->leader
) {
616 spin_unlock_irq(&p
->sighand
->siglock
);
619 __group_send_sig_info(SIGHUP
, SEND_SIG_PRIV
, p
);
620 __group_send_sig_info(SIGCONT
, SEND_SIG_PRIV
, p
);
621 put_pid(p
->signal
->tty_old_pgrp
); /* A noop */
622 spin_lock(&tty
->ctrl_lock
);
623 tty_pgrp
= get_pid(tty
->pgrp
);
625 p
->signal
->tty_old_pgrp
= get_pid(tty
->pgrp
);
626 spin_unlock(&tty
->ctrl_lock
);
627 spin_unlock_irq(&p
->sighand
->siglock
);
628 } while_each_pid_task(tty
->session
, PIDTYPE_SID
, p
);
630 read_unlock(&tasklist_lock
);
634 kill_pgrp(tty_pgrp
, SIGHUP
, exit_session
);
642 * __tty_hangup - actual handler for hangup events
645 * This can be called by a "kworker" kernel thread. That is process
646 * synchronous but doesn't hold any locks, so we need to make sure we
647 * have the appropriate locks for what we're doing.
649 * The hangup event clears any pending redirections onto the hung up
650 * device. It ensures future writes will error and it does the needed
651 * line discipline hangup and signal delivery. The tty object itself
656 * redirect lock for undoing redirection
657 * file list lock for manipulating list of ttys
658 * tty_ldiscs_lock from called functions
659 * termios_rwsem resetting termios data
660 * tasklist_lock to walk task list for hangup event
661 * ->siglock to protect ->signal/->sighand
663 static void __tty_hangup(struct tty_struct
*tty
, int exit_session
)
665 struct file
*cons_filp
= NULL
;
666 struct file
*filp
, *f
= NULL
;
667 struct tty_file_private
*priv
;
668 int closecount
= 0, n
;
675 spin_lock(&redirect_lock
);
676 if (redirect
&& file_tty(redirect
) == tty
) {
680 spin_unlock(&redirect_lock
);
684 if (test_bit(TTY_HUPPED
, &tty
->flags
)) {
689 /* some functions below drop BTM, so we need this bit */
690 set_bit(TTY_HUPPING
, &tty
->flags
);
692 /* inuse_filps is protected by the single tty lock,
693 this really needs to change if we want to flush the
694 workqueue with the lock held */
695 check_tty_count(tty
, "tty_hangup");
697 spin_lock(&tty_files_lock
);
698 /* This breaks for file handles being sent over AF_UNIX sockets ? */
699 list_for_each_entry(priv
, &tty
->tty_files
, list
) {
701 if (filp
->f_op
->write
== redirected_tty_write
)
703 if (filp
->f_op
->write
!= tty_write
)
706 __tty_fasync(-1, filp
, 0); /* can't block */
707 filp
->f_op
= &hung_up_tty_fops
;
709 spin_unlock(&tty_files_lock
);
711 refs
= tty_signal_session_leader(tty
, exit_session
);
712 /* Account for the p->signal references we killed */
717 * it drops BTM and thus races with reopen
718 * we protect the race by TTY_HUPPING
720 tty_ldisc_hangup(tty
);
722 spin_lock_irq(&tty
->ctrl_lock
);
723 clear_bit(TTY_THROTTLED
, &tty
->flags
);
724 clear_bit(TTY_DO_WRITE_WAKEUP
, &tty
->flags
);
725 put_pid(tty
->session
);
729 tty
->ctrl_status
= 0;
730 spin_unlock_irq(&tty
->ctrl_lock
);
733 * If one of the devices matches a console pointer, we
734 * cannot just call hangup() because that will cause
735 * tty->count and state->count to go out of sync.
736 * So we just call close() the right number of times.
740 for (n
= 0; n
< closecount
; n
++)
741 tty
->ops
->close(tty
, cons_filp
);
742 } else if (tty
->ops
->hangup
)
743 tty
->ops
->hangup(tty
);
745 * We don't want to have driver/ldisc interactions beyond
746 * the ones we did here. The driver layer expects no
747 * calls after ->hangup() from the ldisc side. However we
748 * can't yet guarantee all that.
750 set_bit(TTY_HUPPED
, &tty
->flags
);
751 clear_bit(TTY_HUPPING
, &tty
->flags
);
759 static void do_tty_hangup(struct work_struct
*work
)
761 struct tty_struct
*tty
=
762 container_of(work
, struct tty_struct
, hangup_work
);
764 __tty_hangup(tty
, 0);
768 * tty_hangup - trigger a hangup event
769 * @tty: tty to hangup
771 * A carrier loss (virtual or otherwise) has occurred on this like
772 * schedule a hangup sequence to run after this event.
775 void tty_hangup(struct tty_struct
*tty
)
777 #ifdef TTY_DEBUG_HANGUP
779 printk(KERN_DEBUG
"%s hangup...\n", tty_name(tty
, buf
));
781 schedule_work(&tty
->hangup_work
);
784 EXPORT_SYMBOL(tty_hangup
);
787 * tty_vhangup - process vhangup
788 * @tty: tty to hangup
790 * The user has asked via system call for the terminal to be hung up.
791 * We do this synchronously so that when the syscall returns the process
792 * is complete. That guarantee is necessary for security reasons.
795 void tty_vhangup(struct tty_struct
*tty
)
797 #ifdef TTY_DEBUG_HANGUP
800 printk(KERN_DEBUG
"%s vhangup...\n", tty_name(tty
, buf
));
802 __tty_hangup(tty
, 0);
805 EXPORT_SYMBOL(tty_vhangup
);
809 * tty_vhangup_self - process vhangup for own ctty
811 * Perform a vhangup on the current controlling tty
814 void tty_vhangup_self(void)
816 struct tty_struct
*tty
;
818 tty
= get_current_tty();
826 * tty_vhangup_session - hangup session leader exit
827 * @tty: tty to hangup
829 * The session leader is exiting and hanging up its controlling terminal.
830 * Every process in the foreground process group is signalled SIGHUP.
832 * We do this synchronously so that when the syscall returns the process
833 * is complete. That guarantee is necessary for security reasons.
836 static void tty_vhangup_session(struct tty_struct
*tty
)
838 #ifdef TTY_DEBUG_HANGUP
841 printk(KERN_DEBUG
"%s vhangup session...\n", tty_name(tty
, buf
));
843 __tty_hangup(tty
, 1);
847 * tty_hung_up_p - was tty hung up
848 * @filp: file pointer of tty
850 * Return true if the tty has been subject to a vhangup or a carrier
854 int tty_hung_up_p(struct file
*filp
)
856 return (filp
->f_op
== &hung_up_tty_fops
);
859 EXPORT_SYMBOL(tty_hung_up_p
);
862 * disassociate_ctty - disconnect controlling tty
863 * @on_exit: true if exiting so need to "hang up" the session
865 * This function is typically called only by the session leader, when
866 * it wants to disassociate itself from its controlling tty.
868 * It performs the following functions:
869 * (1) Sends a SIGHUP and SIGCONT to the foreground process group
870 * (2) Clears the tty from being controlling the session
871 * (3) Clears the controlling tty for all processes in the
874 * The argument on_exit is set to 1 if called when a process is
875 * exiting; it is 0 if called by the ioctl TIOCNOTTY.
878 * BTM is taken for hysterical raisins, and held when
879 * called from no_tty().
880 * tty_mutex is taken to protect tty
881 * ->siglock is taken to protect ->signal/->sighand
882 * tasklist_lock is taken to walk process list for sessions
883 * ->siglock is taken to protect ->signal/->sighand
886 void disassociate_ctty(int on_exit
)
888 struct tty_struct
*tty
;
890 if (!current
->signal
->leader
)
893 tty
= get_current_tty();
895 if (on_exit
&& tty
->driver
->type
!= TTY_DRIVER_TYPE_PTY
) {
896 tty_vhangup_session(tty
);
898 struct pid
*tty_pgrp
= tty_get_pgrp(tty
);
900 kill_pgrp(tty_pgrp
, SIGHUP
, on_exit
);
902 kill_pgrp(tty_pgrp
, SIGCONT
, on_exit
);
908 } else if (on_exit
) {
909 struct pid
*old_pgrp
;
910 spin_lock_irq(¤t
->sighand
->siglock
);
911 old_pgrp
= current
->signal
->tty_old_pgrp
;
912 current
->signal
->tty_old_pgrp
= NULL
;
913 spin_unlock_irq(¤t
->sighand
->siglock
);
915 kill_pgrp(old_pgrp
, SIGHUP
, on_exit
);
916 kill_pgrp(old_pgrp
, SIGCONT
, on_exit
);
922 spin_lock_irq(¤t
->sighand
->siglock
);
923 put_pid(current
->signal
->tty_old_pgrp
);
924 current
->signal
->tty_old_pgrp
= NULL
;
926 tty
= tty_kref_get(current
->signal
->tty
);
929 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
930 put_pid(tty
->session
);
934 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
937 #ifdef TTY_DEBUG_HANGUP
938 printk(KERN_DEBUG
"error attempted to write to tty [0x%p]"
943 spin_unlock_irq(¤t
->sighand
->siglock
);
944 /* Now clear signal->tty under the lock */
945 read_lock(&tasklist_lock
);
946 session_clear_tty(task_session(current
));
947 read_unlock(&tasklist_lock
);
952 * no_tty - Ensure the current process does not have a controlling tty
956 /* FIXME: Review locking here. The tty_lock never covered any race
957 between a new association and proc_clear_tty but possible we need
958 to protect against this anyway */
959 struct task_struct
*tsk
= current
;
960 disassociate_ctty(0);
966 * stop_tty - propagate flow control
969 * Perform flow control to the driver. May be called
970 * on an already stopped device and will not re-call the driver
973 * This functionality is used by both the line disciplines for
974 * halting incoming flow and by the driver. It may therefore be
975 * called from any context, may be under the tty atomic_write_lock
982 void __stop_tty(struct tty_struct
*tty
)
988 (tty
->ops
->stop
)(tty
);
991 void stop_tty(struct tty_struct
*tty
)
995 spin_lock_irqsave(&tty
->flow_lock
, flags
);
997 spin_unlock_irqrestore(&tty
->flow_lock
, flags
);
999 EXPORT_SYMBOL(stop_tty
);
1002 * start_tty - propagate flow control
1003 * @tty: tty to start
1005 * Start a tty that has been stopped if at all possible. If this
1006 * tty was previous stopped and is now being started, the driver
1007 * start method is invoked and the line discipline woken.
1013 void __start_tty(struct tty_struct
*tty
)
1015 if (!tty
->stopped
|| tty
->flow_stopped
)
1018 if (tty
->ops
->start
)
1019 (tty
->ops
->start
)(tty
);
1023 void start_tty(struct tty_struct
*tty
)
1025 unsigned long flags
;
1027 spin_lock_irqsave(&tty
->flow_lock
, flags
);
1029 spin_unlock_irqrestore(&tty
->flow_lock
, flags
);
1031 EXPORT_SYMBOL(start_tty
);
1033 /* We limit tty time update visibility to every 8 seconds or so. */
1034 static void tty_update_time(struct timespec
*time
)
1036 unsigned long sec
= get_seconds() & ~7;
1037 if ((long)(sec
- time
->tv_sec
) > 0)
1042 * tty_read - read method for tty device files
1043 * @file: pointer to tty file
1045 * @count: size of user buffer
1048 * Perform the read system call function on this terminal device. Checks
1049 * for hung up devices before calling the line discipline method.
1052 * Locks the line discipline internally while needed. Multiple
1053 * read calls may be outstanding in parallel.
1056 static ssize_t
tty_read(struct file
*file
, char __user
*buf
, size_t count
,
1060 struct inode
*inode
= file_inode(file
);
1061 struct tty_struct
*tty
= file_tty(file
);
1062 struct tty_ldisc
*ld
;
1064 if (tty_paranoia_check(tty
, inode
, "tty_read"))
1066 if (!tty
|| (test_bit(TTY_IO_ERROR
, &tty
->flags
)))
1069 /* We want to wait for the line discipline to sort out in this
1071 ld
= tty_ldisc_ref_wait(tty
);
1073 i
= (ld
->ops
->read
)(tty
, file
, buf
, count
);
1076 tty_ldisc_deref(ld
);
1079 tty_update_time(&inode
->i_atime
);
1084 static void tty_write_unlock(struct tty_struct
*tty
)
1086 mutex_unlock(&tty
->atomic_write_lock
);
1087 wake_up_interruptible_poll(&tty
->write_wait
, POLLOUT
);
1090 static int tty_write_lock(struct tty_struct
*tty
, int ndelay
)
1092 if (!mutex_trylock(&tty
->atomic_write_lock
)) {
1095 if (mutex_lock_interruptible(&tty
->atomic_write_lock
))
1096 return -ERESTARTSYS
;
1102 * Split writes up in sane blocksizes to avoid
1103 * denial-of-service type attacks
1105 static inline ssize_t
do_tty_write(
1106 ssize_t (*write
)(struct tty_struct
*, struct file
*, const unsigned char *, size_t),
1107 struct tty_struct
*tty
,
1109 const char __user
*buf
,
1112 ssize_t ret
, written
= 0;
1115 ret
= tty_write_lock(tty
, file
->f_flags
& O_NDELAY
);
1120 * We chunk up writes into a temporary buffer. This
1121 * simplifies low-level drivers immensely, since they
1122 * don't have locking issues and user mode accesses.
1124 * But if TTY_NO_WRITE_SPLIT is set, we should use a
1127 * The default chunk-size is 2kB, because the NTTY
1128 * layer has problems with bigger chunks. It will
1129 * claim to be able to handle more characters than
1132 * FIXME: This can probably go away now except that 64K chunks
1133 * are too likely to fail unless switched to vmalloc...
1136 if (test_bit(TTY_NO_WRITE_SPLIT
, &tty
->flags
))
1141 /* write_buf/write_cnt is protected by the atomic_write_lock mutex */
1142 if (tty
->write_cnt
< chunk
) {
1143 unsigned char *buf_chunk
;
1148 buf_chunk
= kmalloc(chunk
, GFP_KERNEL
);
1153 kfree(tty
->write_buf
);
1154 tty
->write_cnt
= chunk
;
1155 tty
->write_buf
= buf_chunk
;
1158 /* Do the write .. */
1160 size_t size
= count
;
1164 if (copy_from_user(tty
->write_buf
, buf
, size
))
1166 ret
= write(tty
, file
, tty
->write_buf
, size
);
1175 if (signal_pending(current
))
1180 tty_update_time(&file_inode(file
)->i_mtime
);
1184 tty_write_unlock(tty
);
1189 * tty_write_message - write a message to a certain tty, not just the console.
1190 * @tty: the destination tty_struct
1191 * @msg: the message to write
1193 * This is used for messages that need to be redirected to a specific tty.
1194 * We don't put it into the syslog queue right now maybe in the future if
1197 * We must still hold the BTM and test the CLOSING flag for the moment.
1200 void tty_write_message(struct tty_struct
*tty
, char *msg
)
1203 mutex_lock(&tty
->atomic_write_lock
);
1205 if (tty
->ops
->write
&& !test_bit(TTY_CLOSING
, &tty
->flags
)) {
1207 tty
->ops
->write(tty
, msg
, strlen(msg
));
1210 tty_write_unlock(tty
);
1217 * tty_write - write method for tty device file
1218 * @file: tty file pointer
1219 * @buf: user data to write
1220 * @count: bytes to write
1223 * Write data to a tty device via the line discipline.
1226 * Locks the line discipline as required
1227 * Writes to the tty driver are serialized by the atomic_write_lock
1228 * and are then processed in chunks to the device. The line discipline
1229 * write method will not be invoked in parallel for each device.
1232 static ssize_t
tty_write(struct file
*file
, const char __user
*buf
,
1233 size_t count
, loff_t
*ppos
)
1235 struct tty_struct
*tty
= file_tty(file
);
1236 struct tty_ldisc
*ld
;
1239 if (tty_paranoia_check(tty
, file_inode(file
), "tty_write"))
1241 if (!tty
|| !tty
->ops
->write
||
1242 (test_bit(TTY_IO_ERROR
, &tty
->flags
)))
1244 /* Short term debug to catch buggy drivers */
1245 if (tty
->ops
->write_room
== NULL
)
1246 printk(KERN_ERR
"tty driver %s lacks a write_room method.\n",
1248 ld
= tty_ldisc_ref_wait(tty
);
1249 if (!ld
->ops
->write
)
1252 ret
= do_tty_write(ld
->ops
->write
, tty
, file
, buf
, count
);
1253 tty_ldisc_deref(ld
);
1257 ssize_t
redirected_tty_write(struct file
*file
, const char __user
*buf
,
1258 size_t count
, loff_t
*ppos
)
1260 struct file
*p
= NULL
;
1262 spin_lock(&redirect_lock
);
1264 p
= get_file(redirect
);
1265 spin_unlock(&redirect_lock
);
1269 res
= vfs_write(p
, buf
, count
, &p
->f_pos
);
1273 return tty_write(file
, buf
, count
, ppos
);
1277 * tty_send_xchar - send priority character
1279 * Send a high priority character to the tty even if stopped
1281 * Locking: none for xchar method, write ordering for write method.
1284 int tty_send_xchar(struct tty_struct
*tty
, char ch
)
1286 int was_stopped
= tty
->stopped
;
1288 if (tty
->ops
->send_xchar
) {
1289 tty
->ops
->send_xchar(tty
, ch
);
1293 if (tty_write_lock(tty
, 0) < 0)
1294 return -ERESTARTSYS
;
1298 tty
->ops
->write(tty
, &ch
, 1);
1301 tty_write_unlock(tty
);
1305 static char ptychar
[] = "pqrstuvwxyzabcde";
1308 * pty_line_name - generate name for a pty
1309 * @driver: the tty driver in use
1310 * @index: the minor number
1311 * @p: output buffer of at least 6 bytes
1313 * Generate a name from a driver reference and write it to the output
1318 static void pty_line_name(struct tty_driver
*driver
, int index
, char *p
)
1320 int i
= index
+ driver
->name_base
;
1321 /* ->name is initialized to "ttyp", but "tty" is expected */
1322 sprintf(p
, "%s%c%x",
1323 driver
->subtype
== PTY_TYPE_SLAVE
? "tty" : driver
->name
,
1324 ptychar
[i
>> 4 & 0xf], i
& 0xf);
1328 * tty_line_name - generate name for a tty
1329 * @driver: the tty driver in use
1330 * @index: the minor number
1331 * @p: output buffer of at least 7 bytes
1333 * Generate a name from a driver reference and write it to the output
1338 static ssize_t
tty_line_name(struct tty_driver
*driver
, int index
, char *p
)
1340 if (driver
->flags
& TTY_DRIVER_UNNUMBERED_NODE
)
1341 return sprintf(p
, "%s", driver
->name
);
1343 return sprintf(p
, "%s%d", driver
->name
,
1344 index
+ driver
->name_base
);
1348 * tty_driver_lookup_tty() - find an existing tty, if any
1349 * @driver: the driver for the tty
1350 * @idx: the minor number
1352 * Return the tty, if found or ERR_PTR() otherwise.
1354 * Locking: tty_mutex must be held. If tty is found, the mutex must
1355 * be held until the 'fast-open' is also done. Will change once we
1356 * have refcounting in the driver and per driver locking
1358 static struct tty_struct
*tty_driver_lookup_tty(struct tty_driver
*driver
,
1359 struct inode
*inode
, int idx
)
1361 if (driver
->ops
->lookup
)
1362 return driver
->ops
->lookup(driver
, inode
, idx
);
1364 return driver
->ttys
[idx
];
1368 * tty_init_termios - helper for termios setup
1369 * @tty: the tty to set up
1371 * Initialise the termios structures for this tty. Thus runs under
1372 * the tty_mutex currently so we can be relaxed about ordering.
1375 int tty_init_termios(struct tty_struct
*tty
)
1377 struct ktermios
*tp
;
1378 int idx
= tty
->index
;
1380 if (tty
->driver
->flags
& TTY_DRIVER_RESET_TERMIOS
)
1381 tty
->termios
= tty
->driver
->init_termios
;
1383 /* Check for lazy saved data */
1384 tp
= tty
->driver
->termios
[idx
];
1388 tty
->termios
= tty
->driver
->init_termios
;
1390 /* Compatibility until drivers always set this */
1391 tty
->termios
.c_ispeed
= tty_termios_input_baud_rate(&tty
->termios
);
1392 tty
->termios
.c_ospeed
= tty_termios_baud_rate(&tty
->termios
);
1395 EXPORT_SYMBOL_GPL(tty_init_termios
);
1397 int tty_standard_install(struct tty_driver
*driver
, struct tty_struct
*tty
)
1399 int ret
= tty_init_termios(tty
);
1403 tty_driver_kref_get(driver
);
1405 driver
->ttys
[tty
->index
] = tty
;
1408 EXPORT_SYMBOL_GPL(tty_standard_install
);
1411 * tty_driver_install_tty() - install a tty entry in the driver
1412 * @driver: the driver for the tty
1415 * Install a tty object into the driver tables. The tty->index field
1416 * will be set by the time this is called. This method is responsible
1417 * for ensuring any need additional structures are allocated and
1420 * Locking: tty_mutex for now
1422 static int tty_driver_install_tty(struct tty_driver
*driver
,
1423 struct tty_struct
*tty
)
1425 return driver
->ops
->install
? driver
->ops
->install(driver
, tty
) :
1426 tty_standard_install(driver
, tty
);
1430 * tty_driver_remove_tty() - remove a tty from the driver tables
1431 * @driver: the driver for the tty
1432 * @idx: the minor number
1434 * Remvoe a tty object from the driver tables. The tty->index field
1435 * will be set by the time this is called.
1437 * Locking: tty_mutex for now
1439 void tty_driver_remove_tty(struct tty_driver
*driver
, struct tty_struct
*tty
)
1441 if (driver
->ops
->remove
)
1442 driver
->ops
->remove(driver
, tty
);
1444 driver
->ttys
[tty
->index
] = NULL
;
1448 * tty_reopen() - fast re-open of an open tty
1449 * @tty - the tty to open
1451 * Return 0 on success, -errno on error.
1453 * Locking: tty_mutex must be held from the time the tty was found
1454 * till this open completes.
1456 static int tty_reopen(struct tty_struct
*tty
)
1458 struct tty_driver
*driver
= tty
->driver
;
1460 if (test_bit(TTY_CLOSING
, &tty
->flags
) ||
1461 test_bit(TTY_HUPPING
, &tty
->flags
))
1464 if (driver
->type
== TTY_DRIVER_TYPE_PTY
&&
1465 driver
->subtype
== PTY_TYPE_MASTER
) {
1467 * special case for PTY masters: only one open permitted,
1468 * and the slave side open count is incremented as well.
1477 WARN_ON(!tty
->ldisc
);
1483 * tty_init_dev - initialise a tty device
1484 * @driver: tty driver we are opening a device on
1485 * @idx: device index
1486 * @ret_tty: returned tty structure
1488 * Prepare a tty device. This may not be a "new" clean device but
1489 * could also be an active device. The pty drivers require special
1490 * handling because of this.
1493 * The function is called under the tty_mutex, which
1494 * protects us from the tty struct or driver itself going away.
1496 * On exit the tty device has the line discipline attached and
1497 * a reference count of 1. If a pair was created for pty/tty use
1498 * and the other was a pty master then it too has a reference count of 1.
1500 * WSH 06/09/97: Rewritten to remove races and properly clean up after a
1501 * failed open. The new code protects the open with a mutex, so it's
1502 * really quite straightforward. The mutex locking can probably be
1503 * relaxed for the (most common) case of reopening a tty.
1506 struct tty_struct
*tty_init_dev(struct tty_driver
*driver
, int idx
)
1508 struct tty_struct
*tty
;
1512 * First time open is complex, especially for PTY devices.
1513 * This code guarantees that either everything succeeds and the
1514 * TTY is ready for operation, or else the table slots are vacated
1515 * and the allocated memory released. (Except that the termios
1516 * and locked termios may be retained.)
1519 if (!try_module_get(driver
->owner
))
1520 return ERR_PTR(-ENODEV
);
1522 tty
= alloc_tty_struct(driver
, idx
);
1525 goto err_module_put
;
1529 retval
= tty_driver_install_tty(driver
, tty
);
1531 goto err_deinit_tty
;
1534 tty
->port
= driver
->ports
[idx
];
1536 WARN_RATELIMIT(!tty
->port
,
1537 "%s: %s driver does not set tty->port. This will crash the kernel later. Fix the driver!\n",
1538 __func__
, tty
->driver
->name
);
1540 tty
->port
->itty
= tty
;
1543 * Structures all installed ... call the ldisc open routines.
1544 * If we fail here just call release_tty to clean up. No need
1545 * to decrement the use counts, as release_tty doesn't care.
1547 retval
= tty_ldisc_setup(tty
, tty
->link
);
1549 goto err_release_tty
;
1550 /* Return the tty locked so that it cannot vanish under the caller */
1555 deinitialize_tty_struct(tty
);
1556 free_tty_struct(tty
);
1558 module_put(driver
->owner
);
1559 return ERR_PTR(retval
);
1561 /* call the tty release_tty routine to clean out this slot */
1564 printk_ratelimited(KERN_INFO
"tty_init_dev: ldisc open failed, "
1565 "clearing slot %d\n", idx
);
1566 release_tty(tty
, idx
);
1567 return ERR_PTR(retval
);
1570 void tty_free_termios(struct tty_struct
*tty
)
1572 struct ktermios
*tp
;
1573 int idx
= tty
->index
;
1575 /* If the port is going to reset then it has no termios to save */
1576 if (tty
->driver
->flags
& TTY_DRIVER_RESET_TERMIOS
)
1579 /* Stash the termios data */
1580 tp
= tty
->driver
->termios
[idx
];
1582 tp
= kmalloc(sizeof(struct ktermios
), GFP_KERNEL
);
1584 pr_warn("tty: no memory to save termios state.\n");
1587 tty
->driver
->termios
[idx
] = tp
;
1591 EXPORT_SYMBOL(tty_free_termios
);
1594 * tty_flush_works - flush all works of a tty
1595 * @tty: tty device to flush works for
1597 * Sync flush all works belonging to @tty.
1599 static void tty_flush_works(struct tty_struct
*tty
)
1601 flush_work(&tty
->SAK_work
);
1602 flush_work(&tty
->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
);
1695 tty_kref_put(tty
->link
);
1700 * tty_release_checks - check a tty before real release
1701 * @tty: tty to check
1702 * @o_tty: link of @tty (if any)
1703 * @idx: index of the tty
1705 * Performs some paranoid checking before true release of the @tty.
1706 * This is a no-op unless TTY_PARANOIA_CHECK is defined.
1708 static int tty_release_checks(struct tty_struct
*tty
, struct tty_struct
*o_tty
,
1711 #ifdef TTY_PARANOIA_CHECK
1712 if (idx
< 0 || idx
>= tty
->driver
->num
) {
1713 printk(KERN_DEBUG
"%s: bad idx when trying to free (%s)\n",
1714 __func__
, tty
->name
);
1718 /* not much to check for devpts */
1719 if (tty
->driver
->flags
& TTY_DRIVER_DEVPTS_MEM
)
1722 if (tty
!= tty
->driver
->ttys
[idx
]) {
1723 printk(KERN_DEBUG
"%s: driver.table[%d] not tty for (%s)\n",
1724 __func__
, idx
, tty
->name
);
1727 if (tty
->driver
->other
) {
1728 if (o_tty
!= tty
->driver
->other
->ttys
[idx
]) {
1729 printk(KERN_DEBUG
"%s: other->table[%d] not o_tty for (%s)\n",
1730 __func__
, idx
, tty
->name
);
1733 if (o_tty
->link
!= tty
) {
1734 printk(KERN_DEBUG
"%s: bad pty pointers\n", __func__
);
1743 * tty_release - vfs callback for close
1744 * @inode: inode of tty
1745 * @filp: file pointer for handle to tty
1747 * Called the last time each file handle is closed that references
1748 * this tty. There may however be several such references.
1751 * Takes bkl. See tty_release_dev
1753 * Even releasing the tty structures is a tricky business.. We have
1754 * to be very careful that the structures are all released at the
1755 * same time, as interrupts might otherwise get the wrong pointers.
1757 * WSH 09/09/97: rewritten to avoid some nasty race conditions that could
1758 * lead to double frees or releasing memory still in use.
1761 int tty_release(struct inode
*inode
, struct file
*filp
)
1763 struct tty_struct
*tty
= file_tty(filp
);
1764 struct tty_struct
*o_tty
;
1765 int pty_master
, tty_closing
, o_tty_closing
, do_sleep
;
1769 if (tty_paranoia_check(tty
, inode
, __func__
))
1773 check_tty_count(tty
, __func__
);
1775 __tty_fasync(-1, filp
, 0);
1778 pty_master
= (tty
->driver
->type
== TTY_DRIVER_TYPE_PTY
&&
1779 tty
->driver
->subtype
== PTY_TYPE_MASTER
);
1780 /* Review: parallel close */
1783 if (tty_release_checks(tty
, o_tty
, idx
)) {
1788 #ifdef TTY_DEBUG_HANGUP
1789 printk(KERN_DEBUG
"%s: %s (tty count=%d)...\n", __func__
,
1790 tty_name(tty
, buf
), tty
->count
);
1793 if (tty
->ops
->close
)
1794 tty
->ops
->close(tty
, filp
);
1798 * Sanity check: if tty->count is going to zero, there shouldn't be
1799 * any waiters on tty->read_wait or tty->write_wait. We test the
1800 * wait queues and kick everyone out _before_ actually starting to
1801 * close. This ensures that we won't block while releasing the tty
1804 * The test for the o_tty closing is necessary, since the master and
1805 * slave sides may close in any order. If the slave side closes out
1806 * first, its count will be one, since the master side holds an open.
1807 * Thus this test wouldn't be triggered at the time the slave closes,
1810 * Note that it's possible for the tty to be opened again while we're
1811 * flushing out waiters. By recalculating the closing flags before
1812 * each iteration we avoid any problems.
1815 /* Guard against races with tty->count changes elsewhere and
1816 opens on /dev/tty */
1818 mutex_lock(&tty_mutex
);
1819 tty_lock_pair(tty
, o_tty
);
1820 tty_closing
= tty
->count
<= 1;
1821 o_tty_closing
= o_tty
&&
1822 (o_tty
->count
<= (pty_master
? 1 : 0));
1826 if (waitqueue_active(&tty
->read_wait
)) {
1827 wake_up_poll(&tty
->read_wait
, POLLIN
);
1830 if (waitqueue_active(&tty
->write_wait
)) {
1831 wake_up_poll(&tty
->write_wait
, POLLOUT
);
1835 if (o_tty_closing
) {
1836 if (waitqueue_active(&o_tty
->read_wait
)) {
1837 wake_up_poll(&o_tty
->read_wait
, POLLIN
);
1840 if (waitqueue_active(&o_tty
->write_wait
)) {
1841 wake_up_poll(&o_tty
->write_wait
, POLLOUT
);
1848 printk(KERN_WARNING
"%s: %s: read/write wait queue active!\n",
1849 __func__
, tty_name(tty
, buf
));
1850 tty_unlock_pair(tty
, o_tty
);
1851 mutex_unlock(&tty_mutex
);
1856 * The closing flags are now consistent with the open counts on
1857 * both sides, and we've completed the last operation that could
1858 * block, so it's safe to proceed with closing.
1860 * We must *not* drop the tty_mutex until we ensure that a further
1861 * entry into tty_open can not pick up this tty.
1864 if (--o_tty
->count
< 0) {
1865 printk(KERN_WARNING
"%s: bad pty slave count (%d) for %s\n",
1866 __func__
, o_tty
->count
, tty_name(o_tty
, buf
));
1870 if (--tty
->count
< 0) {
1871 printk(KERN_WARNING
"%s: bad tty->count (%d) for %s\n",
1872 __func__
, tty
->count
, tty_name(tty
, buf
));
1877 * We've decremented tty->count, so we need to remove this file
1878 * descriptor off the tty->tty_files list; this serves two
1880 * - check_tty_count sees the correct number of file descriptors
1881 * associated with this tty.
1882 * - do_tty_hangup no longer sees this file descriptor as
1883 * something that needs to be handled for hangups.
1888 * Perform some housekeeping before deciding whether to return.
1890 * Set the TTY_CLOSING flag if this was the last open. In the
1891 * case of a pty we may have to wait around for the other side
1892 * to close, and TTY_CLOSING makes sure we can't be reopened.
1895 set_bit(TTY_CLOSING
, &tty
->flags
);
1897 set_bit(TTY_CLOSING
, &o_tty
->flags
);
1900 * If _either_ side is closing, make sure there aren't any
1901 * processes that still think tty or o_tty is their controlling
1904 if (tty_closing
|| o_tty_closing
) {
1905 read_lock(&tasklist_lock
);
1906 session_clear_tty(tty
->session
);
1908 session_clear_tty(o_tty
->session
);
1909 read_unlock(&tasklist_lock
);
1912 mutex_unlock(&tty_mutex
);
1913 tty_unlock_pair(tty
, o_tty
);
1914 /* At this point the TTY_CLOSING flag should ensure a dead tty
1915 cannot be re-opened by a racing opener */
1917 /* check whether both sides are closing ... */
1918 if (!tty_closing
|| (o_tty
&& !o_tty_closing
))
1921 #ifdef TTY_DEBUG_HANGUP
1922 printk(KERN_DEBUG
"%s: %s: final close\n", __func__
, tty_name(tty
, buf
));
1925 * Ask the line discipline code to release its structures
1927 tty_ldisc_release(tty
, o_tty
);
1929 /* Wait for pending work before tty destruction commmences */
1930 tty_flush_works(tty
);
1932 tty_flush_works(o_tty
);
1934 #ifdef TTY_DEBUG_HANGUP
1935 printk(KERN_DEBUG
"%s: %s: freeing structure...\n", __func__
, tty_name(tty
, buf
));
1938 * The release_tty function takes care of the details of clearing
1939 * the slots and preserving the termios structure. The tty_unlock_pair
1940 * should be safe as we keep a kref while the tty is locked (so the
1941 * unlock never unlocks a freed tty).
1943 mutex_lock(&tty_mutex
);
1944 release_tty(tty
, idx
);
1945 mutex_unlock(&tty_mutex
);
1951 * tty_open_current_tty - get tty of current task for open
1952 * @device: device number
1953 * @filp: file pointer to tty
1954 * @return: tty of the current task iff @device is /dev/tty
1956 * We cannot return driver and index like for the other nodes because
1957 * devpts will not work then. It expects inodes to be from devpts FS.
1959 * We need to move to returning a refcounted object from all the lookup
1960 * paths including this one.
1962 static struct tty_struct
*tty_open_current_tty(dev_t device
, struct file
*filp
)
1964 struct tty_struct
*tty
;
1966 if (device
!= MKDEV(TTYAUX_MAJOR
, 0))
1969 tty
= get_current_tty();
1971 return ERR_PTR(-ENXIO
);
1973 filp
->f_flags
|= O_NONBLOCK
; /* Don't let /dev/tty block */
1976 /* FIXME: we put a reference and return a TTY! */
1977 /* This is only safe because the caller holds tty_mutex */
1982 * tty_lookup_driver - lookup a tty driver for a given device file
1983 * @device: device number
1984 * @filp: file pointer to tty
1985 * @noctty: set if the device should not become a controlling tty
1986 * @index: index for the device in the @return driver
1987 * @return: driver for this inode (with increased refcount)
1989 * If @return is not erroneous, the caller is responsible to decrement the
1990 * refcount by tty_driver_kref_put.
1992 * Locking: tty_mutex protects get_tty_driver
1994 static struct tty_driver
*tty_lookup_driver(dev_t device
, struct file
*filp
,
1995 int *noctty
, int *index
)
1997 struct tty_driver
*driver
;
2001 case MKDEV(TTY_MAJOR
, 0): {
2002 extern struct tty_driver
*console_driver
;
2003 driver
= tty_driver_kref_get(console_driver
);
2004 *index
= fg_console
;
2009 case MKDEV(TTYAUX_MAJOR
, 1): {
2010 struct tty_driver
*console_driver
= console_device(index
);
2011 if (console_driver
) {
2012 driver
= tty_driver_kref_get(console_driver
);
2014 /* Don't let /dev/console block */
2015 filp
->f_flags
|= O_NONBLOCK
;
2020 return ERR_PTR(-ENODEV
);
2023 driver
= get_tty_driver(device
, index
);
2025 return ERR_PTR(-ENODEV
);
2032 * tty_open - open a tty device
2033 * @inode: inode of device file
2034 * @filp: file pointer to tty
2036 * tty_open and tty_release keep up the tty count that contains the
2037 * number of opens done on a tty. We cannot use the inode-count, as
2038 * different inodes might point to the same tty.
2040 * Open-counting is needed for pty masters, as well as for keeping
2041 * track of serial lines: DTR is dropped when the last close happens.
2042 * (This is not done solely through tty->count, now. - Ted 1/27/92)
2044 * The termios state of a pty is reset on first open so that
2045 * settings don't persist across reuse.
2047 * Locking: tty_mutex protects tty, tty_lookup_driver and tty_init_dev.
2048 * tty->count should protect the rest.
2049 * ->siglock protects ->signal/->sighand
2051 * Note: the tty_unlock/lock cases without a ref are only safe due to
2055 static int tty_open(struct inode
*inode
, struct file
*filp
)
2057 struct tty_struct
*tty
;
2059 struct tty_driver
*driver
= NULL
;
2061 dev_t device
= inode
->i_rdev
;
2062 unsigned saved_flags
= filp
->f_flags
;
2064 nonseekable_open(inode
, filp
);
2067 retval
= tty_alloc_file(filp
);
2071 noctty
= filp
->f_flags
& O_NOCTTY
;
2075 mutex_lock(&tty_mutex
);
2076 /* This is protected by the tty_mutex */
2077 tty
= tty_open_current_tty(device
, filp
);
2079 retval
= PTR_ERR(tty
);
2082 driver
= tty_lookup_driver(device
, filp
, &noctty
, &index
);
2083 if (IS_ERR(driver
)) {
2084 retval
= PTR_ERR(driver
);
2088 /* check whether we're reopening an existing tty */
2089 tty
= tty_driver_lookup_tty(driver
, inode
, index
);
2091 retval
= PTR_ERR(tty
);
2098 retval
= tty_reopen(tty
);
2101 tty
= ERR_PTR(retval
);
2103 } else /* Returns with the tty_lock held for now */
2104 tty
= tty_init_dev(driver
, index
);
2106 mutex_unlock(&tty_mutex
);
2108 tty_driver_kref_put(driver
);
2110 retval
= PTR_ERR(tty
);
2114 tty_add_file(tty
, filp
);
2116 check_tty_count(tty
, __func__
);
2117 if (tty
->driver
->type
== TTY_DRIVER_TYPE_PTY
&&
2118 tty
->driver
->subtype
== PTY_TYPE_MASTER
)
2120 #ifdef TTY_DEBUG_HANGUP
2121 printk(KERN_DEBUG
"%s: opening %s...\n", __func__
, tty
->name
);
2124 retval
= tty
->ops
->open(tty
, filp
);
2127 filp
->f_flags
= saved_flags
;
2129 if (!retval
&& test_bit(TTY_EXCLUSIVE
, &tty
->flags
) &&
2130 !capable(CAP_SYS_ADMIN
))
2134 #ifdef TTY_DEBUG_HANGUP
2135 printk(KERN_DEBUG
"%s: error %d in opening %s...\n", __func__
,
2138 tty_unlock(tty
); /* need to call tty_release without BTM */
2139 tty_release(inode
, filp
);
2140 if (retval
!= -ERESTARTSYS
)
2143 if (signal_pending(current
))
2148 * Need to reset f_op in case a hangup happened.
2150 if (filp
->f_op
== &hung_up_tty_fops
)
2151 filp
->f_op
= &tty_fops
;
2154 clear_bit(TTY_HUPPED
, &tty
->flags
);
2158 mutex_lock(&tty_mutex
);
2160 read_lock(&tasklist_lock
);
2161 spin_lock_irq(¤t
->sighand
->siglock
);
2163 current
->signal
->leader
&&
2164 !current
->signal
->tty
&&
2165 tty
->session
== NULL
)
2166 __proc_set_tty(tty
);
2167 spin_unlock_irq(¤t
->sighand
->siglock
);
2168 read_unlock(&tasklist_lock
);
2170 mutex_unlock(&tty_mutex
);
2173 mutex_unlock(&tty_mutex
);
2174 /* after locks to avoid deadlock */
2175 if (!IS_ERR_OR_NULL(driver
))
2176 tty_driver_kref_put(driver
);
2178 tty_free_file(filp
);
2185 * tty_poll - check tty status
2186 * @filp: file being polled
2187 * @wait: poll wait structures to update
2189 * Call the line discipline polling method to obtain the poll
2190 * status of the device.
2192 * Locking: locks called line discipline but ldisc poll method
2193 * may be re-entered freely by other callers.
2196 static unsigned int tty_poll(struct file
*filp
, poll_table
*wait
)
2198 struct tty_struct
*tty
= file_tty(filp
);
2199 struct tty_ldisc
*ld
;
2202 if (tty_paranoia_check(tty
, file_inode(filp
), "tty_poll"))
2205 ld
= tty_ldisc_ref_wait(tty
);
2207 ret
= (ld
->ops
->poll
)(tty
, filp
, wait
);
2208 tty_ldisc_deref(ld
);
2212 static int __tty_fasync(int fd
, struct file
*filp
, int on
)
2214 struct tty_struct
*tty
= file_tty(filp
);
2215 struct tty_ldisc
*ldisc
;
2216 unsigned long flags
;
2219 if (tty_paranoia_check(tty
, file_inode(filp
), "tty_fasync"))
2222 retval
= fasync_helper(fd
, filp
, on
, &tty
->fasync
);
2226 ldisc
= tty_ldisc_ref(tty
);
2228 if (ldisc
->ops
->fasync
)
2229 ldisc
->ops
->fasync(tty
, on
);
2230 tty_ldisc_deref(ldisc
);
2237 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
2240 type
= PIDTYPE_PGID
;
2242 pid
= task_pid(current
);
2246 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
2247 __f_setown(filp
, pid
, type
, 0);
2255 static int tty_fasync(int fd
, struct file
*filp
, int on
)
2257 struct tty_struct
*tty
= file_tty(filp
);
2261 retval
= __tty_fasync(fd
, filp
, on
);
2268 * tiocsti - fake input character
2269 * @tty: tty to fake input into
2270 * @p: pointer to character
2272 * Fake input to a tty device. Does the necessary locking and
2275 * FIXME: does not honour flow control ??
2278 * Called functions take tty_ldiscs_lock
2279 * current->signal->tty check is safe without locks
2281 * FIXME: may race normal receive processing
2284 static int tiocsti(struct tty_struct
*tty
, char __user
*p
)
2287 struct tty_ldisc
*ld
;
2289 if ((current
->signal
->tty
!= tty
) && !capable(CAP_SYS_ADMIN
))
2291 if (get_user(ch
, p
))
2293 tty_audit_tiocsti(tty
, ch
);
2294 ld
= tty_ldisc_ref_wait(tty
);
2295 ld
->ops
->receive_buf(tty
, &ch
, &mbz
, 1);
2296 tty_ldisc_deref(ld
);
2301 * tiocgwinsz - implement window query ioctl
2303 * @arg: user buffer for result
2305 * Copies the kernel idea of the window size into the user buffer.
2307 * Locking: tty->winsize_mutex is taken to ensure the winsize data
2311 static int tiocgwinsz(struct tty_struct
*tty
, struct winsize __user
*arg
)
2315 mutex_lock(&tty
->winsize_mutex
);
2316 err
= copy_to_user(arg
, &tty
->winsize
, sizeof(*arg
));
2317 mutex_unlock(&tty
->winsize_mutex
);
2319 return err
? -EFAULT
: 0;
2323 * tty_do_resize - resize event
2324 * @tty: tty being resized
2325 * @rows: rows (character)
2326 * @cols: cols (character)
2328 * Update the termios variables and send the necessary signals to
2329 * peform a terminal resize correctly
2332 int tty_do_resize(struct tty_struct
*tty
, struct winsize
*ws
)
2337 mutex_lock(&tty
->winsize_mutex
);
2338 if (!memcmp(ws
, &tty
->winsize
, sizeof(*ws
)))
2341 /* Signal the foreground process group */
2342 pgrp
= tty_get_pgrp(tty
);
2344 kill_pgrp(pgrp
, SIGWINCH
, 1);
2349 mutex_unlock(&tty
->winsize_mutex
);
2352 EXPORT_SYMBOL(tty_do_resize
);
2355 * tiocswinsz - implement window size set ioctl
2356 * @tty; tty side of tty
2357 * @arg: user buffer for result
2359 * Copies the user idea of the window size to the kernel. Traditionally
2360 * this is just advisory information but for the Linux console it
2361 * actually has driver level meaning and triggers a VC resize.
2364 * Driver dependent. The default do_resize method takes the
2365 * tty termios mutex and ctrl_lock. The console takes its own lock
2366 * then calls into the default method.
2369 static int tiocswinsz(struct tty_struct
*tty
, struct winsize __user
*arg
)
2371 struct winsize tmp_ws
;
2372 if (copy_from_user(&tmp_ws
, arg
, sizeof(*arg
)))
2375 if (tty
->ops
->resize
)
2376 return tty
->ops
->resize(tty
, &tmp_ws
);
2378 return tty_do_resize(tty
, &tmp_ws
);
2382 * tioccons - allow admin to move logical console
2383 * @file: the file to become console
2385 * Allow the administrator to move the redirected console device
2387 * Locking: uses redirect_lock to guard the redirect information
2390 static int tioccons(struct file
*file
)
2392 if (!capable(CAP_SYS_ADMIN
))
2394 if (file
->f_op
->write
== redirected_tty_write
) {
2396 spin_lock(&redirect_lock
);
2399 spin_unlock(&redirect_lock
);
2404 spin_lock(&redirect_lock
);
2406 spin_unlock(&redirect_lock
);
2409 redirect
= get_file(file
);
2410 spin_unlock(&redirect_lock
);
2415 * fionbio - non blocking ioctl
2416 * @file: file to set blocking value
2417 * @p: user parameter
2419 * Historical tty interfaces had a blocking control ioctl before
2420 * the generic functionality existed. This piece of history is preserved
2421 * in the expected tty API of posix OS's.
2423 * Locking: none, the open file handle ensures it won't go away.
2426 static int fionbio(struct file
*file
, int __user
*p
)
2430 if (get_user(nonblock
, p
))
2433 spin_lock(&file
->f_lock
);
2435 file
->f_flags
|= O_NONBLOCK
;
2437 file
->f_flags
&= ~O_NONBLOCK
;
2438 spin_unlock(&file
->f_lock
);
2443 * tiocsctty - set controlling tty
2444 * @tty: tty structure
2445 * @arg: user argument
2447 * This ioctl is used to manage job control. It permits a session
2448 * leader to set this tty as the controlling tty for the session.
2451 * Takes tty_mutex() to protect tty instance
2452 * Takes tasklist_lock internally to walk sessions
2453 * Takes ->siglock() when updating signal->tty
2456 static int tiocsctty(struct tty_struct
*tty
, int arg
)
2460 mutex_lock(&tty_mutex
);
2461 read_lock(&tasklist_lock
);
2463 if (current
->signal
->leader
&& (task_session(current
) == tty
->session
))
2467 * The process must be a session leader and
2468 * not have a controlling tty already.
2470 if (!current
->signal
->leader
|| current
->signal
->tty
) {
2477 * This tty is already the controlling
2478 * tty for another session group!
2480 if (arg
== 1 && capable(CAP_SYS_ADMIN
)) {
2484 session_clear_tty(tty
->session
);
2492 read_unlock(&tasklist_lock
);
2493 mutex_unlock(&tty_mutex
);
2498 * tty_get_pgrp - return a ref counted pgrp pid
2501 * Returns a refcounted instance of the pid struct for the process
2502 * group controlling the tty.
2505 struct pid
*tty_get_pgrp(struct tty_struct
*tty
)
2507 unsigned long flags
;
2510 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
2511 pgrp
= get_pid(tty
->pgrp
);
2512 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
2516 EXPORT_SYMBOL_GPL(tty_get_pgrp
);
2519 * tiocgpgrp - get process group
2520 * @tty: tty passed by user
2521 * @real_tty: tty side of the tty passed by the user if a pty else the tty
2524 * Obtain the process group of the tty. If there is no process group
2527 * Locking: none. Reference to current->signal->tty is safe.
2530 static int tiocgpgrp(struct tty_struct
*tty
, struct tty_struct
*real_tty
, pid_t __user
*p
)
2535 * (tty == real_tty) is a cheap way of
2536 * testing if the tty is NOT a master pty.
2538 if (tty
== real_tty
&& current
->signal
->tty
!= real_tty
)
2540 pid
= tty_get_pgrp(real_tty
);
2541 ret
= put_user(pid_vnr(pid
), p
);
2547 * tiocspgrp - attempt to set process group
2548 * @tty: tty passed by user
2549 * @real_tty: tty side device matching tty passed by user
2552 * Set the process group of the tty to the session passed. Only
2553 * permitted where the tty session is our session.
2555 * Locking: RCU, ctrl lock
2558 static int tiocspgrp(struct tty_struct
*tty
, struct tty_struct
*real_tty
, pid_t __user
*p
)
2562 int retval
= tty_check_change(real_tty
);
2563 unsigned long flags
;
2569 if (!current
->signal
->tty
||
2570 (current
->signal
->tty
!= real_tty
) ||
2571 (real_tty
->session
!= task_session(current
)))
2573 if (get_user(pgrp_nr
, p
))
2578 pgrp
= find_vpid(pgrp_nr
);
2583 if (session_of_pgrp(pgrp
) != task_session(current
))
2586 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
2587 put_pid(real_tty
->pgrp
);
2588 real_tty
->pgrp
= get_pid(pgrp
);
2589 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
2596 * tiocgsid - get session id
2597 * @tty: tty passed by user
2598 * @real_tty: tty side of the tty passed by the user if a pty else the tty
2599 * @p: pointer to returned session id
2601 * Obtain the session id of the tty. If there is no session
2604 * Locking: none. Reference to current->signal->tty is safe.
2607 static int tiocgsid(struct tty_struct
*tty
, struct tty_struct
*real_tty
, pid_t __user
*p
)
2610 * (tty == real_tty) is a cheap way of
2611 * testing if the tty is NOT a master pty.
2613 if (tty
== real_tty
&& current
->signal
->tty
!= real_tty
)
2615 if (!real_tty
->session
)
2617 return put_user(pid_vnr(real_tty
->session
), p
);
2621 * tiocsetd - set line discipline
2623 * @p: pointer to user data
2625 * Set the line discipline according to user request.
2627 * Locking: see tty_set_ldisc, this function is just a helper
2630 static int tiocsetd(struct tty_struct
*tty
, int __user
*p
)
2635 if (get_user(ldisc
, p
))
2638 ret
= tty_set_ldisc(tty
, ldisc
);
2644 * send_break - performed time break
2645 * @tty: device to break on
2646 * @duration: timeout in mS
2648 * Perform a timed break on hardware that lacks its own driver level
2649 * timed break functionality.
2652 * atomic_write_lock serializes
2656 static int send_break(struct tty_struct
*tty
, unsigned int duration
)
2660 if (tty
->ops
->break_ctl
== NULL
)
2663 if (tty
->driver
->flags
& TTY_DRIVER_HARDWARE_BREAK
)
2664 retval
= tty
->ops
->break_ctl(tty
, duration
);
2666 /* Do the work ourselves */
2667 if (tty_write_lock(tty
, 0) < 0)
2669 retval
= tty
->ops
->break_ctl(tty
, -1);
2672 if (!signal_pending(current
))
2673 msleep_interruptible(duration
);
2674 retval
= tty
->ops
->break_ctl(tty
, 0);
2676 tty_write_unlock(tty
);
2677 if (signal_pending(current
))
2684 * tty_tiocmget - get modem status
2686 * @file: user file pointer
2687 * @p: pointer to result
2689 * Obtain the modem status bits from the tty driver if the feature
2690 * is supported. Return -EINVAL if it is not available.
2692 * Locking: none (up to the driver)
2695 static int tty_tiocmget(struct tty_struct
*tty
, int __user
*p
)
2697 int retval
= -EINVAL
;
2699 if (tty
->ops
->tiocmget
) {
2700 retval
= tty
->ops
->tiocmget(tty
);
2703 retval
= put_user(retval
, p
);
2709 * tty_tiocmset - set modem status
2711 * @cmd: command - clear bits, set bits or set all
2712 * @p: pointer to desired bits
2714 * Set the modem status bits from the tty driver if the feature
2715 * is supported. Return -EINVAL if it is not available.
2717 * Locking: none (up to the driver)
2720 static int tty_tiocmset(struct tty_struct
*tty
, unsigned int cmd
,
2724 unsigned int set
, clear
, val
;
2726 if (tty
->ops
->tiocmset
== NULL
)
2729 retval
= get_user(val
, p
);
2745 set
&= TIOCM_DTR
|TIOCM_RTS
|TIOCM_OUT1
|TIOCM_OUT2
|TIOCM_LOOP
;
2746 clear
&= TIOCM_DTR
|TIOCM_RTS
|TIOCM_OUT1
|TIOCM_OUT2
|TIOCM_LOOP
;
2747 return tty
->ops
->tiocmset(tty
, set
, clear
);
2750 static int tty_tiocgicount(struct tty_struct
*tty
, void __user
*arg
)
2752 int retval
= -EINVAL
;
2753 struct serial_icounter_struct icount
;
2754 memset(&icount
, 0, sizeof(icount
));
2755 if (tty
->ops
->get_icount
)
2756 retval
= tty
->ops
->get_icount(tty
, &icount
);
2759 if (copy_to_user(arg
, &icount
, sizeof(icount
)))
2765 * if pty, return the slave side (real_tty)
2766 * otherwise, return self
2768 static struct tty_struct
*tty_pair_get_tty(struct tty_struct
*tty
)
2770 if (tty
->driver
->type
== TTY_DRIVER_TYPE_PTY
&&
2771 tty
->driver
->subtype
== PTY_TYPE_MASTER
)
2777 * Split this up, as gcc can choke on it otherwise..
2779 long tty_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
2781 struct tty_struct
*tty
= file_tty(file
);
2782 struct tty_struct
*real_tty
;
2783 void __user
*p
= (void __user
*)arg
;
2785 struct tty_ldisc
*ld
;
2787 if (tty_paranoia_check(tty
, file_inode(file
), "tty_ioctl"))
2790 real_tty
= tty_pair_get_tty(tty
);
2793 * Factor out some common prep work
2801 retval
= tty_check_change(tty
);
2804 if (cmd
!= TIOCCBRK
) {
2805 tty_wait_until_sent(tty
, 0);
2806 if (signal_pending(current
))
2817 return tiocsti(tty
, p
);
2819 return tiocgwinsz(real_tty
, p
);
2821 return tiocswinsz(real_tty
, p
);
2823 return real_tty
!= tty
? -EINVAL
: tioccons(file
);
2825 return fionbio(file
, p
);
2827 set_bit(TTY_EXCLUSIVE
, &tty
->flags
);
2830 clear_bit(TTY_EXCLUSIVE
, &tty
->flags
);
2834 int excl
= test_bit(TTY_EXCLUSIVE
, &tty
->flags
);
2835 return put_user(excl
, (int __user
*)p
);
2838 if (current
->signal
->tty
!= tty
)
2843 return tiocsctty(tty
, arg
);
2845 return tiocgpgrp(tty
, real_tty
, p
);
2847 return tiocspgrp(tty
, real_tty
, p
);
2849 return tiocgsid(tty
, real_tty
, p
);
2851 return put_user(tty
->ldisc
->ops
->num
, (int __user
*)p
);
2853 return tiocsetd(tty
, p
);
2855 if (!capable(CAP_SYS_ADMIN
))
2861 unsigned int ret
= new_encode_dev(tty_devnum(real_tty
));
2862 return put_user(ret
, (unsigned int __user
*)p
);
2867 case TIOCSBRK
: /* Turn break on, unconditionally */
2868 if (tty
->ops
->break_ctl
)
2869 return tty
->ops
->break_ctl(tty
, -1);
2871 case TIOCCBRK
: /* Turn break off, unconditionally */
2872 if (tty
->ops
->break_ctl
)
2873 return tty
->ops
->break_ctl(tty
, 0);
2875 case TCSBRK
: /* SVID version: non-zero arg --> no break */
2876 /* non-zero arg means wait for all output data
2877 * to be sent (performed above) but don't send break.
2878 * This is used by the tcdrain() termios function.
2881 return send_break(tty
, 250);
2883 case TCSBRKP
: /* support for POSIX tcsendbreak() */
2884 return send_break(tty
, arg
? arg
*100 : 250);
2887 return tty_tiocmget(tty
, p
);
2891 return tty_tiocmset(tty
, cmd
, p
);
2893 retval
= tty_tiocgicount(tty
, p
);
2894 /* For the moment allow fall through to the old method */
2895 if (retval
!= -EINVAL
)
2902 /* flush tty buffer and allow ldisc to process ioctl */
2903 tty_buffer_flush(tty
);
2908 if (tty
->ops
->ioctl
) {
2909 retval
= (tty
->ops
->ioctl
)(tty
, cmd
, arg
);
2910 if (retval
!= -ENOIOCTLCMD
)
2913 ld
= tty_ldisc_ref_wait(tty
);
2915 if (ld
->ops
->ioctl
) {
2916 retval
= ld
->ops
->ioctl(tty
, file
, cmd
, arg
);
2917 if (retval
== -ENOIOCTLCMD
)
2920 tty_ldisc_deref(ld
);
2924 #ifdef CONFIG_COMPAT
2925 static long tty_compat_ioctl(struct file
*file
, unsigned int cmd
,
2928 struct tty_struct
*tty
= file_tty(file
);
2929 struct tty_ldisc
*ld
;
2930 int retval
= -ENOIOCTLCMD
;
2932 if (tty_paranoia_check(tty
, file_inode(file
), "tty_ioctl"))
2935 if (tty
->ops
->compat_ioctl
) {
2936 retval
= (tty
->ops
->compat_ioctl
)(tty
, cmd
, arg
);
2937 if (retval
!= -ENOIOCTLCMD
)
2941 ld
= tty_ldisc_ref_wait(tty
);
2942 if (ld
->ops
->compat_ioctl
)
2943 retval
= ld
->ops
->compat_ioctl(tty
, file
, cmd
, arg
);
2945 retval
= n_tty_compat_ioctl_helper(tty
, file
, cmd
, arg
);
2946 tty_ldisc_deref(ld
);
2952 static int this_tty(const void *t
, struct file
*file
, unsigned fd
)
2954 if (likely(file
->f_op
->read
!= tty_read
))
2956 return file_tty(file
) != t
? 0 : fd
+ 1;
2960 * This implements the "Secure Attention Key" --- the idea is to
2961 * prevent trojan horses by killing all processes associated with this
2962 * tty when the user hits the "Secure Attention Key". Required for
2963 * super-paranoid applications --- see the Orange Book for more details.
2965 * This code could be nicer; ideally it should send a HUP, wait a few
2966 * seconds, then send a INT, and then a KILL signal. But you then
2967 * have to coordinate with the init process, since all processes associated
2968 * with the current tty must be dead before the new getty is allowed
2971 * Now, if it would be correct ;-/ The current code has a nasty hole -
2972 * it doesn't catch files in flight. We may send the descriptor to ourselves
2973 * via AF_UNIX socket, close it and later fetch from socket. FIXME.
2975 * Nasty bug: do_SAK is being called in interrupt context. This can
2976 * deadlock. We punt it up to process context. AKPM - 16Mar2001
2978 void __do_SAK(struct tty_struct
*tty
)
2983 struct task_struct
*g
, *p
;
2984 struct pid
*session
;
2989 session
= tty
->session
;
2991 tty_ldisc_flush(tty
);
2993 tty_driver_flush_buffer(tty
);
2995 read_lock(&tasklist_lock
);
2996 /* Kill the entire session */
2997 do_each_pid_task(session
, PIDTYPE_SID
, p
) {
2998 printk(KERN_NOTICE
"SAK: killed process %d"
2999 " (%s): task_session(p)==tty->session\n",
3000 task_pid_nr(p
), p
->comm
);
3001 send_sig(SIGKILL
, p
, 1);
3002 } while_each_pid_task(session
, PIDTYPE_SID
, p
);
3003 /* Now kill any processes that happen to have the
3006 do_each_thread(g
, p
) {
3007 if (p
->signal
->tty
== tty
) {
3008 printk(KERN_NOTICE
"SAK: killed process %d"
3009 " (%s): task_session(p)==tty->session\n",
3010 task_pid_nr(p
), p
->comm
);
3011 send_sig(SIGKILL
, p
, 1);
3015 i
= iterate_fd(p
->files
, 0, this_tty
, tty
);
3017 printk(KERN_NOTICE
"SAK: killed process %d"
3018 " (%s): fd#%d opened to the tty\n",
3019 task_pid_nr(p
), p
->comm
, i
- 1);
3020 force_sig(SIGKILL
, p
);
3023 } while_each_thread(g
, p
);
3024 read_unlock(&tasklist_lock
);
3028 static void do_SAK_work(struct work_struct
*work
)
3030 struct tty_struct
*tty
=
3031 container_of(work
, struct tty_struct
, SAK_work
);
3036 * The tq handling here is a little racy - tty->SAK_work may already be queued.
3037 * Fortunately we don't need to worry, because if ->SAK_work is already queued,
3038 * the values which we write to it will be identical to the values which it
3039 * already has. --akpm
3041 void do_SAK(struct tty_struct
*tty
)
3045 schedule_work(&tty
->SAK_work
);
3048 EXPORT_SYMBOL(do_SAK
);
3050 static int dev_match_devt(struct device
*dev
, const void *data
)
3052 const dev_t
*devt
= data
;
3053 return dev
->devt
== *devt
;
3056 /* Must put_device() after it's unused! */
3057 static struct device
*tty_get_device(struct tty_struct
*tty
)
3059 dev_t devt
= tty_devnum(tty
);
3060 return class_find_device(tty_class
, NULL
, &devt
, dev_match_devt
);
3067 * This subroutine allocates and initializes a tty structure.
3069 * Locking: none - tty in question is not exposed at this point
3072 struct tty_struct
*alloc_tty_struct(struct tty_driver
*driver
, int idx
)
3074 struct tty_struct
*tty
;
3076 tty
= kzalloc(sizeof(*tty
), GFP_KERNEL
);
3080 kref_init(&tty
->kref
);
3081 tty
->magic
= TTY_MAGIC
;
3082 tty_ldisc_init(tty
);
3083 tty
->session
= NULL
;
3085 mutex_init(&tty
->legacy_mutex
);
3086 mutex_init(&tty
->throttle_mutex
);
3087 init_rwsem(&tty
->termios_rwsem
);
3088 mutex_init(&tty
->winsize_mutex
);
3089 init_ldsem(&tty
->ldisc_sem
);
3090 init_waitqueue_head(&tty
->write_wait
);
3091 init_waitqueue_head(&tty
->read_wait
);
3092 INIT_WORK(&tty
->hangup_work
, do_tty_hangup
);
3093 mutex_init(&tty
->atomic_write_lock
);
3094 spin_lock_init(&tty
->ctrl_lock
);
3095 spin_lock_init(&tty
->flow_lock
);
3096 INIT_LIST_HEAD(&tty
->tty_files
);
3097 INIT_WORK(&tty
->SAK_work
, do_SAK_work
);
3099 tty
->driver
= driver
;
3100 tty
->ops
= driver
->ops
;
3102 tty_line_name(driver
, idx
, tty
->name
);
3103 tty
->dev
= tty_get_device(tty
);
3109 * deinitialize_tty_struct
3110 * @tty: tty to deinitialize
3112 * This subroutine deinitializes a tty structure that has been newly
3113 * allocated but tty_release cannot be called on that yet.
3115 * Locking: none - tty in question must not be exposed at this point
3117 void deinitialize_tty_struct(struct tty_struct
*tty
)
3119 tty_ldisc_deinit(tty
);
3123 * tty_put_char - write one character to a tty
3127 * Write one byte to the tty using the provided put_char method
3128 * if present. Returns the number of characters successfully output.
3130 * Note: the specific put_char operation in the driver layer may go
3131 * away soon. Don't call it directly, use this method
3134 int tty_put_char(struct tty_struct
*tty
, unsigned char ch
)
3136 if (tty
->ops
->put_char
)
3137 return tty
->ops
->put_char(tty
, ch
);
3138 return tty
->ops
->write(tty
, &ch
, 1);
3140 EXPORT_SYMBOL_GPL(tty_put_char
);
3142 struct class *tty_class
;
3144 static int tty_cdev_add(struct tty_driver
*driver
, dev_t dev
,
3145 unsigned int index
, unsigned int count
)
3147 /* init here, since reused cdevs cause crashes */
3148 cdev_init(&driver
->cdevs
[index
], &tty_fops
);
3149 driver
->cdevs
[index
].owner
= driver
->owner
;
3150 return cdev_add(&driver
->cdevs
[index
], dev
, count
);
3154 * tty_register_device - register a tty device
3155 * @driver: the tty driver that describes the tty device
3156 * @index: the index in the tty driver for this tty device
3157 * @device: a struct device that is associated with this tty device.
3158 * This field is optional, if there is no known struct device
3159 * for this tty device it can be set to NULL safely.
3161 * Returns a pointer to the struct device for this tty device
3162 * (or ERR_PTR(-EFOO) on error).
3164 * This call is required to be made to register an individual tty device
3165 * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If
3166 * that bit is not set, this function should not be called by a tty
3172 struct device
*tty_register_device(struct tty_driver
*driver
, unsigned index
,
3173 struct device
*device
)
3175 return tty_register_device_attr(driver
, index
, device
, NULL
, NULL
);
3177 EXPORT_SYMBOL(tty_register_device
);
3179 static void tty_device_create_release(struct device
*dev
)
3181 pr_debug("device: '%s': %s\n", dev_name(dev
), __func__
);
3186 * tty_register_device_attr - register a tty device
3187 * @driver: the tty driver that describes the tty device
3188 * @index: the index in the tty driver for this tty device
3189 * @device: a struct device that is associated with this tty device.
3190 * This field is optional, if there is no known struct device
3191 * for this tty device it can be set to NULL safely.
3192 * @drvdata: Driver data to be set to device.
3193 * @attr_grp: Attribute group to be set on device.
3195 * Returns a pointer to the struct device for this tty device
3196 * (or ERR_PTR(-EFOO) on error).
3198 * This call is required to be made to register an individual tty device
3199 * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If
3200 * that bit is not set, this function should not be called by a tty
3205 struct device
*tty_register_device_attr(struct tty_driver
*driver
,
3206 unsigned index
, struct device
*device
,
3208 const struct attribute_group
**attr_grp
)
3211 dev_t devt
= MKDEV(driver
->major
, driver
->minor_start
) + index
;
3212 struct device
*dev
= NULL
;
3213 int retval
= -ENODEV
;
3216 if (index
>= driver
->num
) {
3217 printk(KERN_ERR
"Attempt to register invalid tty line number "
3219 return ERR_PTR(-EINVAL
);
3222 if (driver
->type
== TTY_DRIVER_TYPE_PTY
)
3223 pty_line_name(driver
, index
, name
);
3225 tty_line_name(driver
, index
, name
);
3227 if (!(driver
->flags
& TTY_DRIVER_DYNAMIC_ALLOC
)) {
3228 retval
= tty_cdev_add(driver
, devt
, index
, 1);
3234 dev
= kzalloc(sizeof(*dev
), GFP_KERNEL
);
3241 dev
->class = tty_class
;
3242 dev
->parent
= device
;
3243 dev
->release
= tty_device_create_release
;
3244 dev_set_name(dev
, "%s", name
);
3245 dev
->groups
= attr_grp
;
3246 dev_set_drvdata(dev
, drvdata
);
3248 retval
= device_register(dev
);
3257 cdev_del(&driver
->cdevs
[index
]);
3258 return ERR_PTR(retval
);
3260 EXPORT_SYMBOL_GPL(tty_register_device_attr
);
3263 * tty_unregister_device - unregister a tty device
3264 * @driver: the tty driver that describes the tty device
3265 * @index: the index in the tty driver for this tty device
3267 * If a tty device is registered with a call to tty_register_device() then
3268 * this function must be called when the tty device is gone.
3273 void tty_unregister_device(struct tty_driver
*driver
, unsigned index
)
3275 device_destroy(tty_class
,
3276 MKDEV(driver
->major
, driver
->minor_start
) + index
);
3277 if (!(driver
->flags
& TTY_DRIVER_DYNAMIC_ALLOC
))
3278 cdev_del(&driver
->cdevs
[index
]);
3280 EXPORT_SYMBOL(tty_unregister_device
);
3283 * __tty_alloc_driver -- allocate tty driver
3284 * @lines: count of lines this driver can handle at most
3285 * @owner: module which is repsonsible for this driver
3286 * @flags: some of TTY_DRIVER_* flags, will be set in driver->flags
3288 * This should not be called directly, some of the provided macros should be
3289 * used instead. Use IS_ERR and friends on @retval.
3291 struct tty_driver
*__tty_alloc_driver(unsigned int lines
, struct module
*owner
,
3292 unsigned long flags
)
3294 struct tty_driver
*driver
;
3295 unsigned int cdevs
= 1;
3298 if (!lines
|| (flags
& TTY_DRIVER_UNNUMBERED_NODE
&& lines
> 1))
3299 return ERR_PTR(-EINVAL
);
3301 driver
= kzalloc(sizeof(struct tty_driver
), GFP_KERNEL
);
3303 return ERR_PTR(-ENOMEM
);
3305 kref_init(&driver
->kref
);
3306 driver
->magic
= TTY_DRIVER_MAGIC
;
3307 driver
->num
= lines
;
3308 driver
->owner
= owner
;
3309 driver
->flags
= flags
;
3311 if (!(flags
& TTY_DRIVER_DEVPTS_MEM
)) {
3312 driver
->ttys
= kcalloc(lines
, sizeof(*driver
->ttys
),
3314 driver
->termios
= kcalloc(lines
, sizeof(*driver
->termios
),
3316 if (!driver
->ttys
|| !driver
->termios
) {
3322 if (!(flags
& TTY_DRIVER_DYNAMIC_ALLOC
)) {
3323 driver
->ports
= kcalloc(lines
, sizeof(*driver
->ports
),
3325 if (!driver
->ports
) {
3332 driver
->cdevs
= kcalloc(cdevs
, sizeof(*driver
->cdevs
), GFP_KERNEL
);
3333 if (!driver
->cdevs
) {
3340 kfree(driver
->ports
);
3341 kfree(driver
->ttys
);
3342 kfree(driver
->termios
);
3344 return ERR_PTR(err
);
3346 EXPORT_SYMBOL(__tty_alloc_driver
);
3348 static void destruct_tty_driver(struct kref
*kref
)
3350 struct tty_driver
*driver
= container_of(kref
, struct tty_driver
, kref
);
3352 struct ktermios
*tp
;
3354 if (driver
->flags
& TTY_DRIVER_INSTALLED
) {
3356 * Free the termios and termios_locked structures because
3357 * we don't want to get memory leaks when modular tty
3358 * drivers are removed from the kernel.
3360 for (i
= 0; i
< driver
->num
; i
++) {
3361 tp
= driver
->termios
[i
];
3363 driver
->termios
[i
] = NULL
;
3366 if (!(driver
->flags
& TTY_DRIVER_DYNAMIC_DEV
))
3367 tty_unregister_device(driver
, i
);
3369 proc_tty_unregister_driver(driver
);
3370 if (driver
->flags
& TTY_DRIVER_DYNAMIC_ALLOC
)
3371 cdev_del(&driver
->cdevs
[0]);
3373 kfree(driver
->cdevs
);
3374 kfree(driver
->ports
);
3375 kfree(driver
->termios
);
3376 kfree(driver
->ttys
);
3380 void tty_driver_kref_put(struct tty_driver
*driver
)
3382 kref_put(&driver
->kref
, destruct_tty_driver
);
3384 EXPORT_SYMBOL(tty_driver_kref_put
);
3386 void tty_set_operations(struct tty_driver
*driver
,
3387 const struct tty_operations
*op
)
3391 EXPORT_SYMBOL(tty_set_operations
);
3393 void put_tty_driver(struct tty_driver
*d
)
3395 tty_driver_kref_put(d
);
3397 EXPORT_SYMBOL(put_tty_driver
);
3400 * Called by a tty driver to register itself.
3402 int tty_register_driver(struct tty_driver
*driver
)
3409 if (!driver
->major
) {
3410 error
= alloc_chrdev_region(&dev
, driver
->minor_start
,
3411 driver
->num
, driver
->name
);
3413 driver
->major
= MAJOR(dev
);
3414 driver
->minor_start
= MINOR(dev
);
3417 dev
= MKDEV(driver
->major
, driver
->minor_start
);
3418 error
= register_chrdev_region(dev
, driver
->num
, driver
->name
);
3423 if (driver
->flags
& TTY_DRIVER_DYNAMIC_ALLOC
) {
3424 error
= tty_cdev_add(driver
, dev
, 0, driver
->num
);
3426 goto err_unreg_char
;
3429 mutex_lock(&tty_mutex
);
3430 list_add(&driver
->tty_drivers
, &tty_drivers
);
3431 mutex_unlock(&tty_mutex
);
3433 if (!(driver
->flags
& TTY_DRIVER_DYNAMIC_DEV
)) {
3434 for (i
= 0; i
< driver
->num
; i
++) {
3435 d
= tty_register_device(driver
, i
, NULL
);
3438 goto err_unreg_devs
;
3442 proc_tty_register_driver(driver
);
3443 driver
->flags
|= TTY_DRIVER_INSTALLED
;
3447 for (i
--; i
>= 0; i
--)
3448 tty_unregister_device(driver
, i
);
3450 mutex_lock(&tty_mutex
);
3451 list_del(&driver
->tty_drivers
);
3452 mutex_unlock(&tty_mutex
);
3455 unregister_chrdev_region(dev
, driver
->num
);
3459 EXPORT_SYMBOL(tty_register_driver
);
3462 * Called by a tty driver to unregister itself.
3464 int tty_unregister_driver(struct tty_driver
*driver
)
3468 if (driver
->refcount
)
3471 unregister_chrdev_region(MKDEV(driver
->major
, driver
->minor_start
),
3473 mutex_lock(&tty_mutex
);
3474 list_del(&driver
->tty_drivers
);
3475 mutex_unlock(&tty_mutex
);
3479 EXPORT_SYMBOL(tty_unregister_driver
);
3481 dev_t
tty_devnum(struct tty_struct
*tty
)
3483 return MKDEV(tty
->driver
->major
, tty
->driver
->minor_start
) + tty
->index
;
3485 EXPORT_SYMBOL(tty_devnum
);
3487 void tty_default_fops(struct file_operations
*fops
)
3493 * Initialize the console device. This is called *early*, so
3494 * we can't necessarily depend on lots of kernel help here.
3495 * Just do some early initializations, and do the complex setup
3498 void __init
console_init(void)
3502 /* Setup the default TTY line discipline. */
3506 * set up the console device so that later boot sequences can
3507 * inform about problems etc..
3509 call
= __con_initcall_start
;
3510 while (call
< __con_initcall_end
) {
3516 static char *tty_devnode(struct device
*dev
, umode_t
*mode
)
3520 if (dev
->devt
== MKDEV(TTYAUX_MAJOR
, 0) ||
3521 dev
->devt
== MKDEV(TTYAUX_MAJOR
, 2))
3526 static int __init
tty_class_init(void)
3528 tty_class
= class_create(THIS_MODULE
, "tty");
3529 if (IS_ERR(tty_class
))
3530 return PTR_ERR(tty_class
);
3531 tty_class
->devnode
= tty_devnode
;
3535 postcore_initcall(tty_class_init
);
3537 /* 3/2004 jmc: why do these devices exist? */
3538 static struct cdev tty_cdev
, console_cdev
;
3540 static ssize_t
show_cons_active(struct device
*dev
,
3541 struct device_attribute
*attr
, char *buf
)
3543 struct console
*cs
[16];
3549 for_each_console(c
) {
3554 if ((c
->flags
& CON_ENABLED
) == 0)
3557 if (i
>= ARRAY_SIZE(cs
))
3561 int index
= cs
[i
]->index
;
3562 struct tty_driver
*drv
= cs
[i
]->device(cs
[i
], &index
);
3564 /* don't resolve tty0 as some programs depend on it */
3565 if (drv
&& (cs
[i
]->index
> 0 || drv
->major
!= TTY_MAJOR
))
3566 count
+= tty_line_name(drv
, index
, buf
+ count
);
3568 count
+= sprintf(buf
+ count
, "%s%d",
3569 cs
[i
]->name
, cs
[i
]->index
);
3571 count
+= sprintf(buf
+ count
, "%c", i
? ' ':'\n');
3577 static DEVICE_ATTR(active
, S_IRUGO
, show_cons_active
, NULL
);
3579 static struct device
*consdev
;
3581 void console_sysfs_notify(void)
3584 sysfs_notify(&consdev
->kobj
, NULL
, "active");
3588 * Ok, now we can initialize the rest of the tty devices and can count
3589 * on memory allocations, interrupts etc..
3591 int __init
tty_init(void)
3593 cdev_init(&tty_cdev
, &tty_fops
);
3594 if (cdev_add(&tty_cdev
, MKDEV(TTYAUX_MAJOR
, 0), 1) ||
3595 register_chrdev_region(MKDEV(TTYAUX_MAJOR
, 0), 1, "/dev/tty") < 0)
3596 panic("Couldn't register /dev/tty driver\n");
3597 device_create(tty_class
, NULL
, MKDEV(TTYAUX_MAJOR
, 0), NULL
, "tty");
3599 cdev_init(&console_cdev
, &console_fops
);
3600 if (cdev_add(&console_cdev
, MKDEV(TTYAUX_MAJOR
, 1), 1) ||
3601 register_chrdev_region(MKDEV(TTYAUX_MAJOR
, 1), 1, "/dev/console") < 0)
3602 panic("Couldn't register /dev/console driver\n");
3603 consdev
= device_create(tty_class
, NULL
, MKDEV(TTYAUX_MAJOR
, 1), NULL
,
3605 if (IS_ERR(consdev
))
3608 WARN_ON(device_create_file(consdev
, &dev_attr_active
) < 0);
3611 vty_init(&console_fops
);