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
);
156 static void __proc_set_tty(struct task_struct
*tsk
, struct tty_struct
*tty
);
157 static void proc_set_tty(struct task_struct
*tsk
, struct tty_struct
*tty
);
160 * alloc_tty_struct - allocate a tty object
162 * Return a new empty tty structure. The data fields have not
163 * been initialized in any way but has been zeroed
168 struct tty_struct
*alloc_tty_struct(void)
170 return kzalloc(sizeof(struct tty_struct
), GFP_KERNEL
);
174 * free_tty_struct - free a disused tty
175 * @tty: tty struct to free
177 * Free the write buffers, tty queue and tty memory itself.
179 * Locking: none. Must be called after tty is definitely unused
182 void free_tty_struct(struct tty_struct
*tty
)
187 put_device(tty
->dev
);
188 kfree(tty
->write_buf
);
189 tty
->magic
= 0xDEADDEAD;
193 static inline struct tty_struct
*file_tty(struct file
*file
)
195 return ((struct tty_file_private
*)file
->private_data
)->tty
;
198 int tty_alloc_file(struct file
*file
)
200 struct tty_file_private
*priv
;
202 priv
= kmalloc(sizeof(*priv
), GFP_KERNEL
);
206 file
->private_data
= priv
;
211 /* Associate a new file with the tty structure */
212 void tty_add_file(struct tty_struct
*tty
, struct file
*file
)
214 struct tty_file_private
*priv
= file
->private_data
;
219 spin_lock(&tty_files_lock
);
220 list_add(&priv
->list
, &tty
->tty_files
);
221 spin_unlock(&tty_files_lock
);
225 * tty_free_file - free file->private_data
227 * This shall be used only for fail path handling when tty_add_file was not
230 void tty_free_file(struct file
*file
)
232 struct tty_file_private
*priv
= file
->private_data
;
234 file
->private_data
= NULL
;
238 /* Delete file from its tty */
239 static void tty_del_file(struct file
*file
)
241 struct tty_file_private
*priv
= file
->private_data
;
243 spin_lock(&tty_files_lock
);
244 list_del(&priv
->list
);
245 spin_unlock(&tty_files_lock
);
250 #define TTY_NUMBER(tty) ((tty)->index + (tty)->driver->name_base)
253 * tty_name - return tty naming
254 * @tty: tty structure
255 * @buf: buffer for output
257 * Convert a tty structure into a name. The name reflects the kernel
258 * naming policy and if udev is in use may not reflect user space
263 char *tty_name(struct tty_struct
*tty
, char *buf
)
265 if (!tty
) /* Hmm. NULL pointer. That's fun. */
266 strcpy(buf
, "NULL tty");
268 strcpy(buf
, tty
->name
);
272 EXPORT_SYMBOL(tty_name
);
274 int tty_paranoia_check(struct tty_struct
*tty
, struct inode
*inode
,
277 #ifdef TTY_PARANOIA_CHECK
280 "null TTY for (%d:%d) in %s\n",
281 imajor(inode
), iminor(inode
), routine
);
284 if (tty
->magic
!= TTY_MAGIC
) {
286 "bad magic number for tty struct (%d:%d) in %s\n",
287 imajor(inode
), iminor(inode
), routine
);
294 static int check_tty_count(struct tty_struct
*tty
, const char *routine
)
296 #ifdef CHECK_TTY_COUNT
300 spin_lock(&tty_files_lock
);
301 list_for_each(p
, &tty
->tty_files
) {
304 spin_unlock(&tty_files_lock
);
305 if (tty
->driver
->type
== TTY_DRIVER_TYPE_PTY
&&
306 tty
->driver
->subtype
== PTY_TYPE_SLAVE
&&
307 tty
->link
&& tty
->link
->count
)
309 if (tty
->count
!= count
) {
310 printk(KERN_WARNING
"Warning: dev (%s) tty->count(%d) "
311 "!= #fd's(%d) in %s\n",
312 tty
->name
, tty
->count
, count
, routine
);
320 * get_tty_driver - find device of a tty
321 * @dev_t: device identifier
322 * @index: returns the index of the tty
324 * This routine returns a tty driver structure, given a device number
325 * and also passes back the index number.
327 * Locking: caller must hold tty_mutex
330 static struct tty_driver
*get_tty_driver(dev_t device
, int *index
)
332 struct tty_driver
*p
;
334 list_for_each_entry(p
, &tty_drivers
, tty_drivers
) {
335 dev_t base
= MKDEV(p
->major
, p
->minor_start
);
336 if (device
< base
|| device
>= base
+ p
->num
)
338 *index
= device
- base
;
339 return tty_driver_kref_get(p
);
344 #ifdef CONFIG_CONSOLE_POLL
347 * tty_find_polling_driver - find device of a polled tty
348 * @name: name string to match
349 * @line: pointer to resulting tty line nr
351 * This routine returns a tty driver structure, given a name
352 * and the condition that the tty driver is capable of polled
355 struct tty_driver
*tty_find_polling_driver(char *name
, int *line
)
357 struct tty_driver
*p
, *res
= NULL
;
362 for (str
= name
; *str
; str
++)
363 if ((*str
>= '0' && *str
<= '9') || *str
== ',')
369 tty_line
= simple_strtoul(str
, &str
, 10);
371 mutex_lock(&tty_mutex
);
372 /* Search through the tty devices to look for a match */
373 list_for_each_entry(p
, &tty_drivers
, tty_drivers
) {
374 if (strncmp(name
, p
->name
, len
) != 0)
382 if (tty_line
>= 0 && tty_line
< p
->num
&& p
->ops
&&
383 p
->ops
->poll_init
&& !p
->ops
->poll_init(p
, tty_line
, stp
)) {
384 res
= tty_driver_kref_get(p
);
389 mutex_unlock(&tty_mutex
);
393 EXPORT_SYMBOL_GPL(tty_find_polling_driver
);
397 * tty_check_change - check for POSIX terminal changes
400 * If we try to write to, or set the state of, a terminal and we're
401 * not in the foreground, send a SIGTTOU. If the signal is blocked or
402 * ignored, go ahead and perform the operation. (POSIX 7.2)
407 int tty_check_change(struct tty_struct
*tty
)
412 if (current
->signal
->tty
!= tty
)
415 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
418 printk(KERN_WARNING
"tty_check_change: tty->pgrp == NULL!\n");
421 if (task_pgrp(current
) == tty
->pgrp
)
423 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
424 if (is_ignored(SIGTTOU
))
426 if (is_current_pgrp_orphaned()) {
430 kill_pgrp(task_pgrp(current
), SIGTTOU
, 1);
431 set_thread_flag(TIF_SIGPENDING
);
436 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
440 EXPORT_SYMBOL(tty_check_change
);
442 static ssize_t
hung_up_tty_read(struct file
*file
, char __user
*buf
,
443 size_t count
, loff_t
*ppos
)
448 static ssize_t
hung_up_tty_write(struct file
*file
, const char __user
*buf
,
449 size_t count
, loff_t
*ppos
)
454 /* No kernel lock held - none needed ;) */
455 static unsigned int hung_up_tty_poll(struct file
*filp
, poll_table
*wait
)
457 return POLLIN
| POLLOUT
| POLLERR
| POLLHUP
| POLLRDNORM
| POLLWRNORM
;
460 static long hung_up_tty_ioctl(struct file
*file
, unsigned int cmd
,
463 return cmd
== TIOCSPGRP
? -ENOTTY
: -EIO
;
466 static long hung_up_tty_compat_ioctl(struct file
*file
,
467 unsigned int cmd
, unsigned long arg
)
469 return cmd
== TIOCSPGRP
? -ENOTTY
: -EIO
;
472 static const struct file_operations tty_fops
= {
477 .unlocked_ioctl
= tty_ioctl
,
478 .compat_ioctl
= tty_compat_ioctl
,
480 .release
= tty_release
,
481 .fasync
= tty_fasync
,
484 static const struct file_operations console_fops
= {
487 .write
= redirected_tty_write
,
489 .unlocked_ioctl
= tty_ioctl
,
490 .compat_ioctl
= tty_compat_ioctl
,
492 .release
= tty_release
,
493 .fasync
= tty_fasync
,
496 static const struct file_operations hung_up_tty_fops
= {
498 .read
= hung_up_tty_read
,
499 .write
= hung_up_tty_write
,
500 .poll
= hung_up_tty_poll
,
501 .unlocked_ioctl
= hung_up_tty_ioctl
,
502 .compat_ioctl
= hung_up_tty_compat_ioctl
,
503 .release
= tty_release
,
506 static DEFINE_SPINLOCK(redirect_lock
);
507 static struct file
*redirect
;
510 * tty_wakeup - request more data
513 * Internal and external helper for wakeups of tty. This function
514 * informs the line discipline if present that the driver is ready
515 * to receive more output data.
518 void tty_wakeup(struct tty_struct
*tty
)
520 struct tty_ldisc
*ld
;
522 if (test_bit(TTY_DO_WRITE_WAKEUP
, &tty
->flags
)) {
523 ld
= tty_ldisc_ref(tty
);
525 if (ld
->ops
->write_wakeup
)
526 ld
->ops
->write_wakeup(tty
);
530 wake_up_interruptible_poll(&tty
->write_wait
, POLLOUT
);
533 EXPORT_SYMBOL_GPL(tty_wakeup
);
536 * tty_signal_session_leader - sends SIGHUP to session leader
537 * @tty controlling tty
538 * @exit_session if non-zero, signal all foreground group processes
540 * Send SIGHUP and SIGCONT to the session leader and its process group.
541 * Optionally, signal all processes in the foreground process group.
543 * Returns the number of processes in the session with this tty
544 * as their controlling terminal. This value is used to drop
545 * tty references for those processes.
547 static int tty_signal_session_leader(struct tty_struct
*tty
, int exit_session
)
549 struct task_struct
*p
;
551 struct pid
*tty_pgrp
= NULL
;
553 read_lock(&tasklist_lock
);
555 do_each_pid_task(tty
->session
, PIDTYPE_SID
, p
) {
556 spin_lock_irq(&p
->sighand
->siglock
);
557 if (p
->signal
->tty
== tty
) {
558 p
->signal
->tty
= NULL
;
559 /* We defer the dereferences outside fo
563 if (!p
->signal
->leader
) {
564 spin_unlock_irq(&p
->sighand
->siglock
);
567 __group_send_sig_info(SIGHUP
, SEND_SIG_PRIV
, p
);
568 __group_send_sig_info(SIGCONT
, SEND_SIG_PRIV
, p
);
569 put_pid(p
->signal
->tty_old_pgrp
); /* A noop */
570 spin_lock(&tty
->ctrl_lock
);
571 tty_pgrp
= get_pid(tty
->pgrp
);
573 p
->signal
->tty_old_pgrp
= get_pid(tty
->pgrp
);
574 spin_unlock(&tty
->ctrl_lock
);
575 spin_unlock_irq(&p
->sighand
->siglock
);
576 } while_each_pid_task(tty
->session
, PIDTYPE_SID
, p
);
578 read_unlock(&tasklist_lock
);
582 kill_pgrp(tty_pgrp
, SIGHUP
, exit_session
);
590 * __tty_hangup - actual handler for hangup events
593 * This can be called by a "kworker" kernel thread. That is process
594 * synchronous but doesn't hold any locks, so we need to make sure we
595 * have the appropriate locks for what we're doing.
597 * The hangup event clears any pending redirections onto the hung up
598 * device. It ensures future writes will error and it does the needed
599 * line discipline hangup and signal delivery. The tty object itself
604 * redirect lock for undoing redirection
605 * file list lock for manipulating list of ttys
606 * tty_ldisc_lock from called functions
607 * termios_mutex resetting termios data
608 * tasklist_lock to walk task list for hangup event
609 * ->siglock to protect ->signal/->sighand
611 static void __tty_hangup(struct tty_struct
*tty
, int exit_session
)
613 struct file
*cons_filp
= NULL
;
614 struct file
*filp
, *f
= NULL
;
615 struct tty_file_private
*priv
;
616 int closecount
= 0, n
;
623 spin_lock(&redirect_lock
);
624 if (redirect
&& file_tty(redirect
) == tty
) {
628 spin_unlock(&redirect_lock
);
632 /* some functions below drop BTM, so we need this bit */
633 set_bit(TTY_HUPPING
, &tty
->flags
);
635 /* inuse_filps is protected by the single tty lock,
636 this really needs to change if we want to flush the
637 workqueue with the lock held */
638 check_tty_count(tty
, "tty_hangup");
640 spin_lock(&tty_files_lock
);
641 /* This breaks for file handles being sent over AF_UNIX sockets ? */
642 list_for_each_entry(priv
, &tty
->tty_files
, list
) {
644 if (filp
->f_op
->write
== redirected_tty_write
)
646 if (filp
->f_op
->write
!= tty_write
)
649 __tty_fasync(-1, filp
, 0); /* can't block */
650 filp
->f_op
= &hung_up_tty_fops
;
652 spin_unlock(&tty_files_lock
);
654 refs
= tty_signal_session_leader(tty
, exit_session
);
655 /* Account for the p->signal references we killed */
660 * it drops BTM and thus races with reopen
661 * we protect the race by TTY_HUPPING
663 tty_ldisc_hangup(tty
);
665 spin_lock_irq(&tty
->ctrl_lock
);
666 clear_bit(TTY_THROTTLED
, &tty
->flags
);
667 clear_bit(TTY_PUSH
, &tty
->flags
);
668 clear_bit(TTY_DO_WRITE_WAKEUP
, &tty
->flags
);
669 put_pid(tty
->session
);
673 tty
->ctrl_status
= 0;
674 spin_unlock_irq(&tty
->ctrl_lock
);
677 * If one of the devices matches a console pointer, we
678 * cannot just call hangup() because that will cause
679 * tty->count and state->count to go out of sync.
680 * So we just call close() the right number of times.
684 for (n
= 0; n
< closecount
; n
++)
685 tty
->ops
->close(tty
, cons_filp
);
686 } else if (tty
->ops
->hangup
)
687 (tty
->ops
->hangup
)(tty
);
689 * We don't want to have driver/ldisc interactions beyond
690 * the ones we did here. The driver layer expects no
691 * calls after ->hangup() from the ldisc side. However we
692 * can't yet guarantee all that.
694 set_bit(TTY_HUPPED
, &tty
->flags
);
695 clear_bit(TTY_HUPPING
, &tty
->flags
);
703 static void do_tty_hangup(struct work_struct
*work
)
705 struct tty_struct
*tty
=
706 container_of(work
, struct tty_struct
, hangup_work
);
708 __tty_hangup(tty
, 0);
712 * tty_hangup - trigger a hangup event
713 * @tty: tty to hangup
715 * A carrier loss (virtual or otherwise) has occurred on this like
716 * schedule a hangup sequence to run after this event.
719 void tty_hangup(struct tty_struct
*tty
)
721 #ifdef TTY_DEBUG_HANGUP
723 printk(KERN_DEBUG
"%s hangup...\n", tty_name(tty
, buf
));
725 schedule_work(&tty
->hangup_work
);
728 EXPORT_SYMBOL(tty_hangup
);
731 * tty_vhangup - process vhangup
732 * @tty: tty to hangup
734 * The user has asked via system call for the terminal to be hung up.
735 * We do this synchronously so that when the syscall returns the process
736 * is complete. That guarantee is necessary for security reasons.
739 void tty_vhangup(struct tty_struct
*tty
)
741 #ifdef TTY_DEBUG_HANGUP
744 printk(KERN_DEBUG
"%s vhangup...\n", tty_name(tty
, buf
));
746 __tty_hangup(tty
, 0);
749 EXPORT_SYMBOL(tty_vhangup
);
753 * tty_vhangup_self - process vhangup for own ctty
755 * Perform a vhangup on the current controlling tty
758 void tty_vhangup_self(void)
760 struct tty_struct
*tty
;
762 tty
= get_current_tty();
770 * tty_vhangup_session - hangup session leader exit
771 * @tty: tty to hangup
773 * The session leader is exiting and hanging up its controlling terminal.
774 * Every process in the foreground process group is signalled SIGHUP.
776 * We do this synchronously so that when the syscall returns the process
777 * is complete. That guarantee is necessary for security reasons.
780 void tty_vhangup_session(struct tty_struct
*tty
)
782 #ifdef TTY_DEBUG_HANGUP
785 printk(KERN_DEBUG
"%s vhangup session...\n", tty_name(tty
, buf
));
787 __tty_hangup(tty
, 1);
791 * tty_hung_up_p - was tty hung up
792 * @filp: file pointer of tty
794 * Return true if the tty has been subject to a vhangup or a carrier
798 int tty_hung_up_p(struct file
*filp
)
800 return (filp
->f_op
== &hung_up_tty_fops
);
803 EXPORT_SYMBOL(tty_hung_up_p
);
805 static void session_clear_tty(struct pid
*session
)
807 struct task_struct
*p
;
808 do_each_pid_task(session
, PIDTYPE_SID
, p
) {
810 } while_each_pid_task(session
, PIDTYPE_SID
, p
);
814 * disassociate_ctty - disconnect controlling tty
815 * @on_exit: true if exiting so need to "hang up" the session
817 * This function is typically called only by the session leader, when
818 * it wants to disassociate itself from its controlling tty.
820 * It performs the following functions:
821 * (1) Sends a SIGHUP and SIGCONT to the foreground process group
822 * (2) Clears the tty from being controlling the session
823 * (3) Clears the controlling tty for all processes in the
826 * The argument on_exit is set to 1 if called when a process is
827 * exiting; it is 0 if called by the ioctl TIOCNOTTY.
830 * BTM is taken for hysterical raisins, and held when
831 * called from no_tty().
832 * tty_mutex is taken to protect tty
833 * ->siglock is taken to protect ->signal/->sighand
834 * tasklist_lock is taken to walk process list for sessions
835 * ->siglock is taken to protect ->signal/->sighand
838 void disassociate_ctty(int on_exit
)
840 struct tty_struct
*tty
;
842 if (!current
->signal
->leader
)
845 tty
= get_current_tty();
847 if (on_exit
&& tty
->driver
->type
!= TTY_DRIVER_TYPE_PTY
) {
848 tty_vhangup_session(tty
);
850 struct pid
*tty_pgrp
= tty_get_pgrp(tty
);
852 kill_pgrp(tty_pgrp
, SIGHUP
, on_exit
);
853 kill_pgrp(tty_pgrp
, SIGCONT
, on_exit
);
859 } else if (on_exit
) {
860 struct pid
*old_pgrp
;
861 spin_lock_irq(¤t
->sighand
->siglock
);
862 old_pgrp
= current
->signal
->tty_old_pgrp
;
863 current
->signal
->tty_old_pgrp
= NULL
;
864 spin_unlock_irq(¤t
->sighand
->siglock
);
866 kill_pgrp(old_pgrp
, SIGHUP
, on_exit
);
867 kill_pgrp(old_pgrp
, SIGCONT
, on_exit
);
873 spin_lock_irq(¤t
->sighand
->siglock
);
874 put_pid(current
->signal
->tty_old_pgrp
);
875 current
->signal
->tty_old_pgrp
= NULL
;
876 spin_unlock_irq(¤t
->sighand
->siglock
);
878 tty
= get_current_tty();
881 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
882 put_pid(tty
->session
);
886 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
889 #ifdef TTY_DEBUG_HANGUP
890 printk(KERN_DEBUG
"error attempted to write to tty [0x%p]"
895 /* Now clear signal->tty under the lock */
896 read_lock(&tasklist_lock
);
897 session_clear_tty(task_session(current
));
898 read_unlock(&tasklist_lock
);
903 * no_tty - Ensure the current process does not have a controlling tty
907 /* FIXME: Review locking here. The tty_lock never covered any race
908 between a new association and proc_clear_tty but possible we need
909 to protect against this anyway */
910 struct task_struct
*tsk
= current
;
911 disassociate_ctty(0);
917 * stop_tty - propagate flow control
920 * Perform flow control to the driver. For PTY/TTY pairs we
921 * must also propagate the TIOCKPKT status. May be called
922 * on an already stopped device and will not re-call the driver
925 * This functionality is used by both the line disciplines for
926 * halting incoming flow and by the driver. It may therefore be
927 * called from any context, may be under the tty atomic_write_lock
931 * Uses the tty control lock internally
934 void stop_tty(struct tty_struct
*tty
)
937 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
939 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
943 if (tty
->link
&& tty
->link
->packet
) {
944 tty
->ctrl_status
&= ~TIOCPKT_START
;
945 tty
->ctrl_status
|= TIOCPKT_STOP
;
946 wake_up_interruptible_poll(&tty
->link
->read_wait
, POLLIN
);
948 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
950 (tty
->ops
->stop
)(tty
);
953 EXPORT_SYMBOL(stop_tty
);
956 * start_tty - propagate flow control
959 * Start a tty that has been stopped if at all possible. Perform
960 * any necessary wakeups and propagate the TIOCPKT status. If this
961 * is the tty was previous stopped and is being started then the
962 * driver start method is invoked and the line discipline woken.
968 void start_tty(struct tty_struct
*tty
)
971 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
972 if (!tty
->stopped
|| tty
->flow_stopped
) {
973 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
977 if (tty
->link
&& tty
->link
->packet
) {
978 tty
->ctrl_status
&= ~TIOCPKT_STOP
;
979 tty
->ctrl_status
|= TIOCPKT_START
;
980 wake_up_interruptible_poll(&tty
->link
->read_wait
, POLLIN
);
982 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
984 (tty
->ops
->start
)(tty
);
985 /* If we have a running line discipline it may need kicking */
989 EXPORT_SYMBOL(start_tty
);
992 * tty_read - read method for tty device files
993 * @file: pointer to tty file
995 * @count: size of user buffer
998 * Perform the read system call function on this terminal device. Checks
999 * for hung up devices before calling the line discipline method.
1002 * Locks the line discipline internally while needed. Multiple
1003 * read calls may be outstanding in parallel.
1006 static ssize_t
tty_read(struct file
*file
, char __user
*buf
, size_t count
,
1010 struct tty_struct
*tty
= file_tty(file
);
1011 struct tty_ldisc
*ld
;
1013 if (tty_paranoia_check(tty
, file_inode(file
), "tty_read"))
1015 if (!tty
|| (test_bit(TTY_IO_ERROR
, &tty
->flags
)))
1018 /* We want to wait for the line discipline to sort out in this
1020 ld
= tty_ldisc_ref_wait(tty
);
1022 i
= (ld
->ops
->read
)(tty
, file
, buf
, count
);
1025 tty_ldisc_deref(ld
);
1030 void tty_write_unlock(struct tty_struct
*tty
)
1031 __releases(&tty
->atomic_write_lock
)
1033 mutex_unlock(&tty
->atomic_write_lock
);
1034 wake_up_interruptible_poll(&tty
->write_wait
, POLLOUT
);
1037 int tty_write_lock(struct tty_struct
*tty
, int ndelay
)
1038 __acquires(&tty
->atomic_write_lock
)
1040 if (!mutex_trylock(&tty
->atomic_write_lock
)) {
1043 if (mutex_lock_interruptible(&tty
->atomic_write_lock
))
1044 return -ERESTARTSYS
;
1050 * Split writes up in sane blocksizes to avoid
1051 * denial-of-service type attacks
1053 static inline ssize_t
do_tty_write(
1054 ssize_t (*write
)(struct tty_struct
*, struct file
*, const unsigned char *, size_t),
1055 struct tty_struct
*tty
,
1057 const char __user
*buf
,
1060 ssize_t ret
, written
= 0;
1063 ret
= tty_write_lock(tty
, file
->f_flags
& O_NDELAY
);
1068 * We chunk up writes into a temporary buffer. This
1069 * simplifies low-level drivers immensely, since they
1070 * don't have locking issues and user mode accesses.
1072 * But if TTY_NO_WRITE_SPLIT is set, we should use a
1075 * The default chunk-size is 2kB, because the NTTY
1076 * layer has problems with bigger chunks. It will
1077 * claim to be able to handle more characters than
1080 * FIXME: This can probably go away now except that 64K chunks
1081 * are too likely to fail unless switched to vmalloc...
1084 if (test_bit(TTY_NO_WRITE_SPLIT
, &tty
->flags
))
1089 /* write_buf/write_cnt is protected by the atomic_write_lock mutex */
1090 if (tty
->write_cnt
< chunk
) {
1091 unsigned char *buf_chunk
;
1096 buf_chunk
= kmalloc(chunk
, GFP_KERNEL
);
1101 kfree(tty
->write_buf
);
1102 tty
->write_cnt
= chunk
;
1103 tty
->write_buf
= buf_chunk
;
1106 /* Do the write .. */
1108 size_t size
= count
;
1112 if (copy_from_user(tty
->write_buf
, buf
, size
))
1114 ret
= write(tty
, file
, tty
->write_buf
, size
);
1123 if (signal_pending(current
))
1130 tty_write_unlock(tty
);
1135 * tty_write_message - write a message to a certain tty, not just the console.
1136 * @tty: the destination tty_struct
1137 * @msg: the message to write
1139 * This is used for messages that need to be redirected to a specific tty.
1140 * We don't put it into the syslog queue right now maybe in the future if
1143 * We must still hold the BTM and test the CLOSING flag for the moment.
1146 void tty_write_message(struct tty_struct
*tty
, char *msg
)
1149 mutex_lock(&tty
->atomic_write_lock
);
1151 if (tty
->ops
->write
&& !test_bit(TTY_CLOSING
, &tty
->flags
)) {
1153 tty
->ops
->write(tty
, msg
, strlen(msg
));
1156 tty_write_unlock(tty
);
1163 * tty_write - write method for tty device file
1164 * @file: tty file pointer
1165 * @buf: user data to write
1166 * @count: bytes to write
1169 * Write data to a tty device via the line discipline.
1172 * Locks the line discipline as required
1173 * Writes to the tty driver are serialized by the atomic_write_lock
1174 * and are then processed in chunks to the device. The line discipline
1175 * write method will not be invoked in parallel for each device.
1178 static ssize_t
tty_write(struct file
*file
, const char __user
*buf
,
1179 size_t count
, loff_t
*ppos
)
1181 struct tty_struct
*tty
= file_tty(file
);
1182 struct tty_ldisc
*ld
;
1185 if (tty_paranoia_check(tty
, file_inode(file
), "tty_write"))
1187 if (!tty
|| !tty
->ops
->write
||
1188 (test_bit(TTY_IO_ERROR
, &tty
->flags
)))
1190 /* Short term debug to catch buggy drivers */
1191 if (tty
->ops
->write_room
== NULL
)
1192 printk(KERN_ERR
"tty driver %s lacks a write_room method.\n",
1194 ld
= tty_ldisc_ref_wait(tty
);
1195 if (!ld
->ops
->write
)
1198 ret
= do_tty_write(ld
->ops
->write
, tty
, file
, buf
, count
);
1199 tty_ldisc_deref(ld
);
1203 ssize_t
redirected_tty_write(struct file
*file
, const char __user
*buf
,
1204 size_t count
, loff_t
*ppos
)
1206 struct file
*p
= NULL
;
1208 spin_lock(&redirect_lock
);
1210 p
= get_file(redirect
);
1211 spin_unlock(&redirect_lock
);
1215 res
= vfs_write(p
, buf
, count
, &p
->f_pos
);
1219 return tty_write(file
, buf
, count
, ppos
);
1222 static char ptychar
[] = "pqrstuvwxyzabcde";
1225 * pty_line_name - generate name for a pty
1226 * @driver: the tty driver in use
1227 * @index: the minor number
1228 * @p: output buffer of at least 6 bytes
1230 * Generate a name from a driver reference and write it to the output
1235 static void pty_line_name(struct tty_driver
*driver
, int index
, char *p
)
1237 int i
= index
+ driver
->name_base
;
1238 /* ->name is initialized to "ttyp", but "tty" is expected */
1239 sprintf(p
, "%s%c%x",
1240 driver
->subtype
== PTY_TYPE_SLAVE
? "tty" : driver
->name
,
1241 ptychar
[i
>> 4 & 0xf], i
& 0xf);
1245 * tty_line_name - generate name for a tty
1246 * @driver: the tty driver in use
1247 * @index: the minor number
1248 * @p: output buffer of at least 7 bytes
1250 * Generate a name from a driver reference and write it to the output
1255 static void tty_line_name(struct tty_driver
*driver
, int index
, char *p
)
1257 if (driver
->flags
& TTY_DRIVER_UNNUMBERED_NODE
)
1258 strcpy(p
, driver
->name
);
1260 sprintf(p
, "%s%d", driver
->name
, index
+ driver
->name_base
);
1264 * tty_driver_lookup_tty() - find an existing tty, if any
1265 * @driver: the driver for the tty
1266 * @idx: the minor number
1268 * Return the tty, if found or ERR_PTR() otherwise.
1270 * Locking: tty_mutex must be held. If tty is found, the mutex must
1271 * be held until the 'fast-open' is also done. Will change once we
1272 * have refcounting in the driver and per driver locking
1274 static struct tty_struct
*tty_driver_lookup_tty(struct tty_driver
*driver
,
1275 struct inode
*inode
, int idx
)
1277 if (driver
->ops
->lookup
)
1278 return driver
->ops
->lookup(driver
, inode
, idx
);
1280 return driver
->ttys
[idx
];
1284 * tty_init_termios - helper for termios setup
1285 * @tty: the tty to set up
1287 * Initialise the termios structures for this tty. Thus runs under
1288 * the tty_mutex currently so we can be relaxed about ordering.
1291 int tty_init_termios(struct tty_struct
*tty
)
1293 struct ktermios
*tp
;
1294 int idx
= tty
->index
;
1296 if (tty
->driver
->flags
& TTY_DRIVER_RESET_TERMIOS
)
1297 tty
->termios
= tty
->driver
->init_termios
;
1299 /* Check for lazy saved data */
1300 tp
= tty
->driver
->termios
[idx
];
1304 tty
->termios
= tty
->driver
->init_termios
;
1306 /* Compatibility until drivers always set this */
1307 tty
->termios
.c_ispeed
= tty_termios_input_baud_rate(&tty
->termios
);
1308 tty
->termios
.c_ospeed
= tty_termios_baud_rate(&tty
->termios
);
1311 EXPORT_SYMBOL_GPL(tty_init_termios
);
1313 int tty_standard_install(struct tty_driver
*driver
, struct tty_struct
*tty
)
1315 int ret
= tty_init_termios(tty
);
1319 tty_driver_kref_get(driver
);
1321 driver
->ttys
[tty
->index
] = tty
;
1324 EXPORT_SYMBOL_GPL(tty_standard_install
);
1327 * tty_driver_install_tty() - install a tty entry in the driver
1328 * @driver: the driver for the tty
1331 * Install a tty object into the driver tables. The tty->index field
1332 * will be set by the time this is called. This method is responsible
1333 * for ensuring any need additional structures are allocated and
1336 * Locking: tty_mutex for now
1338 static int tty_driver_install_tty(struct tty_driver
*driver
,
1339 struct tty_struct
*tty
)
1341 return driver
->ops
->install
? driver
->ops
->install(driver
, tty
) :
1342 tty_standard_install(driver
, tty
);
1346 * tty_driver_remove_tty() - remove a tty from the driver tables
1347 * @driver: the driver for the tty
1348 * @idx: the minor number
1350 * Remvoe a tty object from the driver tables. The tty->index field
1351 * will be set by the time this is called.
1353 * Locking: tty_mutex for now
1355 void tty_driver_remove_tty(struct tty_driver
*driver
, struct tty_struct
*tty
)
1357 if (driver
->ops
->remove
)
1358 driver
->ops
->remove(driver
, tty
);
1360 driver
->ttys
[tty
->index
] = NULL
;
1364 * tty_reopen() - fast re-open of an open tty
1365 * @tty - the tty to open
1367 * Return 0 on success, -errno on error.
1369 * Locking: tty_mutex must be held from the time the tty was found
1370 * till this open completes.
1372 static int tty_reopen(struct tty_struct
*tty
)
1374 struct tty_driver
*driver
= tty
->driver
;
1376 if (test_bit(TTY_CLOSING
, &tty
->flags
) ||
1377 test_bit(TTY_HUPPING
, &tty
->flags
) ||
1378 test_bit(TTY_LDISC_CHANGING
, &tty
->flags
))
1381 if (driver
->type
== TTY_DRIVER_TYPE_PTY
&&
1382 driver
->subtype
== PTY_TYPE_MASTER
) {
1384 * special case for PTY masters: only one open permitted,
1385 * and the slave side open count is incremented as well.
1394 mutex_lock(&tty
->ldisc_mutex
);
1395 WARN_ON(!test_bit(TTY_LDISC
, &tty
->flags
));
1396 mutex_unlock(&tty
->ldisc_mutex
);
1402 * tty_init_dev - initialise a tty device
1403 * @driver: tty driver we are opening a device on
1404 * @idx: device index
1405 * @ret_tty: returned tty structure
1407 * Prepare a tty device. This may not be a "new" clean device but
1408 * could also be an active device. The pty drivers require special
1409 * handling because of this.
1412 * The function is called under the tty_mutex, which
1413 * protects us from the tty struct or driver itself going away.
1415 * On exit the tty device has the line discipline attached and
1416 * a reference count of 1. If a pair was created for pty/tty use
1417 * and the other was a pty master then it too has a reference count of 1.
1419 * WSH 06/09/97: Rewritten to remove races and properly clean up after a
1420 * failed open. The new code protects the open with a mutex, so it's
1421 * really quite straightforward. The mutex locking can probably be
1422 * relaxed for the (most common) case of reopening a tty.
1425 struct tty_struct
*tty_init_dev(struct tty_driver
*driver
, int idx
)
1427 struct tty_struct
*tty
;
1431 * First time open is complex, especially for PTY devices.
1432 * This code guarantees that either everything succeeds and the
1433 * TTY is ready for operation, or else the table slots are vacated
1434 * and the allocated memory released. (Except that the termios
1435 * and locked termios may be retained.)
1438 if (!try_module_get(driver
->owner
))
1439 return ERR_PTR(-ENODEV
);
1441 tty
= alloc_tty_struct();
1444 goto err_module_put
;
1446 initialize_tty_struct(tty
, driver
, idx
);
1449 retval
= tty_driver_install_tty(driver
, tty
);
1451 goto err_deinit_tty
;
1454 tty
->port
= driver
->ports
[idx
];
1456 WARN_RATELIMIT(!tty
->port
,
1457 "%s: %s driver does not set tty->port. This will crash the kernel later. Fix the driver!\n",
1458 __func__
, tty
->driver
->name
);
1460 tty
->port
->itty
= tty
;
1463 * Structures all installed ... call the ldisc open routines.
1464 * If we fail here just call release_tty to clean up. No need
1465 * to decrement the use counts, as release_tty doesn't care.
1467 retval
= tty_ldisc_setup(tty
, tty
->link
);
1469 goto err_release_tty
;
1470 /* Return the tty locked so that it cannot vanish under the caller */
1475 deinitialize_tty_struct(tty
);
1476 free_tty_struct(tty
);
1478 module_put(driver
->owner
);
1479 return ERR_PTR(retval
);
1481 /* call the tty release_tty routine to clean out this slot */
1484 printk_ratelimited(KERN_INFO
"tty_init_dev: ldisc open failed, "
1485 "clearing slot %d\n", idx
);
1486 release_tty(tty
, idx
);
1487 return ERR_PTR(retval
);
1490 void tty_free_termios(struct tty_struct
*tty
)
1492 struct ktermios
*tp
;
1493 int idx
= tty
->index
;
1495 /* If the port is going to reset then it has no termios to save */
1496 if (tty
->driver
->flags
& TTY_DRIVER_RESET_TERMIOS
)
1499 /* Stash the termios data */
1500 tp
= tty
->driver
->termios
[idx
];
1502 tp
= kmalloc(sizeof(struct ktermios
), GFP_KERNEL
);
1504 pr_warn("tty: no memory to save termios state.\n");
1507 tty
->driver
->termios
[idx
] = tp
;
1511 EXPORT_SYMBOL(tty_free_termios
);
1514 * tty_flush_works - flush all works of a tty
1515 * @tty: tty device to flush works for
1517 * Sync flush all works belonging to @tty.
1519 static void tty_flush_works(struct tty_struct
*tty
)
1521 flush_work(&tty
->SAK_work
);
1522 flush_work(&tty
->hangup_work
);
1526 * release_one_tty - release tty structure memory
1527 * @kref: kref of tty we are obliterating
1529 * Releases memory associated with a tty structure, and clears out the
1530 * driver table slots. This function is called when a device is no longer
1531 * in use. It also gets called when setup of a device fails.
1534 * takes the file list lock internally when working on the list
1535 * of ttys that the driver keeps.
1537 * This method gets called from a work queue so that the driver private
1538 * cleanup ops can sleep (needed for USB at least)
1540 static void release_one_tty(struct work_struct
*work
)
1542 struct tty_struct
*tty
=
1543 container_of(work
, struct tty_struct
, hangup_work
);
1544 struct tty_driver
*driver
= tty
->driver
;
1546 if (tty
->ops
->cleanup
)
1547 tty
->ops
->cleanup(tty
);
1550 tty_driver_kref_put(driver
);
1551 module_put(driver
->owner
);
1553 spin_lock(&tty_files_lock
);
1554 list_del_init(&tty
->tty_files
);
1555 spin_unlock(&tty_files_lock
);
1558 put_pid(tty
->session
);
1559 free_tty_struct(tty
);
1562 static void queue_release_one_tty(struct kref
*kref
)
1564 struct tty_struct
*tty
= container_of(kref
, struct tty_struct
, kref
);
1566 /* The hangup queue is now free so we can reuse it rather than
1567 waste a chunk of memory for each port */
1568 INIT_WORK(&tty
->hangup_work
, release_one_tty
);
1569 schedule_work(&tty
->hangup_work
);
1573 * tty_kref_put - release a tty kref
1576 * Release a reference to a tty device and if need be let the kref
1577 * layer destruct the object for us
1580 void tty_kref_put(struct tty_struct
*tty
)
1583 kref_put(&tty
->kref
, queue_release_one_tty
);
1585 EXPORT_SYMBOL(tty_kref_put
);
1588 * release_tty - release tty structure memory
1590 * Release both @tty and a possible linked partner (think pty pair),
1591 * and decrement the refcount of the backing module.
1595 * takes the file list lock internally when working on the list
1596 * of ttys that the driver keeps.
1599 static void release_tty(struct tty_struct
*tty
, int idx
)
1601 /* This should always be true but check for the moment */
1602 WARN_ON(tty
->index
!= idx
);
1603 WARN_ON(!mutex_is_locked(&tty_mutex
));
1604 if (tty
->ops
->shutdown
)
1605 tty
->ops
->shutdown(tty
);
1606 tty_free_termios(tty
);
1607 tty_driver_remove_tty(tty
->driver
, tty
);
1608 tty
->port
->itty
= NULL
;
1609 cancel_work_sync(&tty
->port
->buf
.work
);
1612 tty_kref_put(tty
->link
);
1617 * tty_release_checks - check a tty before real release
1618 * @tty: tty to check
1619 * @o_tty: link of @tty (if any)
1620 * @idx: index of the tty
1622 * Performs some paranoid checking before true release of the @tty.
1623 * This is a no-op unless TTY_PARANOIA_CHECK is defined.
1625 static int tty_release_checks(struct tty_struct
*tty
, struct tty_struct
*o_tty
,
1628 #ifdef TTY_PARANOIA_CHECK
1629 if (idx
< 0 || idx
>= tty
->driver
->num
) {
1630 printk(KERN_DEBUG
"%s: bad idx when trying to free (%s)\n",
1631 __func__
, tty
->name
);
1635 /* not much to check for devpts */
1636 if (tty
->driver
->flags
& TTY_DRIVER_DEVPTS_MEM
)
1639 if (tty
!= tty
->driver
->ttys
[idx
]) {
1640 printk(KERN_DEBUG
"%s: driver.table[%d] not tty for (%s)\n",
1641 __func__
, idx
, tty
->name
);
1644 if (tty
->driver
->other
) {
1645 if (o_tty
!= tty
->driver
->other
->ttys
[idx
]) {
1646 printk(KERN_DEBUG
"%s: other->table[%d] not o_tty for (%s)\n",
1647 __func__
, idx
, tty
->name
);
1650 if (o_tty
->link
!= tty
) {
1651 printk(KERN_DEBUG
"%s: bad pty pointers\n", __func__
);
1660 * tty_release - vfs callback for close
1661 * @inode: inode of tty
1662 * @filp: file pointer for handle to tty
1664 * Called the last time each file handle is closed that references
1665 * this tty. There may however be several such references.
1668 * Takes bkl. See tty_release_dev
1670 * Even releasing the tty structures is a tricky business.. We have
1671 * to be very careful that the structures are all released at the
1672 * same time, as interrupts might otherwise get the wrong pointers.
1674 * WSH 09/09/97: rewritten to avoid some nasty race conditions that could
1675 * lead to double frees or releasing memory still in use.
1678 int tty_release(struct inode
*inode
, struct file
*filp
)
1680 struct tty_struct
*tty
= file_tty(filp
);
1681 struct tty_struct
*o_tty
;
1682 int pty_master
, tty_closing
, o_tty_closing
, do_sleep
;
1686 if (tty_paranoia_check(tty
, inode
, __func__
))
1690 check_tty_count(tty
, __func__
);
1692 __tty_fasync(-1, filp
, 0);
1695 pty_master
= (tty
->driver
->type
== TTY_DRIVER_TYPE_PTY
&&
1696 tty
->driver
->subtype
== PTY_TYPE_MASTER
);
1697 /* Review: parallel close */
1700 if (tty_release_checks(tty
, o_tty
, idx
)) {
1705 #ifdef TTY_DEBUG_HANGUP
1706 printk(KERN_DEBUG
"%s: %s (tty count=%d)...\n", __func__
,
1707 tty_name(tty
, buf
), tty
->count
);
1710 if (tty
->ops
->close
)
1711 tty
->ops
->close(tty
, filp
);
1715 * Sanity check: if tty->count is going to zero, there shouldn't be
1716 * any waiters on tty->read_wait or tty->write_wait. We test the
1717 * wait queues and kick everyone out _before_ actually starting to
1718 * close. This ensures that we won't block while releasing the tty
1721 * The test for the o_tty closing is necessary, since the master and
1722 * slave sides may close in any order. If the slave side closes out
1723 * first, its count will be one, since the master side holds an open.
1724 * Thus this test wouldn't be triggered at the time the slave closes,
1727 * Note that it's possible for the tty to be opened again while we're
1728 * flushing out waiters. By recalculating the closing flags before
1729 * each iteration we avoid any problems.
1732 /* Guard against races with tty->count changes elsewhere and
1733 opens on /dev/tty */
1735 mutex_lock(&tty_mutex
);
1736 tty_lock_pair(tty
, o_tty
);
1737 tty_closing
= tty
->count
<= 1;
1738 o_tty_closing
= o_tty
&&
1739 (o_tty
->count
<= (pty_master
? 1 : 0));
1743 if (waitqueue_active(&tty
->read_wait
)) {
1744 wake_up_poll(&tty
->read_wait
, POLLIN
);
1747 if (waitqueue_active(&tty
->write_wait
)) {
1748 wake_up_poll(&tty
->write_wait
, POLLOUT
);
1752 if (o_tty_closing
) {
1753 if (waitqueue_active(&o_tty
->read_wait
)) {
1754 wake_up_poll(&o_tty
->read_wait
, POLLIN
);
1757 if (waitqueue_active(&o_tty
->write_wait
)) {
1758 wake_up_poll(&o_tty
->write_wait
, POLLOUT
);
1765 printk(KERN_WARNING
"%s: %s: read/write wait queue active!\n",
1766 __func__
, tty_name(tty
, buf
));
1767 tty_unlock_pair(tty
, o_tty
);
1768 mutex_unlock(&tty_mutex
);
1773 * The closing flags are now consistent with the open counts on
1774 * both sides, and we've completed the last operation that could
1775 * block, so it's safe to proceed with closing.
1777 * We must *not* drop the tty_mutex until we ensure that a further
1778 * entry into tty_open can not pick up this tty.
1781 if (--o_tty
->count
< 0) {
1782 printk(KERN_WARNING
"%s: bad pty slave count (%d) for %s\n",
1783 __func__
, o_tty
->count
, tty_name(o_tty
, buf
));
1787 if (--tty
->count
< 0) {
1788 printk(KERN_WARNING
"%s: bad tty->count (%d) for %s\n",
1789 __func__
, tty
->count
, tty_name(tty
, buf
));
1794 * We've decremented tty->count, so we need to remove this file
1795 * descriptor off the tty->tty_files list; this serves two
1797 * - check_tty_count sees the correct number of file descriptors
1798 * associated with this tty.
1799 * - do_tty_hangup no longer sees this file descriptor as
1800 * something that needs to be handled for hangups.
1805 * Perform some housekeeping before deciding whether to return.
1807 * Set the TTY_CLOSING flag if this was the last open. In the
1808 * case of a pty we may have to wait around for the other side
1809 * to close, and TTY_CLOSING makes sure we can't be reopened.
1812 set_bit(TTY_CLOSING
, &tty
->flags
);
1814 set_bit(TTY_CLOSING
, &o_tty
->flags
);
1817 * If _either_ side is closing, make sure there aren't any
1818 * processes that still think tty or o_tty is their controlling
1821 if (tty_closing
|| o_tty_closing
) {
1822 read_lock(&tasklist_lock
);
1823 session_clear_tty(tty
->session
);
1825 session_clear_tty(o_tty
->session
);
1826 read_unlock(&tasklist_lock
);
1829 mutex_unlock(&tty_mutex
);
1830 tty_unlock_pair(tty
, o_tty
);
1831 /* At this point the TTY_CLOSING flag should ensure a dead tty
1832 cannot be re-opened by a racing opener */
1834 /* check whether both sides are closing ... */
1835 if (!tty_closing
|| (o_tty
&& !o_tty_closing
))
1838 #ifdef TTY_DEBUG_HANGUP
1839 printk(KERN_DEBUG
"%s: freeing tty structure...\n", __func__
);
1842 * Ask the line discipline code to release its structures
1844 tty_ldisc_release(tty
, o_tty
);
1846 /* Wait for pending work before tty destruction commmences */
1847 tty_flush_works(tty
);
1849 tty_flush_works(o_tty
);
1852 * The release_tty function takes care of the details of clearing
1853 * the slots and preserving the termios structure. The tty_unlock_pair
1854 * should be safe as we keep a kref while the tty is locked (so the
1855 * unlock never unlocks a freed tty).
1857 mutex_lock(&tty_mutex
);
1858 release_tty(tty
, idx
);
1859 mutex_unlock(&tty_mutex
);
1865 * tty_open_current_tty - get tty of current task for open
1866 * @device: device number
1867 * @filp: file pointer to tty
1868 * @return: tty of the current task iff @device is /dev/tty
1870 * We cannot return driver and index like for the other nodes because
1871 * devpts will not work then. It expects inodes to be from devpts FS.
1873 * We need to move to returning a refcounted object from all the lookup
1874 * paths including this one.
1876 static struct tty_struct
*tty_open_current_tty(dev_t device
, struct file
*filp
)
1878 struct tty_struct
*tty
;
1880 if (device
!= MKDEV(TTYAUX_MAJOR
, 0))
1883 tty
= get_current_tty();
1885 return ERR_PTR(-ENXIO
);
1887 filp
->f_flags
|= O_NONBLOCK
; /* Don't let /dev/tty block */
1890 /* FIXME: we put a reference and return a TTY! */
1891 /* This is only safe because the caller holds tty_mutex */
1896 * tty_lookup_driver - lookup a tty driver for a given device file
1897 * @device: device number
1898 * @filp: file pointer to tty
1899 * @noctty: set if the device should not become a controlling tty
1900 * @index: index for the device in the @return driver
1901 * @return: driver for this inode (with increased refcount)
1903 * If @return is not erroneous, the caller is responsible to decrement the
1904 * refcount by tty_driver_kref_put.
1906 * Locking: tty_mutex protects get_tty_driver
1908 static struct tty_driver
*tty_lookup_driver(dev_t device
, struct file
*filp
,
1909 int *noctty
, int *index
)
1911 struct tty_driver
*driver
;
1915 case MKDEV(TTY_MAJOR
, 0): {
1916 extern struct tty_driver
*console_driver
;
1917 driver
= tty_driver_kref_get(console_driver
);
1918 *index
= fg_console
;
1923 case MKDEV(TTYAUX_MAJOR
, 1): {
1924 struct tty_driver
*console_driver
= console_device(index
);
1925 if (console_driver
) {
1926 driver
= tty_driver_kref_get(console_driver
);
1928 /* Don't let /dev/console block */
1929 filp
->f_flags
|= O_NONBLOCK
;
1934 return ERR_PTR(-ENODEV
);
1937 driver
= get_tty_driver(device
, index
);
1939 return ERR_PTR(-ENODEV
);
1946 * tty_open - open a tty device
1947 * @inode: inode of device file
1948 * @filp: file pointer to tty
1950 * tty_open and tty_release keep up the tty count that contains the
1951 * number of opens done on a tty. We cannot use the inode-count, as
1952 * different inodes might point to the same tty.
1954 * Open-counting is needed for pty masters, as well as for keeping
1955 * track of serial lines: DTR is dropped when the last close happens.
1956 * (This is not done solely through tty->count, now. - Ted 1/27/92)
1958 * The termios state of a pty is reset on first open so that
1959 * settings don't persist across reuse.
1961 * Locking: tty_mutex protects tty, tty_lookup_driver and tty_init_dev.
1962 * tty->count should protect the rest.
1963 * ->siglock protects ->signal/->sighand
1965 * Note: the tty_unlock/lock cases without a ref are only safe due to
1969 static int tty_open(struct inode
*inode
, struct file
*filp
)
1971 struct tty_struct
*tty
;
1973 struct tty_driver
*driver
= NULL
;
1975 dev_t device
= inode
->i_rdev
;
1976 unsigned saved_flags
= filp
->f_flags
;
1978 nonseekable_open(inode
, filp
);
1981 retval
= tty_alloc_file(filp
);
1985 noctty
= filp
->f_flags
& O_NOCTTY
;
1989 mutex_lock(&tty_mutex
);
1990 /* This is protected by the tty_mutex */
1991 tty
= tty_open_current_tty(device
, filp
);
1993 retval
= PTR_ERR(tty
);
1996 driver
= tty_lookup_driver(device
, filp
, &noctty
, &index
);
1997 if (IS_ERR(driver
)) {
1998 retval
= PTR_ERR(driver
);
2002 /* check whether we're reopening an existing tty */
2003 tty
= tty_driver_lookup_tty(driver
, inode
, index
);
2005 retval
= PTR_ERR(tty
);
2012 retval
= tty_reopen(tty
);
2015 tty
= ERR_PTR(retval
);
2017 } else /* Returns with the tty_lock held for now */
2018 tty
= tty_init_dev(driver
, index
);
2020 mutex_unlock(&tty_mutex
);
2022 tty_driver_kref_put(driver
);
2024 retval
= PTR_ERR(tty
);
2028 tty_add_file(tty
, filp
);
2030 check_tty_count(tty
, __func__
);
2031 if (tty
->driver
->type
== TTY_DRIVER_TYPE_PTY
&&
2032 tty
->driver
->subtype
== PTY_TYPE_MASTER
)
2034 #ifdef TTY_DEBUG_HANGUP
2035 printk(KERN_DEBUG
"%s: opening %s...\n", __func__
, tty
->name
);
2038 retval
= tty
->ops
->open(tty
, filp
);
2041 filp
->f_flags
= saved_flags
;
2043 if (!retval
&& test_bit(TTY_EXCLUSIVE
, &tty
->flags
) &&
2044 !capable(CAP_SYS_ADMIN
))
2048 #ifdef TTY_DEBUG_HANGUP
2049 printk(KERN_DEBUG
"%s: error %d in opening %s...\n", __func__
,
2052 tty_unlock(tty
); /* need to call tty_release without BTM */
2053 tty_release(inode
, filp
);
2054 if (retval
!= -ERESTARTSYS
)
2057 if (signal_pending(current
))
2062 * Need to reset f_op in case a hangup happened.
2064 if (filp
->f_op
== &hung_up_tty_fops
)
2065 filp
->f_op
= &tty_fops
;
2071 mutex_lock(&tty_mutex
);
2073 spin_lock_irq(¤t
->sighand
->siglock
);
2075 current
->signal
->leader
&&
2076 !current
->signal
->tty
&&
2077 tty
->session
== NULL
)
2078 __proc_set_tty(current
, tty
);
2079 spin_unlock_irq(¤t
->sighand
->siglock
);
2081 mutex_unlock(&tty_mutex
);
2084 mutex_unlock(&tty_mutex
);
2085 /* after locks to avoid deadlock */
2086 if (!IS_ERR_OR_NULL(driver
))
2087 tty_driver_kref_put(driver
);
2089 tty_free_file(filp
);
2096 * tty_poll - check tty status
2097 * @filp: file being polled
2098 * @wait: poll wait structures to update
2100 * Call the line discipline polling method to obtain the poll
2101 * status of the device.
2103 * Locking: locks called line discipline but ldisc poll method
2104 * may be re-entered freely by other callers.
2107 static unsigned int tty_poll(struct file
*filp
, poll_table
*wait
)
2109 struct tty_struct
*tty
= file_tty(filp
);
2110 struct tty_ldisc
*ld
;
2113 if (tty_paranoia_check(tty
, file_inode(filp
), "tty_poll"))
2116 ld
= tty_ldisc_ref_wait(tty
);
2118 ret
= (ld
->ops
->poll
)(tty
, filp
, wait
);
2119 tty_ldisc_deref(ld
);
2123 static int __tty_fasync(int fd
, struct file
*filp
, int on
)
2125 struct tty_struct
*tty
= file_tty(filp
);
2126 unsigned long flags
;
2129 if (tty_paranoia_check(tty
, file_inode(filp
), "tty_fasync"))
2132 retval
= fasync_helper(fd
, filp
, on
, &tty
->fasync
);
2139 if (!waitqueue_active(&tty
->read_wait
))
2140 tty
->minimum_to_wake
= 1;
2141 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
2144 type
= PIDTYPE_PGID
;
2146 pid
= task_pid(current
);
2150 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
2151 retval
= __f_setown(filp
, pid
, type
, 0);
2156 if (!tty
->fasync
&& !waitqueue_active(&tty
->read_wait
))
2157 tty
->minimum_to_wake
= N_TTY_BUF_SIZE
;
2164 static int tty_fasync(int fd
, struct file
*filp
, int on
)
2166 struct tty_struct
*tty
= file_tty(filp
);
2170 retval
= __tty_fasync(fd
, filp
, on
);
2177 * tiocsti - fake input character
2178 * @tty: tty to fake input into
2179 * @p: pointer to character
2181 * Fake input to a tty device. Does the necessary locking and
2184 * FIXME: does not honour flow control ??
2187 * Called functions take tty_ldisc_lock
2188 * current->signal->tty check is safe without locks
2190 * FIXME: may race normal receive processing
2193 static int tiocsti(struct tty_struct
*tty
, char __user
*p
)
2196 struct tty_ldisc
*ld
;
2198 if ((current
->signal
->tty
!= tty
) && !capable(CAP_SYS_ADMIN
))
2200 if (get_user(ch
, p
))
2202 tty_audit_tiocsti(tty
, ch
);
2203 ld
= tty_ldisc_ref_wait(tty
);
2204 ld
->ops
->receive_buf(tty
, &ch
, &mbz
, 1);
2205 tty_ldisc_deref(ld
);
2210 * tiocgwinsz - implement window query ioctl
2212 * @arg: user buffer for result
2214 * Copies the kernel idea of the window size into the user buffer.
2216 * Locking: tty->termios_mutex is taken to ensure the winsize data
2220 static int tiocgwinsz(struct tty_struct
*tty
, struct winsize __user
*arg
)
2224 mutex_lock(&tty
->termios_mutex
);
2225 err
= copy_to_user(arg
, &tty
->winsize
, sizeof(*arg
));
2226 mutex_unlock(&tty
->termios_mutex
);
2228 return err
? -EFAULT
: 0;
2232 * tty_do_resize - resize event
2233 * @tty: tty being resized
2234 * @rows: rows (character)
2235 * @cols: cols (character)
2237 * Update the termios variables and send the necessary signals to
2238 * peform a terminal resize correctly
2241 int tty_do_resize(struct tty_struct
*tty
, struct winsize
*ws
)
2244 unsigned long flags
;
2247 mutex_lock(&tty
->termios_mutex
);
2248 if (!memcmp(ws
, &tty
->winsize
, sizeof(*ws
)))
2250 /* Get the PID values and reference them so we can
2251 avoid holding the tty ctrl lock while sending signals */
2252 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
2253 pgrp
= get_pid(tty
->pgrp
);
2254 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
2257 kill_pgrp(pgrp
, SIGWINCH
, 1);
2262 mutex_unlock(&tty
->termios_mutex
);
2265 EXPORT_SYMBOL(tty_do_resize
);
2268 * tiocswinsz - implement window size set ioctl
2269 * @tty; tty side of tty
2270 * @arg: user buffer for result
2272 * Copies the user idea of the window size to the kernel. Traditionally
2273 * this is just advisory information but for the Linux console it
2274 * actually has driver level meaning and triggers a VC resize.
2277 * Driver dependent. The default do_resize method takes the
2278 * tty termios mutex and ctrl_lock. The console takes its own lock
2279 * then calls into the default method.
2282 static int tiocswinsz(struct tty_struct
*tty
, struct winsize __user
*arg
)
2284 struct winsize tmp_ws
;
2285 if (copy_from_user(&tmp_ws
, arg
, sizeof(*arg
)))
2288 if (tty
->ops
->resize
)
2289 return tty
->ops
->resize(tty
, &tmp_ws
);
2291 return tty_do_resize(tty
, &tmp_ws
);
2295 * tioccons - allow admin to move logical console
2296 * @file: the file to become console
2298 * Allow the administrator to move the redirected console device
2300 * Locking: uses redirect_lock to guard the redirect information
2303 static int tioccons(struct file
*file
)
2305 if (!capable(CAP_SYS_ADMIN
))
2307 if (file
->f_op
->write
== redirected_tty_write
) {
2309 spin_lock(&redirect_lock
);
2312 spin_unlock(&redirect_lock
);
2317 spin_lock(&redirect_lock
);
2319 spin_unlock(&redirect_lock
);
2322 redirect
= get_file(file
);
2323 spin_unlock(&redirect_lock
);
2328 * fionbio - non blocking ioctl
2329 * @file: file to set blocking value
2330 * @p: user parameter
2332 * Historical tty interfaces had a blocking control ioctl before
2333 * the generic functionality existed. This piece of history is preserved
2334 * in the expected tty API of posix OS's.
2336 * Locking: none, the open file handle ensures it won't go away.
2339 static int fionbio(struct file
*file
, int __user
*p
)
2343 if (get_user(nonblock
, p
))
2346 spin_lock(&file
->f_lock
);
2348 file
->f_flags
|= O_NONBLOCK
;
2350 file
->f_flags
&= ~O_NONBLOCK
;
2351 spin_unlock(&file
->f_lock
);
2356 * tiocsctty - set controlling tty
2357 * @tty: tty structure
2358 * @arg: user argument
2360 * This ioctl is used to manage job control. It permits a session
2361 * leader to set this tty as the controlling tty for the session.
2364 * Takes tty_mutex() to protect tty instance
2365 * Takes tasklist_lock internally to walk sessions
2366 * Takes ->siglock() when updating signal->tty
2369 static int tiocsctty(struct tty_struct
*tty
, int arg
)
2372 if (current
->signal
->leader
&& (task_session(current
) == tty
->session
))
2375 mutex_lock(&tty_mutex
);
2377 * The process must be a session leader and
2378 * not have a controlling tty already.
2380 if (!current
->signal
->leader
|| current
->signal
->tty
) {
2387 * This tty is already the controlling
2388 * tty for another session group!
2390 if (arg
== 1 && capable(CAP_SYS_ADMIN
)) {
2394 read_lock(&tasklist_lock
);
2395 session_clear_tty(tty
->session
);
2396 read_unlock(&tasklist_lock
);
2402 proc_set_tty(current
, tty
);
2404 mutex_unlock(&tty_mutex
);
2409 * tty_get_pgrp - return a ref counted pgrp pid
2412 * Returns a refcounted instance of the pid struct for the process
2413 * group controlling the tty.
2416 struct pid
*tty_get_pgrp(struct tty_struct
*tty
)
2418 unsigned long flags
;
2421 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
2422 pgrp
= get_pid(tty
->pgrp
);
2423 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
2427 EXPORT_SYMBOL_GPL(tty_get_pgrp
);
2430 * tiocgpgrp - get process group
2431 * @tty: tty passed by user
2432 * @real_tty: tty side of the tty passed by the user if a pty else the tty
2435 * Obtain the process group of the tty. If there is no process group
2438 * Locking: none. Reference to current->signal->tty is safe.
2441 static int tiocgpgrp(struct tty_struct
*tty
, struct tty_struct
*real_tty
, pid_t __user
*p
)
2446 * (tty == real_tty) is a cheap way of
2447 * testing if the tty is NOT a master pty.
2449 if (tty
== real_tty
&& current
->signal
->tty
!= real_tty
)
2451 pid
= tty_get_pgrp(real_tty
);
2452 ret
= put_user(pid_vnr(pid
), p
);
2458 * tiocspgrp - attempt to set process group
2459 * @tty: tty passed by user
2460 * @real_tty: tty side device matching tty passed by user
2463 * Set the process group of the tty to the session passed. Only
2464 * permitted where the tty session is our session.
2466 * Locking: RCU, ctrl lock
2469 static int tiocspgrp(struct tty_struct
*tty
, struct tty_struct
*real_tty
, pid_t __user
*p
)
2473 int retval
= tty_check_change(real_tty
);
2474 unsigned long flags
;
2480 if (!current
->signal
->tty
||
2481 (current
->signal
->tty
!= real_tty
) ||
2482 (real_tty
->session
!= task_session(current
)))
2484 if (get_user(pgrp_nr
, p
))
2489 pgrp
= find_vpid(pgrp_nr
);
2494 if (session_of_pgrp(pgrp
) != task_session(current
))
2497 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
2498 put_pid(real_tty
->pgrp
);
2499 real_tty
->pgrp
= get_pid(pgrp
);
2500 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
2507 * tiocgsid - get session id
2508 * @tty: tty passed by user
2509 * @real_tty: tty side of the tty passed by the user if a pty else the tty
2510 * @p: pointer to returned session id
2512 * Obtain the session id of the tty. If there is no session
2515 * Locking: none. Reference to current->signal->tty is safe.
2518 static int tiocgsid(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 if (!real_tty
->session
)
2528 return put_user(pid_vnr(real_tty
->session
), p
);
2532 * tiocsetd - set line discipline
2534 * @p: pointer to user data
2536 * Set the line discipline according to user request.
2538 * Locking: see tty_set_ldisc, this function is just a helper
2541 static int tiocsetd(struct tty_struct
*tty
, int __user
*p
)
2546 if (get_user(ldisc
, p
))
2549 ret
= tty_set_ldisc(tty
, ldisc
);
2555 * send_break - performed time break
2556 * @tty: device to break on
2557 * @duration: timeout in mS
2559 * Perform a timed break on hardware that lacks its own driver level
2560 * timed break functionality.
2563 * atomic_write_lock serializes
2567 static int send_break(struct tty_struct
*tty
, unsigned int duration
)
2571 if (tty
->ops
->break_ctl
== NULL
)
2574 if (tty
->driver
->flags
& TTY_DRIVER_HARDWARE_BREAK
)
2575 retval
= tty
->ops
->break_ctl(tty
, duration
);
2577 /* Do the work ourselves */
2578 if (tty_write_lock(tty
, 0) < 0)
2580 retval
= tty
->ops
->break_ctl(tty
, -1);
2583 if (!signal_pending(current
))
2584 msleep_interruptible(duration
);
2585 retval
= tty
->ops
->break_ctl(tty
, 0);
2587 tty_write_unlock(tty
);
2588 if (signal_pending(current
))
2595 * tty_tiocmget - get modem status
2597 * @file: user file pointer
2598 * @p: pointer to result
2600 * Obtain the modem status bits from the tty driver if the feature
2601 * is supported. Return -EINVAL if it is not available.
2603 * Locking: none (up to the driver)
2606 static int tty_tiocmget(struct tty_struct
*tty
, int __user
*p
)
2608 int retval
= -EINVAL
;
2610 if (tty
->ops
->tiocmget
) {
2611 retval
= tty
->ops
->tiocmget(tty
);
2614 retval
= put_user(retval
, p
);
2620 * tty_tiocmset - set modem status
2622 * @cmd: command - clear bits, set bits or set all
2623 * @p: pointer to desired bits
2625 * Set the modem status bits from the tty driver if the feature
2626 * is supported. Return -EINVAL if it is not available.
2628 * Locking: none (up to the driver)
2631 static int tty_tiocmset(struct tty_struct
*tty
, unsigned int cmd
,
2635 unsigned int set
, clear
, val
;
2637 if (tty
->ops
->tiocmset
== NULL
)
2640 retval
= get_user(val
, p
);
2656 set
&= TIOCM_DTR
|TIOCM_RTS
|TIOCM_OUT1
|TIOCM_OUT2
|TIOCM_LOOP
;
2657 clear
&= TIOCM_DTR
|TIOCM_RTS
|TIOCM_OUT1
|TIOCM_OUT2
|TIOCM_LOOP
;
2658 return tty
->ops
->tiocmset(tty
, set
, clear
);
2661 static int tty_tiocgicount(struct tty_struct
*tty
, void __user
*arg
)
2663 int retval
= -EINVAL
;
2664 struct serial_icounter_struct icount
;
2665 memset(&icount
, 0, sizeof(icount
));
2666 if (tty
->ops
->get_icount
)
2667 retval
= tty
->ops
->get_icount(tty
, &icount
);
2670 if (copy_to_user(arg
, &icount
, sizeof(icount
)))
2675 struct tty_struct
*tty_pair_get_tty(struct tty_struct
*tty
)
2677 if (tty
->driver
->type
== TTY_DRIVER_TYPE_PTY
&&
2678 tty
->driver
->subtype
== PTY_TYPE_MASTER
)
2682 EXPORT_SYMBOL(tty_pair_get_tty
);
2684 struct tty_struct
*tty_pair_get_pty(struct tty_struct
*tty
)
2686 if (tty
->driver
->type
== TTY_DRIVER_TYPE_PTY
&&
2687 tty
->driver
->subtype
== PTY_TYPE_MASTER
)
2691 EXPORT_SYMBOL(tty_pair_get_pty
);
2694 * Split this up, as gcc can choke on it otherwise..
2696 long tty_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
2698 struct tty_struct
*tty
= file_tty(file
);
2699 struct tty_struct
*real_tty
;
2700 void __user
*p
= (void __user
*)arg
;
2702 struct tty_ldisc
*ld
;
2704 if (tty_paranoia_check(tty
, file_inode(file
), "tty_ioctl"))
2707 real_tty
= tty_pair_get_tty(tty
);
2710 * Factor out some common prep work
2718 retval
= tty_check_change(tty
);
2721 if (cmd
!= TIOCCBRK
) {
2722 tty_wait_until_sent(tty
, 0);
2723 if (signal_pending(current
))
2734 return tiocsti(tty
, p
);
2736 return tiocgwinsz(real_tty
, p
);
2738 return tiocswinsz(real_tty
, p
);
2740 return real_tty
!= tty
? -EINVAL
: tioccons(file
);
2742 return fionbio(file
, p
);
2744 set_bit(TTY_EXCLUSIVE
, &tty
->flags
);
2747 clear_bit(TTY_EXCLUSIVE
, &tty
->flags
);
2751 int excl
= test_bit(TTY_EXCLUSIVE
, &tty
->flags
);
2752 return put_user(excl
, (int __user
*)p
);
2755 if (current
->signal
->tty
!= tty
)
2760 return tiocsctty(tty
, arg
);
2762 return tiocgpgrp(tty
, real_tty
, p
);
2764 return tiocspgrp(tty
, real_tty
, p
);
2766 return tiocgsid(tty
, real_tty
, p
);
2768 return put_user(tty
->ldisc
->ops
->num
, (int __user
*)p
);
2770 return tiocsetd(tty
, p
);
2772 if (!capable(CAP_SYS_ADMIN
))
2778 unsigned int ret
= new_encode_dev(tty_devnum(real_tty
));
2779 return put_user(ret
, (unsigned int __user
*)p
);
2784 case TIOCSBRK
: /* Turn break on, unconditionally */
2785 if (tty
->ops
->break_ctl
)
2786 return tty
->ops
->break_ctl(tty
, -1);
2788 case TIOCCBRK
: /* Turn break off, unconditionally */
2789 if (tty
->ops
->break_ctl
)
2790 return tty
->ops
->break_ctl(tty
, 0);
2792 case TCSBRK
: /* SVID version: non-zero arg --> no break */
2793 /* non-zero arg means wait for all output data
2794 * to be sent (performed above) but don't send break.
2795 * This is used by the tcdrain() termios function.
2798 return send_break(tty
, 250);
2800 case TCSBRKP
: /* support for POSIX tcsendbreak() */
2801 return send_break(tty
, arg
? arg
*100 : 250);
2804 return tty_tiocmget(tty
, p
);
2808 return tty_tiocmset(tty
, cmd
, p
);
2810 retval
= tty_tiocgicount(tty
, p
);
2811 /* For the moment allow fall through to the old method */
2812 if (retval
!= -EINVAL
)
2819 /* flush tty buffer and allow ldisc to process ioctl */
2820 tty_buffer_flush(tty
);
2825 if (tty
->ops
->ioctl
) {
2826 retval
= (tty
->ops
->ioctl
)(tty
, cmd
, arg
);
2827 if (retval
!= -ENOIOCTLCMD
)
2830 ld
= tty_ldisc_ref_wait(tty
);
2832 if (ld
->ops
->ioctl
) {
2833 retval
= ld
->ops
->ioctl(tty
, file
, cmd
, arg
);
2834 if (retval
== -ENOIOCTLCMD
)
2837 tty_ldisc_deref(ld
);
2841 #ifdef CONFIG_COMPAT
2842 static long tty_compat_ioctl(struct file
*file
, unsigned int cmd
,
2845 struct tty_struct
*tty
= file_tty(file
);
2846 struct tty_ldisc
*ld
;
2847 int retval
= -ENOIOCTLCMD
;
2849 if (tty_paranoia_check(tty
, file_inode(file
), "tty_ioctl"))
2852 if (tty
->ops
->compat_ioctl
) {
2853 retval
= (tty
->ops
->compat_ioctl
)(tty
, cmd
, arg
);
2854 if (retval
!= -ENOIOCTLCMD
)
2858 ld
= tty_ldisc_ref_wait(tty
);
2859 if (ld
->ops
->compat_ioctl
)
2860 retval
= ld
->ops
->compat_ioctl(tty
, file
, cmd
, arg
);
2862 retval
= n_tty_compat_ioctl_helper(tty
, file
, cmd
, arg
);
2863 tty_ldisc_deref(ld
);
2869 static int this_tty(const void *t
, struct file
*file
, unsigned fd
)
2871 if (likely(file
->f_op
->read
!= tty_read
))
2873 return file_tty(file
) != t
? 0 : fd
+ 1;
2877 * This implements the "Secure Attention Key" --- the idea is to
2878 * prevent trojan horses by killing all processes associated with this
2879 * tty when the user hits the "Secure Attention Key". Required for
2880 * super-paranoid applications --- see the Orange Book for more details.
2882 * This code could be nicer; ideally it should send a HUP, wait a few
2883 * seconds, then send a INT, and then a KILL signal. But you then
2884 * have to coordinate with the init process, since all processes associated
2885 * with the current tty must be dead before the new getty is allowed
2888 * Now, if it would be correct ;-/ The current code has a nasty hole -
2889 * it doesn't catch files in flight. We may send the descriptor to ourselves
2890 * via AF_UNIX socket, close it and later fetch from socket. FIXME.
2892 * Nasty bug: do_SAK is being called in interrupt context. This can
2893 * deadlock. We punt it up to process context. AKPM - 16Mar2001
2895 void __do_SAK(struct tty_struct
*tty
)
2900 struct task_struct
*g
, *p
;
2901 struct pid
*session
;
2906 session
= tty
->session
;
2908 tty_ldisc_flush(tty
);
2910 tty_driver_flush_buffer(tty
);
2912 read_lock(&tasklist_lock
);
2913 /* Kill the entire session */
2914 do_each_pid_task(session
, PIDTYPE_SID
, p
) {
2915 printk(KERN_NOTICE
"SAK: killed process %d"
2916 " (%s): task_session(p)==tty->session\n",
2917 task_pid_nr(p
), p
->comm
);
2918 send_sig(SIGKILL
, p
, 1);
2919 } while_each_pid_task(session
, PIDTYPE_SID
, p
);
2920 /* Now kill any processes that happen to have the
2923 do_each_thread(g
, p
) {
2924 if (p
->signal
->tty
== tty
) {
2925 printk(KERN_NOTICE
"SAK: killed process %d"
2926 " (%s): task_session(p)==tty->session\n",
2927 task_pid_nr(p
), p
->comm
);
2928 send_sig(SIGKILL
, p
, 1);
2932 i
= iterate_fd(p
->files
, 0, this_tty
, tty
);
2934 printk(KERN_NOTICE
"SAK: killed process %d"
2935 " (%s): fd#%d opened to the tty\n",
2936 task_pid_nr(p
), p
->comm
, i
- 1);
2937 force_sig(SIGKILL
, p
);
2940 } while_each_thread(g
, p
);
2941 read_unlock(&tasklist_lock
);
2945 static void do_SAK_work(struct work_struct
*work
)
2947 struct tty_struct
*tty
=
2948 container_of(work
, struct tty_struct
, SAK_work
);
2953 * The tq handling here is a little racy - tty->SAK_work may already be queued.
2954 * Fortunately we don't need to worry, because if ->SAK_work is already queued,
2955 * the values which we write to it will be identical to the values which it
2956 * already has. --akpm
2958 void do_SAK(struct tty_struct
*tty
)
2962 schedule_work(&tty
->SAK_work
);
2965 EXPORT_SYMBOL(do_SAK
);
2967 static int dev_match_devt(struct device
*dev
, const void *data
)
2969 const dev_t
*devt
= data
;
2970 return dev
->devt
== *devt
;
2973 /* Must put_device() after it's unused! */
2974 static struct device
*tty_get_device(struct tty_struct
*tty
)
2976 dev_t devt
= tty_devnum(tty
);
2977 return class_find_device(tty_class
, NULL
, &devt
, dev_match_devt
);
2982 * initialize_tty_struct
2983 * @tty: tty to initialize
2985 * This subroutine initializes a tty structure that has been newly
2988 * Locking: none - tty in question must not be exposed at this point
2991 void initialize_tty_struct(struct tty_struct
*tty
,
2992 struct tty_driver
*driver
, int idx
)
2994 memset(tty
, 0, sizeof(struct tty_struct
));
2995 kref_init(&tty
->kref
);
2996 tty
->magic
= TTY_MAGIC
;
2997 tty_ldisc_init(tty
);
2998 tty
->session
= NULL
;
3000 mutex_init(&tty
->legacy_mutex
);
3001 mutex_init(&tty
->termios_mutex
);
3002 mutex_init(&tty
->ldisc_mutex
);
3003 init_waitqueue_head(&tty
->write_wait
);
3004 init_waitqueue_head(&tty
->read_wait
);
3005 INIT_WORK(&tty
->hangup_work
, do_tty_hangup
);
3006 mutex_init(&tty
->atomic_write_lock
);
3007 spin_lock_init(&tty
->ctrl_lock
);
3008 INIT_LIST_HEAD(&tty
->tty_files
);
3009 INIT_WORK(&tty
->SAK_work
, do_SAK_work
);
3011 tty
->driver
= driver
;
3012 tty
->ops
= driver
->ops
;
3014 tty_line_name(driver
, idx
, tty
->name
);
3015 tty
->dev
= tty_get_device(tty
);
3019 * deinitialize_tty_struct
3020 * @tty: tty to deinitialize
3022 * This subroutine deinitializes a tty structure that has been newly
3023 * allocated but tty_release cannot be called on that yet.
3025 * Locking: none - tty in question must not be exposed at this point
3027 void deinitialize_tty_struct(struct tty_struct
*tty
)
3029 tty_ldisc_deinit(tty
);
3033 * tty_put_char - write one character to a tty
3037 * Write one byte to the tty using the provided put_char method
3038 * if present. Returns the number of characters successfully output.
3040 * Note: the specific put_char operation in the driver layer may go
3041 * away soon. Don't call it directly, use this method
3044 int tty_put_char(struct tty_struct
*tty
, unsigned char ch
)
3046 if (tty
->ops
->put_char
)
3047 return tty
->ops
->put_char(tty
, ch
);
3048 return tty
->ops
->write(tty
, &ch
, 1);
3050 EXPORT_SYMBOL_GPL(tty_put_char
);
3052 struct class *tty_class
;
3054 static int tty_cdev_add(struct tty_driver
*driver
, dev_t dev
,
3055 unsigned int index
, unsigned int count
)
3057 /* init here, since reused cdevs cause crashes */
3058 cdev_init(&driver
->cdevs
[index
], &tty_fops
);
3059 driver
->cdevs
[index
].owner
= driver
->owner
;
3060 return cdev_add(&driver
->cdevs
[index
], dev
, count
);
3064 * tty_register_device - register a tty device
3065 * @driver: the tty driver that describes the tty device
3066 * @index: the index in the tty driver for this tty device
3067 * @device: a struct device that is associated with this tty device.
3068 * This field is optional, if there is no known struct device
3069 * for this tty device it can be set to NULL safely.
3071 * Returns a pointer to the struct device for this tty device
3072 * (or ERR_PTR(-EFOO) on error).
3074 * This call is required to be made to register an individual tty device
3075 * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If
3076 * that bit is not set, this function should not be called by a tty
3082 struct device
*tty_register_device(struct tty_driver
*driver
, unsigned index
,
3083 struct device
*device
)
3085 return tty_register_device_attr(driver
, index
, device
, NULL
, NULL
);
3087 EXPORT_SYMBOL(tty_register_device
);
3089 static void tty_device_create_release(struct device
*dev
)
3091 pr_debug("device: '%s': %s\n", dev_name(dev
), __func__
);
3096 * tty_register_device_attr - register a tty device
3097 * @driver: the tty driver that describes the tty device
3098 * @index: the index in the tty driver for this tty device
3099 * @device: a struct device that is associated with this tty device.
3100 * This field is optional, if there is no known struct device
3101 * for this tty device it can be set to NULL safely.
3102 * @drvdata: Driver data to be set to device.
3103 * @attr_grp: Attribute group to be set on device.
3105 * Returns a pointer to the struct device for this tty device
3106 * (or ERR_PTR(-EFOO) on error).
3108 * This call is required to be made to register an individual tty device
3109 * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If
3110 * that bit is not set, this function should not be called by a tty
3115 struct device
*tty_register_device_attr(struct tty_driver
*driver
,
3116 unsigned index
, struct device
*device
,
3118 const struct attribute_group
**attr_grp
)
3121 dev_t devt
= MKDEV(driver
->major
, driver
->minor_start
) + index
;
3122 struct device
*dev
= NULL
;
3123 int retval
= -ENODEV
;
3126 if (index
>= driver
->num
) {
3127 printk(KERN_ERR
"Attempt to register invalid tty line number "
3129 return ERR_PTR(-EINVAL
);
3132 if (driver
->type
== TTY_DRIVER_TYPE_PTY
)
3133 pty_line_name(driver
, index
, name
);
3135 tty_line_name(driver
, index
, name
);
3137 if (!(driver
->flags
& TTY_DRIVER_DYNAMIC_ALLOC
)) {
3138 retval
= tty_cdev_add(driver
, devt
, index
, 1);
3144 dev
= kzalloc(sizeof(*dev
), GFP_KERNEL
);
3151 dev
->class = tty_class
;
3152 dev
->parent
= device
;
3153 dev
->release
= tty_device_create_release
;
3154 dev_set_name(dev
, "%s", name
);
3155 dev
->groups
= attr_grp
;
3156 dev_set_drvdata(dev
, drvdata
);
3158 retval
= device_register(dev
);
3167 cdev_del(&driver
->cdevs
[index
]);
3168 return ERR_PTR(retval
);
3170 EXPORT_SYMBOL_GPL(tty_register_device_attr
);
3173 * tty_unregister_device - unregister a tty device
3174 * @driver: the tty driver that describes the tty device
3175 * @index: the index in the tty driver for this tty device
3177 * If a tty device is registered with a call to tty_register_device() then
3178 * this function must be called when the tty device is gone.
3183 void tty_unregister_device(struct tty_driver
*driver
, unsigned index
)
3185 device_destroy(tty_class
,
3186 MKDEV(driver
->major
, driver
->minor_start
) + index
);
3187 if (!(driver
->flags
& TTY_DRIVER_DYNAMIC_ALLOC
))
3188 cdev_del(&driver
->cdevs
[index
]);
3190 EXPORT_SYMBOL(tty_unregister_device
);
3193 * __tty_alloc_driver -- allocate tty driver
3194 * @lines: count of lines this driver can handle at most
3195 * @owner: module which is repsonsible for this driver
3196 * @flags: some of TTY_DRIVER_* flags, will be set in driver->flags
3198 * This should not be called directly, some of the provided macros should be
3199 * used instead. Use IS_ERR and friends on @retval.
3201 struct tty_driver
*__tty_alloc_driver(unsigned int lines
, struct module
*owner
,
3202 unsigned long flags
)
3204 struct tty_driver
*driver
;
3205 unsigned int cdevs
= 1;
3208 if (!lines
|| (flags
& TTY_DRIVER_UNNUMBERED_NODE
&& lines
> 1))
3209 return ERR_PTR(-EINVAL
);
3211 driver
= kzalloc(sizeof(struct tty_driver
), GFP_KERNEL
);
3213 return ERR_PTR(-ENOMEM
);
3215 kref_init(&driver
->kref
);
3216 driver
->magic
= TTY_DRIVER_MAGIC
;
3217 driver
->num
= lines
;
3218 driver
->owner
= owner
;
3219 driver
->flags
= flags
;
3221 if (!(flags
& TTY_DRIVER_DEVPTS_MEM
)) {
3222 driver
->ttys
= kcalloc(lines
, sizeof(*driver
->ttys
),
3224 driver
->termios
= kcalloc(lines
, sizeof(*driver
->termios
),
3226 if (!driver
->ttys
|| !driver
->termios
) {
3232 if (!(flags
& TTY_DRIVER_DYNAMIC_ALLOC
)) {
3233 driver
->ports
= kcalloc(lines
, sizeof(*driver
->ports
),
3235 if (!driver
->ports
) {
3242 driver
->cdevs
= kcalloc(cdevs
, sizeof(*driver
->cdevs
), GFP_KERNEL
);
3243 if (!driver
->cdevs
) {
3250 kfree(driver
->ports
);
3251 kfree(driver
->ttys
);
3252 kfree(driver
->termios
);
3254 return ERR_PTR(err
);
3256 EXPORT_SYMBOL(__tty_alloc_driver
);
3258 static void destruct_tty_driver(struct kref
*kref
)
3260 struct tty_driver
*driver
= container_of(kref
, struct tty_driver
, kref
);
3262 struct ktermios
*tp
;
3264 if (driver
->flags
& TTY_DRIVER_INSTALLED
) {
3266 * Free the termios and termios_locked structures because
3267 * we don't want to get memory leaks when modular tty
3268 * drivers are removed from the kernel.
3270 for (i
= 0; i
< driver
->num
; i
++) {
3271 tp
= driver
->termios
[i
];
3273 driver
->termios
[i
] = NULL
;
3276 if (!(driver
->flags
& TTY_DRIVER_DYNAMIC_DEV
))
3277 tty_unregister_device(driver
, i
);
3279 proc_tty_unregister_driver(driver
);
3280 if (driver
->flags
& TTY_DRIVER_DYNAMIC_ALLOC
)
3281 cdev_del(&driver
->cdevs
[0]);
3283 kfree(driver
->cdevs
);
3284 kfree(driver
->ports
);
3285 kfree(driver
->termios
);
3286 kfree(driver
->ttys
);
3290 void tty_driver_kref_put(struct tty_driver
*driver
)
3292 kref_put(&driver
->kref
, destruct_tty_driver
);
3294 EXPORT_SYMBOL(tty_driver_kref_put
);
3296 void tty_set_operations(struct tty_driver
*driver
,
3297 const struct tty_operations
*op
)
3301 EXPORT_SYMBOL(tty_set_operations
);
3303 void put_tty_driver(struct tty_driver
*d
)
3305 tty_driver_kref_put(d
);
3307 EXPORT_SYMBOL(put_tty_driver
);
3310 * Called by a tty driver to register itself.
3312 int tty_register_driver(struct tty_driver
*driver
)
3319 if (!driver
->major
) {
3320 error
= alloc_chrdev_region(&dev
, driver
->minor_start
,
3321 driver
->num
, driver
->name
);
3323 driver
->major
= MAJOR(dev
);
3324 driver
->minor_start
= MINOR(dev
);
3327 dev
= MKDEV(driver
->major
, driver
->minor_start
);
3328 error
= register_chrdev_region(dev
, driver
->num
, driver
->name
);
3333 if (driver
->flags
& TTY_DRIVER_DYNAMIC_ALLOC
) {
3334 error
= tty_cdev_add(driver
, dev
, 0, driver
->num
);
3336 goto err_unreg_char
;
3339 mutex_lock(&tty_mutex
);
3340 list_add(&driver
->tty_drivers
, &tty_drivers
);
3341 mutex_unlock(&tty_mutex
);
3343 if (!(driver
->flags
& TTY_DRIVER_DYNAMIC_DEV
)) {
3344 for (i
= 0; i
< driver
->num
; i
++) {
3345 d
= tty_register_device(driver
, i
, NULL
);
3348 goto err_unreg_devs
;
3352 proc_tty_register_driver(driver
);
3353 driver
->flags
|= TTY_DRIVER_INSTALLED
;
3357 for (i
--; i
>= 0; i
--)
3358 tty_unregister_device(driver
, i
);
3360 mutex_lock(&tty_mutex
);
3361 list_del(&driver
->tty_drivers
);
3362 mutex_unlock(&tty_mutex
);
3365 unregister_chrdev_region(dev
, driver
->num
);
3369 EXPORT_SYMBOL(tty_register_driver
);
3372 * Called by a tty driver to unregister itself.
3374 int tty_unregister_driver(struct tty_driver
*driver
)
3378 if (driver
->refcount
)
3381 unregister_chrdev_region(MKDEV(driver
->major
, driver
->minor_start
),
3383 mutex_lock(&tty_mutex
);
3384 list_del(&driver
->tty_drivers
);
3385 mutex_unlock(&tty_mutex
);
3389 EXPORT_SYMBOL(tty_unregister_driver
);
3391 dev_t
tty_devnum(struct tty_struct
*tty
)
3393 return MKDEV(tty
->driver
->major
, tty
->driver
->minor_start
) + tty
->index
;
3395 EXPORT_SYMBOL(tty_devnum
);
3397 void proc_clear_tty(struct task_struct
*p
)
3399 unsigned long flags
;
3400 struct tty_struct
*tty
;
3401 spin_lock_irqsave(&p
->sighand
->siglock
, flags
);
3402 tty
= p
->signal
->tty
;
3403 p
->signal
->tty
= NULL
;
3404 spin_unlock_irqrestore(&p
->sighand
->siglock
, flags
);
3408 /* Called under the sighand lock */
3410 static void __proc_set_tty(struct task_struct
*tsk
, struct tty_struct
*tty
)
3413 unsigned long flags
;
3414 /* We should not have a session or pgrp to put here but.... */
3415 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
3416 put_pid(tty
->session
);
3418 tty
->pgrp
= get_pid(task_pgrp(tsk
));
3419 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
3420 tty
->session
= get_pid(task_session(tsk
));
3421 if (tsk
->signal
->tty
) {
3422 printk(KERN_DEBUG
"tty not NULL!!\n");
3423 tty_kref_put(tsk
->signal
->tty
);
3426 put_pid(tsk
->signal
->tty_old_pgrp
);
3427 tsk
->signal
->tty
= tty_kref_get(tty
);
3428 tsk
->signal
->tty_old_pgrp
= NULL
;
3431 static void proc_set_tty(struct task_struct
*tsk
, struct tty_struct
*tty
)
3433 spin_lock_irq(&tsk
->sighand
->siglock
);
3434 __proc_set_tty(tsk
, tty
);
3435 spin_unlock_irq(&tsk
->sighand
->siglock
);
3438 struct tty_struct
*get_current_tty(void)
3440 struct tty_struct
*tty
;
3441 unsigned long flags
;
3443 spin_lock_irqsave(¤t
->sighand
->siglock
, flags
);
3444 tty
= tty_kref_get(current
->signal
->tty
);
3445 spin_unlock_irqrestore(¤t
->sighand
->siglock
, flags
);
3448 EXPORT_SYMBOL_GPL(get_current_tty
);
3450 void tty_default_fops(struct file_operations
*fops
)
3456 * Initialize the console device. This is called *early*, so
3457 * we can't necessarily depend on lots of kernel help here.
3458 * Just do some early initializations, and do the complex setup
3461 void __init
console_init(void)
3465 /* Setup the default TTY line discipline. */
3469 * set up the console device so that later boot sequences can
3470 * inform about problems etc..
3472 call
= __con_initcall_start
;
3473 while (call
< __con_initcall_end
) {
3479 static char *tty_devnode(struct device
*dev
, umode_t
*mode
)
3483 if (dev
->devt
== MKDEV(TTYAUX_MAJOR
, 0) ||
3484 dev
->devt
== MKDEV(TTYAUX_MAJOR
, 2))
3489 static int __init
tty_class_init(void)
3491 tty_class
= class_create(THIS_MODULE
, "tty");
3492 if (IS_ERR(tty_class
))
3493 return PTR_ERR(tty_class
);
3494 tty_class
->devnode
= tty_devnode
;
3498 postcore_initcall(tty_class_init
);
3500 /* 3/2004 jmc: why do these devices exist? */
3501 static struct cdev tty_cdev
, console_cdev
;
3503 static ssize_t
show_cons_active(struct device
*dev
,
3504 struct device_attribute
*attr
, char *buf
)
3506 struct console
*cs
[16];
3512 for_each_console(c
) {
3517 if ((c
->flags
& CON_ENABLED
) == 0)
3520 if (i
>= ARRAY_SIZE(cs
))
3524 count
+= sprintf(buf
+ count
, "%s%d%c",
3525 cs
[i
]->name
, cs
[i
]->index
, i
? ' ':'\n');
3530 static DEVICE_ATTR(active
, S_IRUGO
, show_cons_active
, NULL
);
3532 static struct device
*consdev
;
3534 void console_sysfs_notify(void)
3537 sysfs_notify(&consdev
->kobj
, NULL
, "active");
3541 * Ok, now we can initialize the rest of the tty devices and can count
3542 * on memory allocations, interrupts etc..
3544 int __init
tty_init(void)
3546 cdev_init(&tty_cdev
, &tty_fops
);
3547 if (cdev_add(&tty_cdev
, MKDEV(TTYAUX_MAJOR
, 0), 1) ||
3548 register_chrdev_region(MKDEV(TTYAUX_MAJOR
, 0), 1, "/dev/tty") < 0)
3549 panic("Couldn't register /dev/tty driver\n");
3550 device_create(tty_class
, NULL
, MKDEV(TTYAUX_MAJOR
, 0), NULL
, "tty");
3552 cdev_init(&console_cdev
, &console_fops
);
3553 if (cdev_add(&console_cdev
, MKDEV(TTYAUX_MAJOR
, 1), 1) ||
3554 register_chrdev_region(MKDEV(TTYAUX_MAJOR
, 1), 1, "/dev/console") < 0)
3555 panic("Couldn't register /dev/console driver\n");
3556 consdev
= device_create(tty_class
, NULL
, MKDEV(TTYAUX_MAJOR
, 1), NULL
,
3558 if (IS_ERR(consdev
))
3561 WARN_ON(device_create_file(consdev
, &dev_attr_active
) < 0);
3564 vty_init(&console_fops
);