2 * Copyright (C) 1991, 1992 Linus Torvalds
6 * 'tty_io.c' gives an orthogonal feeling to tty's, be they consoles
7 * or rs-channels. It also implements echoing, cooked mode etc.
9 * Kill-line thanks to John T Kohl, who also corrected VMIN = VTIME = 0.
11 * Modified by Theodore Ts'o, 9/14/92, to dynamically allocate the
12 * tty_struct and tty_queue structures. Previously there was an array
13 * of 256 tty_struct's which was statically allocated, and the
14 * tty_queue structures were allocated at boot time. Both are now
15 * dynamically allocated only when the tty is open.
17 * Also restructured routines so that there is more of a separation
18 * between the high-level tty routines (tty_io.c and tty_ioctl.c) and
19 * the low-level tty routines (serial.c, pty.c, console.c). This
20 * makes for cleaner and more compact code. -TYT, 9/17/92
22 * Modified by Fred N. van Kempen, 01/29/93, to add line disciplines
23 * which can be dynamically activated and de-activated by the line
24 * discipline handling modules (like SLIP).
26 * NOTE: pay no attention to the line discipline code (yet); its
27 * interface is still subject to change in this version...
30 * Added functionality to the OPOST tty handling. No delays, but all
31 * other bits should be there.
32 * -- Nick Holloway <alfie@dcs.warwick.ac.uk>, 27th May 1993.
34 * Rewrote canonical mode and added more termios flags.
35 * -- julian@uhunix.uhcc.hawaii.edu (J. Cowley), 13Jan94
37 * Reorganized FASYNC support so mouse code can share it.
38 * -- ctm@ardi.com, 9Sep95
40 * New TIOCLINUX variants added.
41 * -- mj@k332.feld.cvut.cz, 19-Nov-95
43 * Restrict vt switching via ioctl()
44 * -- grif@cs.ucr.edu, 5-Dec-95
46 * Move console and virtual terminal code to more appropriate files,
47 * implement CONFIG_VT and generalize console device interface.
48 * -- Marko Kohtala <Marko.Kohtala@hut.fi>, March 97
50 * Rewrote tty_init_dev and tty_release_dev to eliminate races.
51 * -- Bill Hawes <whawes@star.net>, June 97
53 * Added devfs support.
54 * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 13-Jan-1998
56 * Added support for a Unix98-style ptmx device.
57 * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 14-Jan-1998
59 * Reduced memory usage for older ARM systems
60 * -- Russell King <rmk@arm.linux.org.uk>
62 * Move do_SAK() into process context. Less stack use in devfs functions.
63 * alloc_tty_struct() always uses kmalloc()
64 * -- Andrew Morton <andrewm@uow.edu.eu> 17Mar01
67 #include <linux/types.h>
68 #include <linux/major.h>
69 #include <linux/errno.h>
70 #include <linux/signal.h>
71 #include <linux/fcntl.h>
72 #include <linux/sched.h>
73 #include <linux/interrupt.h>
74 #include <linux/tty.h>
75 #include <linux/tty_driver.h>
76 #include <linux/tty_flip.h>
77 #include <linux/devpts_fs.h>
78 #include <linux/file.h>
79 #include <linux/fdtable.h>
80 #include <linux/console.h>
81 #include <linux/timer.h>
82 #include <linux/ctype.h>
85 #include <linux/string.h>
86 #include <linux/slab.h>
87 #include <linux/poll.h>
88 #include <linux/proc_fs.h>
89 #include <linux/init.h>
90 #include <linux/module.h>
91 #include <linux/device.h>
92 #include <linux/wait.h>
93 #include <linux/bitops.h>
94 #include <linux/delay.h>
95 #include <linux/seq_file.h>
96 #include <linux/serial.h>
97 #include <linux/ratelimit.h>
99 #include <linux/uaccess.h>
101 #include <linux/kbd_kern.h>
102 #include <linux/vt_kern.h>
103 #include <linux/selection.h>
105 #include <linux/kmod.h>
106 #include <linux/nsproxy.h>
108 #undef TTY_DEBUG_HANGUP
109 #ifdef TTY_DEBUG_HANGUP
110 # define tty_debug_hangup(tty, f, args...) tty_debug(tty, f, ##args)
112 # define tty_debug_hangup(tty, f, args...) do { } while (0)
115 #define TTY_PARANOIA_CHECK 1
116 #define CHECK_TTY_COUNT 1
118 struct ktermios tty_std_termios
= { /* for the benefit of tty drivers */
119 .c_iflag
= ICRNL
| IXON
,
120 .c_oflag
= OPOST
| ONLCR
,
121 .c_cflag
= B38400
| CS8
| CREAD
| HUPCL
,
122 .c_lflag
= ISIG
| ICANON
| ECHO
| ECHOE
| ECHOK
|
123 ECHOCTL
| ECHOKE
| IEXTEN
,
127 /* .c_line = N_TTY, */
130 EXPORT_SYMBOL(tty_std_termios
);
132 /* This list gets poked at by procfs and various bits of boot up code. This
133 could do with some rationalisation such as pulling the tty proc function
136 LIST_HEAD(tty_drivers
); /* linked list of tty drivers */
138 /* Mutex to protect creating and releasing a tty */
139 DEFINE_MUTEX(tty_mutex
);
141 /* Spinlock to protect the tty->tty_files list */
142 DEFINE_SPINLOCK(tty_files_lock
);
144 static ssize_t
tty_read(struct file
*, char __user
*, size_t, loff_t
*);
145 static ssize_t
tty_write(struct file
*, const char __user
*, size_t, loff_t
*);
146 ssize_t
redirected_tty_write(struct file
*, const char __user
*,
148 static unsigned int tty_poll(struct file
*, poll_table
*);
149 static int tty_open(struct inode
*, struct file
*);
150 long tty_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
);
152 static long tty_compat_ioctl(struct file
*file
, unsigned int cmd
,
155 #define tty_compat_ioctl NULL
157 static int __tty_fasync(int fd
, struct file
*filp
, int on
);
158 static int tty_fasync(int fd
, struct file
*filp
, int on
);
159 static void release_tty(struct tty_struct
*tty
, int idx
);
162 * free_tty_struct - free a disused tty
163 * @tty: tty struct to free
165 * Free the write buffers, tty queue and tty memory itself.
167 * Locking: none. Must be called after tty is definitely unused
170 static void free_tty_struct(struct tty_struct
*tty
)
172 tty_ldisc_deinit(tty
);
173 put_device(tty
->dev
);
174 kfree(tty
->write_buf
);
175 tty
->magic
= 0xDEADDEAD;
179 static inline struct tty_struct
*file_tty(struct file
*file
)
181 return ((struct tty_file_private
*)file
->private_data
)->tty
;
184 int tty_alloc_file(struct file
*file
)
186 struct tty_file_private
*priv
;
188 priv
= kmalloc(sizeof(*priv
), GFP_KERNEL
);
192 file
->private_data
= priv
;
197 /* Associate a new file with the tty structure */
198 void tty_add_file(struct tty_struct
*tty
, struct file
*file
)
200 struct tty_file_private
*priv
= file
->private_data
;
205 spin_lock(&tty_files_lock
);
206 list_add(&priv
->list
, &tty
->tty_files
);
207 spin_unlock(&tty_files_lock
);
211 * tty_free_file - free file->private_data
213 * This shall be used only for fail path handling when tty_add_file was not
216 void tty_free_file(struct file
*file
)
218 struct tty_file_private
*priv
= file
->private_data
;
220 file
->private_data
= NULL
;
224 /* Delete file from its tty */
225 static void tty_del_file(struct file
*file
)
227 struct tty_file_private
*priv
= file
->private_data
;
229 spin_lock(&tty_files_lock
);
230 list_del(&priv
->list
);
231 spin_unlock(&tty_files_lock
);
236 #define TTY_NUMBER(tty) ((tty)->index + (tty)->driver->name_base)
239 * tty_name - return tty naming
240 * @tty: tty structure
242 * Convert a tty structure into a name. The name reflects the kernel
243 * naming policy and if udev is in use may not reflect user space
248 const char *tty_name(const struct tty_struct
*tty
)
250 if (!tty
) /* Hmm. NULL pointer. That's fun. */
255 EXPORT_SYMBOL(tty_name
);
257 const char *tty_driver_name(const struct tty_struct
*tty
)
259 if (!tty
|| !tty
->driver
)
261 return tty
->driver
->name
;
264 static int tty_paranoia_check(struct tty_struct
*tty
, struct inode
*inode
,
267 #ifdef TTY_PARANOIA_CHECK
269 pr_warn("(%d:%d): %s: NULL tty\n",
270 imajor(inode
), iminor(inode
), routine
);
273 if (tty
->magic
!= TTY_MAGIC
) {
274 pr_warn("(%d:%d): %s: bad magic number\n",
275 imajor(inode
), iminor(inode
), routine
);
282 /* Caller must hold tty_lock */
283 static int check_tty_count(struct tty_struct
*tty
, const char *routine
)
285 #ifdef CHECK_TTY_COUNT
289 spin_lock(&tty_files_lock
);
290 list_for_each(p
, &tty
->tty_files
) {
293 spin_unlock(&tty_files_lock
);
294 if (tty
->driver
->type
== TTY_DRIVER_TYPE_PTY
&&
295 tty
->driver
->subtype
== PTY_TYPE_SLAVE
&&
296 tty
->link
&& tty
->link
->count
)
298 if (tty
->count
!= count
) {
299 tty_warn(tty
, "%s: tty->count(%d) != #fd's(%d)\n",
300 routine
, tty
->count
, count
);
308 * get_tty_driver - find device of a tty
309 * @dev_t: device identifier
310 * @index: returns the index of the tty
312 * This routine returns a tty driver structure, given a device number
313 * and also passes back the index number.
315 * Locking: caller must hold tty_mutex
318 static struct tty_driver
*get_tty_driver(dev_t device
, int *index
)
320 struct tty_driver
*p
;
322 list_for_each_entry(p
, &tty_drivers
, tty_drivers
) {
323 dev_t base
= MKDEV(p
->major
, p
->minor_start
);
324 if (device
< base
|| device
>= base
+ p
->num
)
326 *index
= device
- base
;
327 return tty_driver_kref_get(p
);
332 #ifdef CONFIG_CONSOLE_POLL
335 * tty_find_polling_driver - find device of a polled tty
336 * @name: name string to match
337 * @line: pointer to resulting tty line nr
339 * This routine returns a tty driver structure, given a name
340 * and the condition that the tty driver is capable of polled
343 struct tty_driver
*tty_find_polling_driver(char *name
, int *line
)
345 struct tty_driver
*p
, *res
= NULL
;
350 for (str
= name
; *str
; str
++)
351 if ((*str
>= '0' && *str
<= '9') || *str
== ',')
357 tty_line
= simple_strtoul(str
, &str
, 10);
359 mutex_lock(&tty_mutex
);
360 /* Search through the tty devices to look for a match */
361 list_for_each_entry(p
, &tty_drivers
, tty_drivers
) {
362 if (strncmp(name
, p
->name
, len
) != 0)
370 if (tty_line
>= 0 && tty_line
< p
->num
&& p
->ops
&&
371 p
->ops
->poll_init
&& !p
->ops
->poll_init(p
, tty_line
, stp
)) {
372 res
= tty_driver_kref_get(p
);
377 mutex_unlock(&tty_mutex
);
381 EXPORT_SYMBOL_GPL(tty_find_polling_driver
);
385 * tty_check_change - check for POSIX terminal changes
388 * If we try to write to, or set the state of, a terminal and we're
389 * not in the foreground, send a SIGTTOU. If the signal is blocked or
390 * ignored, go ahead and perform the operation. (POSIX 7.2)
395 int __tty_check_change(struct tty_struct
*tty
, int sig
)
398 struct pid
*pgrp
, *tty_pgrp
;
401 if (current
->signal
->tty
!= tty
)
405 pgrp
= task_pgrp(current
);
407 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
408 tty_pgrp
= tty
->pgrp
;
409 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
411 if (tty_pgrp
&& pgrp
!= tty
->pgrp
) {
412 if (is_ignored(sig
)) {
415 } else if (is_current_pgrp_orphaned())
418 kill_pgrp(pgrp
, sig
, 1);
419 set_thread_flag(TIF_SIGPENDING
);
426 tty_warn(tty
, "sig=%d, tty->pgrp == NULL!\n", sig
);
431 int tty_check_change(struct tty_struct
*tty
)
433 return __tty_check_change(tty
, SIGTTOU
);
435 EXPORT_SYMBOL(tty_check_change
);
437 static ssize_t
hung_up_tty_read(struct file
*file
, char __user
*buf
,
438 size_t count
, loff_t
*ppos
)
443 static ssize_t
hung_up_tty_write(struct file
*file
, const char __user
*buf
,
444 size_t count
, loff_t
*ppos
)
449 /* No kernel lock held - none needed ;) */
450 static unsigned int hung_up_tty_poll(struct file
*filp
, poll_table
*wait
)
452 return POLLIN
| POLLOUT
| POLLERR
| POLLHUP
| POLLRDNORM
| POLLWRNORM
;
455 static long hung_up_tty_ioctl(struct file
*file
, unsigned int cmd
,
458 return cmd
== TIOCSPGRP
? -ENOTTY
: -EIO
;
461 static long hung_up_tty_compat_ioctl(struct file
*file
,
462 unsigned int cmd
, unsigned long arg
)
464 return cmd
== TIOCSPGRP
? -ENOTTY
: -EIO
;
467 static const struct file_operations tty_fops
= {
472 .unlocked_ioctl
= tty_ioctl
,
473 .compat_ioctl
= tty_compat_ioctl
,
475 .release
= tty_release
,
476 .fasync
= tty_fasync
,
479 static const struct file_operations console_fops
= {
482 .write
= redirected_tty_write
,
484 .unlocked_ioctl
= tty_ioctl
,
485 .compat_ioctl
= tty_compat_ioctl
,
487 .release
= tty_release
,
488 .fasync
= tty_fasync
,
491 static const struct file_operations hung_up_tty_fops
= {
493 .read
= hung_up_tty_read
,
494 .write
= hung_up_tty_write
,
495 .poll
= hung_up_tty_poll
,
496 .unlocked_ioctl
= hung_up_tty_ioctl
,
497 .compat_ioctl
= hung_up_tty_compat_ioctl
,
498 .release
= tty_release
,
501 static DEFINE_SPINLOCK(redirect_lock
);
502 static struct file
*redirect
;
505 void proc_clear_tty(struct task_struct
*p
)
508 struct tty_struct
*tty
;
509 spin_lock_irqsave(&p
->sighand
->siglock
, flags
);
510 tty
= p
->signal
->tty
;
511 p
->signal
->tty
= NULL
;
512 spin_unlock_irqrestore(&p
->sighand
->siglock
, flags
);
517 * proc_set_tty - set the controlling terminal
519 * Only callable by the session leader and only if it does not already have
520 * a controlling terminal.
522 * Caller must hold: tty_lock()
523 * a readlock on tasklist_lock
526 static void __proc_set_tty(struct tty_struct
*tty
)
530 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
532 * The session and fg pgrp references will be non-NULL if
533 * tiocsctty() is stealing the controlling tty
535 put_pid(tty
->session
);
537 tty
->pgrp
= get_pid(task_pgrp(current
));
538 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
539 tty
->session
= get_pid(task_session(current
));
540 if (current
->signal
->tty
) {
541 tty_debug(tty
, "current tty %s not NULL!!\n",
542 current
->signal
->tty
->name
);
543 tty_kref_put(current
->signal
->tty
);
545 put_pid(current
->signal
->tty_old_pgrp
);
546 current
->signal
->tty
= tty_kref_get(tty
);
547 current
->signal
->tty_old_pgrp
= NULL
;
550 static void proc_set_tty(struct tty_struct
*tty
)
552 spin_lock_irq(¤t
->sighand
->siglock
);
554 spin_unlock_irq(¤t
->sighand
->siglock
);
557 struct tty_struct
*get_current_tty(void)
559 struct tty_struct
*tty
;
562 spin_lock_irqsave(¤t
->sighand
->siglock
, flags
);
563 tty
= tty_kref_get(current
->signal
->tty
);
564 spin_unlock_irqrestore(¤t
->sighand
->siglock
, flags
);
567 EXPORT_SYMBOL_GPL(get_current_tty
);
569 static void session_clear_tty(struct pid
*session
)
571 struct task_struct
*p
;
572 do_each_pid_task(session
, PIDTYPE_SID
, p
) {
574 } while_each_pid_task(session
, PIDTYPE_SID
, p
);
578 * tty_wakeup - request more data
581 * Internal and external helper for wakeups of tty. This function
582 * informs the line discipline if present that the driver is ready
583 * to receive more output data.
586 void tty_wakeup(struct tty_struct
*tty
)
588 struct tty_ldisc
*ld
;
590 if (test_bit(TTY_DO_WRITE_WAKEUP
, &tty
->flags
)) {
591 ld
= tty_ldisc_ref(tty
);
593 if (ld
->ops
->write_wakeup
)
594 ld
->ops
->write_wakeup(tty
);
598 wake_up_interruptible_poll(&tty
->write_wait
, POLLOUT
);
601 EXPORT_SYMBOL_GPL(tty_wakeup
);
604 * tty_signal_session_leader - sends SIGHUP to session leader
605 * @tty controlling tty
606 * @exit_session if non-zero, signal all foreground group processes
608 * Send SIGHUP and SIGCONT to the session leader and its process group.
609 * Optionally, signal all processes in the foreground process group.
611 * Returns the number of processes in the session with this tty
612 * as their controlling terminal. This value is used to drop
613 * tty references for those processes.
615 static int tty_signal_session_leader(struct tty_struct
*tty
, int exit_session
)
617 struct task_struct
*p
;
619 struct pid
*tty_pgrp
= NULL
;
621 read_lock(&tasklist_lock
);
623 do_each_pid_task(tty
->session
, PIDTYPE_SID
, p
) {
624 spin_lock_irq(&p
->sighand
->siglock
);
625 if (p
->signal
->tty
== tty
) {
626 p
->signal
->tty
= NULL
;
627 /* We defer the dereferences outside fo
631 if (!p
->signal
->leader
) {
632 spin_unlock_irq(&p
->sighand
->siglock
);
635 __group_send_sig_info(SIGHUP
, SEND_SIG_PRIV
, p
);
636 __group_send_sig_info(SIGCONT
, SEND_SIG_PRIV
, p
);
637 put_pid(p
->signal
->tty_old_pgrp
); /* A noop */
638 spin_lock(&tty
->ctrl_lock
);
639 tty_pgrp
= get_pid(tty
->pgrp
);
641 p
->signal
->tty_old_pgrp
= get_pid(tty
->pgrp
);
642 spin_unlock(&tty
->ctrl_lock
);
643 spin_unlock_irq(&p
->sighand
->siglock
);
644 } while_each_pid_task(tty
->session
, PIDTYPE_SID
, p
);
646 read_unlock(&tasklist_lock
);
650 kill_pgrp(tty_pgrp
, SIGHUP
, exit_session
);
658 * __tty_hangup - actual handler for hangup events
661 * This can be called by a "kworker" kernel thread. That is process
662 * synchronous but doesn't hold any locks, so we need to make sure we
663 * have the appropriate locks for what we're doing.
665 * The hangup event clears any pending redirections onto the hung up
666 * device. It ensures future writes will error and it does the needed
667 * line discipline hangup and signal delivery. The tty object itself
672 * redirect lock for undoing redirection
673 * file list lock for manipulating list of ttys
674 * tty_ldiscs_lock from called functions
675 * termios_rwsem resetting termios data
676 * tasklist_lock to walk task list for hangup event
677 * ->siglock to protect ->signal/->sighand
679 static void __tty_hangup(struct tty_struct
*tty
, int exit_session
)
681 struct file
*cons_filp
= NULL
;
682 struct file
*filp
, *f
= NULL
;
683 struct tty_file_private
*priv
;
684 int closecount
= 0, n
;
691 spin_lock(&redirect_lock
);
692 if (redirect
&& file_tty(redirect
) == tty
) {
696 spin_unlock(&redirect_lock
);
700 if (test_bit(TTY_HUPPED
, &tty
->flags
)) {
705 /* inuse_filps is protected by the single tty lock,
706 this really needs to change if we want to flush the
707 workqueue with the lock held */
708 check_tty_count(tty
, "tty_hangup");
710 spin_lock(&tty_files_lock
);
711 /* This breaks for file handles being sent over AF_UNIX sockets ? */
712 list_for_each_entry(priv
, &tty
->tty_files
, list
) {
714 if (filp
->f_op
->write
== redirected_tty_write
)
716 if (filp
->f_op
->write
!= tty_write
)
719 __tty_fasync(-1, filp
, 0); /* can't block */
720 filp
->f_op
= &hung_up_tty_fops
;
722 spin_unlock(&tty_files_lock
);
724 refs
= tty_signal_session_leader(tty
, exit_session
);
725 /* Account for the p->signal references we killed */
729 tty_ldisc_hangup(tty
, cons_filp
!= NULL
);
731 spin_lock_irq(&tty
->ctrl_lock
);
732 clear_bit(TTY_THROTTLED
, &tty
->flags
);
733 clear_bit(TTY_DO_WRITE_WAKEUP
, &tty
->flags
);
734 put_pid(tty
->session
);
738 tty
->ctrl_status
= 0;
739 spin_unlock_irq(&tty
->ctrl_lock
);
742 * If one of the devices matches a console pointer, we
743 * cannot just call hangup() because that will cause
744 * tty->count and state->count to go out of sync.
745 * So we just call close() the right number of times.
749 for (n
= 0; n
< closecount
; n
++)
750 tty
->ops
->close(tty
, cons_filp
);
751 } else if (tty
->ops
->hangup
)
752 tty
->ops
->hangup(tty
);
754 * We don't want to have driver/ldisc interactions beyond the ones
755 * we did here. The driver layer expects no calls after ->hangup()
756 * from the ldisc side, which is now guaranteed.
758 set_bit(TTY_HUPPED
, &tty
->flags
);
765 static void do_tty_hangup(struct work_struct
*work
)
767 struct tty_struct
*tty
=
768 container_of(work
, struct tty_struct
, hangup_work
);
770 __tty_hangup(tty
, 0);
774 * tty_hangup - trigger a hangup event
775 * @tty: tty to hangup
777 * A carrier loss (virtual or otherwise) has occurred on this like
778 * schedule a hangup sequence to run after this event.
781 void tty_hangup(struct tty_struct
*tty
)
783 tty_debug_hangup(tty
, "hangup\n");
784 schedule_work(&tty
->hangup_work
);
787 EXPORT_SYMBOL(tty_hangup
);
790 * tty_vhangup - process vhangup
791 * @tty: tty to hangup
793 * The user has asked via system call for the terminal to be hung up.
794 * We do this synchronously so that when the syscall returns the process
795 * is complete. That guarantee is necessary for security reasons.
798 void tty_vhangup(struct tty_struct
*tty
)
800 tty_debug_hangup(tty
, "vhangup\n");
801 __tty_hangup(tty
, 0);
804 EXPORT_SYMBOL(tty_vhangup
);
808 * tty_vhangup_self - process vhangup for own ctty
810 * Perform a vhangup on the current controlling tty
813 void tty_vhangup_self(void)
815 struct tty_struct
*tty
;
817 tty
= get_current_tty();
825 * tty_vhangup_session - hangup session leader exit
826 * @tty: tty to hangup
828 * The session leader is exiting and hanging up its controlling terminal.
829 * Every process in the foreground process group is signalled SIGHUP.
831 * We do this synchronously so that when the syscall returns the process
832 * is complete. That guarantee is necessary for security reasons.
835 static void tty_vhangup_session(struct tty_struct
*tty
)
837 tty_debug_hangup(tty
, "session hangup\n");
838 __tty_hangup(tty
, 1);
842 * tty_hung_up_p - was tty hung up
843 * @filp: file pointer of tty
845 * Return true if the tty has been subject to a vhangup or a carrier
849 int tty_hung_up_p(struct file
*filp
)
851 return (filp
->f_op
== &hung_up_tty_fops
);
854 EXPORT_SYMBOL(tty_hung_up_p
);
857 * disassociate_ctty - disconnect controlling tty
858 * @on_exit: true if exiting so need to "hang up" the session
860 * This function is typically called only by the session leader, when
861 * it wants to disassociate itself from its controlling tty.
863 * It performs the following functions:
864 * (1) Sends a SIGHUP and SIGCONT to the foreground process group
865 * (2) Clears the tty from being controlling the session
866 * (3) Clears the controlling tty for all processes in the
869 * The argument on_exit is set to 1 if called when a process is
870 * exiting; it is 0 if called by the ioctl TIOCNOTTY.
873 * BTM is taken for hysterical raisins, and held when
874 * called from no_tty().
875 * tty_mutex is taken to protect tty
876 * ->siglock is taken to protect ->signal/->sighand
877 * tasklist_lock is taken to walk process list for sessions
878 * ->siglock is taken to protect ->signal/->sighand
881 void disassociate_ctty(int on_exit
)
883 struct tty_struct
*tty
;
885 if (!current
->signal
->leader
)
888 tty
= get_current_tty();
890 if (on_exit
&& tty
->driver
->type
!= TTY_DRIVER_TYPE_PTY
) {
891 tty_vhangup_session(tty
);
893 struct pid
*tty_pgrp
= tty_get_pgrp(tty
);
895 kill_pgrp(tty_pgrp
, SIGHUP
, on_exit
);
897 kill_pgrp(tty_pgrp
, SIGCONT
, on_exit
);
903 } else if (on_exit
) {
904 struct pid
*old_pgrp
;
905 spin_lock_irq(¤t
->sighand
->siglock
);
906 old_pgrp
= current
->signal
->tty_old_pgrp
;
907 current
->signal
->tty_old_pgrp
= NULL
;
908 spin_unlock_irq(¤t
->sighand
->siglock
);
910 kill_pgrp(old_pgrp
, SIGHUP
, on_exit
);
911 kill_pgrp(old_pgrp
, SIGCONT
, on_exit
);
917 spin_lock_irq(¤t
->sighand
->siglock
);
918 put_pid(current
->signal
->tty_old_pgrp
);
919 current
->signal
->tty_old_pgrp
= NULL
;
921 tty
= tty_kref_get(current
->signal
->tty
);
924 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
925 put_pid(tty
->session
);
929 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
932 tty_debug_hangup(tty
, "no current tty\n");
934 spin_unlock_irq(¤t
->sighand
->siglock
);
935 /* Now clear signal->tty under the lock */
936 read_lock(&tasklist_lock
);
937 session_clear_tty(task_session(current
));
938 read_unlock(&tasklist_lock
);
943 * no_tty - Ensure the current process does not have a controlling tty
947 /* FIXME: Review locking here. The tty_lock never covered any race
948 between a new association and proc_clear_tty but possible we need
949 to protect against this anyway */
950 struct task_struct
*tsk
= current
;
951 disassociate_ctty(0);
957 * stop_tty - propagate flow control
960 * Perform flow control to the driver. May be called
961 * on an already stopped device and will not re-call the driver
964 * This functionality is used by both the line disciplines for
965 * halting incoming flow and by the driver. It may therefore be
966 * called from any context, may be under the tty atomic_write_lock
973 void __stop_tty(struct tty_struct
*tty
)
982 void stop_tty(struct tty_struct
*tty
)
986 spin_lock_irqsave(&tty
->flow_lock
, flags
);
988 spin_unlock_irqrestore(&tty
->flow_lock
, flags
);
990 EXPORT_SYMBOL(stop_tty
);
993 * start_tty - propagate flow control
996 * Start a tty that has been stopped if at all possible. If this
997 * tty was previous stopped and is now being started, the driver
998 * start method is invoked and the line discipline woken.
1004 void __start_tty(struct tty_struct
*tty
)
1006 if (!tty
->stopped
|| tty
->flow_stopped
)
1009 if (tty
->ops
->start
)
1010 tty
->ops
->start(tty
);
1014 void start_tty(struct tty_struct
*tty
)
1016 unsigned long flags
;
1018 spin_lock_irqsave(&tty
->flow_lock
, flags
);
1020 spin_unlock_irqrestore(&tty
->flow_lock
, flags
);
1022 EXPORT_SYMBOL(start_tty
);
1024 static void tty_update_time(struct timespec
*time
)
1026 unsigned long sec
= get_seconds();
1029 * We only care if the two values differ in anything other than the
1030 * lower three bits (i.e every 8 seconds). If so, then we can update
1031 * the time of the tty device, otherwise it could be construded as a
1032 * security leak to let userspace know the exact timing of the tty.
1034 if ((sec
^ time
->tv_sec
) & ~7)
1039 * tty_read - read method for tty device files
1040 * @file: pointer to tty file
1042 * @count: size of user buffer
1045 * Perform the read system call function on this terminal device. Checks
1046 * for hung up devices before calling the line discipline method.
1049 * Locks the line discipline internally while needed. Multiple
1050 * read calls may be outstanding in parallel.
1053 static ssize_t
tty_read(struct file
*file
, char __user
*buf
, size_t count
,
1057 struct inode
*inode
= file_inode(file
);
1058 struct tty_struct
*tty
= file_tty(file
);
1059 struct tty_ldisc
*ld
;
1061 if (tty_paranoia_check(tty
, inode
, "tty_read"))
1063 if (!tty
|| (test_bit(TTY_IO_ERROR
, &tty
->flags
)))
1066 /* We want to wait for the line discipline to sort out in this
1068 ld
= tty_ldisc_ref_wait(tty
);
1070 return hung_up_tty_read(file
, buf
, count
, ppos
);
1072 i
= ld
->ops
->read(tty
, file
, buf
, count
);
1075 tty_ldisc_deref(ld
);
1078 tty_update_time(&inode
->i_atime
);
1083 static void tty_write_unlock(struct tty_struct
*tty
)
1085 mutex_unlock(&tty
->atomic_write_lock
);
1086 wake_up_interruptible_poll(&tty
->write_wait
, POLLOUT
);
1089 static int tty_write_lock(struct tty_struct
*tty
, int ndelay
)
1091 if (!mutex_trylock(&tty
->atomic_write_lock
)) {
1094 if (mutex_lock_interruptible(&tty
->atomic_write_lock
))
1095 return -ERESTARTSYS
;
1101 * Split writes up in sane blocksizes to avoid
1102 * denial-of-service type attacks
1104 static inline ssize_t
do_tty_write(
1105 ssize_t (*write
)(struct tty_struct
*, struct file
*, const unsigned char *, size_t),
1106 struct tty_struct
*tty
,
1108 const char __user
*buf
,
1111 ssize_t ret
, written
= 0;
1114 ret
= tty_write_lock(tty
, file
->f_flags
& O_NDELAY
);
1119 * We chunk up writes into a temporary buffer. This
1120 * simplifies low-level drivers immensely, since they
1121 * don't have locking issues and user mode accesses.
1123 * But if TTY_NO_WRITE_SPLIT is set, we should use a
1126 * The default chunk-size is 2kB, because the NTTY
1127 * layer has problems with bigger chunks. It will
1128 * claim to be able to handle more characters than
1131 * FIXME: This can probably go away now except that 64K chunks
1132 * are too likely to fail unless switched to vmalloc...
1135 if (test_bit(TTY_NO_WRITE_SPLIT
, &tty
->flags
))
1140 /* write_buf/write_cnt is protected by the atomic_write_lock mutex */
1141 if (tty
->write_cnt
< chunk
) {
1142 unsigned char *buf_chunk
;
1147 buf_chunk
= kmalloc(chunk
, GFP_KERNEL
);
1152 kfree(tty
->write_buf
);
1153 tty
->write_cnt
= chunk
;
1154 tty
->write_buf
= buf_chunk
;
1157 /* Do the write .. */
1159 size_t size
= count
;
1163 if (copy_from_user(tty
->write_buf
, buf
, size
))
1165 ret
= write(tty
, file
, tty
->write_buf
, size
);
1174 if (signal_pending(current
))
1179 tty_update_time(&file_inode(file
)->i_mtime
);
1183 tty_write_unlock(tty
);
1188 * tty_write_message - write a message to a certain tty, not just the console.
1189 * @tty: the destination tty_struct
1190 * @msg: the message to write
1192 * This is used for messages that need to be redirected to a specific tty.
1193 * We don't put it into the syslog queue right now maybe in the future if
1196 * We must still hold the BTM and test the CLOSING flag for the moment.
1199 void tty_write_message(struct tty_struct
*tty
, char *msg
)
1202 mutex_lock(&tty
->atomic_write_lock
);
1204 if (tty
->ops
->write
&& tty
->count
> 0)
1205 tty
->ops
->write(tty
, msg
, strlen(msg
));
1207 tty_write_unlock(tty
);
1214 * tty_write - write method for tty device file
1215 * @file: tty file pointer
1216 * @buf: user data to write
1217 * @count: bytes to write
1220 * Write data to a tty device via the line discipline.
1223 * Locks the line discipline as required
1224 * Writes to the tty driver are serialized by the atomic_write_lock
1225 * and are then processed in chunks to the device. The line discipline
1226 * write method will not be invoked in parallel for each device.
1229 static ssize_t
tty_write(struct file
*file
, const char __user
*buf
,
1230 size_t count
, loff_t
*ppos
)
1232 struct tty_struct
*tty
= file_tty(file
);
1233 struct tty_ldisc
*ld
;
1236 if (tty_paranoia_check(tty
, file_inode(file
), "tty_write"))
1238 if (!tty
|| !tty
->ops
->write
||
1239 (test_bit(TTY_IO_ERROR
, &tty
->flags
)))
1241 /* Short term debug to catch buggy drivers */
1242 if (tty
->ops
->write_room
== NULL
)
1243 tty_err(tty
, "missing write_room method\n");
1244 ld
= tty_ldisc_ref_wait(tty
);
1246 return hung_up_tty_write(file
, buf
, count
, ppos
);
1247 if (!ld
->ops
->write
)
1250 ret
= do_tty_write(ld
->ops
->write
, tty
, file
, buf
, count
);
1251 tty_ldisc_deref(ld
);
1255 ssize_t
redirected_tty_write(struct file
*file
, const char __user
*buf
,
1256 size_t count
, loff_t
*ppos
)
1258 struct file
*p
= NULL
;
1260 spin_lock(&redirect_lock
);
1262 p
= get_file(redirect
);
1263 spin_unlock(&redirect_lock
);
1267 res
= vfs_write(p
, buf
, count
, &p
->f_pos
);
1271 return tty_write(file
, buf
, count
, ppos
);
1275 * tty_send_xchar - send priority character
1277 * Send a high priority character to the tty even if stopped
1279 * Locking: none for xchar method, write ordering for write method.
1282 int tty_send_xchar(struct tty_struct
*tty
, char ch
)
1284 int was_stopped
= tty
->stopped
;
1286 if (tty
->ops
->send_xchar
) {
1287 down_read(&tty
->termios_rwsem
);
1288 tty
->ops
->send_xchar(tty
, ch
);
1289 up_read(&tty
->termios_rwsem
);
1293 if (tty_write_lock(tty
, 0) < 0)
1294 return -ERESTARTSYS
;
1296 down_read(&tty
->termios_rwsem
);
1299 tty
->ops
->write(tty
, &ch
, 1);
1302 up_read(&tty
->termios_rwsem
);
1303 tty_write_unlock(tty
);
1307 static char ptychar
[] = "pqrstuvwxyzabcde";
1310 * pty_line_name - generate name for a pty
1311 * @driver: the tty driver in use
1312 * @index: the minor number
1313 * @p: output buffer of at least 6 bytes
1315 * Generate a name from a driver reference and write it to the output
1320 static void pty_line_name(struct tty_driver
*driver
, int index
, char *p
)
1322 int i
= index
+ driver
->name_base
;
1323 /* ->name is initialized to "ttyp", but "tty" is expected */
1324 sprintf(p
, "%s%c%x",
1325 driver
->subtype
== PTY_TYPE_SLAVE
? "tty" : driver
->name
,
1326 ptychar
[i
>> 4 & 0xf], i
& 0xf);
1330 * tty_line_name - generate name for a tty
1331 * @driver: the tty driver in use
1332 * @index: the minor number
1333 * @p: output buffer of at least 7 bytes
1335 * Generate a name from a driver reference and write it to the output
1340 static ssize_t
tty_line_name(struct tty_driver
*driver
, int index
, char *p
)
1342 if (driver
->flags
& TTY_DRIVER_UNNUMBERED_NODE
)
1343 return sprintf(p
, "%s", driver
->name
);
1345 return sprintf(p
, "%s%d", driver
->name
,
1346 index
+ driver
->name_base
);
1350 * tty_driver_lookup_tty() - find an existing tty, if any
1351 * @driver: the driver for the tty
1352 * @idx: the minor number
1354 * Return the tty, if found. If not found, return NULL or ERR_PTR() if the
1355 * driver lookup() method returns an error.
1357 * Locking: tty_mutex must be held. If the tty is found, bump the tty kref.
1359 static struct tty_struct
*tty_driver_lookup_tty(struct tty_driver
*driver
,
1360 struct inode
*inode
, int idx
)
1362 struct tty_struct
*tty
;
1364 if (driver
->ops
->lookup
)
1365 tty
= driver
->ops
->lookup(driver
, inode
, idx
);
1367 tty
= driver
->ttys
[idx
];
1375 * tty_init_termios - helper for termios setup
1376 * @tty: the tty to set up
1378 * Initialise the termios structures for this tty. Thus runs under
1379 * the tty_mutex currently so we can be relaxed about ordering.
1382 void tty_init_termios(struct tty_struct
*tty
)
1384 struct ktermios
*tp
;
1385 int idx
= tty
->index
;
1387 if (tty
->driver
->flags
& TTY_DRIVER_RESET_TERMIOS
)
1388 tty
->termios
= tty
->driver
->init_termios
;
1390 /* Check for lazy saved data */
1391 tp
= tty
->driver
->termios
[idx
];
1394 tty
->termios
.c_line
= tty
->driver
->init_termios
.c_line
;
1396 tty
->termios
= tty
->driver
->init_termios
;
1398 /* Compatibility until drivers always set this */
1399 tty
->termios
.c_ispeed
= tty_termios_input_baud_rate(&tty
->termios
);
1400 tty
->termios
.c_ospeed
= tty_termios_baud_rate(&tty
->termios
);
1402 EXPORT_SYMBOL_GPL(tty_init_termios
);
1404 int tty_standard_install(struct tty_driver
*driver
, struct tty_struct
*tty
)
1406 tty_init_termios(tty
);
1407 tty_driver_kref_get(driver
);
1409 driver
->ttys
[tty
->index
] = tty
;
1412 EXPORT_SYMBOL_GPL(tty_standard_install
);
1415 * tty_driver_install_tty() - install a tty entry in the driver
1416 * @driver: the driver for the tty
1419 * Install a tty object into the driver tables. The tty->index field
1420 * will be set by the time this is called. This method is responsible
1421 * for ensuring any need additional structures are allocated and
1424 * Locking: tty_mutex for now
1426 static int tty_driver_install_tty(struct tty_driver
*driver
,
1427 struct tty_struct
*tty
)
1429 return driver
->ops
->install
? driver
->ops
->install(driver
, tty
) :
1430 tty_standard_install(driver
, tty
);
1434 * tty_driver_remove_tty() - remove a tty from the driver tables
1435 * @driver: the driver for the tty
1436 * @idx: the minor number
1438 * Remvoe a tty object from the driver tables. The tty->index field
1439 * will be set by the time this is called.
1441 * Locking: tty_mutex for now
1443 static void tty_driver_remove_tty(struct tty_driver
*driver
, struct tty_struct
*tty
)
1445 if (driver
->ops
->remove
)
1446 driver
->ops
->remove(driver
, tty
);
1448 driver
->ttys
[tty
->index
] = NULL
;
1452 * tty_reopen() - fast re-open of an open tty
1453 * @tty - the tty to open
1455 * Return 0 on success, -errno on error.
1456 * Re-opens on master ptys are not allowed and return -EIO.
1458 * Locking: Caller must hold tty_lock
1460 static int tty_reopen(struct tty_struct
*tty
)
1462 struct tty_driver
*driver
= tty
->driver
;
1464 if (driver
->type
== TTY_DRIVER_TYPE_PTY
&&
1465 driver
->subtype
== PTY_TYPE_MASTER
)
1471 if (test_bit(TTY_EXCLUSIVE
, &tty
->flags
) && !capable(CAP_SYS_ADMIN
))
1477 return tty_ldisc_reinit(tty
, tty
->termios
.c_line
);
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
);
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 free_tty_struct(tty
);
1557 module_put(driver
->owner
);
1558 return ERR_PTR(retval
);
1560 /* call the tty release_tty routine to clean out this slot */
1563 tty_info_ratelimited(tty
, "ldisc open failed (%d), clearing slot %d\n",
1565 release_tty(tty
, idx
);
1566 return ERR_PTR(retval
);
1569 static void tty_free_termios(struct tty_struct
*tty
)
1571 struct ktermios
*tp
;
1572 int idx
= tty
->index
;
1574 /* If the port is going to reset then it has no termios to save */
1575 if (tty
->driver
->flags
& TTY_DRIVER_RESET_TERMIOS
)
1578 /* Stash the termios data */
1579 tp
= tty
->driver
->termios
[idx
];
1581 tp
= kmalloc(sizeof(struct ktermios
), GFP_KERNEL
);
1584 tty
->driver
->termios
[idx
] = tp
;
1590 * tty_flush_works - flush all works of a tty/pty pair
1591 * @tty: tty device to flush works for (or either end of a pty pair)
1593 * Sync flush all works belonging to @tty (and the 'other' tty).
1595 static void tty_flush_works(struct tty_struct
*tty
)
1597 flush_work(&tty
->SAK_work
);
1598 flush_work(&tty
->hangup_work
);
1600 flush_work(&tty
->link
->SAK_work
);
1601 flush_work(&tty
->link
->hangup_work
);
1606 * release_one_tty - release tty structure memory
1607 * @kref: kref of tty we are obliterating
1609 * Releases memory associated with a tty structure, and clears out the
1610 * driver table slots. This function is called when a device is no longer
1611 * in use. It also gets called when setup of a device fails.
1614 * takes the file list lock internally when working on the list
1615 * of ttys that the driver keeps.
1617 * This method gets called from a work queue so that the driver private
1618 * cleanup ops can sleep (needed for USB at least)
1620 static void release_one_tty(struct work_struct
*work
)
1622 struct tty_struct
*tty
=
1623 container_of(work
, struct tty_struct
, hangup_work
);
1624 struct tty_driver
*driver
= tty
->driver
;
1625 struct module
*owner
= driver
->owner
;
1627 if (tty
->ops
->cleanup
)
1628 tty
->ops
->cleanup(tty
);
1631 tty_driver_kref_put(driver
);
1634 spin_lock(&tty_files_lock
);
1635 list_del_init(&tty
->tty_files
);
1636 spin_unlock(&tty_files_lock
);
1639 put_pid(tty
->session
);
1640 free_tty_struct(tty
);
1643 static void queue_release_one_tty(struct kref
*kref
)
1645 struct tty_struct
*tty
= container_of(kref
, struct tty_struct
, kref
);
1647 /* The hangup queue is now free so we can reuse it rather than
1648 waste a chunk of memory for each port */
1649 INIT_WORK(&tty
->hangup_work
, release_one_tty
);
1650 schedule_work(&tty
->hangup_work
);
1654 * tty_kref_put - release a tty kref
1657 * Release a reference to a tty device and if need be let the kref
1658 * layer destruct the object for us
1661 void tty_kref_put(struct tty_struct
*tty
)
1664 kref_put(&tty
->kref
, queue_release_one_tty
);
1666 EXPORT_SYMBOL(tty_kref_put
);
1669 * release_tty - release tty structure memory
1671 * Release both @tty and a possible linked partner (think pty pair),
1672 * and decrement the refcount of the backing module.
1676 * takes the file list lock internally when working on the list
1677 * of ttys that the driver keeps.
1680 static void release_tty(struct tty_struct
*tty
, int idx
)
1682 /* This should always be true but check for the moment */
1683 WARN_ON(tty
->index
!= idx
);
1684 WARN_ON(!mutex_is_locked(&tty_mutex
));
1685 if (tty
->ops
->shutdown
)
1686 tty
->ops
->shutdown(tty
);
1687 tty_free_termios(tty
);
1688 tty_driver_remove_tty(tty
->driver
, tty
);
1689 tty
->port
->itty
= NULL
;
1691 tty
->link
->port
->itty
= NULL
;
1692 tty_buffer_cancel_work(tty
->port
);
1694 tty_kref_put(tty
->link
);
1699 * tty_release_checks - check a tty before real release
1700 * @tty: tty to check
1701 * @o_tty: link of @tty (if any)
1702 * @idx: index of the tty
1704 * Performs some paranoid checking before true release of the @tty.
1705 * This is a no-op unless TTY_PARANOIA_CHECK is defined.
1707 static int tty_release_checks(struct tty_struct
*tty
, int idx
)
1709 #ifdef TTY_PARANOIA_CHECK
1710 if (idx
< 0 || idx
>= tty
->driver
->num
) {
1711 tty_debug(tty
, "bad idx %d\n", idx
);
1715 /* not much to check for devpts */
1716 if (tty
->driver
->flags
& TTY_DRIVER_DEVPTS_MEM
)
1719 if (tty
!= tty
->driver
->ttys
[idx
]) {
1720 tty_debug(tty
, "bad driver table[%d] = %p\n",
1721 idx
, tty
->driver
->ttys
[idx
]);
1724 if (tty
->driver
->other
) {
1725 struct tty_struct
*o_tty
= tty
->link
;
1727 if (o_tty
!= tty
->driver
->other
->ttys
[idx
]) {
1728 tty_debug(tty
, "bad other table[%d] = %p\n",
1729 idx
, tty
->driver
->other
->ttys
[idx
]);
1732 if (o_tty
->link
!= tty
) {
1733 tty_debug(tty
, "bad link = %p\n", o_tty
->link
);
1742 * tty_release - vfs callback for close
1743 * @inode: inode of tty
1744 * @filp: file pointer for handle to tty
1746 * Called the last time each file handle is closed that references
1747 * this tty. There may however be several such references.
1750 * Takes bkl. See tty_release_dev
1752 * Even releasing the tty structures is a tricky business.. We have
1753 * to be very careful that the structures are all released at the
1754 * same time, as interrupts might otherwise get the wrong pointers.
1756 * WSH 09/09/97: rewritten to avoid some nasty race conditions that could
1757 * lead to double frees or releasing memory still in use.
1760 int tty_release(struct inode
*inode
, struct file
*filp
)
1762 struct tty_struct
*tty
= file_tty(filp
);
1763 struct tty_struct
*o_tty
= NULL
;
1764 int do_sleep
, final
;
1769 if (tty_paranoia_check(tty
, inode
, __func__
))
1773 check_tty_count(tty
, __func__
);
1775 __tty_fasync(-1, filp
, 0);
1778 if (tty
->driver
->type
== TTY_DRIVER_TYPE_PTY
&&
1779 tty
->driver
->subtype
== PTY_TYPE_MASTER
)
1782 if (tty_release_checks(tty
, idx
)) {
1787 tty_debug_hangup(tty
, "releasing (count=%d)\n", tty
->count
);
1789 if (tty
->ops
->close
)
1790 tty
->ops
->close(tty
, filp
);
1792 /* If tty is pty master, lock the slave pty (stable lock order) */
1793 tty_lock_slave(o_tty
);
1796 * Sanity check: if tty->count is going to zero, there shouldn't be
1797 * any waiters on tty->read_wait or tty->write_wait. We test the
1798 * wait queues and kick everyone out _before_ actually starting to
1799 * close. This ensures that we won't block while releasing the tty
1802 * The test for the o_tty closing is necessary, since the master and
1803 * slave sides may close in any order. If the slave side closes out
1804 * first, its count will be one, since the master side holds an open.
1805 * Thus this test wouldn't be triggered at the time the slave closed,
1811 if (tty
->count
<= 1) {
1812 if (waitqueue_active(&tty
->read_wait
)) {
1813 wake_up_poll(&tty
->read_wait
, POLLIN
);
1816 if (waitqueue_active(&tty
->write_wait
)) {
1817 wake_up_poll(&tty
->write_wait
, POLLOUT
);
1821 if (o_tty
&& o_tty
->count
<= 1) {
1822 if (waitqueue_active(&o_tty
->read_wait
)) {
1823 wake_up_poll(&o_tty
->read_wait
, POLLIN
);
1826 if (waitqueue_active(&o_tty
->write_wait
)) {
1827 wake_up_poll(&o_tty
->write_wait
, POLLOUT
);
1836 tty_warn(tty
, "read/write wait queue active!\n");
1838 schedule_timeout_killable(timeout
);
1839 if (timeout
< 120 * HZ
)
1840 timeout
= 2 * timeout
+ 1;
1842 timeout
= MAX_SCHEDULE_TIMEOUT
;
1846 if (--o_tty
->count
< 0) {
1847 tty_warn(tty
, "bad slave count (%d)\n", o_tty
->count
);
1851 if (--tty
->count
< 0) {
1852 tty_warn(tty
, "bad tty->count (%d)\n", tty
->count
);
1857 * We've decremented tty->count, so we need to remove this file
1858 * descriptor off the tty->tty_files list; this serves two
1860 * - check_tty_count sees the correct number of file descriptors
1861 * associated with this tty.
1862 * - do_tty_hangup no longer sees this file descriptor as
1863 * something that needs to be handled for hangups.
1868 * Perform some housekeeping before deciding whether to return.
1870 * If _either_ side is closing, make sure there aren't any
1871 * processes that still think tty or o_tty is their controlling
1875 read_lock(&tasklist_lock
);
1876 session_clear_tty(tty
->session
);
1878 session_clear_tty(o_tty
->session
);
1879 read_unlock(&tasklist_lock
);
1882 /* check whether both sides are closing ... */
1883 final
= !tty
->count
&& !(o_tty
&& o_tty
->count
);
1885 tty_unlock_slave(o_tty
);
1888 /* At this point, the tty->count == 0 should ensure a dead tty
1889 cannot be re-opened by a racing opener */
1894 tty_debug_hangup(tty
, "final close\n");
1896 * Ask the line discipline code to release its structures
1898 tty_ldisc_release(tty
);
1900 /* Wait for pending work before tty destruction commmences */
1901 tty_flush_works(tty
);
1903 tty_debug_hangup(tty
, "freeing structure\n");
1905 * The release_tty function takes care of the details of clearing
1906 * the slots and preserving the termios structure. The tty_unlock_pair
1907 * should be safe as we keep a kref while the tty is locked (so the
1908 * unlock never unlocks a freed tty).
1910 mutex_lock(&tty_mutex
);
1911 release_tty(tty
, idx
);
1912 mutex_unlock(&tty_mutex
);
1918 * tty_open_current_tty - get locked tty of current task
1919 * @device: device number
1920 * @filp: file pointer to tty
1921 * @return: locked tty of the current task iff @device is /dev/tty
1923 * Performs a re-open of the current task's controlling tty.
1925 * We cannot return driver and index like for the other nodes because
1926 * devpts will not work then. It expects inodes to be from devpts FS.
1928 static struct tty_struct
*tty_open_current_tty(dev_t device
, struct file
*filp
)
1930 struct tty_struct
*tty
;
1933 if (device
!= MKDEV(TTYAUX_MAJOR
, 0))
1936 tty
= get_current_tty();
1938 return ERR_PTR(-ENXIO
);
1940 filp
->f_flags
|= O_NONBLOCK
; /* Don't let /dev/tty block */
1943 tty_kref_put(tty
); /* safe to drop the kref now */
1945 retval
= tty_reopen(tty
);
1948 tty
= ERR_PTR(retval
);
1954 * tty_lookup_driver - lookup a tty driver for a given device file
1955 * @device: device number
1956 * @filp: file pointer to tty
1957 * @noctty: set if the device should not become a controlling tty
1958 * @index: index for the device in the @return driver
1959 * @return: driver for this inode (with increased refcount)
1961 * If @return is not erroneous, the caller is responsible to decrement the
1962 * refcount by tty_driver_kref_put.
1964 * Locking: tty_mutex protects get_tty_driver
1966 static struct tty_driver
*tty_lookup_driver(dev_t device
, struct file
*filp
,
1969 struct tty_driver
*driver
;
1973 case MKDEV(TTY_MAJOR
, 0): {
1974 extern struct tty_driver
*console_driver
;
1975 driver
= tty_driver_kref_get(console_driver
);
1976 *index
= fg_console
;
1980 case MKDEV(TTYAUX_MAJOR
, 1): {
1981 struct tty_driver
*console_driver
= console_device(index
);
1982 if (console_driver
) {
1983 driver
= tty_driver_kref_get(console_driver
);
1985 /* Don't let /dev/console block */
1986 filp
->f_flags
|= O_NONBLOCK
;
1990 return ERR_PTR(-ENODEV
);
1993 driver
= get_tty_driver(device
, index
);
1995 return ERR_PTR(-ENODEV
);
2002 * tty_open_by_driver - open a tty device
2003 * @device: dev_t of device to open
2004 * @inode: inode of device file
2005 * @filp: file pointer to tty
2007 * Performs the driver lookup, checks for a reopen, or otherwise
2008 * performs the first-time tty initialization.
2010 * Returns the locked initialized or re-opened &tty_struct
2012 * Claims the global tty_mutex to serialize:
2013 * - concurrent first-time tty initialization
2014 * - concurrent tty driver removal w/ lookup
2015 * - concurrent tty removal from driver table
2017 static struct tty_struct
*tty_open_by_driver(dev_t device
, struct inode
*inode
,
2020 struct tty_struct
*tty
;
2021 struct tty_driver
*driver
= NULL
;
2025 mutex_lock(&tty_mutex
);
2026 driver
= tty_lookup_driver(device
, filp
, &index
);
2027 if (IS_ERR(driver
)) {
2028 mutex_unlock(&tty_mutex
);
2029 return ERR_CAST(driver
);
2032 /* check whether we're reopening an existing tty */
2033 tty
= tty_driver_lookup_tty(driver
, inode
, index
);
2035 mutex_unlock(&tty_mutex
);
2040 mutex_unlock(&tty_mutex
);
2041 retval
= tty_lock_interruptible(tty
);
2043 if (retval
== -EINTR
)
2044 retval
= -ERESTARTSYS
;
2045 tty
= ERR_PTR(retval
);
2048 /* safe to drop the kref from tty_driver_lookup_tty() */
2050 retval
= tty_reopen(tty
);
2053 tty
= ERR_PTR(retval
);
2055 } else { /* Returns with the tty_lock held for now */
2056 tty
= tty_init_dev(driver
, index
);
2057 mutex_unlock(&tty_mutex
);
2060 tty_driver_kref_put(driver
);
2065 * tty_open - open a tty device
2066 * @inode: inode of device file
2067 * @filp: file pointer to tty
2069 * tty_open and tty_release keep up the tty count that contains the
2070 * number of opens done on a tty. We cannot use the inode-count, as
2071 * different inodes might point to the same tty.
2073 * Open-counting is needed for pty masters, as well as for keeping
2074 * track of serial lines: DTR is dropped when the last close happens.
2075 * (This is not done solely through tty->count, now. - Ted 1/27/92)
2077 * The termios state of a pty is reset on first open so that
2078 * settings don't persist across reuse.
2080 * Locking: tty_mutex protects tty, tty_lookup_driver and tty_init_dev.
2081 * tty->count should protect the rest.
2082 * ->siglock protects ->signal/->sighand
2084 * Note: the tty_unlock/lock cases without a ref are only safe due to
2088 static int tty_open(struct inode
*inode
, struct file
*filp
)
2090 struct tty_struct
*tty
;
2092 dev_t device
= inode
->i_rdev
;
2093 unsigned saved_flags
= filp
->f_flags
;
2095 nonseekable_open(inode
, filp
);
2098 retval
= tty_alloc_file(filp
);
2102 tty
= tty_open_current_tty(device
, filp
);
2104 tty
= tty_open_by_driver(device
, inode
, filp
);
2107 tty_free_file(filp
);
2108 retval
= PTR_ERR(tty
);
2109 if (retval
!= -EAGAIN
|| signal_pending(current
))
2115 tty_add_file(tty
, filp
);
2117 check_tty_count(tty
, __func__
);
2118 tty_debug_hangup(tty
, "opening (count=%d)\n", tty
->count
);
2121 retval
= tty
->ops
->open(tty
, filp
);
2124 filp
->f_flags
= saved_flags
;
2127 tty_debug_hangup(tty
, "open error %d, releasing\n", retval
);
2129 tty_unlock(tty
); /* need to call tty_release without BTM */
2130 tty_release(inode
, filp
);
2131 if (retval
!= -ERESTARTSYS
)
2134 if (signal_pending(current
))
2139 * Need to reset f_op in case a hangup happened.
2141 if (tty_hung_up_p(filp
))
2142 filp
->f_op
= &tty_fops
;
2145 clear_bit(TTY_HUPPED
, &tty
->flags
);
2148 read_lock(&tasklist_lock
);
2149 spin_lock_irq(¤t
->sighand
->siglock
);
2150 noctty
= (filp
->f_flags
& O_NOCTTY
) ||
2151 device
== MKDEV(TTY_MAJOR
, 0) ||
2152 device
== MKDEV(TTYAUX_MAJOR
, 1) ||
2153 (tty
->driver
->type
== TTY_DRIVER_TYPE_PTY
&&
2154 tty
->driver
->subtype
== PTY_TYPE_MASTER
);
2157 current
->signal
->leader
&&
2158 !current
->signal
->tty
&&
2159 tty
->session
== NULL
) {
2161 * Don't let a process that only has write access to the tty
2162 * obtain the privileges associated with having a tty as
2163 * controlling terminal (being able to reopen it with full
2164 * access through /dev/tty, being able to perform pushback).
2165 * Many distributions set the group of all ttys to "tty" and
2166 * grant write-only access to all terminals for setgid tty
2167 * binaries, which should not imply full privileges on all ttys.
2169 * This could theoretically break old code that performs open()
2170 * on a write-only file descriptor. In that case, it might be
2171 * necessary to also permit this if
2172 * inode_permission(inode, MAY_READ) == 0.
2174 if (filp
->f_mode
& FMODE_READ
)
2175 __proc_set_tty(tty
);
2177 spin_unlock_irq(¤t
->sighand
->siglock
);
2178 read_unlock(&tasklist_lock
);
2186 * tty_poll - check tty status
2187 * @filp: file being polled
2188 * @wait: poll wait structures to update
2190 * Call the line discipline polling method to obtain the poll
2191 * status of the device.
2193 * Locking: locks called line discipline but ldisc poll method
2194 * may be re-entered freely by other callers.
2197 static unsigned int tty_poll(struct file
*filp
, poll_table
*wait
)
2199 struct tty_struct
*tty
= file_tty(filp
);
2200 struct tty_ldisc
*ld
;
2203 if (tty_paranoia_check(tty
, file_inode(filp
), "tty_poll"))
2206 ld
= tty_ldisc_ref_wait(tty
);
2208 return hung_up_tty_poll(filp
, wait
);
2210 ret
= ld
->ops
->poll(tty
, filp
, wait
);
2211 tty_ldisc_deref(ld
);
2215 static int __tty_fasync(int fd
, struct file
*filp
, int on
)
2217 struct tty_struct
*tty
= file_tty(filp
);
2218 struct tty_ldisc
*ldisc
;
2219 unsigned long flags
;
2222 if (tty_paranoia_check(tty
, file_inode(filp
), "tty_fasync"))
2225 retval
= fasync_helper(fd
, filp
, on
, &tty
->fasync
);
2229 ldisc
= tty_ldisc_ref(tty
);
2231 if (ldisc
->ops
->fasync
)
2232 ldisc
->ops
->fasync(tty
, on
);
2233 tty_ldisc_deref(ldisc
);
2240 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
2243 type
= PIDTYPE_PGID
;
2245 pid
= task_pid(current
);
2249 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
2250 __f_setown(filp
, pid
, type
, 0);
2258 static int tty_fasync(int fd
, struct file
*filp
, int on
)
2260 struct tty_struct
*tty
= file_tty(filp
);
2264 retval
= __tty_fasync(fd
, filp
, on
);
2271 * tiocsti - fake input character
2272 * @tty: tty to fake input into
2273 * @p: pointer to character
2275 * Fake input to a tty device. Does the necessary locking and
2278 * FIXME: does not honour flow control ??
2281 * Called functions take tty_ldiscs_lock
2282 * current->signal->tty check is safe without locks
2284 * FIXME: may race normal receive processing
2287 static int tiocsti(struct tty_struct
*tty
, char __user
*p
)
2290 struct tty_ldisc
*ld
;
2292 if ((current
->signal
->tty
!= tty
) && !capable(CAP_SYS_ADMIN
))
2294 if (get_user(ch
, p
))
2296 tty_audit_tiocsti(tty
, ch
);
2297 ld
= tty_ldisc_ref_wait(tty
);
2300 ld
->ops
->receive_buf(tty
, &ch
, &mbz
, 1);
2301 tty_ldisc_deref(ld
);
2306 * tiocgwinsz - implement window query ioctl
2308 * @arg: user buffer for result
2310 * Copies the kernel idea of the window size into the user buffer.
2312 * Locking: tty->winsize_mutex is taken to ensure the winsize data
2316 static int tiocgwinsz(struct tty_struct
*tty
, struct winsize __user
*arg
)
2320 mutex_lock(&tty
->winsize_mutex
);
2321 err
= copy_to_user(arg
, &tty
->winsize
, sizeof(*arg
));
2322 mutex_unlock(&tty
->winsize_mutex
);
2324 return err
? -EFAULT
: 0;
2328 * tty_do_resize - resize event
2329 * @tty: tty being resized
2330 * @rows: rows (character)
2331 * @cols: cols (character)
2333 * Update the termios variables and send the necessary signals to
2334 * peform a terminal resize correctly
2337 int tty_do_resize(struct tty_struct
*tty
, struct winsize
*ws
)
2342 mutex_lock(&tty
->winsize_mutex
);
2343 if (!memcmp(ws
, &tty
->winsize
, sizeof(*ws
)))
2346 /* Signal the foreground process group */
2347 pgrp
= tty_get_pgrp(tty
);
2349 kill_pgrp(pgrp
, SIGWINCH
, 1);
2354 mutex_unlock(&tty
->winsize_mutex
);
2357 EXPORT_SYMBOL(tty_do_resize
);
2360 * tiocswinsz - implement window size set ioctl
2361 * @tty; tty side of tty
2362 * @arg: user buffer for result
2364 * Copies the user idea of the window size to the kernel. Traditionally
2365 * this is just advisory information but for the Linux console it
2366 * actually has driver level meaning and triggers a VC resize.
2369 * Driver dependent. The default do_resize method takes the
2370 * tty termios mutex and ctrl_lock. The console takes its own lock
2371 * then calls into the default method.
2374 static int tiocswinsz(struct tty_struct
*tty
, struct winsize __user
*arg
)
2376 struct winsize tmp_ws
;
2377 if (copy_from_user(&tmp_ws
, arg
, sizeof(*arg
)))
2380 if (tty
->ops
->resize
)
2381 return tty
->ops
->resize(tty
, &tmp_ws
);
2383 return tty_do_resize(tty
, &tmp_ws
);
2387 * tioccons - allow admin to move logical console
2388 * @file: the file to become console
2390 * Allow the administrator to move the redirected console device
2392 * Locking: uses redirect_lock to guard the redirect information
2395 static int tioccons(struct file
*file
)
2397 if (!capable(CAP_SYS_ADMIN
))
2399 if (file
->f_op
->write
== redirected_tty_write
) {
2401 spin_lock(&redirect_lock
);
2404 spin_unlock(&redirect_lock
);
2409 spin_lock(&redirect_lock
);
2411 spin_unlock(&redirect_lock
);
2414 redirect
= get_file(file
);
2415 spin_unlock(&redirect_lock
);
2420 * fionbio - non blocking ioctl
2421 * @file: file to set blocking value
2422 * @p: user parameter
2424 * Historical tty interfaces had a blocking control ioctl before
2425 * the generic functionality existed. This piece of history is preserved
2426 * in the expected tty API of posix OS's.
2428 * Locking: none, the open file handle ensures it won't go away.
2431 static int fionbio(struct file
*file
, int __user
*p
)
2435 if (get_user(nonblock
, p
))
2438 spin_lock(&file
->f_lock
);
2440 file
->f_flags
|= O_NONBLOCK
;
2442 file
->f_flags
&= ~O_NONBLOCK
;
2443 spin_unlock(&file
->f_lock
);
2448 * tiocsctty - set controlling tty
2449 * @tty: tty structure
2450 * @arg: user argument
2452 * This ioctl is used to manage job control. It permits a session
2453 * leader to set this tty as the controlling tty for the session.
2456 * Takes tty_lock() to serialize proc_set_tty() for this tty
2457 * Takes tasklist_lock internally to walk sessions
2458 * Takes ->siglock() when updating signal->tty
2461 static int tiocsctty(struct tty_struct
*tty
, struct file
*file
, int arg
)
2466 read_lock(&tasklist_lock
);
2468 if (current
->signal
->leader
&& (task_session(current
) == tty
->session
))
2472 * The process must be a session leader and
2473 * not have a controlling tty already.
2475 if (!current
->signal
->leader
|| current
->signal
->tty
) {
2482 * This tty is already the controlling
2483 * tty for another session group!
2485 if (arg
== 1 && capable(CAP_SYS_ADMIN
)) {
2489 session_clear_tty(tty
->session
);
2496 /* See the comment in tty_open(). */
2497 if ((file
->f_mode
& FMODE_READ
) == 0 && !capable(CAP_SYS_ADMIN
)) {
2504 read_unlock(&tasklist_lock
);
2510 * tty_get_pgrp - return a ref counted pgrp pid
2513 * Returns a refcounted instance of the pid struct for the process
2514 * group controlling the tty.
2517 struct pid
*tty_get_pgrp(struct tty_struct
*tty
)
2519 unsigned long flags
;
2522 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
2523 pgrp
= get_pid(tty
->pgrp
);
2524 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
2528 EXPORT_SYMBOL_GPL(tty_get_pgrp
);
2531 * This checks not only the pgrp, but falls back on the pid if no
2532 * satisfactory pgrp is found. I dunno - gdb doesn't work correctly
2535 * The caller must hold rcu lock or the tasklist lock.
2537 static struct pid
*session_of_pgrp(struct pid
*pgrp
)
2539 struct task_struct
*p
;
2540 struct pid
*sid
= NULL
;
2542 p
= pid_task(pgrp
, PIDTYPE_PGID
);
2544 p
= pid_task(pgrp
, PIDTYPE_PID
);
2546 sid
= task_session(p
);
2552 * tiocgpgrp - get process group
2553 * @tty: tty passed by user
2554 * @real_tty: tty side of the tty passed by the user if a pty else the tty
2557 * Obtain the process group of the tty. If there is no process group
2560 * Locking: none. Reference to current->signal->tty is safe.
2563 static int tiocgpgrp(struct tty_struct
*tty
, struct tty_struct
*real_tty
, pid_t __user
*p
)
2568 * (tty == real_tty) is a cheap way of
2569 * testing if the tty is NOT a master pty.
2571 if (tty
== real_tty
&& current
->signal
->tty
!= real_tty
)
2573 pid
= tty_get_pgrp(real_tty
);
2574 ret
= put_user(pid_vnr(pid
), p
);
2580 * tiocspgrp - attempt to set process group
2581 * @tty: tty passed by user
2582 * @real_tty: tty side device matching tty passed by user
2585 * Set the process group of the tty to the session passed. Only
2586 * permitted where the tty session is our session.
2588 * Locking: RCU, ctrl lock
2591 static int tiocspgrp(struct tty_struct
*tty
, struct tty_struct
*real_tty
, pid_t __user
*p
)
2595 int retval
= tty_check_change(real_tty
);
2601 if (!current
->signal
->tty
||
2602 (current
->signal
->tty
!= real_tty
) ||
2603 (real_tty
->session
!= task_session(current
)))
2605 if (get_user(pgrp_nr
, p
))
2610 pgrp
= find_vpid(pgrp_nr
);
2615 if (session_of_pgrp(pgrp
) != task_session(current
))
2618 spin_lock_irq(&tty
->ctrl_lock
);
2619 put_pid(real_tty
->pgrp
);
2620 real_tty
->pgrp
= get_pid(pgrp
);
2621 spin_unlock_irq(&tty
->ctrl_lock
);
2628 * tiocgsid - get session id
2629 * @tty: tty passed by user
2630 * @real_tty: tty side of the tty passed by the user if a pty else the tty
2631 * @p: pointer to returned session id
2633 * Obtain the session id of the tty. If there is no session
2636 * Locking: none. Reference to current->signal->tty is safe.
2639 static int tiocgsid(struct tty_struct
*tty
, struct tty_struct
*real_tty
, pid_t __user
*p
)
2642 * (tty == real_tty) is a cheap way of
2643 * testing if the tty is NOT a master pty.
2645 if (tty
== real_tty
&& current
->signal
->tty
!= real_tty
)
2647 if (!real_tty
->session
)
2649 return put_user(pid_vnr(real_tty
->session
), p
);
2653 * tiocsetd - set line discipline
2655 * @p: pointer to user data
2657 * Set the line discipline according to user request.
2659 * Locking: see tty_set_ldisc, this function is just a helper
2662 static int tiocsetd(struct tty_struct
*tty
, int __user
*p
)
2667 if (get_user(disc
, p
))
2670 ret
= tty_set_ldisc(tty
, disc
);
2676 * tiocgetd - get line discipline
2678 * @p: pointer to user data
2680 * Retrieves the line discipline id directly from the ldisc.
2682 * Locking: waits for ldisc reference (in case the line discipline
2683 * is changing or the tty is being hungup)
2686 static int tiocgetd(struct tty_struct
*tty
, int __user
*p
)
2688 struct tty_ldisc
*ld
;
2691 ld
= tty_ldisc_ref_wait(tty
);
2694 ret
= put_user(ld
->ops
->num
, p
);
2695 tty_ldisc_deref(ld
);
2700 * send_break - performed time break
2701 * @tty: device to break on
2702 * @duration: timeout in mS
2704 * Perform a timed break on hardware that lacks its own driver level
2705 * timed break functionality.
2708 * atomic_write_lock serializes
2712 static int send_break(struct tty_struct
*tty
, unsigned int duration
)
2716 if (tty
->ops
->break_ctl
== NULL
)
2719 if (tty
->driver
->flags
& TTY_DRIVER_HARDWARE_BREAK
)
2720 retval
= tty
->ops
->break_ctl(tty
, duration
);
2722 /* Do the work ourselves */
2723 if (tty_write_lock(tty
, 0) < 0)
2725 retval
= tty
->ops
->break_ctl(tty
, -1);
2728 if (!signal_pending(current
))
2729 msleep_interruptible(duration
);
2730 retval
= tty
->ops
->break_ctl(tty
, 0);
2732 tty_write_unlock(tty
);
2733 if (signal_pending(current
))
2740 * tty_tiocmget - get modem status
2742 * @file: user file pointer
2743 * @p: pointer to result
2745 * Obtain the modem status bits from the tty driver if the feature
2746 * is supported. Return -EINVAL if it is not available.
2748 * Locking: none (up to the driver)
2751 static int tty_tiocmget(struct tty_struct
*tty
, int __user
*p
)
2753 int retval
= -EINVAL
;
2755 if (tty
->ops
->tiocmget
) {
2756 retval
= tty
->ops
->tiocmget(tty
);
2759 retval
= put_user(retval
, p
);
2765 * tty_tiocmset - set modem status
2767 * @cmd: command - clear bits, set bits or set all
2768 * @p: pointer to desired bits
2770 * Set the modem status bits from the tty driver if the feature
2771 * is supported. Return -EINVAL if it is not available.
2773 * Locking: none (up to the driver)
2776 static int tty_tiocmset(struct tty_struct
*tty
, unsigned int cmd
,
2780 unsigned int set
, clear
, val
;
2782 if (tty
->ops
->tiocmset
== NULL
)
2785 retval
= get_user(val
, p
);
2801 set
&= TIOCM_DTR
|TIOCM_RTS
|TIOCM_OUT1
|TIOCM_OUT2
|TIOCM_LOOP
;
2802 clear
&= TIOCM_DTR
|TIOCM_RTS
|TIOCM_OUT1
|TIOCM_OUT2
|TIOCM_LOOP
;
2803 return tty
->ops
->tiocmset(tty
, set
, clear
);
2806 static int tty_tiocgicount(struct tty_struct
*tty
, void __user
*arg
)
2808 int retval
= -EINVAL
;
2809 struct serial_icounter_struct icount
;
2810 memset(&icount
, 0, sizeof(icount
));
2811 if (tty
->ops
->get_icount
)
2812 retval
= tty
->ops
->get_icount(tty
, &icount
);
2815 if (copy_to_user(arg
, &icount
, sizeof(icount
)))
2820 static void tty_warn_deprecated_flags(struct serial_struct __user
*ss
)
2822 static DEFINE_RATELIMIT_STATE(depr_flags
,
2823 DEFAULT_RATELIMIT_INTERVAL
,
2824 DEFAULT_RATELIMIT_BURST
);
2825 char comm
[TASK_COMM_LEN
];
2828 if (get_user(flags
, &ss
->flags
))
2831 flags
&= ASYNC_DEPRECATED
;
2833 if (flags
&& __ratelimit(&depr_flags
))
2834 pr_warning("%s: '%s' is using deprecated serial flags (with no effect): %.8x\n",
2835 __func__
, get_task_comm(comm
, current
), flags
);
2839 * if pty, return the slave side (real_tty)
2840 * otherwise, return self
2842 static struct tty_struct
*tty_pair_get_tty(struct tty_struct
*tty
)
2844 if (tty
->driver
->type
== TTY_DRIVER_TYPE_PTY
&&
2845 tty
->driver
->subtype
== PTY_TYPE_MASTER
)
2851 * Split this up, as gcc can choke on it otherwise..
2853 long tty_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
2855 struct tty_struct
*tty
= file_tty(file
);
2856 struct tty_struct
*real_tty
;
2857 void __user
*p
= (void __user
*)arg
;
2859 struct tty_ldisc
*ld
;
2861 if (tty_paranoia_check(tty
, file_inode(file
), "tty_ioctl"))
2864 real_tty
= tty_pair_get_tty(tty
);
2867 * Factor out some common prep work
2875 retval
= tty_check_change(tty
);
2878 if (cmd
!= TIOCCBRK
) {
2879 tty_wait_until_sent(tty
, 0);
2880 if (signal_pending(current
))
2891 return tiocsti(tty
, p
);
2893 return tiocgwinsz(real_tty
, p
);
2895 return tiocswinsz(real_tty
, p
);
2897 return real_tty
!= tty
? -EINVAL
: tioccons(file
);
2899 return fionbio(file
, p
);
2901 set_bit(TTY_EXCLUSIVE
, &tty
->flags
);
2904 clear_bit(TTY_EXCLUSIVE
, &tty
->flags
);
2908 int excl
= test_bit(TTY_EXCLUSIVE
, &tty
->flags
);
2909 return put_user(excl
, (int __user
*)p
);
2912 if (current
->signal
->tty
!= tty
)
2917 return tiocsctty(real_tty
, file
, arg
);
2919 return tiocgpgrp(tty
, real_tty
, p
);
2921 return tiocspgrp(tty
, real_tty
, p
);
2923 return tiocgsid(tty
, real_tty
, p
);
2925 return tiocgetd(tty
, p
);
2927 return tiocsetd(tty
, p
);
2929 if (!capable(CAP_SYS_ADMIN
))
2935 unsigned int ret
= new_encode_dev(tty_devnum(real_tty
));
2936 return put_user(ret
, (unsigned int __user
*)p
);
2941 case TIOCSBRK
: /* Turn break on, unconditionally */
2942 if (tty
->ops
->break_ctl
)
2943 return tty
->ops
->break_ctl(tty
, -1);
2945 case TIOCCBRK
: /* Turn break off, unconditionally */
2946 if (tty
->ops
->break_ctl
)
2947 return tty
->ops
->break_ctl(tty
, 0);
2949 case TCSBRK
: /* SVID version: non-zero arg --> no break */
2950 /* non-zero arg means wait for all output data
2951 * to be sent (performed above) but don't send break.
2952 * This is used by the tcdrain() termios function.
2955 return send_break(tty
, 250);
2957 case TCSBRKP
: /* support for POSIX tcsendbreak() */
2958 return send_break(tty
, arg
? arg
*100 : 250);
2961 return tty_tiocmget(tty
, p
);
2965 return tty_tiocmset(tty
, cmd
, p
);
2967 retval
= tty_tiocgicount(tty
, p
);
2968 /* For the moment allow fall through to the old method */
2969 if (retval
!= -EINVAL
)
2976 /* flush tty buffer and allow ldisc to process ioctl */
2977 tty_buffer_flush(tty
, NULL
);
2982 tty_warn_deprecated_flags(p
);
2985 if (tty
->ops
->ioctl
) {
2986 retval
= tty
->ops
->ioctl(tty
, cmd
, arg
);
2987 if (retval
!= -ENOIOCTLCMD
)
2990 ld
= tty_ldisc_ref_wait(tty
);
2992 return hung_up_tty_ioctl(file
, cmd
, arg
);
2994 if (ld
->ops
->ioctl
) {
2995 retval
= ld
->ops
->ioctl(tty
, file
, cmd
, arg
);
2996 if (retval
== -ENOIOCTLCMD
)
2999 tty_ldisc_deref(ld
);
3003 #ifdef CONFIG_COMPAT
3004 static long tty_compat_ioctl(struct file
*file
, unsigned int cmd
,
3007 struct tty_struct
*tty
= file_tty(file
);
3008 struct tty_ldisc
*ld
;
3009 int retval
= -ENOIOCTLCMD
;
3011 if (tty_paranoia_check(tty
, file_inode(file
), "tty_ioctl"))
3014 if (tty
->ops
->compat_ioctl
) {
3015 retval
= tty
->ops
->compat_ioctl(tty
, cmd
, arg
);
3016 if (retval
!= -ENOIOCTLCMD
)
3020 ld
= tty_ldisc_ref_wait(tty
);
3022 return hung_up_tty_compat_ioctl(file
, cmd
, arg
);
3023 if (ld
->ops
->compat_ioctl
)
3024 retval
= ld
->ops
->compat_ioctl(tty
, file
, cmd
, arg
);
3026 retval
= n_tty_compat_ioctl_helper(tty
, file
, cmd
, arg
);
3027 tty_ldisc_deref(ld
);
3033 static int this_tty(const void *t
, struct file
*file
, unsigned fd
)
3035 if (likely(file
->f_op
->read
!= tty_read
))
3037 return file_tty(file
) != t
? 0 : fd
+ 1;
3041 * This implements the "Secure Attention Key" --- the idea is to
3042 * prevent trojan horses by killing all processes associated with this
3043 * tty when the user hits the "Secure Attention Key". Required for
3044 * super-paranoid applications --- see the Orange Book for more details.
3046 * This code could be nicer; ideally it should send a HUP, wait a few
3047 * seconds, then send a INT, and then a KILL signal. But you then
3048 * have to coordinate with the init process, since all processes associated
3049 * with the current tty must be dead before the new getty is allowed
3052 * Now, if it would be correct ;-/ The current code has a nasty hole -
3053 * it doesn't catch files in flight. We may send the descriptor to ourselves
3054 * via AF_UNIX socket, close it and later fetch from socket. FIXME.
3056 * Nasty bug: do_SAK is being called in interrupt context. This can
3057 * deadlock. We punt it up to process context. AKPM - 16Mar2001
3059 void __do_SAK(struct tty_struct
*tty
)
3064 struct task_struct
*g
, *p
;
3065 struct pid
*session
;
3070 session
= tty
->session
;
3072 tty_ldisc_flush(tty
);
3074 tty_driver_flush_buffer(tty
);
3076 read_lock(&tasklist_lock
);
3077 /* Kill the entire session */
3078 do_each_pid_task(session
, PIDTYPE_SID
, p
) {
3079 tty_notice(tty
, "SAK: killed process %d (%s): by session\n",
3080 task_pid_nr(p
), p
->comm
);
3081 send_sig(SIGKILL
, p
, 1);
3082 } while_each_pid_task(session
, PIDTYPE_SID
, p
);
3084 /* Now kill any processes that happen to have the tty open */
3085 do_each_thread(g
, p
) {
3086 if (p
->signal
->tty
== tty
) {
3087 tty_notice(tty
, "SAK: killed process %d (%s): by controlling tty\n",
3088 task_pid_nr(p
), p
->comm
);
3089 send_sig(SIGKILL
, p
, 1);
3093 i
= iterate_fd(p
->files
, 0, this_tty
, tty
);
3095 tty_notice(tty
, "SAK: killed process %d (%s): by fd#%d\n",
3096 task_pid_nr(p
), p
->comm
, i
- 1);
3097 force_sig(SIGKILL
, p
);
3100 } while_each_thread(g
, p
);
3101 read_unlock(&tasklist_lock
);
3105 static void do_SAK_work(struct work_struct
*work
)
3107 struct tty_struct
*tty
=
3108 container_of(work
, struct tty_struct
, SAK_work
);
3113 * The tq handling here is a little racy - tty->SAK_work may already be queued.
3114 * Fortunately we don't need to worry, because if ->SAK_work is already queued,
3115 * the values which we write to it will be identical to the values which it
3116 * already has. --akpm
3118 void do_SAK(struct tty_struct
*tty
)
3122 schedule_work(&tty
->SAK_work
);
3125 EXPORT_SYMBOL(do_SAK
);
3127 static int dev_match_devt(struct device
*dev
, const void *data
)
3129 const dev_t
*devt
= data
;
3130 return dev
->devt
== *devt
;
3133 /* Must put_device() after it's unused! */
3134 static struct device
*tty_get_device(struct tty_struct
*tty
)
3136 dev_t devt
= tty_devnum(tty
);
3137 return class_find_device(tty_class
, NULL
, &devt
, dev_match_devt
);
3144 * This subroutine allocates and initializes a tty structure.
3146 * Locking: none - tty in question is not exposed at this point
3149 struct tty_struct
*alloc_tty_struct(struct tty_driver
*driver
, int idx
)
3151 struct tty_struct
*tty
;
3153 tty
= kzalloc(sizeof(*tty
), GFP_KERNEL
);
3157 kref_init(&tty
->kref
);
3158 tty
->magic
= TTY_MAGIC
;
3159 tty_ldisc_init(tty
);
3160 tty
->session
= NULL
;
3162 mutex_init(&tty
->legacy_mutex
);
3163 mutex_init(&tty
->throttle_mutex
);
3164 init_rwsem(&tty
->termios_rwsem
);
3165 mutex_init(&tty
->winsize_mutex
);
3166 init_ldsem(&tty
->ldisc_sem
);
3167 init_waitqueue_head(&tty
->write_wait
);
3168 init_waitqueue_head(&tty
->read_wait
);
3169 INIT_WORK(&tty
->hangup_work
, do_tty_hangup
);
3170 mutex_init(&tty
->atomic_write_lock
);
3171 spin_lock_init(&tty
->ctrl_lock
);
3172 spin_lock_init(&tty
->flow_lock
);
3173 INIT_LIST_HEAD(&tty
->tty_files
);
3174 INIT_WORK(&tty
->SAK_work
, do_SAK_work
);
3176 tty
->driver
= driver
;
3177 tty
->ops
= driver
->ops
;
3179 tty_line_name(driver
, idx
, tty
->name
);
3180 tty
->dev
= tty_get_device(tty
);
3186 * tty_put_char - write one character to a tty
3190 * Write one byte to the tty using the provided put_char method
3191 * if present. Returns the number of characters successfully output.
3193 * Note: the specific put_char operation in the driver layer may go
3194 * away soon. Don't call it directly, use this method
3197 int tty_put_char(struct tty_struct
*tty
, unsigned char ch
)
3199 if (tty
->ops
->put_char
)
3200 return tty
->ops
->put_char(tty
, ch
);
3201 return tty
->ops
->write(tty
, &ch
, 1);
3203 EXPORT_SYMBOL_GPL(tty_put_char
);
3205 struct class *tty_class
;
3207 static int tty_cdev_add(struct tty_driver
*driver
, dev_t dev
,
3208 unsigned int index
, unsigned int count
)
3212 /* init here, since reused cdevs cause crashes */
3213 driver
->cdevs
[index
] = cdev_alloc();
3214 if (!driver
->cdevs
[index
])
3216 driver
->cdevs
[index
]->ops
= &tty_fops
;
3217 driver
->cdevs
[index
]->owner
= driver
->owner
;
3218 err
= cdev_add(driver
->cdevs
[index
], dev
, count
);
3220 kobject_put(&driver
->cdevs
[index
]->kobj
);
3225 * tty_register_device - register a tty device
3226 * @driver: the tty driver that describes the tty device
3227 * @index: the index in the tty driver for this tty device
3228 * @device: a struct device that is associated with this tty device.
3229 * This field is optional, if there is no known struct device
3230 * for this tty device it can be set to NULL safely.
3232 * Returns a pointer to the struct device for this tty device
3233 * (or ERR_PTR(-EFOO) on error).
3235 * This call is required to be made to register an individual tty device
3236 * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If
3237 * that bit is not set, this function should not be called by a tty
3243 struct device
*tty_register_device(struct tty_driver
*driver
, unsigned index
,
3244 struct device
*device
)
3246 return tty_register_device_attr(driver
, index
, device
, NULL
, NULL
);
3248 EXPORT_SYMBOL(tty_register_device
);
3250 static void tty_device_create_release(struct device
*dev
)
3252 dev_dbg(dev
, "releasing...\n");
3257 * tty_register_device_attr - register a tty device
3258 * @driver: the tty driver that describes the tty device
3259 * @index: the index in the tty driver for this tty device
3260 * @device: a struct device that is associated with this tty device.
3261 * This field is optional, if there is no known struct device
3262 * for this tty device it can be set to NULL safely.
3263 * @drvdata: Driver data to be set to device.
3264 * @attr_grp: Attribute group to be set on device.
3266 * Returns a pointer to the struct device for this tty device
3267 * (or ERR_PTR(-EFOO) on error).
3269 * This call is required to be made to register an individual tty device
3270 * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If
3271 * that bit is not set, this function should not be called by a tty
3276 struct device
*tty_register_device_attr(struct tty_driver
*driver
,
3277 unsigned index
, struct device
*device
,
3279 const struct attribute_group
**attr_grp
)
3282 dev_t devt
= MKDEV(driver
->major
, driver
->minor_start
) + index
;
3283 struct device
*dev
= NULL
;
3284 int retval
= -ENODEV
;
3287 if (index
>= driver
->num
) {
3288 pr_err("%s: Attempt to register invalid tty line number (%d)\n",
3289 driver
->name
, index
);
3290 return ERR_PTR(-EINVAL
);
3293 if (driver
->type
== TTY_DRIVER_TYPE_PTY
)
3294 pty_line_name(driver
, index
, name
);
3296 tty_line_name(driver
, index
, name
);
3298 if (!(driver
->flags
& TTY_DRIVER_DYNAMIC_ALLOC
)) {
3299 retval
= tty_cdev_add(driver
, devt
, index
, 1);
3305 dev
= kzalloc(sizeof(*dev
), GFP_KERNEL
);
3312 dev
->class = tty_class
;
3313 dev
->parent
= device
;
3314 dev
->release
= tty_device_create_release
;
3315 dev_set_name(dev
, "%s", name
);
3316 dev
->groups
= attr_grp
;
3317 dev_set_drvdata(dev
, drvdata
);
3319 retval
= device_register(dev
);
3328 cdev_del(driver
->cdevs
[index
]);
3329 driver
->cdevs
[index
] = NULL
;
3331 return ERR_PTR(retval
);
3333 EXPORT_SYMBOL_GPL(tty_register_device_attr
);
3336 * tty_unregister_device - unregister a tty device
3337 * @driver: the tty driver that describes the tty device
3338 * @index: the index in the tty driver for this tty device
3340 * If a tty device is registered with a call to tty_register_device() then
3341 * this function must be called when the tty device is gone.
3346 void tty_unregister_device(struct tty_driver
*driver
, unsigned index
)
3348 device_destroy(tty_class
,
3349 MKDEV(driver
->major
, driver
->minor_start
) + index
);
3350 if (!(driver
->flags
& TTY_DRIVER_DYNAMIC_ALLOC
)) {
3351 cdev_del(driver
->cdevs
[index
]);
3352 driver
->cdevs
[index
] = NULL
;
3355 EXPORT_SYMBOL(tty_unregister_device
);
3358 * __tty_alloc_driver -- allocate tty driver
3359 * @lines: count of lines this driver can handle at most
3360 * @owner: module which is repsonsible for this driver
3361 * @flags: some of TTY_DRIVER_* flags, will be set in driver->flags
3363 * This should not be called directly, some of the provided macros should be
3364 * used instead. Use IS_ERR and friends on @retval.
3366 struct tty_driver
*__tty_alloc_driver(unsigned int lines
, struct module
*owner
,
3367 unsigned long flags
)
3369 struct tty_driver
*driver
;
3370 unsigned int cdevs
= 1;
3373 if (!lines
|| (flags
& TTY_DRIVER_UNNUMBERED_NODE
&& lines
> 1))
3374 return ERR_PTR(-EINVAL
);
3376 driver
= kzalloc(sizeof(struct tty_driver
), GFP_KERNEL
);
3378 return ERR_PTR(-ENOMEM
);
3380 kref_init(&driver
->kref
);
3381 driver
->magic
= TTY_DRIVER_MAGIC
;
3382 driver
->num
= lines
;
3383 driver
->owner
= owner
;
3384 driver
->flags
= flags
;
3386 if (!(flags
& TTY_DRIVER_DEVPTS_MEM
)) {
3387 driver
->ttys
= kcalloc(lines
, sizeof(*driver
->ttys
),
3389 driver
->termios
= kcalloc(lines
, sizeof(*driver
->termios
),
3391 if (!driver
->ttys
|| !driver
->termios
) {
3397 if (!(flags
& TTY_DRIVER_DYNAMIC_ALLOC
)) {
3398 driver
->ports
= kcalloc(lines
, sizeof(*driver
->ports
),
3400 if (!driver
->ports
) {
3407 driver
->cdevs
= kcalloc(cdevs
, sizeof(*driver
->cdevs
), GFP_KERNEL
);
3408 if (!driver
->cdevs
) {
3415 kfree(driver
->ports
);
3416 kfree(driver
->ttys
);
3417 kfree(driver
->termios
);
3418 kfree(driver
->cdevs
);
3420 return ERR_PTR(err
);
3422 EXPORT_SYMBOL(__tty_alloc_driver
);
3424 static void destruct_tty_driver(struct kref
*kref
)
3426 struct tty_driver
*driver
= container_of(kref
, struct tty_driver
, kref
);
3428 struct ktermios
*tp
;
3430 if (driver
->flags
& TTY_DRIVER_INSTALLED
) {
3432 * Free the termios and termios_locked structures because
3433 * we don't want to get memory leaks when modular tty
3434 * drivers are removed from the kernel.
3436 for (i
= 0; i
< driver
->num
; i
++) {
3437 tp
= driver
->termios
[i
];
3439 driver
->termios
[i
] = NULL
;
3442 if (!(driver
->flags
& TTY_DRIVER_DYNAMIC_DEV
))
3443 tty_unregister_device(driver
, i
);
3445 proc_tty_unregister_driver(driver
);
3446 if (driver
->flags
& TTY_DRIVER_DYNAMIC_ALLOC
)
3447 cdev_del(driver
->cdevs
[0]);
3449 kfree(driver
->cdevs
);
3450 kfree(driver
->ports
);
3451 kfree(driver
->termios
);
3452 kfree(driver
->ttys
);
3456 void tty_driver_kref_put(struct tty_driver
*driver
)
3458 kref_put(&driver
->kref
, destruct_tty_driver
);
3460 EXPORT_SYMBOL(tty_driver_kref_put
);
3462 void tty_set_operations(struct tty_driver
*driver
,
3463 const struct tty_operations
*op
)
3467 EXPORT_SYMBOL(tty_set_operations
);
3469 void put_tty_driver(struct tty_driver
*d
)
3471 tty_driver_kref_put(d
);
3473 EXPORT_SYMBOL(put_tty_driver
);
3476 * Called by a tty driver to register itself.
3478 int tty_register_driver(struct tty_driver
*driver
)
3485 if (!driver
->major
) {
3486 error
= alloc_chrdev_region(&dev
, driver
->minor_start
,
3487 driver
->num
, driver
->name
);
3489 driver
->major
= MAJOR(dev
);
3490 driver
->minor_start
= MINOR(dev
);
3493 dev
= MKDEV(driver
->major
, driver
->minor_start
);
3494 error
= register_chrdev_region(dev
, driver
->num
, driver
->name
);
3499 if (driver
->flags
& TTY_DRIVER_DYNAMIC_ALLOC
) {
3500 error
= tty_cdev_add(driver
, dev
, 0, driver
->num
);
3502 goto err_unreg_char
;
3505 mutex_lock(&tty_mutex
);
3506 list_add(&driver
->tty_drivers
, &tty_drivers
);
3507 mutex_unlock(&tty_mutex
);
3509 if (!(driver
->flags
& TTY_DRIVER_DYNAMIC_DEV
)) {
3510 for (i
= 0; i
< driver
->num
; i
++) {
3511 d
= tty_register_device(driver
, i
, NULL
);
3514 goto err_unreg_devs
;
3518 proc_tty_register_driver(driver
);
3519 driver
->flags
|= TTY_DRIVER_INSTALLED
;
3523 for (i
--; i
>= 0; i
--)
3524 tty_unregister_device(driver
, i
);
3526 mutex_lock(&tty_mutex
);
3527 list_del(&driver
->tty_drivers
);
3528 mutex_unlock(&tty_mutex
);
3531 unregister_chrdev_region(dev
, driver
->num
);
3535 EXPORT_SYMBOL(tty_register_driver
);
3538 * Called by a tty driver to unregister itself.
3540 int tty_unregister_driver(struct tty_driver
*driver
)
3544 if (driver
->refcount
)
3547 unregister_chrdev_region(MKDEV(driver
->major
, driver
->minor_start
),
3549 mutex_lock(&tty_mutex
);
3550 list_del(&driver
->tty_drivers
);
3551 mutex_unlock(&tty_mutex
);
3555 EXPORT_SYMBOL(tty_unregister_driver
);
3557 dev_t
tty_devnum(struct tty_struct
*tty
)
3559 return MKDEV(tty
->driver
->major
, tty
->driver
->minor_start
) + tty
->index
;
3561 EXPORT_SYMBOL(tty_devnum
);
3563 void tty_default_fops(struct file_operations
*fops
)
3569 * Initialize the console device. This is called *early*, so
3570 * we can't necessarily depend on lots of kernel help here.
3571 * Just do some early initializations, and do the complex setup
3574 void __init
console_init(void)
3578 /* Setup the default TTY line discipline. */
3582 * set up the console device so that later boot sequences can
3583 * inform about problems etc..
3585 call
= __con_initcall_start
;
3586 while (call
< __con_initcall_end
) {
3592 static char *tty_devnode(struct device
*dev
, umode_t
*mode
)
3596 if (dev
->devt
== MKDEV(TTYAUX_MAJOR
, 0) ||
3597 dev
->devt
== MKDEV(TTYAUX_MAJOR
, 2))
3602 static int __init
tty_class_init(void)
3604 tty_class
= class_create(THIS_MODULE
, "tty");
3605 if (IS_ERR(tty_class
))
3606 return PTR_ERR(tty_class
);
3607 tty_class
->devnode
= tty_devnode
;
3611 postcore_initcall(tty_class_init
);
3613 /* 3/2004 jmc: why do these devices exist? */
3614 static struct cdev tty_cdev
, console_cdev
;
3616 static ssize_t
show_cons_active(struct device
*dev
,
3617 struct device_attribute
*attr
, char *buf
)
3619 struct console
*cs
[16];
3625 for_each_console(c
) {
3630 if ((c
->flags
& CON_ENABLED
) == 0)
3633 if (i
>= ARRAY_SIZE(cs
))
3637 int index
= cs
[i
]->index
;
3638 struct tty_driver
*drv
= cs
[i
]->device(cs
[i
], &index
);
3640 /* don't resolve tty0 as some programs depend on it */
3641 if (drv
&& (cs
[i
]->index
> 0 || drv
->major
!= TTY_MAJOR
))
3642 count
+= tty_line_name(drv
, index
, buf
+ count
);
3644 count
+= sprintf(buf
+ count
, "%s%d",
3645 cs
[i
]->name
, cs
[i
]->index
);
3647 count
+= sprintf(buf
+ count
, "%c", i
? ' ':'\n');
3653 static DEVICE_ATTR(active
, S_IRUGO
, show_cons_active
, NULL
);
3655 static struct attribute
*cons_dev_attrs
[] = {
3656 &dev_attr_active
.attr
,
3660 ATTRIBUTE_GROUPS(cons_dev
);
3662 static struct device
*consdev
;
3664 void console_sysfs_notify(void)
3667 sysfs_notify(&consdev
->kobj
, NULL
, "active");
3671 * Ok, now we can initialize the rest of the tty devices and can count
3672 * on memory allocations, interrupts etc..
3674 int __init
tty_init(void)
3676 cdev_init(&tty_cdev
, &tty_fops
);
3677 if (cdev_add(&tty_cdev
, MKDEV(TTYAUX_MAJOR
, 0), 1) ||
3678 register_chrdev_region(MKDEV(TTYAUX_MAJOR
, 0), 1, "/dev/tty") < 0)
3679 panic("Couldn't register /dev/tty driver\n");
3680 device_create(tty_class
, NULL
, MKDEV(TTYAUX_MAJOR
, 0), NULL
, "tty");
3682 cdev_init(&console_cdev
, &console_fops
);
3683 if (cdev_add(&console_cdev
, MKDEV(TTYAUX_MAJOR
, 1), 1) ||
3684 register_chrdev_region(MKDEV(TTYAUX_MAJOR
, 1), 1, "/dev/console") < 0)
3685 panic("Couldn't register /dev/console driver\n");
3686 consdev
= device_create_with_groups(tty_class
, NULL
,
3687 MKDEV(TTYAUX_MAJOR
, 1), NULL
,
3688 cons_dev_groups
, "console");
3689 if (IS_ERR(consdev
))
3693 vty_init(&console_fops
);