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 * free_tty_struct - free a disused tty
161 * @tty: tty struct to free
163 * Free the write buffers, tty queue and tty memory itself.
165 * Locking: none. Must be called after tty is definitely unused
168 void free_tty_struct(struct tty_struct
*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
241 * @buf: buffer for output
243 * Convert a tty structure into a name. The name reflects the kernel
244 * naming policy and if udev is in use may not reflect user space
249 char *tty_name(struct tty_struct
*tty
, char *buf
)
251 if (!tty
) /* Hmm. NULL pointer. That's fun. */
252 strcpy(buf
, "NULL tty");
254 strcpy(buf
, tty
->name
);
258 EXPORT_SYMBOL(tty_name
);
260 int tty_paranoia_check(struct tty_struct
*tty
, struct inode
*inode
,
263 #ifdef TTY_PARANOIA_CHECK
266 "null TTY for (%d:%d) in %s\n",
267 imajor(inode
), iminor(inode
), routine
);
270 if (tty
->magic
!= TTY_MAGIC
) {
272 "bad magic number for tty struct (%d:%d) in %s\n",
273 imajor(inode
), iminor(inode
), routine
);
280 static int check_tty_count(struct tty_struct
*tty
, const char *routine
)
282 #ifdef CHECK_TTY_COUNT
286 spin_lock(&tty_files_lock
);
287 list_for_each(p
, &tty
->tty_files
) {
290 spin_unlock(&tty_files_lock
);
291 if (tty
->driver
->type
== TTY_DRIVER_TYPE_PTY
&&
292 tty
->driver
->subtype
== PTY_TYPE_SLAVE
&&
293 tty
->link
&& tty
->link
->count
)
295 if (tty
->count
!= count
) {
296 printk(KERN_WARNING
"Warning: dev (%s) tty->count(%d) "
297 "!= #fd's(%d) in %s\n",
298 tty
->name
, tty
->count
, count
, routine
);
306 * get_tty_driver - find device of a tty
307 * @dev_t: device identifier
308 * @index: returns the index of the tty
310 * This routine returns a tty driver structure, given a device number
311 * and also passes back the index number.
313 * Locking: caller must hold tty_mutex
316 static struct tty_driver
*get_tty_driver(dev_t device
, int *index
)
318 struct tty_driver
*p
;
320 list_for_each_entry(p
, &tty_drivers
, tty_drivers
) {
321 dev_t base
= MKDEV(p
->major
, p
->minor_start
);
322 if (device
< base
|| device
>= base
+ p
->num
)
324 *index
= device
- base
;
325 return tty_driver_kref_get(p
);
330 #ifdef CONFIG_CONSOLE_POLL
333 * tty_find_polling_driver - find device of a polled tty
334 * @name: name string to match
335 * @line: pointer to resulting tty line nr
337 * This routine returns a tty driver structure, given a name
338 * and the condition that the tty driver is capable of polled
341 struct tty_driver
*tty_find_polling_driver(char *name
, int *line
)
343 struct tty_driver
*p
, *res
= NULL
;
348 for (str
= name
; *str
; str
++)
349 if ((*str
>= '0' && *str
<= '9') || *str
== ',')
355 tty_line
= simple_strtoul(str
, &str
, 10);
357 mutex_lock(&tty_mutex
);
358 /* Search through the tty devices to look for a match */
359 list_for_each_entry(p
, &tty_drivers
, tty_drivers
) {
360 if (strncmp(name
, p
->name
, len
) != 0)
368 if (tty_line
>= 0 && tty_line
< p
->num
&& p
->ops
&&
369 p
->ops
->poll_init
&& !p
->ops
->poll_init(p
, tty_line
, stp
)) {
370 res
= tty_driver_kref_get(p
);
375 mutex_unlock(&tty_mutex
);
379 EXPORT_SYMBOL_GPL(tty_find_polling_driver
);
383 * tty_check_change - check for POSIX terminal changes
386 * If we try to write to, or set the state of, a terminal and we're
387 * not in the foreground, send a SIGTTOU. If the signal is blocked or
388 * ignored, go ahead and perform the operation. (POSIX 7.2)
393 int tty_check_change(struct tty_struct
*tty
)
398 if (current
->signal
->tty
!= tty
)
401 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
404 printk(KERN_WARNING
"tty_check_change: tty->pgrp == NULL!\n");
407 if (task_pgrp(current
) == tty
->pgrp
)
409 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
410 if (is_ignored(SIGTTOU
))
412 if (is_current_pgrp_orphaned()) {
416 kill_pgrp(task_pgrp(current
), SIGTTOU
, 1);
417 set_thread_flag(TIF_SIGPENDING
);
422 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
426 EXPORT_SYMBOL(tty_check_change
);
428 static ssize_t
hung_up_tty_read(struct file
*file
, char __user
*buf
,
429 size_t count
, loff_t
*ppos
)
434 static ssize_t
hung_up_tty_write(struct file
*file
, const char __user
*buf
,
435 size_t count
, loff_t
*ppos
)
440 /* No kernel lock held - none needed ;) */
441 static unsigned int hung_up_tty_poll(struct file
*filp
, poll_table
*wait
)
443 return POLLIN
| POLLOUT
| POLLERR
| POLLHUP
| POLLRDNORM
| POLLWRNORM
;
446 static long hung_up_tty_ioctl(struct file
*file
, unsigned int cmd
,
449 return cmd
== TIOCSPGRP
? -ENOTTY
: -EIO
;
452 static long hung_up_tty_compat_ioctl(struct file
*file
,
453 unsigned int cmd
, unsigned long arg
)
455 return cmd
== TIOCSPGRP
? -ENOTTY
: -EIO
;
458 static const struct file_operations tty_fops
= {
463 .unlocked_ioctl
= tty_ioctl
,
464 .compat_ioctl
= tty_compat_ioctl
,
466 .release
= tty_release
,
467 .fasync
= tty_fasync
,
470 static const struct file_operations console_fops
= {
473 .write
= redirected_tty_write
,
475 .unlocked_ioctl
= tty_ioctl
,
476 .compat_ioctl
= tty_compat_ioctl
,
478 .release
= tty_release
,
479 .fasync
= tty_fasync
,
482 static const struct file_operations hung_up_tty_fops
= {
484 .read
= hung_up_tty_read
,
485 .write
= hung_up_tty_write
,
486 .poll
= hung_up_tty_poll
,
487 .unlocked_ioctl
= hung_up_tty_ioctl
,
488 .compat_ioctl
= hung_up_tty_compat_ioctl
,
489 .release
= tty_release
,
492 static DEFINE_SPINLOCK(redirect_lock
);
493 static struct file
*redirect
;
496 * tty_wakeup - request more data
499 * Internal and external helper for wakeups of tty. This function
500 * informs the line discipline if present that the driver is ready
501 * to receive more output data.
504 void tty_wakeup(struct tty_struct
*tty
)
506 struct tty_ldisc
*ld
;
508 if (test_bit(TTY_DO_WRITE_WAKEUP
, &tty
->flags
)) {
509 ld
= tty_ldisc_ref(tty
);
511 if (ld
->ops
->write_wakeup
)
512 ld
->ops
->write_wakeup(tty
);
516 wake_up_interruptible_poll(&tty
->write_wait
, POLLOUT
);
519 EXPORT_SYMBOL_GPL(tty_wakeup
);
522 * tty_signal_session_leader - sends SIGHUP to session leader
523 * @tty controlling tty
524 * @exit_session if non-zero, signal all foreground group processes
526 * Send SIGHUP and SIGCONT to the session leader and its process group.
527 * Optionally, signal all processes in the foreground process group.
529 * Returns the number of processes in the session with this tty
530 * as their controlling terminal. This value is used to drop
531 * tty references for those processes.
533 static int tty_signal_session_leader(struct tty_struct
*tty
, int exit_session
)
535 struct task_struct
*p
;
537 struct pid
*tty_pgrp
= NULL
;
539 read_lock(&tasklist_lock
);
541 do_each_pid_task(tty
->session
, PIDTYPE_SID
, p
) {
542 spin_lock_irq(&p
->sighand
->siglock
);
543 if (p
->signal
->tty
== tty
) {
544 p
->signal
->tty
= NULL
;
545 /* We defer the dereferences outside fo
549 if (!p
->signal
->leader
) {
550 spin_unlock_irq(&p
->sighand
->siglock
);
553 __group_send_sig_info(SIGHUP
, SEND_SIG_PRIV
, p
);
554 __group_send_sig_info(SIGCONT
, SEND_SIG_PRIV
, p
);
555 put_pid(p
->signal
->tty_old_pgrp
); /* A noop */
556 spin_lock(&tty
->ctrl_lock
);
557 tty_pgrp
= get_pid(tty
->pgrp
);
559 p
->signal
->tty_old_pgrp
= get_pid(tty
->pgrp
);
560 spin_unlock(&tty
->ctrl_lock
);
561 spin_unlock_irq(&p
->sighand
->siglock
);
562 } while_each_pid_task(tty
->session
, PIDTYPE_SID
, p
);
564 read_unlock(&tasklist_lock
);
568 kill_pgrp(tty_pgrp
, SIGHUP
, exit_session
);
576 * __tty_hangup - actual handler for hangup events
579 * This can be called by a "kworker" kernel thread. That is process
580 * synchronous but doesn't hold any locks, so we need to make sure we
581 * have the appropriate locks for what we're doing.
583 * The hangup event clears any pending redirections onto the hung up
584 * device. It ensures future writes will error and it does the needed
585 * line discipline hangup and signal delivery. The tty object itself
590 * redirect lock for undoing redirection
591 * file list lock for manipulating list of ttys
592 * tty_ldiscs_lock from called functions
593 * termios_rwsem resetting termios data
594 * tasklist_lock to walk task list for hangup event
595 * ->siglock to protect ->signal/->sighand
597 static void __tty_hangup(struct tty_struct
*tty
, int exit_session
)
599 struct file
*cons_filp
= NULL
;
600 struct file
*filp
, *f
= NULL
;
601 struct tty_file_private
*priv
;
602 int closecount
= 0, n
;
609 spin_lock(&redirect_lock
);
610 if (redirect
&& file_tty(redirect
) == tty
) {
614 spin_unlock(&redirect_lock
);
618 if (test_bit(TTY_HUPPED
, &tty
->flags
)) {
623 /* some functions below drop BTM, so we need this bit */
624 set_bit(TTY_HUPPING
, &tty
->flags
);
626 /* inuse_filps is protected by the single tty lock,
627 this really needs to change if we want to flush the
628 workqueue with the lock held */
629 check_tty_count(tty
, "tty_hangup");
631 spin_lock(&tty_files_lock
);
632 /* This breaks for file handles being sent over AF_UNIX sockets ? */
633 list_for_each_entry(priv
, &tty
->tty_files
, list
) {
635 if (filp
->f_op
->write
== redirected_tty_write
)
637 if (filp
->f_op
->write
!= tty_write
)
640 __tty_fasync(-1, filp
, 0); /* can't block */
641 filp
->f_op
= &hung_up_tty_fops
;
643 spin_unlock(&tty_files_lock
);
645 refs
= tty_signal_session_leader(tty
, exit_session
);
646 /* Account for the p->signal references we killed */
651 * it drops BTM and thus races with reopen
652 * we protect the race by TTY_HUPPING
654 tty_ldisc_hangup(tty
);
656 spin_lock_irq(&tty
->ctrl_lock
);
657 clear_bit(TTY_THROTTLED
, &tty
->flags
);
658 clear_bit(TTY_DO_WRITE_WAKEUP
, &tty
->flags
);
659 put_pid(tty
->session
);
663 tty
->ctrl_status
= 0;
664 spin_unlock_irq(&tty
->ctrl_lock
);
667 * If one of the devices matches a console pointer, we
668 * cannot just call hangup() because that will cause
669 * tty->count and state->count to go out of sync.
670 * So we just call close() the right number of times.
674 for (n
= 0; n
< closecount
; n
++)
675 tty
->ops
->close(tty
, cons_filp
);
676 } else if (tty
->ops
->hangup
)
677 tty
->ops
->hangup(tty
);
679 * We don't want to have driver/ldisc interactions beyond
680 * the ones we did here. The driver layer expects no
681 * calls after ->hangup() from the ldisc side. However we
682 * can't yet guarantee all that.
684 set_bit(TTY_HUPPED
, &tty
->flags
);
685 clear_bit(TTY_HUPPING
, &tty
->flags
);
693 static void do_tty_hangup(struct work_struct
*work
)
695 struct tty_struct
*tty
=
696 container_of(work
, struct tty_struct
, hangup_work
);
698 __tty_hangup(tty
, 0);
702 * tty_hangup - trigger a hangup event
703 * @tty: tty to hangup
705 * A carrier loss (virtual or otherwise) has occurred on this like
706 * schedule a hangup sequence to run after this event.
709 void tty_hangup(struct tty_struct
*tty
)
711 #ifdef TTY_DEBUG_HANGUP
713 printk(KERN_DEBUG
"%s hangup...\n", tty_name(tty
, buf
));
715 schedule_work(&tty
->hangup_work
);
718 EXPORT_SYMBOL(tty_hangup
);
721 * tty_vhangup - process vhangup
722 * @tty: tty to hangup
724 * The user has asked via system call for the terminal to be hung up.
725 * We do this synchronously so that when the syscall returns the process
726 * is complete. That guarantee is necessary for security reasons.
729 void tty_vhangup(struct tty_struct
*tty
)
731 #ifdef TTY_DEBUG_HANGUP
734 printk(KERN_DEBUG
"%s vhangup...\n", tty_name(tty
, buf
));
736 __tty_hangup(tty
, 0);
739 EXPORT_SYMBOL(tty_vhangup
);
743 * tty_vhangup_self - process vhangup for own ctty
745 * Perform a vhangup on the current controlling tty
748 void tty_vhangup_self(void)
750 struct tty_struct
*tty
;
752 tty
= get_current_tty();
760 * tty_vhangup_session - hangup session leader exit
761 * @tty: tty to hangup
763 * The session leader is exiting and hanging up its controlling terminal.
764 * Every process in the foreground process group is signalled SIGHUP.
766 * We do this synchronously so that when the syscall returns the process
767 * is complete. That guarantee is necessary for security reasons.
770 static void tty_vhangup_session(struct tty_struct
*tty
)
772 #ifdef TTY_DEBUG_HANGUP
775 printk(KERN_DEBUG
"%s vhangup session...\n", tty_name(tty
, buf
));
777 __tty_hangup(tty
, 1);
781 * tty_hung_up_p - was tty hung up
782 * @filp: file pointer of tty
784 * Return true if the tty has been subject to a vhangup or a carrier
788 int tty_hung_up_p(struct file
*filp
)
790 return (filp
->f_op
== &hung_up_tty_fops
);
793 EXPORT_SYMBOL(tty_hung_up_p
);
795 static void session_clear_tty(struct pid
*session
)
797 struct task_struct
*p
;
798 do_each_pid_task(session
, PIDTYPE_SID
, p
) {
800 } while_each_pid_task(session
, PIDTYPE_SID
, p
);
804 * disassociate_ctty - disconnect controlling tty
805 * @on_exit: true if exiting so need to "hang up" the session
807 * This function is typically called only by the session leader, when
808 * it wants to disassociate itself from its controlling tty.
810 * It performs the following functions:
811 * (1) Sends a SIGHUP and SIGCONT to the foreground process group
812 * (2) Clears the tty from being controlling the session
813 * (3) Clears the controlling tty for all processes in the
816 * The argument on_exit is set to 1 if called when a process is
817 * exiting; it is 0 if called by the ioctl TIOCNOTTY.
820 * BTM is taken for hysterical raisins, and held when
821 * called from no_tty().
822 * tty_mutex is taken to protect tty
823 * ->siglock is taken to protect ->signal/->sighand
824 * tasklist_lock is taken to walk process list for sessions
825 * ->siglock is taken to protect ->signal/->sighand
828 void disassociate_ctty(int on_exit
)
830 struct tty_struct
*tty
;
832 if (!current
->signal
->leader
)
835 tty
= get_current_tty();
837 if (on_exit
&& tty
->driver
->type
!= TTY_DRIVER_TYPE_PTY
) {
838 tty_vhangup_session(tty
);
840 struct pid
*tty_pgrp
= tty_get_pgrp(tty
);
842 kill_pgrp(tty_pgrp
, SIGHUP
, on_exit
);
844 kill_pgrp(tty_pgrp
, SIGCONT
, on_exit
);
850 } else if (on_exit
) {
851 struct pid
*old_pgrp
;
852 spin_lock_irq(¤t
->sighand
->siglock
);
853 old_pgrp
= current
->signal
->tty_old_pgrp
;
854 current
->signal
->tty_old_pgrp
= NULL
;
855 spin_unlock_irq(¤t
->sighand
->siglock
);
857 kill_pgrp(old_pgrp
, SIGHUP
, on_exit
);
858 kill_pgrp(old_pgrp
, SIGCONT
, on_exit
);
864 spin_lock_irq(¤t
->sighand
->siglock
);
865 put_pid(current
->signal
->tty_old_pgrp
);
866 current
->signal
->tty_old_pgrp
= NULL
;
868 tty
= tty_kref_get(current
->signal
->tty
);
871 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
872 put_pid(tty
->session
);
876 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
879 #ifdef TTY_DEBUG_HANGUP
880 printk(KERN_DEBUG
"error attempted to write to tty [0x%p]"
885 spin_unlock_irq(¤t
->sighand
->siglock
);
886 /* Now clear signal->tty under the lock */
887 read_lock(&tasklist_lock
);
888 session_clear_tty(task_session(current
));
889 read_unlock(&tasklist_lock
);
894 * no_tty - Ensure the current process does not have a controlling tty
898 /* FIXME: Review locking here. The tty_lock never covered any race
899 between a new association and proc_clear_tty but possible we need
900 to protect against this anyway */
901 struct task_struct
*tsk
= current
;
902 disassociate_ctty(0);
908 * stop_tty - propagate flow control
911 * Perform flow control to the driver. May be called
912 * on an already stopped device and will not re-call the driver
915 * This functionality is used by both the line disciplines for
916 * halting incoming flow and by the driver. It may therefore be
917 * called from any context, may be under the tty atomic_write_lock
924 void __stop_tty(struct tty_struct
*tty
)
930 (tty
->ops
->stop
)(tty
);
933 void stop_tty(struct tty_struct
*tty
)
937 spin_lock_irqsave(&tty
->flow_lock
, flags
);
939 spin_unlock_irqrestore(&tty
->flow_lock
, flags
);
941 EXPORT_SYMBOL(stop_tty
);
944 * start_tty - propagate flow control
947 * Start a tty that has been stopped if at all possible. If this
948 * tty was previous stopped and is now being started, the driver
949 * start method is invoked and the line discipline woken.
955 void __start_tty(struct tty_struct
*tty
)
957 if (!tty
->stopped
|| tty
->flow_stopped
)
961 (tty
->ops
->start
)(tty
);
965 void start_tty(struct tty_struct
*tty
)
969 spin_lock_irqsave(&tty
->flow_lock
, flags
);
971 spin_unlock_irqrestore(&tty
->flow_lock
, flags
);
973 EXPORT_SYMBOL(start_tty
);
975 /* We limit tty time update visibility to every 8 seconds or so. */
976 static void tty_update_time(struct timespec
*time
)
978 unsigned long sec
= get_seconds() & ~7;
979 if ((long)(sec
- time
->tv_sec
) > 0)
984 * tty_read - read method for tty device files
985 * @file: pointer to tty file
987 * @count: size of user buffer
990 * Perform the read system call function on this terminal device. Checks
991 * for hung up devices before calling the line discipline method.
994 * Locks the line discipline internally while needed. Multiple
995 * read calls may be outstanding in parallel.
998 static ssize_t
tty_read(struct file
*file
, char __user
*buf
, size_t count
,
1002 struct inode
*inode
= file_inode(file
);
1003 struct tty_struct
*tty
= file_tty(file
);
1004 struct tty_ldisc
*ld
;
1006 if (tty_paranoia_check(tty
, inode
, "tty_read"))
1008 if (!tty
|| (test_bit(TTY_IO_ERROR
, &tty
->flags
)))
1011 /* We want to wait for the line discipline to sort out in this
1013 ld
= tty_ldisc_ref_wait(tty
);
1015 i
= (ld
->ops
->read
)(tty
, file
, buf
, count
);
1018 tty_ldisc_deref(ld
);
1021 tty_update_time(&inode
->i_atime
);
1026 static void tty_write_unlock(struct tty_struct
*tty
)
1027 __releases(&tty
->atomic_write_lock
)
1029 mutex_unlock(&tty
->atomic_write_lock
);
1030 wake_up_interruptible_poll(&tty
->write_wait
, POLLOUT
);
1033 static int tty_write_lock(struct tty_struct
*tty
, int ndelay
)
1034 __acquires(&tty
->atomic_write_lock
)
1036 if (!mutex_trylock(&tty
->atomic_write_lock
)) {
1039 if (mutex_lock_interruptible(&tty
->atomic_write_lock
))
1040 return -ERESTARTSYS
;
1046 * Split writes up in sane blocksizes to avoid
1047 * denial-of-service type attacks
1049 static inline ssize_t
do_tty_write(
1050 ssize_t (*write
)(struct tty_struct
*, struct file
*, const unsigned char *, size_t),
1051 struct tty_struct
*tty
,
1053 const char __user
*buf
,
1056 ssize_t ret
, written
= 0;
1059 ret
= tty_write_lock(tty
, file
->f_flags
& O_NDELAY
);
1064 * We chunk up writes into a temporary buffer. This
1065 * simplifies low-level drivers immensely, since they
1066 * don't have locking issues and user mode accesses.
1068 * But if TTY_NO_WRITE_SPLIT is set, we should use a
1071 * The default chunk-size is 2kB, because the NTTY
1072 * layer has problems with bigger chunks. It will
1073 * claim to be able to handle more characters than
1076 * FIXME: This can probably go away now except that 64K chunks
1077 * are too likely to fail unless switched to vmalloc...
1080 if (test_bit(TTY_NO_WRITE_SPLIT
, &tty
->flags
))
1085 /* write_buf/write_cnt is protected by the atomic_write_lock mutex */
1086 if (tty
->write_cnt
< chunk
) {
1087 unsigned char *buf_chunk
;
1092 buf_chunk
= kmalloc(chunk
, GFP_KERNEL
);
1097 kfree(tty
->write_buf
);
1098 tty
->write_cnt
= chunk
;
1099 tty
->write_buf
= buf_chunk
;
1102 /* Do the write .. */
1104 size_t size
= count
;
1108 if (copy_from_user(tty
->write_buf
, buf
, size
))
1110 ret
= write(tty
, file
, tty
->write_buf
, size
);
1119 if (signal_pending(current
))
1124 tty_update_time(&file_inode(file
)->i_mtime
);
1128 tty_write_unlock(tty
);
1133 * tty_write_message - write a message to a certain tty, not just the console.
1134 * @tty: the destination tty_struct
1135 * @msg: the message to write
1137 * This is used for messages that need to be redirected to a specific tty.
1138 * We don't put it into the syslog queue right now maybe in the future if
1141 * We must still hold the BTM and test the CLOSING flag for the moment.
1144 void tty_write_message(struct tty_struct
*tty
, char *msg
)
1147 mutex_lock(&tty
->atomic_write_lock
);
1149 if (tty
->ops
->write
&& !test_bit(TTY_CLOSING
, &tty
->flags
)) {
1151 tty
->ops
->write(tty
, msg
, strlen(msg
));
1154 tty_write_unlock(tty
);
1161 * tty_write - write method for tty device file
1162 * @file: tty file pointer
1163 * @buf: user data to write
1164 * @count: bytes to write
1167 * Write data to a tty device via the line discipline.
1170 * Locks the line discipline as required
1171 * Writes to the tty driver are serialized by the atomic_write_lock
1172 * and are then processed in chunks to the device. The line discipline
1173 * write method will not be invoked in parallel for each device.
1176 static ssize_t
tty_write(struct file
*file
, const char __user
*buf
,
1177 size_t count
, loff_t
*ppos
)
1179 struct tty_struct
*tty
= file_tty(file
);
1180 struct tty_ldisc
*ld
;
1183 if (tty_paranoia_check(tty
, file_inode(file
), "tty_write"))
1185 if (!tty
|| !tty
->ops
->write
||
1186 (test_bit(TTY_IO_ERROR
, &tty
->flags
)))
1188 /* Short term debug to catch buggy drivers */
1189 if (tty
->ops
->write_room
== NULL
)
1190 printk(KERN_ERR
"tty driver %s lacks a write_room method.\n",
1192 ld
= tty_ldisc_ref_wait(tty
);
1193 if (!ld
->ops
->write
)
1196 ret
= do_tty_write(ld
->ops
->write
, tty
, file
, buf
, count
);
1197 tty_ldisc_deref(ld
);
1201 ssize_t
redirected_tty_write(struct file
*file
, const char __user
*buf
,
1202 size_t count
, loff_t
*ppos
)
1204 struct file
*p
= NULL
;
1206 spin_lock(&redirect_lock
);
1208 p
= get_file(redirect
);
1209 spin_unlock(&redirect_lock
);
1213 res
= vfs_write(p
, buf
, count
, &p
->f_pos
);
1217 return tty_write(file
, buf
, count
, ppos
);
1221 * tty_send_xchar - send priority character
1223 * Send a high priority character to the tty even if stopped
1225 * Locking: none for xchar method, write ordering for write method.
1228 int tty_send_xchar(struct tty_struct
*tty
, char ch
)
1230 int was_stopped
= tty
->stopped
;
1232 if (tty
->ops
->send_xchar
) {
1233 tty
->ops
->send_xchar(tty
, ch
);
1237 if (tty_write_lock(tty
, 0) < 0)
1238 return -ERESTARTSYS
;
1242 tty
->ops
->write(tty
, &ch
, 1);
1245 tty_write_unlock(tty
);
1249 static char ptychar
[] = "pqrstuvwxyzabcde";
1252 * pty_line_name - generate name for a pty
1253 * @driver: the tty driver in use
1254 * @index: the minor number
1255 * @p: output buffer of at least 6 bytes
1257 * Generate a name from a driver reference and write it to the output
1262 static void pty_line_name(struct tty_driver
*driver
, int index
, char *p
)
1264 int i
= index
+ driver
->name_base
;
1265 /* ->name is initialized to "ttyp", but "tty" is expected */
1266 sprintf(p
, "%s%c%x",
1267 driver
->subtype
== PTY_TYPE_SLAVE
? "tty" : driver
->name
,
1268 ptychar
[i
>> 4 & 0xf], i
& 0xf);
1272 * tty_line_name - generate name for a tty
1273 * @driver: the tty driver in use
1274 * @index: the minor number
1275 * @p: output buffer of at least 7 bytes
1277 * Generate a name from a driver reference and write it to the output
1282 static ssize_t
tty_line_name(struct tty_driver
*driver
, int index
, char *p
)
1284 if (driver
->flags
& TTY_DRIVER_UNNUMBERED_NODE
)
1285 return sprintf(p
, "%s", driver
->name
);
1287 return sprintf(p
, "%s%d", driver
->name
,
1288 index
+ driver
->name_base
);
1292 * tty_driver_lookup_tty() - find an existing tty, if any
1293 * @driver: the driver for the tty
1294 * @idx: the minor number
1296 * Return the tty, if found or ERR_PTR() otherwise.
1298 * Locking: tty_mutex must be held. If tty is found, the mutex must
1299 * be held until the 'fast-open' is also done. Will change once we
1300 * have refcounting in the driver and per driver locking
1302 static struct tty_struct
*tty_driver_lookup_tty(struct tty_driver
*driver
,
1303 struct inode
*inode
, int idx
)
1305 if (driver
->ops
->lookup
)
1306 return driver
->ops
->lookup(driver
, inode
, idx
);
1308 return driver
->ttys
[idx
];
1312 * tty_init_termios - helper for termios setup
1313 * @tty: the tty to set up
1315 * Initialise the termios structures for this tty. Thus runs under
1316 * the tty_mutex currently so we can be relaxed about ordering.
1319 int tty_init_termios(struct tty_struct
*tty
)
1321 struct ktermios
*tp
;
1322 int idx
= tty
->index
;
1324 if (tty
->driver
->flags
& TTY_DRIVER_RESET_TERMIOS
)
1325 tty
->termios
= tty
->driver
->init_termios
;
1327 /* Check for lazy saved data */
1328 tp
= tty
->driver
->termios
[idx
];
1332 tty
->termios
= tty
->driver
->init_termios
;
1334 /* Compatibility until drivers always set this */
1335 tty
->termios
.c_ispeed
= tty_termios_input_baud_rate(&tty
->termios
);
1336 tty
->termios
.c_ospeed
= tty_termios_baud_rate(&tty
->termios
);
1339 EXPORT_SYMBOL_GPL(tty_init_termios
);
1341 int tty_standard_install(struct tty_driver
*driver
, struct tty_struct
*tty
)
1343 int ret
= tty_init_termios(tty
);
1347 tty_driver_kref_get(driver
);
1349 driver
->ttys
[tty
->index
] = tty
;
1352 EXPORT_SYMBOL_GPL(tty_standard_install
);
1355 * tty_driver_install_tty() - install a tty entry in the driver
1356 * @driver: the driver for the tty
1359 * Install a tty object into the driver tables. The tty->index field
1360 * will be set by the time this is called. This method is responsible
1361 * for ensuring any need additional structures are allocated and
1364 * Locking: tty_mutex for now
1366 static int tty_driver_install_tty(struct tty_driver
*driver
,
1367 struct tty_struct
*tty
)
1369 return driver
->ops
->install
? driver
->ops
->install(driver
, tty
) :
1370 tty_standard_install(driver
, tty
);
1374 * tty_driver_remove_tty() - remove a tty from the driver tables
1375 * @driver: the driver for the tty
1376 * @idx: the minor number
1378 * Remvoe a tty object from the driver tables. The tty->index field
1379 * will be set by the time this is called.
1381 * Locking: tty_mutex for now
1383 void tty_driver_remove_tty(struct tty_driver
*driver
, struct tty_struct
*tty
)
1385 if (driver
->ops
->remove
)
1386 driver
->ops
->remove(driver
, tty
);
1388 driver
->ttys
[tty
->index
] = NULL
;
1392 * tty_reopen() - fast re-open of an open tty
1393 * @tty - the tty to open
1395 * Return 0 on success, -errno on error.
1397 * Locking: tty_mutex must be held from the time the tty was found
1398 * till this open completes.
1400 static int tty_reopen(struct tty_struct
*tty
)
1402 struct tty_driver
*driver
= tty
->driver
;
1404 if (test_bit(TTY_CLOSING
, &tty
->flags
) ||
1405 test_bit(TTY_HUPPING
, &tty
->flags
))
1408 if (driver
->type
== TTY_DRIVER_TYPE_PTY
&&
1409 driver
->subtype
== PTY_TYPE_MASTER
) {
1411 * special case for PTY masters: only one open permitted,
1412 * and the slave side open count is incremented as well.
1421 WARN_ON(!tty
->ldisc
);
1427 * tty_init_dev - initialise a tty device
1428 * @driver: tty driver we are opening a device on
1429 * @idx: device index
1430 * @ret_tty: returned tty structure
1432 * Prepare a tty device. This may not be a "new" clean device but
1433 * could also be an active device. The pty drivers require special
1434 * handling because of this.
1437 * The function is called under the tty_mutex, which
1438 * protects us from the tty struct or driver itself going away.
1440 * On exit the tty device has the line discipline attached and
1441 * a reference count of 1. If a pair was created for pty/tty use
1442 * and the other was a pty master then it too has a reference count of 1.
1444 * WSH 06/09/97: Rewritten to remove races and properly clean up after a
1445 * failed open. The new code protects the open with a mutex, so it's
1446 * really quite straightforward. The mutex locking can probably be
1447 * relaxed for the (most common) case of reopening a tty.
1450 struct tty_struct
*tty_init_dev(struct tty_driver
*driver
, int idx
)
1452 struct tty_struct
*tty
;
1456 * First time open is complex, especially for PTY devices.
1457 * This code guarantees that either everything succeeds and the
1458 * TTY is ready for operation, or else the table slots are vacated
1459 * and the allocated memory released. (Except that the termios
1460 * and locked termios may be retained.)
1463 if (!try_module_get(driver
->owner
))
1464 return ERR_PTR(-ENODEV
);
1466 tty
= alloc_tty_struct(driver
, idx
);
1469 goto err_module_put
;
1473 retval
= tty_driver_install_tty(driver
, tty
);
1475 goto err_deinit_tty
;
1478 tty
->port
= driver
->ports
[idx
];
1480 WARN_RATELIMIT(!tty
->port
,
1481 "%s: %s driver does not set tty->port. This will crash the kernel later. Fix the driver!\n",
1482 __func__
, tty
->driver
->name
);
1484 tty
->port
->itty
= tty
;
1487 * Structures all installed ... call the ldisc open routines.
1488 * If we fail here just call release_tty to clean up. No need
1489 * to decrement the use counts, as release_tty doesn't care.
1491 retval
= tty_ldisc_setup(tty
, tty
->link
);
1493 goto err_release_tty
;
1494 /* Return the tty locked so that it cannot vanish under the caller */
1499 deinitialize_tty_struct(tty
);
1500 free_tty_struct(tty
);
1502 module_put(driver
->owner
);
1503 return ERR_PTR(retval
);
1505 /* call the tty release_tty routine to clean out this slot */
1508 printk_ratelimited(KERN_INFO
"tty_init_dev: ldisc open failed, "
1509 "clearing slot %d\n", idx
);
1510 release_tty(tty
, idx
);
1511 return ERR_PTR(retval
);
1514 void tty_free_termios(struct tty_struct
*tty
)
1516 struct ktermios
*tp
;
1517 int idx
= tty
->index
;
1519 /* If the port is going to reset then it has no termios to save */
1520 if (tty
->driver
->flags
& TTY_DRIVER_RESET_TERMIOS
)
1523 /* Stash the termios data */
1524 tp
= tty
->driver
->termios
[idx
];
1526 tp
= kmalloc(sizeof(struct ktermios
), GFP_KERNEL
);
1528 pr_warn("tty: no memory to save termios state.\n");
1531 tty
->driver
->termios
[idx
] = tp
;
1535 EXPORT_SYMBOL(tty_free_termios
);
1538 * tty_flush_works - flush all works of a tty
1539 * @tty: tty device to flush works for
1541 * Sync flush all works belonging to @tty.
1543 static void tty_flush_works(struct tty_struct
*tty
)
1545 flush_work(&tty
->SAK_work
);
1546 flush_work(&tty
->hangup_work
);
1550 * release_one_tty - release tty structure memory
1551 * @kref: kref of tty we are obliterating
1553 * Releases memory associated with a tty structure, and clears out the
1554 * driver table slots. This function is called when a device is no longer
1555 * in use. It also gets called when setup of a device fails.
1558 * takes the file list lock internally when working on the list
1559 * of ttys that the driver keeps.
1561 * This method gets called from a work queue so that the driver private
1562 * cleanup ops can sleep (needed for USB at least)
1564 static void release_one_tty(struct work_struct
*work
)
1566 struct tty_struct
*tty
=
1567 container_of(work
, struct tty_struct
, hangup_work
);
1568 struct tty_driver
*driver
= tty
->driver
;
1569 struct module
*owner
= driver
->owner
;
1571 if (tty
->ops
->cleanup
)
1572 tty
->ops
->cleanup(tty
);
1575 tty_driver_kref_put(driver
);
1578 spin_lock(&tty_files_lock
);
1579 list_del_init(&tty
->tty_files
);
1580 spin_unlock(&tty_files_lock
);
1583 put_pid(tty
->session
);
1584 free_tty_struct(tty
);
1587 static void queue_release_one_tty(struct kref
*kref
)
1589 struct tty_struct
*tty
= container_of(kref
, struct tty_struct
, kref
);
1591 /* The hangup queue is now free so we can reuse it rather than
1592 waste a chunk of memory for each port */
1593 INIT_WORK(&tty
->hangup_work
, release_one_tty
);
1594 schedule_work(&tty
->hangup_work
);
1598 * tty_kref_put - release a tty kref
1601 * Release a reference to a tty device and if need be let the kref
1602 * layer destruct the object for us
1605 void tty_kref_put(struct tty_struct
*tty
)
1608 kref_put(&tty
->kref
, queue_release_one_tty
);
1610 EXPORT_SYMBOL(tty_kref_put
);
1613 * release_tty - release tty structure memory
1615 * Release both @tty and a possible linked partner (think pty pair),
1616 * and decrement the refcount of the backing module.
1620 * takes the file list lock internally when working on the list
1621 * of ttys that the driver keeps.
1624 static void release_tty(struct tty_struct
*tty
, int idx
)
1626 /* This should always be true but check for the moment */
1627 WARN_ON(tty
->index
!= idx
);
1628 WARN_ON(!mutex_is_locked(&tty_mutex
));
1629 if (tty
->ops
->shutdown
)
1630 tty
->ops
->shutdown(tty
);
1631 tty_free_termios(tty
);
1632 tty_driver_remove_tty(tty
->driver
, tty
);
1633 tty
->port
->itty
= NULL
;
1635 tty
->link
->port
->itty
= NULL
;
1636 cancel_work_sync(&tty
->port
->buf
.work
);
1639 tty_kref_put(tty
->link
);
1644 * tty_release_checks - check a tty before real release
1645 * @tty: tty to check
1646 * @o_tty: link of @tty (if any)
1647 * @idx: index of the tty
1649 * Performs some paranoid checking before true release of the @tty.
1650 * This is a no-op unless TTY_PARANOIA_CHECK is defined.
1652 static int tty_release_checks(struct tty_struct
*tty
, struct tty_struct
*o_tty
,
1655 #ifdef TTY_PARANOIA_CHECK
1656 if (idx
< 0 || idx
>= tty
->driver
->num
) {
1657 printk(KERN_DEBUG
"%s: bad idx when trying to free (%s)\n",
1658 __func__
, tty
->name
);
1662 /* not much to check for devpts */
1663 if (tty
->driver
->flags
& TTY_DRIVER_DEVPTS_MEM
)
1666 if (tty
!= tty
->driver
->ttys
[idx
]) {
1667 printk(KERN_DEBUG
"%s: driver.table[%d] not tty for (%s)\n",
1668 __func__
, idx
, tty
->name
);
1671 if (tty
->driver
->other
) {
1672 if (o_tty
!= tty
->driver
->other
->ttys
[idx
]) {
1673 printk(KERN_DEBUG
"%s: other->table[%d] not o_tty for (%s)\n",
1674 __func__
, idx
, tty
->name
);
1677 if (o_tty
->link
!= tty
) {
1678 printk(KERN_DEBUG
"%s: bad pty pointers\n", __func__
);
1687 * tty_release - vfs callback for close
1688 * @inode: inode of tty
1689 * @filp: file pointer for handle to tty
1691 * Called the last time each file handle is closed that references
1692 * this tty. There may however be several such references.
1695 * Takes bkl. See tty_release_dev
1697 * Even releasing the tty structures is a tricky business.. We have
1698 * to be very careful that the structures are all released at the
1699 * same time, as interrupts might otherwise get the wrong pointers.
1701 * WSH 09/09/97: rewritten to avoid some nasty race conditions that could
1702 * lead to double frees or releasing memory still in use.
1705 int tty_release(struct inode
*inode
, struct file
*filp
)
1707 struct tty_struct
*tty
= file_tty(filp
);
1708 struct tty_struct
*o_tty
;
1709 int pty_master
, tty_closing
, o_tty_closing
, do_sleep
;
1713 if (tty_paranoia_check(tty
, inode
, __func__
))
1717 check_tty_count(tty
, __func__
);
1719 __tty_fasync(-1, filp
, 0);
1722 pty_master
= (tty
->driver
->type
== TTY_DRIVER_TYPE_PTY
&&
1723 tty
->driver
->subtype
== PTY_TYPE_MASTER
);
1724 /* Review: parallel close */
1727 if (tty_release_checks(tty
, o_tty
, idx
)) {
1732 #ifdef TTY_DEBUG_HANGUP
1733 printk(KERN_DEBUG
"%s: %s (tty count=%d)...\n", __func__
,
1734 tty_name(tty
, buf
), tty
->count
);
1737 if (tty
->ops
->close
)
1738 tty
->ops
->close(tty
, filp
);
1742 * Sanity check: if tty->count is going to zero, there shouldn't be
1743 * any waiters on tty->read_wait or tty->write_wait. We test the
1744 * wait queues and kick everyone out _before_ actually starting to
1745 * close. This ensures that we won't block while releasing the tty
1748 * The test for the o_tty closing is necessary, since the master and
1749 * slave sides may close in any order. If the slave side closes out
1750 * first, its count will be one, since the master side holds an open.
1751 * Thus this test wouldn't be triggered at the time the slave closes,
1754 * Note that it's possible for the tty to be opened again while we're
1755 * flushing out waiters. By recalculating the closing flags before
1756 * each iteration we avoid any problems.
1759 /* Guard against races with tty->count changes elsewhere and
1760 opens on /dev/tty */
1762 mutex_lock(&tty_mutex
);
1763 tty_lock_pair(tty
, o_tty
);
1764 tty_closing
= tty
->count
<= 1;
1765 o_tty_closing
= o_tty
&&
1766 (o_tty
->count
<= (pty_master
? 1 : 0));
1770 if (waitqueue_active(&tty
->read_wait
)) {
1771 wake_up_poll(&tty
->read_wait
, POLLIN
);
1774 if (waitqueue_active(&tty
->write_wait
)) {
1775 wake_up_poll(&tty
->write_wait
, POLLOUT
);
1779 if (o_tty_closing
) {
1780 if (waitqueue_active(&o_tty
->read_wait
)) {
1781 wake_up_poll(&o_tty
->read_wait
, POLLIN
);
1784 if (waitqueue_active(&o_tty
->write_wait
)) {
1785 wake_up_poll(&o_tty
->write_wait
, POLLOUT
);
1792 printk(KERN_WARNING
"%s: %s: read/write wait queue active!\n",
1793 __func__
, tty_name(tty
, buf
));
1794 tty_unlock_pair(tty
, o_tty
);
1795 mutex_unlock(&tty_mutex
);
1800 * The closing flags are now consistent with the open counts on
1801 * both sides, and we've completed the last operation that could
1802 * block, so it's safe to proceed with closing.
1804 * We must *not* drop the tty_mutex until we ensure that a further
1805 * entry into tty_open can not pick up this tty.
1808 if (--o_tty
->count
< 0) {
1809 printk(KERN_WARNING
"%s: bad pty slave count (%d) for %s\n",
1810 __func__
, o_tty
->count
, tty_name(o_tty
, buf
));
1814 if (--tty
->count
< 0) {
1815 printk(KERN_WARNING
"%s: bad tty->count (%d) for %s\n",
1816 __func__
, tty
->count
, tty_name(tty
, buf
));
1821 * We've decremented tty->count, so we need to remove this file
1822 * descriptor off the tty->tty_files list; this serves two
1824 * - check_tty_count sees the correct number of file descriptors
1825 * associated with this tty.
1826 * - do_tty_hangup no longer sees this file descriptor as
1827 * something that needs to be handled for hangups.
1832 * Perform some housekeeping before deciding whether to return.
1834 * Set the TTY_CLOSING flag if this was the last open. In the
1835 * case of a pty we may have to wait around for the other side
1836 * to close, and TTY_CLOSING makes sure we can't be reopened.
1839 set_bit(TTY_CLOSING
, &tty
->flags
);
1841 set_bit(TTY_CLOSING
, &o_tty
->flags
);
1844 * If _either_ side is closing, make sure there aren't any
1845 * processes that still think tty or o_tty is their controlling
1848 if (tty_closing
|| o_tty_closing
) {
1849 read_lock(&tasklist_lock
);
1850 session_clear_tty(tty
->session
);
1852 session_clear_tty(o_tty
->session
);
1853 read_unlock(&tasklist_lock
);
1856 mutex_unlock(&tty_mutex
);
1857 tty_unlock_pair(tty
, o_tty
);
1858 /* At this point the TTY_CLOSING flag should ensure a dead tty
1859 cannot be re-opened by a racing opener */
1861 /* check whether both sides are closing ... */
1862 if (!tty_closing
|| (o_tty
&& !o_tty_closing
))
1865 #ifdef TTY_DEBUG_HANGUP
1866 printk(KERN_DEBUG
"%s: %s: final close\n", __func__
, tty_name(tty
, buf
));
1869 * Ask the line discipline code to release its structures
1871 tty_ldisc_release(tty
, o_tty
);
1873 /* Wait for pending work before tty destruction commmences */
1874 tty_flush_works(tty
);
1876 tty_flush_works(o_tty
);
1878 #ifdef TTY_DEBUG_HANGUP
1879 printk(KERN_DEBUG
"%s: %s: freeing structure...\n", __func__
, tty_name(tty
, buf
));
1882 * The release_tty function takes care of the details of clearing
1883 * the slots and preserving the termios structure. The tty_unlock_pair
1884 * should be safe as we keep a kref while the tty is locked (so the
1885 * unlock never unlocks a freed tty).
1887 mutex_lock(&tty_mutex
);
1888 release_tty(tty
, idx
);
1889 mutex_unlock(&tty_mutex
);
1895 * tty_open_current_tty - get tty of current task for open
1896 * @device: device number
1897 * @filp: file pointer to tty
1898 * @return: tty of the current task iff @device is /dev/tty
1900 * We cannot return driver and index like for the other nodes because
1901 * devpts will not work then. It expects inodes to be from devpts FS.
1903 * We need to move to returning a refcounted object from all the lookup
1904 * paths including this one.
1906 static struct tty_struct
*tty_open_current_tty(dev_t device
, struct file
*filp
)
1908 struct tty_struct
*tty
;
1910 if (device
!= MKDEV(TTYAUX_MAJOR
, 0))
1913 tty
= get_current_tty();
1915 return ERR_PTR(-ENXIO
);
1917 filp
->f_flags
|= O_NONBLOCK
; /* Don't let /dev/tty block */
1920 /* FIXME: we put a reference and return a TTY! */
1921 /* This is only safe because the caller holds tty_mutex */
1926 * tty_lookup_driver - lookup a tty driver for a given device file
1927 * @device: device number
1928 * @filp: file pointer to tty
1929 * @noctty: set if the device should not become a controlling tty
1930 * @index: index for the device in the @return driver
1931 * @return: driver for this inode (with increased refcount)
1933 * If @return is not erroneous, the caller is responsible to decrement the
1934 * refcount by tty_driver_kref_put.
1936 * Locking: tty_mutex protects get_tty_driver
1938 static struct tty_driver
*tty_lookup_driver(dev_t device
, struct file
*filp
,
1939 int *noctty
, int *index
)
1941 struct tty_driver
*driver
;
1945 case MKDEV(TTY_MAJOR
, 0): {
1946 extern struct tty_driver
*console_driver
;
1947 driver
= tty_driver_kref_get(console_driver
);
1948 *index
= fg_console
;
1953 case MKDEV(TTYAUX_MAJOR
, 1): {
1954 struct tty_driver
*console_driver
= console_device(index
);
1955 if (console_driver
) {
1956 driver
= tty_driver_kref_get(console_driver
);
1958 /* Don't let /dev/console block */
1959 filp
->f_flags
|= O_NONBLOCK
;
1964 return ERR_PTR(-ENODEV
);
1967 driver
= get_tty_driver(device
, index
);
1969 return ERR_PTR(-ENODEV
);
1976 * tty_open - open a tty device
1977 * @inode: inode of device file
1978 * @filp: file pointer to tty
1980 * tty_open and tty_release keep up the tty count that contains the
1981 * number of opens done on a tty. We cannot use the inode-count, as
1982 * different inodes might point to the same tty.
1984 * Open-counting is needed for pty masters, as well as for keeping
1985 * track of serial lines: DTR is dropped when the last close happens.
1986 * (This is not done solely through tty->count, now. - Ted 1/27/92)
1988 * The termios state of a pty is reset on first open so that
1989 * settings don't persist across reuse.
1991 * Locking: tty_mutex protects tty, tty_lookup_driver and tty_init_dev.
1992 * tty->count should protect the rest.
1993 * ->siglock protects ->signal/->sighand
1995 * Note: the tty_unlock/lock cases without a ref are only safe due to
1999 static int tty_open(struct inode
*inode
, struct file
*filp
)
2001 struct tty_struct
*tty
;
2003 struct tty_driver
*driver
= NULL
;
2005 dev_t device
= inode
->i_rdev
;
2006 unsigned saved_flags
= filp
->f_flags
;
2008 nonseekable_open(inode
, filp
);
2011 retval
= tty_alloc_file(filp
);
2015 noctty
= filp
->f_flags
& O_NOCTTY
;
2019 mutex_lock(&tty_mutex
);
2020 /* This is protected by the tty_mutex */
2021 tty
= tty_open_current_tty(device
, filp
);
2023 retval
= PTR_ERR(tty
);
2026 driver
= tty_lookup_driver(device
, filp
, &noctty
, &index
);
2027 if (IS_ERR(driver
)) {
2028 retval
= PTR_ERR(driver
);
2032 /* check whether we're reopening an existing tty */
2033 tty
= tty_driver_lookup_tty(driver
, inode
, index
);
2035 retval
= PTR_ERR(tty
);
2042 retval
= tty_reopen(tty
);
2045 tty
= ERR_PTR(retval
);
2047 } else /* Returns with the tty_lock held for now */
2048 tty
= tty_init_dev(driver
, index
);
2050 mutex_unlock(&tty_mutex
);
2052 tty_driver_kref_put(driver
);
2054 retval
= PTR_ERR(tty
);
2058 tty_add_file(tty
, filp
);
2060 check_tty_count(tty
, __func__
);
2061 if (tty
->driver
->type
== TTY_DRIVER_TYPE_PTY
&&
2062 tty
->driver
->subtype
== PTY_TYPE_MASTER
)
2064 #ifdef TTY_DEBUG_HANGUP
2065 printk(KERN_DEBUG
"%s: opening %s...\n", __func__
, tty
->name
);
2068 retval
= tty
->ops
->open(tty
, filp
);
2071 filp
->f_flags
= saved_flags
;
2073 if (!retval
&& test_bit(TTY_EXCLUSIVE
, &tty
->flags
) &&
2074 !capable(CAP_SYS_ADMIN
))
2078 #ifdef TTY_DEBUG_HANGUP
2079 printk(KERN_DEBUG
"%s: error %d in opening %s...\n", __func__
,
2082 tty_unlock(tty
); /* need to call tty_release without BTM */
2083 tty_release(inode
, filp
);
2084 if (retval
!= -ERESTARTSYS
)
2087 if (signal_pending(current
))
2092 * Need to reset f_op in case a hangup happened.
2094 if (filp
->f_op
== &hung_up_tty_fops
)
2095 filp
->f_op
= &tty_fops
;
2098 clear_bit(TTY_HUPPED
, &tty
->flags
);
2102 mutex_lock(&tty_mutex
);
2104 spin_lock_irq(¤t
->sighand
->siglock
);
2106 current
->signal
->leader
&&
2107 !current
->signal
->tty
&&
2108 tty
->session
== NULL
)
2109 __proc_set_tty(current
, tty
);
2110 spin_unlock_irq(¤t
->sighand
->siglock
);
2112 mutex_unlock(&tty_mutex
);
2115 mutex_unlock(&tty_mutex
);
2116 /* after locks to avoid deadlock */
2117 if (!IS_ERR_OR_NULL(driver
))
2118 tty_driver_kref_put(driver
);
2120 tty_free_file(filp
);
2127 * tty_poll - check tty status
2128 * @filp: file being polled
2129 * @wait: poll wait structures to update
2131 * Call the line discipline polling method to obtain the poll
2132 * status of the device.
2134 * Locking: locks called line discipline but ldisc poll method
2135 * may be re-entered freely by other callers.
2138 static unsigned int tty_poll(struct file
*filp
, poll_table
*wait
)
2140 struct tty_struct
*tty
= file_tty(filp
);
2141 struct tty_ldisc
*ld
;
2144 if (tty_paranoia_check(tty
, file_inode(filp
), "tty_poll"))
2147 ld
= tty_ldisc_ref_wait(tty
);
2149 ret
= (ld
->ops
->poll
)(tty
, filp
, wait
);
2150 tty_ldisc_deref(ld
);
2154 static int __tty_fasync(int fd
, struct file
*filp
, int on
)
2156 struct tty_struct
*tty
= file_tty(filp
);
2157 struct tty_ldisc
*ldisc
;
2158 unsigned long flags
;
2161 if (tty_paranoia_check(tty
, file_inode(filp
), "tty_fasync"))
2164 retval
= fasync_helper(fd
, filp
, on
, &tty
->fasync
);
2168 ldisc
= tty_ldisc_ref(tty
);
2170 if (ldisc
->ops
->fasync
)
2171 ldisc
->ops
->fasync(tty
, on
);
2172 tty_ldisc_deref(ldisc
);
2179 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
2182 type
= PIDTYPE_PGID
;
2184 pid
= task_pid(current
);
2188 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
2189 __f_setown(filp
, pid
, type
, 0);
2197 static int tty_fasync(int fd
, struct file
*filp
, int on
)
2199 struct tty_struct
*tty
= file_tty(filp
);
2203 retval
= __tty_fasync(fd
, filp
, on
);
2210 * tiocsti - fake input character
2211 * @tty: tty to fake input into
2212 * @p: pointer to character
2214 * Fake input to a tty device. Does the necessary locking and
2217 * FIXME: does not honour flow control ??
2220 * Called functions take tty_ldiscs_lock
2221 * current->signal->tty check is safe without locks
2223 * FIXME: may race normal receive processing
2226 static int tiocsti(struct tty_struct
*tty
, char __user
*p
)
2229 struct tty_ldisc
*ld
;
2231 if ((current
->signal
->tty
!= tty
) && !capable(CAP_SYS_ADMIN
))
2233 if (get_user(ch
, p
))
2235 tty_audit_tiocsti(tty
, ch
);
2236 ld
= tty_ldisc_ref_wait(tty
);
2237 ld
->ops
->receive_buf(tty
, &ch
, &mbz
, 1);
2238 tty_ldisc_deref(ld
);
2243 * tiocgwinsz - implement window query ioctl
2245 * @arg: user buffer for result
2247 * Copies the kernel idea of the window size into the user buffer.
2249 * Locking: tty->winsize_mutex is taken to ensure the winsize data
2253 static int tiocgwinsz(struct tty_struct
*tty
, struct winsize __user
*arg
)
2257 mutex_lock(&tty
->winsize_mutex
);
2258 err
= copy_to_user(arg
, &tty
->winsize
, sizeof(*arg
));
2259 mutex_unlock(&tty
->winsize_mutex
);
2261 return err
? -EFAULT
: 0;
2265 * tty_do_resize - resize event
2266 * @tty: tty being resized
2267 * @rows: rows (character)
2268 * @cols: cols (character)
2270 * Update the termios variables and send the necessary signals to
2271 * peform a terminal resize correctly
2274 int tty_do_resize(struct tty_struct
*tty
, struct winsize
*ws
)
2277 unsigned long flags
;
2280 mutex_lock(&tty
->winsize_mutex
);
2281 if (!memcmp(ws
, &tty
->winsize
, sizeof(*ws
)))
2283 /* Get the PID values and reference them so we can
2284 avoid holding the tty ctrl lock while sending signals */
2285 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
2286 pgrp
= get_pid(tty
->pgrp
);
2287 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
2290 kill_pgrp(pgrp
, SIGWINCH
, 1);
2295 mutex_unlock(&tty
->winsize_mutex
);
2298 EXPORT_SYMBOL(tty_do_resize
);
2301 * tiocswinsz - implement window size set ioctl
2302 * @tty; tty side of tty
2303 * @arg: user buffer for result
2305 * Copies the user idea of the window size to the kernel. Traditionally
2306 * this is just advisory information but for the Linux console it
2307 * actually has driver level meaning and triggers a VC resize.
2310 * Driver dependent. The default do_resize method takes the
2311 * tty termios mutex and ctrl_lock. The console takes its own lock
2312 * then calls into the default method.
2315 static int tiocswinsz(struct tty_struct
*tty
, struct winsize __user
*arg
)
2317 struct winsize tmp_ws
;
2318 if (copy_from_user(&tmp_ws
, arg
, sizeof(*arg
)))
2321 if (tty
->ops
->resize
)
2322 return tty
->ops
->resize(tty
, &tmp_ws
);
2324 return tty_do_resize(tty
, &tmp_ws
);
2328 * tioccons - allow admin to move logical console
2329 * @file: the file to become console
2331 * Allow the administrator to move the redirected console device
2333 * Locking: uses redirect_lock to guard the redirect information
2336 static int tioccons(struct file
*file
)
2338 if (!capable(CAP_SYS_ADMIN
))
2340 if (file
->f_op
->write
== redirected_tty_write
) {
2342 spin_lock(&redirect_lock
);
2345 spin_unlock(&redirect_lock
);
2350 spin_lock(&redirect_lock
);
2352 spin_unlock(&redirect_lock
);
2355 redirect
= get_file(file
);
2356 spin_unlock(&redirect_lock
);
2361 * fionbio - non blocking ioctl
2362 * @file: file to set blocking value
2363 * @p: user parameter
2365 * Historical tty interfaces had a blocking control ioctl before
2366 * the generic functionality existed. This piece of history is preserved
2367 * in the expected tty API of posix OS's.
2369 * Locking: none, the open file handle ensures it won't go away.
2372 static int fionbio(struct file
*file
, int __user
*p
)
2376 if (get_user(nonblock
, p
))
2379 spin_lock(&file
->f_lock
);
2381 file
->f_flags
|= O_NONBLOCK
;
2383 file
->f_flags
&= ~O_NONBLOCK
;
2384 spin_unlock(&file
->f_lock
);
2389 * tiocsctty - set controlling tty
2390 * @tty: tty structure
2391 * @arg: user argument
2393 * This ioctl is used to manage job control. It permits a session
2394 * leader to set this tty as the controlling tty for the session.
2397 * Takes tty_mutex() to protect tty instance
2398 * Takes tasklist_lock internally to walk sessions
2399 * Takes ->siglock() when updating signal->tty
2402 static int tiocsctty(struct tty_struct
*tty
, int arg
)
2405 if (current
->signal
->leader
&& (task_session(current
) == tty
->session
))
2408 mutex_lock(&tty_mutex
);
2410 * The process must be a session leader and
2411 * not have a controlling tty already.
2413 if (!current
->signal
->leader
|| current
->signal
->tty
) {
2420 * This tty is already the controlling
2421 * tty for another session group!
2423 if (arg
== 1 && capable(CAP_SYS_ADMIN
)) {
2427 read_lock(&tasklist_lock
);
2428 session_clear_tty(tty
->session
);
2429 read_unlock(&tasklist_lock
);
2435 proc_set_tty(current
, tty
);
2437 mutex_unlock(&tty_mutex
);
2442 * tty_get_pgrp - return a ref counted pgrp pid
2445 * Returns a refcounted instance of the pid struct for the process
2446 * group controlling the tty.
2449 struct pid
*tty_get_pgrp(struct tty_struct
*tty
)
2451 unsigned long flags
;
2454 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
2455 pgrp
= get_pid(tty
->pgrp
);
2456 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
2460 EXPORT_SYMBOL_GPL(tty_get_pgrp
);
2463 * tiocgpgrp - get process group
2464 * @tty: tty passed by user
2465 * @real_tty: tty side of the tty passed by the user if a pty else the tty
2468 * Obtain the process group of the tty. If there is no process group
2471 * Locking: none. Reference to current->signal->tty is safe.
2474 static int tiocgpgrp(struct tty_struct
*tty
, struct tty_struct
*real_tty
, pid_t __user
*p
)
2479 * (tty == real_tty) is a cheap way of
2480 * testing if the tty is NOT a master pty.
2482 if (tty
== real_tty
&& current
->signal
->tty
!= real_tty
)
2484 pid
= tty_get_pgrp(real_tty
);
2485 ret
= put_user(pid_vnr(pid
), p
);
2491 * tiocspgrp - attempt to set process group
2492 * @tty: tty passed by user
2493 * @real_tty: tty side device matching tty passed by user
2496 * Set the process group of the tty to the session passed. Only
2497 * permitted where the tty session is our session.
2499 * Locking: RCU, ctrl lock
2502 static int tiocspgrp(struct tty_struct
*tty
, struct tty_struct
*real_tty
, pid_t __user
*p
)
2506 int retval
= tty_check_change(real_tty
);
2507 unsigned long flags
;
2513 if (!current
->signal
->tty
||
2514 (current
->signal
->tty
!= real_tty
) ||
2515 (real_tty
->session
!= task_session(current
)))
2517 if (get_user(pgrp_nr
, p
))
2522 pgrp
= find_vpid(pgrp_nr
);
2527 if (session_of_pgrp(pgrp
) != task_session(current
))
2530 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
2531 put_pid(real_tty
->pgrp
);
2532 real_tty
->pgrp
= get_pid(pgrp
);
2533 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
2540 * tiocgsid - get session id
2541 * @tty: tty passed by user
2542 * @real_tty: tty side of the tty passed by the user if a pty else the tty
2543 * @p: pointer to returned session id
2545 * Obtain the session id of the tty. If there is no session
2548 * Locking: none. Reference to current->signal->tty is safe.
2551 static int tiocgsid(struct tty_struct
*tty
, struct tty_struct
*real_tty
, pid_t __user
*p
)
2554 * (tty == real_tty) is a cheap way of
2555 * testing if the tty is NOT a master pty.
2557 if (tty
== real_tty
&& current
->signal
->tty
!= real_tty
)
2559 if (!real_tty
->session
)
2561 return put_user(pid_vnr(real_tty
->session
), p
);
2565 * tiocsetd - set line discipline
2567 * @p: pointer to user data
2569 * Set the line discipline according to user request.
2571 * Locking: see tty_set_ldisc, this function is just a helper
2574 static int tiocsetd(struct tty_struct
*tty
, int __user
*p
)
2579 if (get_user(ldisc
, p
))
2582 ret
= tty_set_ldisc(tty
, ldisc
);
2588 * send_break - performed time break
2589 * @tty: device to break on
2590 * @duration: timeout in mS
2592 * Perform a timed break on hardware that lacks its own driver level
2593 * timed break functionality.
2596 * atomic_write_lock serializes
2600 static int send_break(struct tty_struct
*tty
, unsigned int duration
)
2604 if (tty
->ops
->break_ctl
== NULL
)
2607 if (tty
->driver
->flags
& TTY_DRIVER_HARDWARE_BREAK
)
2608 retval
= tty
->ops
->break_ctl(tty
, duration
);
2610 /* Do the work ourselves */
2611 if (tty_write_lock(tty
, 0) < 0)
2613 retval
= tty
->ops
->break_ctl(tty
, -1);
2616 if (!signal_pending(current
))
2617 msleep_interruptible(duration
);
2618 retval
= tty
->ops
->break_ctl(tty
, 0);
2620 tty_write_unlock(tty
);
2621 if (signal_pending(current
))
2628 * tty_tiocmget - get modem status
2630 * @file: user file pointer
2631 * @p: pointer to result
2633 * Obtain the modem status bits from the tty driver if the feature
2634 * is supported. Return -EINVAL if it is not available.
2636 * Locking: none (up to the driver)
2639 static int tty_tiocmget(struct tty_struct
*tty
, int __user
*p
)
2641 int retval
= -EINVAL
;
2643 if (tty
->ops
->tiocmget
) {
2644 retval
= tty
->ops
->tiocmget(tty
);
2647 retval
= put_user(retval
, p
);
2653 * tty_tiocmset - set modem status
2655 * @cmd: command - clear bits, set bits or set all
2656 * @p: pointer to desired bits
2658 * Set the modem status bits from the tty driver if the feature
2659 * is supported. Return -EINVAL if it is not available.
2661 * Locking: none (up to the driver)
2664 static int tty_tiocmset(struct tty_struct
*tty
, unsigned int cmd
,
2668 unsigned int set
, clear
, val
;
2670 if (tty
->ops
->tiocmset
== NULL
)
2673 retval
= get_user(val
, p
);
2689 set
&= TIOCM_DTR
|TIOCM_RTS
|TIOCM_OUT1
|TIOCM_OUT2
|TIOCM_LOOP
;
2690 clear
&= TIOCM_DTR
|TIOCM_RTS
|TIOCM_OUT1
|TIOCM_OUT2
|TIOCM_LOOP
;
2691 return tty
->ops
->tiocmset(tty
, set
, clear
);
2694 static int tty_tiocgicount(struct tty_struct
*tty
, void __user
*arg
)
2696 int retval
= -EINVAL
;
2697 struct serial_icounter_struct icount
;
2698 memset(&icount
, 0, sizeof(icount
));
2699 if (tty
->ops
->get_icount
)
2700 retval
= tty
->ops
->get_icount(tty
, &icount
);
2703 if (copy_to_user(arg
, &icount
, sizeof(icount
)))
2708 struct tty_struct
*tty_pair_get_tty(struct tty_struct
*tty
)
2710 if (tty
->driver
->type
== TTY_DRIVER_TYPE_PTY
&&
2711 tty
->driver
->subtype
== PTY_TYPE_MASTER
)
2715 EXPORT_SYMBOL(tty_pair_get_tty
);
2717 struct tty_struct
*tty_pair_get_pty(struct tty_struct
*tty
)
2719 if (tty
->driver
->type
== TTY_DRIVER_TYPE_PTY
&&
2720 tty
->driver
->subtype
== PTY_TYPE_MASTER
)
2724 EXPORT_SYMBOL(tty_pair_get_pty
);
2727 * Split this up, as gcc can choke on it otherwise..
2729 long tty_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
2731 struct tty_struct
*tty
= file_tty(file
);
2732 struct tty_struct
*real_tty
;
2733 void __user
*p
= (void __user
*)arg
;
2735 struct tty_ldisc
*ld
;
2737 if (tty_paranoia_check(tty
, file_inode(file
), "tty_ioctl"))
2740 real_tty
= tty_pair_get_tty(tty
);
2743 * Factor out some common prep work
2751 retval
= tty_check_change(tty
);
2754 if (cmd
!= TIOCCBRK
) {
2755 tty_wait_until_sent(tty
, 0);
2756 if (signal_pending(current
))
2767 return tiocsti(tty
, p
);
2769 return tiocgwinsz(real_tty
, p
);
2771 return tiocswinsz(real_tty
, p
);
2773 return real_tty
!= tty
? -EINVAL
: tioccons(file
);
2775 return fionbio(file
, p
);
2777 set_bit(TTY_EXCLUSIVE
, &tty
->flags
);
2780 clear_bit(TTY_EXCLUSIVE
, &tty
->flags
);
2784 int excl
= test_bit(TTY_EXCLUSIVE
, &tty
->flags
);
2785 return put_user(excl
, (int __user
*)p
);
2788 if (current
->signal
->tty
!= tty
)
2793 return tiocsctty(tty
, arg
);
2795 return tiocgpgrp(tty
, real_tty
, p
);
2797 return tiocspgrp(tty
, real_tty
, p
);
2799 return tiocgsid(tty
, real_tty
, p
);
2801 return put_user(tty
->ldisc
->ops
->num
, (int __user
*)p
);
2803 return tiocsetd(tty
, p
);
2805 if (!capable(CAP_SYS_ADMIN
))
2811 unsigned int ret
= new_encode_dev(tty_devnum(real_tty
));
2812 return put_user(ret
, (unsigned int __user
*)p
);
2817 case TIOCSBRK
: /* Turn break on, unconditionally */
2818 if (tty
->ops
->break_ctl
)
2819 return tty
->ops
->break_ctl(tty
, -1);
2821 case TIOCCBRK
: /* Turn break off, unconditionally */
2822 if (tty
->ops
->break_ctl
)
2823 return tty
->ops
->break_ctl(tty
, 0);
2825 case TCSBRK
: /* SVID version: non-zero arg --> no break */
2826 /* non-zero arg means wait for all output data
2827 * to be sent (performed above) but don't send break.
2828 * This is used by the tcdrain() termios function.
2831 return send_break(tty
, 250);
2833 case TCSBRKP
: /* support for POSIX tcsendbreak() */
2834 return send_break(tty
, arg
? arg
*100 : 250);
2837 return tty_tiocmget(tty
, p
);
2841 return tty_tiocmset(tty
, cmd
, p
);
2843 retval
= tty_tiocgicount(tty
, p
);
2844 /* For the moment allow fall through to the old method */
2845 if (retval
!= -EINVAL
)
2852 /* flush tty buffer and allow ldisc to process ioctl */
2853 tty_buffer_flush(tty
);
2858 if (tty
->ops
->ioctl
) {
2859 retval
= (tty
->ops
->ioctl
)(tty
, cmd
, arg
);
2860 if (retval
!= -ENOIOCTLCMD
)
2863 ld
= tty_ldisc_ref_wait(tty
);
2865 if (ld
->ops
->ioctl
) {
2866 retval
= ld
->ops
->ioctl(tty
, file
, cmd
, arg
);
2867 if (retval
== -ENOIOCTLCMD
)
2870 tty_ldisc_deref(ld
);
2874 #ifdef CONFIG_COMPAT
2875 static long tty_compat_ioctl(struct file
*file
, unsigned int cmd
,
2878 struct tty_struct
*tty
= file_tty(file
);
2879 struct tty_ldisc
*ld
;
2880 int retval
= -ENOIOCTLCMD
;
2882 if (tty_paranoia_check(tty
, file_inode(file
), "tty_ioctl"))
2885 if (tty
->ops
->compat_ioctl
) {
2886 retval
= (tty
->ops
->compat_ioctl
)(tty
, cmd
, arg
);
2887 if (retval
!= -ENOIOCTLCMD
)
2891 ld
= tty_ldisc_ref_wait(tty
);
2892 if (ld
->ops
->compat_ioctl
)
2893 retval
= ld
->ops
->compat_ioctl(tty
, file
, cmd
, arg
);
2895 retval
= n_tty_compat_ioctl_helper(tty
, file
, cmd
, arg
);
2896 tty_ldisc_deref(ld
);
2902 static int this_tty(const void *t
, struct file
*file
, unsigned fd
)
2904 if (likely(file
->f_op
->read
!= tty_read
))
2906 return file_tty(file
) != t
? 0 : fd
+ 1;
2910 * This implements the "Secure Attention Key" --- the idea is to
2911 * prevent trojan horses by killing all processes associated with this
2912 * tty when the user hits the "Secure Attention Key". Required for
2913 * super-paranoid applications --- see the Orange Book for more details.
2915 * This code could be nicer; ideally it should send a HUP, wait a few
2916 * seconds, then send a INT, and then a KILL signal. But you then
2917 * have to coordinate with the init process, since all processes associated
2918 * with the current tty must be dead before the new getty is allowed
2921 * Now, if it would be correct ;-/ The current code has a nasty hole -
2922 * it doesn't catch files in flight. We may send the descriptor to ourselves
2923 * via AF_UNIX socket, close it and later fetch from socket. FIXME.
2925 * Nasty bug: do_SAK is being called in interrupt context. This can
2926 * deadlock. We punt it up to process context. AKPM - 16Mar2001
2928 void __do_SAK(struct tty_struct
*tty
)
2933 struct task_struct
*g
, *p
;
2934 struct pid
*session
;
2939 session
= tty
->session
;
2941 tty_ldisc_flush(tty
);
2943 tty_driver_flush_buffer(tty
);
2945 read_lock(&tasklist_lock
);
2946 /* Kill the entire session */
2947 do_each_pid_task(session
, PIDTYPE_SID
, p
) {
2948 printk(KERN_NOTICE
"SAK: killed process %d"
2949 " (%s): task_session(p)==tty->session\n",
2950 task_pid_nr(p
), p
->comm
);
2951 send_sig(SIGKILL
, p
, 1);
2952 } while_each_pid_task(session
, PIDTYPE_SID
, p
);
2953 /* Now kill any processes that happen to have the
2956 do_each_thread(g
, p
) {
2957 if (p
->signal
->tty
== tty
) {
2958 printk(KERN_NOTICE
"SAK: killed process %d"
2959 " (%s): task_session(p)==tty->session\n",
2960 task_pid_nr(p
), p
->comm
);
2961 send_sig(SIGKILL
, p
, 1);
2965 i
= iterate_fd(p
->files
, 0, this_tty
, tty
);
2967 printk(KERN_NOTICE
"SAK: killed process %d"
2968 " (%s): fd#%d opened to the tty\n",
2969 task_pid_nr(p
), p
->comm
, i
- 1);
2970 force_sig(SIGKILL
, p
);
2973 } while_each_thread(g
, p
);
2974 read_unlock(&tasklist_lock
);
2978 static void do_SAK_work(struct work_struct
*work
)
2980 struct tty_struct
*tty
=
2981 container_of(work
, struct tty_struct
, SAK_work
);
2986 * The tq handling here is a little racy - tty->SAK_work may already be queued.
2987 * Fortunately we don't need to worry, because if ->SAK_work is already queued,
2988 * the values which we write to it will be identical to the values which it
2989 * already has. --akpm
2991 void do_SAK(struct tty_struct
*tty
)
2995 schedule_work(&tty
->SAK_work
);
2998 EXPORT_SYMBOL(do_SAK
);
3000 static int dev_match_devt(struct device
*dev
, const void *data
)
3002 const dev_t
*devt
= data
;
3003 return dev
->devt
== *devt
;
3006 /* Must put_device() after it's unused! */
3007 static struct device
*tty_get_device(struct tty_struct
*tty
)
3009 dev_t devt
= tty_devnum(tty
);
3010 return class_find_device(tty_class
, NULL
, &devt
, dev_match_devt
);
3017 * This subroutine allocates and initializes a tty structure.
3019 * Locking: none - tty in question is not exposed at this point
3022 struct tty_struct
*alloc_tty_struct(struct tty_driver
*driver
, int idx
)
3024 struct tty_struct
*tty
;
3026 tty
= kzalloc(sizeof(*tty
), GFP_KERNEL
);
3030 kref_init(&tty
->kref
);
3031 tty
->magic
= TTY_MAGIC
;
3032 tty_ldisc_init(tty
);
3033 tty
->session
= NULL
;
3035 mutex_init(&tty
->legacy_mutex
);
3036 mutex_init(&tty
->throttle_mutex
);
3037 init_rwsem(&tty
->termios_rwsem
);
3038 mutex_init(&tty
->winsize_mutex
);
3039 init_ldsem(&tty
->ldisc_sem
);
3040 init_waitqueue_head(&tty
->write_wait
);
3041 init_waitqueue_head(&tty
->read_wait
);
3042 INIT_WORK(&tty
->hangup_work
, do_tty_hangup
);
3043 mutex_init(&tty
->atomic_write_lock
);
3044 spin_lock_init(&tty
->ctrl_lock
);
3045 spin_lock_init(&tty
->flow_lock
);
3046 INIT_LIST_HEAD(&tty
->tty_files
);
3047 INIT_WORK(&tty
->SAK_work
, do_SAK_work
);
3049 tty
->driver
= driver
;
3050 tty
->ops
= driver
->ops
;
3052 tty_line_name(driver
, idx
, tty
->name
);
3053 tty
->dev
= tty_get_device(tty
);
3059 * deinitialize_tty_struct
3060 * @tty: tty to deinitialize
3062 * This subroutine deinitializes a tty structure that has been newly
3063 * allocated but tty_release cannot be called on that yet.
3065 * Locking: none - tty in question must not be exposed at this point
3067 void deinitialize_tty_struct(struct tty_struct
*tty
)
3069 tty_ldisc_deinit(tty
);
3073 * tty_put_char - write one character to a tty
3077 * Write one byte to the tty using the provided put_char method
3078 * if present. Returns the number of characters successfully output.
3080 * Note: the specific put_char operation in the driver layer may go
3081 * away soon. Don't call it directly, use this method
3084 int tty_put_char(struct tty_struct
*tty
, unsigned char ch
)
3086 if (tty
->ops
->put_char
)
3087 return tty
->ops
->put_char(tty
, ch
);
3088 return tty
->ops
->write(tty
, &ch
, 1);
3090 EXPORT_SYMBOL_GPL(tty_put_char
);
3092 struct class *tty_class
;
3094 static int tty_cdev_add(struct tty_driver
*driver
, dev_t dev
,
3095 unsigned int index
, unsigned int count
)
3097 /* init here, since reused cdevs cause crashes */
3098 cdev_init(&driver
->cdevs
[index
], &tty_fops
);
3099 driver
->cdevs
[index
].owner
= driver
->owner
;
3100 return cdev_add(&driver
->cdevs
[index
], dev
, count
);
3104 * tty_register_device - register a tty device
3105 * @driver: the tty driver that describes the tty device
3106 * @index: the index in the tty driver for this tty device
3107 * @device: a struct device that is associated with this tty device.
3108 * This field is optional, if there is no known struct device
3109 * for this tty device it can be set to NULL safely.
3111 * Returns a pointer to the struct device for this tty device
3112 * (or ERR_PTR(-EFOO) on error).
3114 * This call is required to be made to register an individual tty device
3115 * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If
3116 * that bit is not set, this function should not be called by a tty
3122 struct device
*tty_register_device(struct tty_driver
*driver
, unsigned index
,
3123 struct device
*device
)
3125 return tty_register_device_attr(driver
, index
, device
, NULL
, NULL
);
3127 EXPORT_SYMBOL(tty_register_device
);
3129 static void tty_device_create_release(struct device
*dev
)
3131 pr_debug("device: '%s': %s\n", dev_name(dev
), __func__
);
3136 * tty_register_device_attr - register a tty device
3137 * @driver: the tty driver that describes the tty device
3138 * @index: the index in the tty driver for this tty device
3139 * @device: a struct device that is associated with this tty device.
3140 * This field is optional, if there is no known struct device
3141 * for this tty device it can be set to NULL safely.
3142 * @drvdata: Driver data to be set to device.
3143 * @attr_grp: Attribute group to be set on device.
3145 * Returns a pointer to the struct device for this tty device
3146 * (or ERR_PTR(-EFOO) on error).
3148 * This call is required to be made to register an individual tty device
3149 * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If
3150 * that bit is not set, this function should not be called by a tty
3155 struct device
*tty_register_device_attr(struct tty_driver
*driver
,
3156 unsigned index
, struct device
*device
,
3158 const struct attribute_group
**attr_grp
)
3161 dev_t devt
= MKDEV(driver
->major
, driver
->minor_start
) + index
;
3162 struct device
*dev
= NULL
;
3163 int retval
= -ENODEV
;
3166 if (index
>= driver
->num
) {
3167 printk(KERN_ERR
"Attempt to register invalid tty line number "
3169 return ERR_PTR(-EINVAL
);
3172 if (driver
->type
== TTY_DRIVER_TYPE_PTY
)
3173 pty_line_name(driver
, index
, name
);
3175 tty_line_name(driver
, index
, name
);
3177 if (!(driver
->flags
& TTY_DRIVER_DYNAMIC_ALLOC
)) {
3178 retval
= tty_cdev_add(driver
, devt
, index
, 1);
3184 dev
= kzalloc(sizeof(*dev
), GFP_KERNEL
);
3191 dev
->class = tty_class
;
3192 dev
->parent
= device
;
3193 dev
->release
= tty_device_create_release
;
3194 dev_set_name(dev
, "%s", name
);
3195 dev
->groups
= attr_grp
;
3196 dev_set_drvdata(dev
, drvdata
);
3198 retval
= device_register(dev
);
3207 cdev_del(&driver
->cdevs
[index
]);
3208 return ERR_PTR(retval
);
3210 EXPORT_SYMBOL_GPL(tty_register_device_attr
);
3213 * tty_unregister_device - unregister a tty device
3214 * @driver: the tty driver that describes the tty device
3215 * @index: the index in the tty driver for this tty device
3217 * If a tty device is registered with a call to tty_register_device() then
3218 * this function must be called when the tty device is gone.
3223 void tty_unregister_device(struct tty_driver
*driver
, unsigned index
)
3225 device_destroy(tty_class
,
3226 MKDEV(driver
->major
, driver
->minor_start
) + index
);
3227 if (!(driver
->flags
& TTY_DRIVER_DYNAMIC_ALLOC
))
3228 cdev_del(&driver
->cdevs
[index
]);
3230 EXPORT_SYMBOL(tty_unregister_device
);
3233 * __tty_alloc_driver -- allocate tty driver
3234 * @lines: count of lines this driver can handle at most
3235 * @owner: module which is repsonsible for this driver
3236 * @flags: some of TTY_DRIVER_* flags, will be set in driver->flags
3238 * This should not be called directly, some of the provided macros should be
3239 * used instead. Use IS_ERR and friends on @retval.
3241 struct tty_driver
*__tty_alloc_driver(unsigned int lines
, struct module
*owner
,
3242 unsigned long flags
)
3244 struct tty_driver
*driver
;
3245 unsigned int cdevs
= 1;
3248 if (!lines
|| (flags
& TTY_DRIVER_UNNUMBERED_NODE
&& lines
> 1))
3249 return ERR_PTR(-EINVAL
);
3251 driver
= kzalloc(sizeof(struct tty_driver
), GFP_KERNEL
);
3253 return ERR_PTR(-ENOMEM
);
3255 kref_init(&driver
->kref
);
3256 driver
->magic
= TTY_DRIVER_MAGIC
;
3257 driver
->num
= lines
;
3258 driver
->owner
= owner
;
3259 driver
->flags
= flags
;
3261 if (!(flags
& TTY_DRIVER_DEVPTS_MEM
)) {
3262 driver
->ttys
= kcalloc(lines
, sizeof(*driver
->ttys
),
3264 driver
->termios
= kcalloc(lines
, sizeof(*driver
->termios
),
3266 if (!driver
->ttys
|| !driver
->termios
) {
3272 if (!(flags
& TTY_DRIVER_DYNAMIC_ALLOC
)) {
3273 driver
->ports
= kcalloc(lines
, sizeof(*driver
->ports
),
3275 if (!driver
->ports
) {
3282 driver
->cdevs
= kcalloc(cdevs
, sizeof(*driver
->cdevs
), GFP_KERNEL
);
3283 if (!driver
->cdevs
) {
3290 kfree(driver
->ports
);
3291 kfree(driver
->ttys
);
3292 kfree(driver
->termios
);
3294 return ERR_PTR(err
);
3296 EXPORT_SYMBOL(__tty_alloc_driver
);
3298 static void destruct_tty_driver(struct kref
*kref
)
3300 struct tty_driver
*driver
= container_of(kref
, struct tty_driver
, kref
);
3302 struct ktermios
*tp
;
3304 if (driver
->flags
& TTY_DRIVER_INSTALLED
) {
3306 * Free the termios and termios_locked structures because
3307 * we don't want to get memory leaks when modular tty
3308 * drivers are removed from the kernel.
3310 for (i
= 0; i
< driver
->num
; i
++) {
3311 tp
= driver
->termios
[i
];
3313 driver
->termios
[i
] = NULL
;
3316 if (!(driver
->flags
& TTY_DRIVER_DYNAMIC_DEV
))
3317 tty_unregister_device(driver
, i
);
3319 proc_tty_unregister_driver(driver
);
3320 if (driver
->flags
& TTY_DRIVER_DYNAMIC_ALLOC
)
3321 cdev_del(&driver
->cdevs
[0]);
3323 kfree(driver
->cdevs
);
3324 kfree(driver
->ports
);
3325 kfree(driver
->termios
);
3326 kfree(driver
->ttys
);
3330 void tty_driver_kref_put(struct tty_driver
*driver
)
3332 kref_put(&driver
->kref
, destruct_tty_driver
);
3334 EXPORT_SYMBOL(tty_driver_kref_put
);
3336 void tty_set_operations(struct tty_driver
*driver
,
3337 const struct tty_operations
*op
)
3341 EXPORT_SYMBOL(tty_set_operations
);
3343 void put_tty_driver(struct tty_driver
*d
)
3345 tty_driver_kref_put(d
);
3347 EXPORT_SYMBOL(put_tty_driver
);
3350 * Called by a tty driver to register itself.
3352 int tty_register_driver(struct tty_driver
*driver
)
3359 if (!driver
->major
) {
3360 error
= alloc_chrdev_region(&dev
, driver
->minor_start
,
3361 driver
->num
, driver
->name
);
3363 driver
->major
= MAJOR(dev
);
3364 driver
->minor_start
= MINOR(dev
);
3367 dev
= MKDEV(driver
->major
, driver
->minor_start
);
3368 error
= register_chrdev_region(dev
, driver
->num
, driver
->name
);
3373 if (driver
->flags
& TTY_DRIVER_DYNAMIC_ALLOC
) {
3374 error
= tty_cdev_add(driver
, dev
, 0, driver
->num
);
3376 goto err_unreg_char
;
3379 mutex_lock(&tty_mutex
);
3380 list_add(&driver
->tty_drivers
, &tty_drivers
);
3381 mutex_unlock(&tty_mutex
);
3383 if (!(driver
->flags
& TTY_DRIVER_DYNAMIC_DEV
)) {
3384 for (i
= 0; i
< driver
->num
; i
++) {
3385 d
= tty_register_device(driver
, i
, NULL
);
3388 goto err_unreg_devs
;
3392 proc_tty_register_driver(driver
);
3393 driver
->flags
|= TTY_DRIVER_INSTALLED
;
3397 for (i
--; i
>= 0; i
--)
3398 tty_unregister_device(driver
, i
);
3400 mutex_lock(&tty_mutex
);
3401 list_del(&driver
->tty_drivers
);
3402 mutex_unlock(&tty_mutex
);
3405 unregister_chrdev_region(dev
, driver
->num
);
3409 EXPORT_SYMBOL(tty_register_driver
);
3412 * Called by a tty driver to unregister itself.
3414 int tty_unregister_driver(struct tty_driver
*driver
)
3418 if (driver
->refcount
)
3421 unregister_chrdev_region(MKDEV(driver
->major
, driver
->minor_start
),
3423 mutex_lock(&tty_mutex
);
3424 list_del(&driver
->tty_drivers
);
3425 mutex_unlock(&tty_mutex
);
3429 EXPORT_SYMBOL(tty_unregister_driver
);
3431 dev_t
tty_devnum(struct tty_struct
*tty
)
3433 return MKDEV(tty
->driver
->major
, tty
->driver
->minor_start
) + tty
->index
;
3435 EXPORT_SYMBOL(tty_devnum
);
3437 void proc_clear_tty(struct task_struct
*p
)
3439 unsigned long flags
;
3440 struct tty_struct
*tty
;
3441 spin_lock_irqsave(&p
->sighand
->siglock
, flags
);
3442 tty
= p
->signal
->tty
;
3443 p
->signal
->tty
= NULL
;
3444 spin_unlock_irqrestore(&p
->sighand
->siglock
, flags
);
3448 /* Called under the sighand lock */
3450 static void __proc_set_tty(struct task_struct
*tsk
, struct tty_struct
*tty
)
3453 unsigned long flags
;
3454 /* We should not have a session or pgrp to put here but.... */
3455 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
3456 put_pid(tty
->session
);
3458 tty
->pgrp
= get_pid(task_pgrp(tsk
));
3459 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
3460 tty
->session
= get_pid(task_session(tsk
));
3461 if (tsk
->signal
->tty
) {
3462 printk(KERN_DEBUG
"tty not NULL!!\n");
3463 tty_kref_put(tsk
->signal
->tty
);
3466 put_pid(tsk
->signal
->tty_old_pgrp
);
3467 tsk
->signal
->tty
= tty_kref_get(tty
);
3468 tsk
->signal
->tty_old_pgrp
= NULL
;
3471 static void proc_set_tty(struct task_struct
*tsk
, struct tty_struct
*tty
)
3473 spin_lock_irq(&tsk
->sighand
->siglock
);
3474 __proc_set_tty(tsk
, tty
);
3475 spin_unlock_irq(&tsk
->sighand
->siglock
);
3478 struct tty_struct
*get_current_tty(void)
3480 struct tty_struct
*tty
;
3481 unsigned long flags
;
3483 spin_lock_irqsave(¤t
->sighand
->siglock
, flags
);
3484 tty
= tty_kref_get(current
->signal
->tty
);
3485 spin_unlock_irqrestore(¤t
->sighand
->siglock
, flags
);
3488 EXPORT_SYMBOL_GPL(get_current_tty
);
3490 void tty_default_fops(struct file_operations
*fops
)
3496 * Initialize the console device. This is called *early*, so
3497 * we can't necessarily depend on lots of kernel help here.
3498 * Just do some early initializations, and do the complex setup
3501 void __init
console_init(void)
3505 /* Setup the default TTY line discipline. */
3509 * set up the console device so that later boot sequences can
3510 * inform about problems etc..
3512 call
= __con_initcall_start
;
3513 while (call
< __con_initcall_end
) {
3519 static char *tty_devnode(struct device
*dev
, umode_t
*mode
)
3523 if (dev
->devt
== MKDEV(TTYAUX_MAJOR
, 0) ||
3524 dev
->devt
== MKDEV(TTYAUX_MAJOR
, 2))
3529 static int __init
tty_class_init(void)
3531 tty_class
= class_create(THIS_MODULE
, "tty");
3532 if (IS_ERR(tty_class
))
3533 return PTR_ERR(tty_class
);
3534 tty_class
->devnode
= tty_devnode
;
3538 postcore_initcall(tty_class_init
);
3540 /* 3/2004 jmc: why do these devices exist? */
3541 static struct cdev tty_cdev
, console_cdev
;
3543 static ssize_t
show_cons_active(struct device
*dev
,
3544 struct device_attribute
*attr
, char *buf
)
3546 struct console
*cs
[16];
3552 for_each_console(c
) {
3557 if ((c
->flags
& CON_ENABLED
) == 0)
3560 if (i
>= ARRAY_SIZE(cs
))
3564 int index
= cs
[i
]->index
;
3565 struct tty_driver
*drv
= cs
[i
]->device(cs
[i
], &index
);
3567 /* don't resolve tty0 as some programs depend on it */
3568 if (drv
&& (cs
[i
]->index
> 0 || drv
->major
!= TTY_MAJOR
))
3569 count
+= tty_line_name(drv
, index
, buf
+ count
);
3571 count
+= sprintf(buf
+ count
, "%s%d",
3572 cs
[i
]->name
, cs
[i
]->index
);
3574 count
+= sprintf(buf
+ count
, "%c", i
? ' ':'\n');
3580 static DEVICE_ATTR(active
, S_IRUGO
, show_cons_active
, NULL
);
3582 static struct device
*consdev
;
3584 void console_sysfs_notify(void)
3587 sysfs_notify(&consdev
->kobj
, NULL
, "active");
3591 * Ok, now we can initialize the rest of the tty devices and can count
3592 * on memory allocations, interrupts etc..
3594 int __init
tty_init(void)
3596 cdev_init(&tty_cdev
, &tty_fops
);
3597 if (cdev_add(&tty_cdev
, MKDEV(TTYAUX_MAJOR
, 0), 1) ||
3598 register_chrdev_region(MKDEV(TTYAUX_MAJOR
, 0), 1, "/dev/tty") < 0)
3599 panic("Couldn't register /dev/tty driver\n");
3600 device_create(tty_class
, NULL
, MKDEV(TTYAUX_MAJOR
, 0), NULL
, "tty");
3602 cdev_init(&console_cdev
, &console_fops
);
3603 if (cdev_add(&console_cdev
, MKDEV(TTYAUX_MAJOR
, 1), 1) ||
3604 register_chrdev_region(MKDEV(TTYAUX_MAJOR
, 1), 1, "/dev/console") < 0)
3605 panic("Couldn't register /dev/console driver\n");
3606 consdev
= device_create(tty_class
, NULL
, MKDEV(TTYAUX_MAJOR
, 1), NULL
,
3608 if (IS_ERR(consdev
))
3611 WARN_ON(device_create_file(consdev
, &dev_attr_active
) < 0);
3614 vty_init(&console_fops
);