2 * Copyright (C) 1991, 1992 Linus Torvalds
6 * 'tty_io.c' gives an orthogonal feeling to tty's, be they consoles
7 * or rs-channels. It also implements echoing, cooked mode etc.
9 * Kill-line thanks to John T Kohl, who also corrected VMIN = VTIME = 0.
11 * Modified by Theodore Ts'o, 9/14/92, to dynamically allocate the
12 * tty_struct and tty_queue structures. Previously there was an array
13 * of 256 tty_struct's which was statically allocated, and the
14 * tty_queue structures were allocated at boot time. Both are now
15 * dynamically allocated only when the tty is open.
17 * Also restructured routines so that there is more of a separation
18 * between the high-level tty routines (tty_io.c and tty_ioctl.c) and
19 * the low-level tty routines (serial.c, pty.c, console.c). This
20 * makes for cleaner and more compact code. -TYT, 9/17/92
22 * Modified by Fred N. van Kempen, 01/29/93, to add line disciplines
23 * which can be dynamically activated and de-activated by the line
24 * discipline handling modules (like SLIP).
26 * NOTE: pay no attention to the line discipline code (yet); its
27 * interface is still subject to change in this version...
30 * Added functionality to the OPOST tty handling. No delays, but all
31 * other bits should be there.
32 * -- Nick Holloway <alfie@dcs.warwick.ac.uk>, 27th May 1993.
34 * Rewrote canonical mode and added more termios flags.
35 * -- julian@uhunix.uhcc.hawaii.edu (J. Cowley), 13Jan94
37 * Reorganized FASYNC support so mouse code can share it.
38 * -- ctm@ardi.com, 9Sep95
40 * New TIOCLINUX variants added.
41 * -- mj@k332.feld.cvut.cz, 19-Nov-95
43 * Restrict vt switching via ioctl()
44 * -- grif@cs.ucr.edu, 5-Dec-95
46 * Move console and virtual terminal code to more appropriate files,
47 * implement CONFIG_VT and generalize console device interface.
48 * -- Marko Kohtala <Marko.Kohtala@hut.fi>, March 97
50 * Rewrote tty_init_dev and tty_release_dev to eliminate races.
51 * -- Bill Hawes <whawes@star.net>, June 97
53 * Added devfs support.
54 * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 13-Jan-1998
56 * Added support for a Unix98-style ptmx device.
57 * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 14-Jan-1998
59 * Reduced memory usage for older ARM systems
60 * -- Russell King <rmk@arm.linux.org.uk>
62 * Move do_SAK() into process context. Less stack use in devfs functions.
63 * alloc_tty_struct() always uses kmalloc()
64 * -- Andrew Morton <andrewm@uow.edu.eu> 17Mar01
67 #include <linux/types.h>
68 #include <linux/major.h>
69 #include <linux/errno.h>
70 #include <linux/signal.h>
71 #include <linux/fcntl.h>
72 #include <linux/sched.h>
73 #include <linux/interrupt.h>
74 #include <linux/tty.h>
75 #include <linux/tty_driver.h>
76 #include <linux/tty_flip.h>
77 #include <linux/devpts_fs.h>
78 #include <linux/file.h>
79 #include <linux/fdtable.h>
80 #include <linux/console.h>
81 #include <linux/timer.h>
82 #include <linux/ctype.h>
85 #include <linux/string.h>
86 #include <linux/slab.h>
87 #include <linux/poll.h>
88 #include <linux/proc_fs.h>
89 #include <linux/init.h>
90 #include <linux/module.h>
91 #include <linux/device.h>
92 #include <linux/wait.h>
93 #include <linux/bitops.h>
94 #include <linux/delay.h>
95 #include <linux/seq_file.h>
96 #include <linux/serial.h>
97 #include <linux/ratelimit.h>
99 #include <linux/uaccess.h>
101 #include <linux/kbd_kern.h>
102 #include <linux/vt_kern.h>
103 #include <linux/selection.h>
105 #include <linux/kmod.h>
106 #include <linux/nsproxy.h>
108 #undef TTY_DEBUG_HANGUP
110 #define TTY_PARANOIA_CHECK 1
111 #define CHECK_TTY_COUNT 1
113 struct ktermios tty_std_termios
= { /* for the benefit of tty drivers */
114 .c_iflag
= ICRNL
| IXON
,
115 .c_oflag
= OPOST
| ONLCR
,
116 .c_cflag
= B38400
| CS8
| CREAD
| HUPCL
,
117 .c_lflag
= ISIG
| ICANON
| ECHO
| ECHOE
| ECHOK
|
118 ECHOCTL
| ECHOKE
| IEXTEN
,
124 EXPORT_SYMBOL(tty_std_termios
);
126 /* This list gets poked at by procfs and various bits of boot up code. This
127 could do with some rationalisation such as pulling the tty proc function
130 LIST_HEAD(tty_drivers
); /* linked list of tty drivers */
132 /* Mutex to protect creating and releasing a tty. This is shared with
133 vt.c for deeply disgusting hack reasons */
134 DEFINE_MUTEX(tty_mutex
);
135 EXPORT_SYMBOL(tty_mutex
);
137 /* Spinlock to protect the tty->tty_files list */
138 DEFINE_SPINLOCK(tty_files_lock
);
140 static ssize_t
tty_read(struct file
*, char __user
*, size_t, loff_t
*);
141 static ssize_t
tty_write(struct file
*, const char __user
*, size_t, loff_t
*);
142 ssize_t
redirected_tty_write(struct file
*, const char __user
*,
144 static unsigned int tty_poll(struct file
*, poll_table
*);
145 static int tty_open(struct inode
*, struct file
*);
146 long tty_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
);
148 static long tty_compat_ioctl(struct file
*file
, unsigned int cmd
,
151 #define tty_compat_ioctl NULL
153 static int __tty_fasync(int fd
, struct file
*filp
, int on
);
154 static int tty_fasync(int fd
, struct file
*filp
, int on
);
155 static void release_tty(struct tty_struct
*tty
, int idx
);
156 static void __proc_set_tty(struct task_struct
*tsk
, struct tty_struct
*tty
);
157 static void proc_set_tty(struct task_struct
*tsk
, struct tty_struct
*tty
);
160 * alloc_tty_struct - allocate a tty object
162 * Return a new empty tty structure. The data fields have not
163 * been initialized in any way but has been zeroed
168 struct tty_struct
*alloc_tty_struct(void)
170 return kzalloc(sizeof(struct tty_struct
), GFP_KERNEL
);
174 * free_tty_struct - free a disused tty
175 * @tty: tty struct to free
177 * Free the write buffers, tty queue and tty memory itself.
179 * Locking: none. Must be called after tty is definitely unused
182 void free_tty_struct(struct tty_struct
*tty
)
187 put_device(tty
->dev
);
188 kfree(tty
->write_buf
);
189 tty
->magic
= 0xDEADDEAD;
193 static inline struct tty_struct
*file_tty(struct file
*file
)
195 return ((struct tty_file_private
*)file
->private_data
)->tty
;
198 int tty_alloc_file(struct file
*file
)
200 struct tty_file_private
*priv
;
202 priv
= kmalloc(sizeof(*priv
), GFP_KERNEL
);
206 file
->private_data
= priv
;
211 /* Associate a new file with the tty structure */
212 void tty_add_file(struct tty_struct
*tty
, struct file
*file
)
214 struct tty_file_private
*priv
= file
->private_data
;
219 spin_lock(&tty_files_lock
);
220 list_add(&priv
->list
, &tty
->tty_files
);
221 spin_unlock(&tty_files_lock
);
225 * tty_free_file - free file->private_data
227 * This shall be used only for fail path handling when tty_add_file was not
230 void tty_free_file(struct file
*file
)
232 struct tty_file_private
*priv
= file
->private_data
;
234 file
->private_data
= NULL
;
238 /* Delete file from its tty */
239 static void tty_del_file(struct file
*file
)
241 struct tty_file_private
*priv
= file
->private_data
;
243 spin_lock(&tty_files_lock
);
244 list_del(&priv
->list
);
245 spin_unlock(&tty_files_lock
);
250 #define TTY_NUMBER(tty) ((tty)->index + (tty)->driver->name_base)
253 * tty_name - return tty naming
254 * @tty: tty structure
255 * @buf: buffer for output
257 * Convert a tty structure into a name. The name reflects the kernel
258 * naming policy and if udev is in use may not reflect user space
263 char *tty_name(struct tty_struct
*tty
, char *buf
)
265 if (!tty
) /* Hmm. NULL pointer. That's fun. */
266 strcpy(buf
, "NULL tty");
268 strcpy(buf
, tty
->name
);
272 EXPORT_SYMBOL(tty_name
);
274 int tty_paranoia_check(struct tty_struct
*tty
, struct inode
*inode
,
277 #ifdef TTY_PARANOIA_CHECK
280 "null TTY for (%d:%d) in %s\n",
281 imajor(inode
), iminor(inode
), routine
);
284 if (tty
->magic
!= TTY_MAGIC
) {
286 "bad magic number for tty struct (%d:%d) in %s\n",
287 imajor(inode
), iminor(inode
), routine
);
294 static int check_tty_count(struct tty_struct
*tty
, const char *routine
)
296 #ifdef CHECK_TTY_COUNT
300 spin_lock(&tty_files_lock
);
301 list_for_each(p
, &tty
->tty_files
) {
304 spin_unlock(&tty_files_lock
);
305 if (tty
->driver
->type
== TTY_DRIVER_TYPE_PTY
&&
306 tty
->driver
->subtype
== PTY_TYPE_SLAVE
&&
307 tty
->link
&& tty
->link
->count
)
309 if (tty
->count
!= count
) {
310 printk(KERN_WARNING
"Warning: dev (%s) tty->count(%d) "
311 "!= #fd's(%d) in %s\n",
312 tty
->name
, tty
->count
, count
, routine
);
320 * get_tty_driver - find device of a tty
321 * @dev_t: device identifier
322 * @index: returns the index of the tty
324 * This routine returns a tty driver structure, given a device number
325 * and also passes back the index number.
327 * Locking: caller must hold tty_mutex
330 static struct tty_driver
*get_tty_driver(dev_t device
, int *index
)
332 struct tty_driver
*p
;
334 list_for_each_entry(p
, &tty_drivers
, tty_drivers
) {
335 dev_t base
= MKDEV(p
->major
, p
->minor_start
);
336 if (device
< base
|| device
>= base
+ p
->num
)
338 *index
= device
- base
;
339 return tty_driver_kref_get(p
);
344 #ifdef CONFIG_CONSOLE_POLL
347 * tty_find_polling_driver - find device of a polled tty
348 * @name: name string to match
349 * @line: pointer to resulting tty line nr
351 * This routine returns a tty driver structure, given a name
352 * and the condition that the tty driver is capable of polled
355 struct tty_driver
*tty_find_polling_driver(char *name
, int *line
)
357 struct tty_driver
*p
, *res
= NULL
;
362 for (str
= name
; *str
; str
++)
363 if ((*str
>= '0' && *str
<= '9') || *str
== ',')
369 tty_line
= simple_strtoul(str
, &str
, 10);
371 mutex_lock(&tty_mutex
);
372 /* Search through the tty devices to look for a match */
373 list_for_each_entry(p
, &tty_drivers
, tty_drivers
) {
374 if (strncmp(name
, p
->name
, len
) != 0)
382 if (tty_line
>= 0 && tty_line
< p
->num
&& p
->ops
&&
383 p
->ops
->poll_init
&& !p
->ops
->poll_init(p
, tty_line
, stp
)) {
384 res
= tty_driver_kref_get(p
);
389 mutex_unlock(&tty_mutex
);
393 EXPORT_SYMBOL_GPL(tty_find_polling_driver
);
397 * tty_check_change - check for POSIX terminal changes
400 * If we try to write to, or set the state of, a terminal and we're
401 * not in the foreground, send a SIGTTOU. If the signal is blocked or
402 * ignored, go ahead and perform the operation. (POSIX 7.2)
407 int tty_check_change(struct tty_struct
*tty
)
412 if (current
->signal
->tty
!= tty
)
415 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
418 printk(KERN_WARNING
"tty_check_change: tty->pgrp == NULL!\n");
421 if (task_pgrp(current
) == tty
->pgrp
)
423 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
424 if (is_ignored(SIGTTOU
))
426 if (is_current_pgrp_orphaned()) {
430 kill_pgrp(task_pgrp(current
), SIGTTOU
, 1);
431 set_thread_flag(TIF_SIGPENDING
);
436 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
440 EXPORT_SYMBOL(tty_check_change
);
442 static ssize_t
hung_up_tty_read(struct file
*file
, char __user
*buf
,
443 size_t count
, loff_t
*ppos
)
448 static ssize_t
hung_up_tty_write(struct file
*file
, const char __user
*buf
,
449 size_t count
, loff_t
*ppos
)
454 /* No kernel lock held - none needed ;) */
455 static unsigned int hung_up_tty_poll(struct file
*filp
, poll_table
*wait
)
457 return POLLIN
| POLLOUT
| POLLERR
| POLLHUP
| POLLRDNORM
| POLLWRNORM
;
460 static long hung_up_tty_ioctl(struct file
*file
, unsigned int cmd
,
463 return cmd
== TIOCSPGRP
? -ENOTTY
: -EIO
;
466 static long hung_up_tty_compat_ioctl(struct file
*file
,
467 unsigned int cmd
, unsigned long arg
)
469 return cmd
== TIOCSPGRP
? -ENOTTY
: -EIO
;
472 static const struct file_operations tty_fops
= {
477 .unlocked_ioctl
= tty_ioctl
,
478 .compat_ioctl
= tty_compat_ioctl
,
480 .release
= tty_release
,
481 .fasync
= tty_fasync
,
484 static const struct file_operations console_fops
= {
487 .write
= redirected_tty_write
,
489 .unlocked_ioctl
= tty_ioctl
,
490 .compat_ioctl
= tty_compat_ioctl
,
492 .release
= tty_release
,
493 .fasync
= tty_fasync
,
496 static const struct file_operations hung_up_tty_fops
= {
498 .read
= hung_up_tty_read
,
499 .write
= hung_up_tty_write
,
500 .poll
= hung_up_tty_poll
,
501 .unlocked_ioctl
= hung_up_tty_ioctl
,
502 .compat_ioctl
= hung_up_tty_compat_ioctl
,
503 .release
= tty_release
,
506 static DEFINE_SPINLOCK(redirect_lock
);
507 static struct file
*redirect
;
510 * tty_wakeup - request more data
513 * Internal and external helper for wakeups of tty. This function
514 * informs the line discipline if present that the driver is ready
515 * to receive more output data.
518 void tty_wakeup(struct tty_struct
*tty
)
520 struct tty_ldisc
*ld
;
522 if (test_bit(TTY_DO_WRITE_WAKEUP
, &tty
->flags
)) {
523 ld
= tty_ldisc_ref(tty
);
525 if (ld
->ops
->write_wakeup
)
526 ld
->ops
->write_wakeup(tty
);
530 wake_up_interruptible_poll(&tty
->write_wait
, POLLOUT
);
533 EXPORT_SYMBOL_GPL(tty_wakeup
);
536 * tty_signal_session_leader - sends SIGHUP to session leader
537 * @tty controlling tty
538 * @exit_session if non-zero, signal all foreground group processes
540 * Send SIGHUP and SIGCONT to the session leader and its process group.
541 * Optionally, signal all processes in the foreground process group.
543 * Returns the number of processes in the session with this tty
544 * as their controlling terminal. This value is used to drop
545 * tty references for those processes.
547 static int tty_signal_session_leader(struct tty_struct
*tty
, int exit_session
)
549 struct task_struct
*p
;
551 struct pid
*tty_pgrp
= NULL
;
553 read_lock(&tasklist_lock
);
555 do_each_pid_task(tty
->session
, PIDTYPE_SID
, p
) {
556 spin_lock_irq(&p
->sighand
->siglock
);
557 if (p
->signal
->tty
== tty
) {
558 p
->signal
->tty
= NULL
;
559 /* We defer the dereferences outside fo
563 if (!p
->signal
->leader
) {
564 spin_unlock_irq(&p
->sighand
->siglock
);
567 __group_send_sig_info(SIGHUP
, SEND_SIG_PRIV
, p
);
568 __group_send_sig_info(SIGCONT
, SEND_SIG_PRIV
, p
);
569 put_pid(p
->signal
->tty_old_pgrp
); /* A noop */
570 spin_lock(&tty
->ctrl_lock
);
571 tty_pgrp
= get_pid(tty
->pgrp
);
573 p
->signal
->tty_old_pgrp
= get_pid(tty
->pgrp
);
574 spin_unlock(&tty
->ctrl_lock
);
575 spin_unlock_irq(&p
->sighand
->siglock
);
576 } while_each_pid_task(tty
->session
, PIDTYPE_SID
, p
);
578 read_unlock(&tasklist_lock
);
582 kill_pgrp(tty_pgrp
, SIGHUP
, exit_session
);
590 * __tty_hangup - actual handler for hangup events
593 * This can be called by a "kworker" kernel thread. That is process
594 * synchronous but doesn't hold any locks, so we need to make sure we
595 * have the appropriate locks for what we're doing.
597 * The hangup event clears any pending redirections onto the hung up
598 * device. It ensures future writes will error and it does the needed
599 * line discipline hangup and signal delivery. The tty object itself
604 * redirect lock for undoing redirection
605 * file list lock for manipulating list of ttys
606 * tty_ldiscs_lock from called functions
607 * termios_rwsem resetting termios data
608 * tasklist_lock to walk task list for hangup event
609 * ->siglock to protect ->signal/->sighand
611 static void __tty_hangup(struct tty_struct
*tty
, int exit_session
)
613 struct file
*cons_filp
= NULL
;
614 struct file
*filp
, *f
= NULL
;
615 struct tty_file_private
*priv
;
616 int closecount
= 0, n
;
623 spin_lock(&redirect_lock
);
624 if (redirect
&& file_tty(redirect
) == tty
) {
628 spin_unlock(&redirect_lock
);
632 if (test_bit(TTY_HUPPED
, &tty
->flags
)) {
637 /* some functions below drop BTM, so we need this bit */
638 set_bit(TTY_HUPPING
, &tty
->flags
);
640 /* inuse_filps is protected by the single tty lock,
641 this really needs to change if we want to flush the
642 workqueue with the lock held */
643 check_tty_count(tty
, "tty_hangup");
645 spin_lock(&tty_files_lock
);
646 /* This breaks for file handles being sent over AF_UNIX sockets ? */
647 list_for_each_entry(priv
, &tty
->tty_files
, list
) {
649 if (filp
->f_op
->write
== redirected_tty_write
)
651 if (filp
->f_op
->write
!= tty_write
)
654 __tty_fasync(-1, filp
, 0); /* can't block */
655 filp
->f_op
= &hung_up_tty_fops
;
657 spin_unlock(&tty_files_lock
);
659 refs
= tty_signal_session_leader(tty
, exit_session
);
660 /* Account for the p->signal references we killed */
665 * it drops BTM and thus races with reopen
666 * we protect the race by TTY_HUPPING
668 tty_ldisc_hangup(tty
);
670 spin_lock_irq(&tty
->ctrl_lock
);
671 clear_bit(TTY_THROTTLED
, &tty
->flags
);
672 clear_bit(TTY_DO_WRITE_WAKEUP
, &tty
->flags
);
673 put_pid(tty
->session
);
677 tty
->ctrl_status
= 0;
678 spin_unlock_irq(&tty
->ctrl_lock
);
681 * If one of the devices matches a console pointer, we
682 * cannot just call hangup() because that will cause
683 * tty->count and state->count to go out of sync.
684 * So we just call close() the right number of times.
688 for (n
= 0; n
< closecount
; n
++)
689 tty
->ops
->close(tty
, cons_filp
);
690 } else if (tty
->ops
->hangup
)
691 (tty
->ops
->hangup
)(tty
);
693 * We don't want to have driver/ldisc interactions beyond
694 * the ones we did here. The driver layer expects no
695 * calls after ->hangup() from the ldisc side. However we
696 * can't yet guarantee all that.
698 set_bit(TTY_HUPPED
, &tty
->flags
);
699 clear_bit(TTY_HUPPING
, &tty
->flags
);
707 static void do_tty_hangup(struct work_struct
*work
)
709 struct tty_struct
*tty
=
710 container_of(work
, struct tty_struct
, hangup_work
);
712 __tty_hangup(tty
, 0);
716 * tty_hangup - trigger a hangup event
717 * @tty: tty to hangup
719 * A carrier loss (virtual or otherwise) has occurred on this like
720 * schedule a hangup sequence to run after this event.
723 void tty_hangup(struct tty_struct
*tty
)
725 #ifdef TTY_DEBUG_HANGUP
727 printk(KERN_DEBUG
"%s hangup...\n", tty_name(tty
, buf
));
729 schedule_work(&tty
->hangup_work
);
732 EXPORT_SYMBOL(tty_hangup
);
735 * tty_vhangup - process vhangup
736 * @tty: tty to hangup
738 * The user has asked via system call for the terminal to be hung up.
739 * We do this synchronously so that when the syscall returns the process
740 * is complete. That guarantee is necessary for security reasons.
743 void tty_vhangup(struct tty_struct
*tty
)
745 #ifdef TTY_DEBUG_HANGUP
748 printk(KERN_DEBUG
"%s vhangup...\n", tty_name(tty
, buf
));
750 __tty_hangup(tty
, 0);
753 EXPORT_SYMBOL(tty_vhangup
);
757 * tty_vhangup_self - process vhangup for own ctty
759 * Perform a vhangup on the current controlling tty
762 void tty_vhangup_self(void)
764 struct tty_struct
*tty
;
766 tty
= get_current_tty();
774 * tty_vhangup_session - hangup session leader exit
775 * @tty: tty to hangup
777 * The session leader is exiting and hanging up its controlling terminal.
778 * Every process in the foreground process group is signalled SIGHUP.
780 * We do this synchronously so that when the syscall returns the process
781 * is complete. That guarantee is necessary for security reasons.
784 static void tty_vhangup_session(struct tty_struct
*tty
)
786 #ifdef TTY_DEBUG_HANGUP
789 printk(KERN_DEBUG
"%s vhangup session...\n", tty_name(tty
, buf
));
791 __tty_hangup(tty
, 1);
795 * tty_hung_up_p - was tty hung up
796 * @filp: file pointer of tty
798 * Return true if the tty has been subject to a vhangup or a carrier
802 int tty_hung_up_p(struct file
*filp
)
804 return (filp
->f_op
== &hung_up_tty_fops
);
807 EXPORT_SYMBOL(tty_hung_up_p
);
809 static void session_clear_tty(struct pid
*session
)
811 struct task_struct
*p
;
812 do_each_pid_task(session
, PIDTYPE_SID
, p
) {
814 } while_each_pid_task(session
, PIDTYPE_SID
, p
);
818 * disassociate_ctty - disconnect controlling tty
819 * @on_exit: true if exiting so need to "hang up" the session
821 * This function is typically called only by the session leader, when
822 * it wants to disassociate itself from its controlling tty.
824 * It performs the following functions:
825 * (1) Sends a SIGHUP and SIGCONT to the foreground process group
826 * (2) Clears the tty from being controlling the session
827 * (3) Clears the controlling tty for all processes in the
830 * The argument on_exit is set to 1 if called when a process is
831 * exiting; it is 0 if called by the ioctl TIOCNOTTY.
834 * BTM is taken for hysterical raisins, and held when
835 * called from no_tty().
836 * tty_mutex is taken to protect tty
837 * ->siglock is taken to protect ->signal/->sighand
838 * tasklist_lock is taken to walk process list for sessions
839 * ->siglock is taken to protect ->signal/->sighand
842 void disassociate_ctty(int on_exit
)
844 struct tty_struct
*tty
;
846 if (!current
->signal
->leader
)
849 tty
= get_current_tty();
851 if (on_exit
&& tty
->driver
->type
!= TTY_DRIVER_TYPE_PTY
) {
852 tty_vhangup_session(tty
);
854 struct pid
*tty_pgrp
= tty_get_pgrp(tty
);
856 kill_pgrp(tty_pgrp
, SIGHUP
, on_exit
);
857 kill_pgrp(tty_pgrp
, SIGCONT
, on_exit
);
863 } else if (on_exit
) {
864 struct pid
*old_pgrp
;
865 spin_lock_irq(¤t
->sighand
->siglock
);
866 old_pgrp
= current
->signal
->tty_old_pgrp
;
867 current
->signal
->tty_old_pgrp
= NULL
;
868 spin_unlock_irq(¤t
->sighand
->siglock
);
870 kill_pgrp(old_pgrp
, SIGHUP
, on_exit
);
871 kill_pgrp(old_pgrp
, SIGCONT
, on_exit
);
877 spin_lock_irq(¤t
->sighand
->siglock
);
878 put_pid(current
->signal
->tty_old_pgrp
);
879 current
->signal
->tty_old_pgrp
= NULL
;
880 spin_unlock_irq(¤t
->sighand
->siglock
);
882 tty
= get_current_tty();
885 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
886 put_pid(tty
->session
);
890 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
893 #ifdef TTY_DEBUG_HANGUP
894 printk(KERN_DEBUG
"error attempted to write to tty [0x%p]"
899 /* Now clear signal->tty under the lock */
900 read_lock(&tasklist_lock
);
901 session_clear_tty(task_session(current
));
902 read_unlock(&tasklist_lock
);
907 * no_tty - Ensure the current process does not have a controlling tty
911 /* FIXME: Review locking here. The tty_lock never covered any race
912 between a new association and proc_clear_tty but possible we need
913 to protect against this anyway */
914 struct task_struct
*tsk
= current
;
915 disassociate_ctty(0);
921 * stop_tty - propagate flow control
924 * Perform flow control to the driver. For PTY/TTY pairs we
925 * must also propagate the TIOCKPKT status. May be called
926 * on an already stopped device and will not re-call the driver
929 * This functionality is used by both the line disciplines for
930 * halting incoming flow and by the driver. It may therefore be
931 * called from any context, may be under the tty atomic_write_lock
935 * Uses the tty control lock internally
938 void stop_tty(struct tty_struct
*tty
)
941 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
943 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
947 if (tty
->link
&& tty
->link
->packet
) {
948 tty
->ctrl_status
&= ~TIOCPKT_START
;
949 tty
->ctrl_status
|= TIOCPKT_STOP
;
950 wake_up_interruptible_poll(&tty
->link
->read_wait
, POLLIN
);
952 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
954 (tty
->ops
->stop
)(tty
);
957 EXPORT_SYMBOL(stop_tty
);
960 * start_tty - propagate flow control
963 * Start a tty that has been stopped if at all possible. Perform
964 * any necessary wakeups and propagate the TIOCPKT status. If this
965 * is the tty was previous stopped and is being started then the
966 * driver start method is invoked and the line discipline woken.
972 void start_tty(struct tty_struct
*tty
)
975 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
976 if (!tty
->stopped
|| tty
->flow_stopped
) {
977 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
981 if (tty
->link
&& tty
->link
->packet
) {
982 tty
->ctrl_status
&= ~TIOCPKT_STOP
;
983 tty
->ctrl_status
|= TIOCPKT_START
;
984 wake_up_interruptible_poll(&tty
->link
->read_wait
, POLLIN
);
986 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
988 (tty
->ops
->start
)(tty
);
989 /* If we have a running line discipline it may need kicking */
993 EXPORT_SYMBOL(start_tty
);
995 /* We limit tty time update visibility to every 8 seconds or so. */
996 static void tty_update_time(struct timespec
*time
)
998 unsigned long sec
= get_seconds() & ~7;
999 if ((long)(sec
- time
->tv_sec
) > 0)
1004 * tty_read - read method for tty device files
1005 * @file: pointer to tty file
1007 * @count: size of user buffer
1010 * Perform the read system call function on this terminal device. Checks
1011 * for hung up devices before calling the line discipline method.
1014 * Locks the line discipline internally while needed. Multiple
1015 * read calls may be outstanding in parallel.
1018 static ssize_t
tty_read(struct file
*file
, char __user
*buf
, size_t count
,
1022 struct inode
*inode
= file_inode(file
);
1023 struct tty_struct
*tty
= file_tty(file
);
1024 struct tty_ldisc
*ld
;
1026 if (tty_paranoia_check(tty
, inode
, "tty_read"))
1028 if (!tty
|| (test_bit(TTY_IO_ERROR
, &tty
->flags
)))
1031 /* We want to wait for the line discipline to sort out in this
1033 ld
= tty_ldisc_ref_wait(tty
);
1035 i
= (ld
->ops
->read
)(tty
, file
, buf
, count
);
1038 tty_ldisc_deref(ld
);
1041 tty_update_time(&inode
->i_atime
);
1046 void tty_write_unlock(struct tty_struct
*tty
)
1047 __releases(&tty
->atomic_write_lock
)
1049 mutex_unlock(&tty
->atomic_write_lock
);
1050 wake_up_interruptible_poll(&tty
->write_wait
, POLLOUT
);
1053 int tty_write_lock(struct tty_struct
*tty
, int ndelay
)
1054 __acquires(&tty
->atomic_write_lock
)
1056 if (!mutex_trylock(&tty
->atomic_write_lock
)) {
1059 if (mutex_lock_interruptible(&tty
->atomic_write_lock
))
1060 return -ERESTARTSYS
;
1066 * Split writes up in sane blocksizes to avoid
1067 * denial-of-service type attacks
1069 static inline ssize_t
do_tty_write(
1070 ssize_t (*write
)(struct tty_struct
*, struct file
*, const unsigned char *, size_t),
1071 struct tty_struct
*tty
,
1073 const char __user
*buf
,
1076 ssize_t ret
, written
= 0;
1079 ret
= tty_write_lock(tty
, file
->f_flags
& O_NDELAY
);
1084 * We chunk up writes into a temporary buffer. This
1085 * simplifies low-level drivers immensely, since they
1086 * don't have locking issues and user mode accesses.
1088 * But if TTY_NO_WRITE_SPLIT is set, we should use a
1091 * The default chunk-size is 2kB, because the NTTY
1092 * layer has problems with bigger chunks. It will
1093 * claim to be able to handle more characters than
1096 * FIXME: This can probably go away now except that 64K chunks
1097 * are too likely to fail unless switched to vmalloc...
1100 if (test_bit(TTY_NO_WRITE_SPLIT
, &tty
->flags
))
1105 /* write_buf/write_cnt is protected by the atomic_write_lock mutex */
1106 if (tty
->write_cnt
< chunk
) {
1107 unsigned char *buf_chunk
;
1112 buf_chunk
= kmalloc(chunk
, GFP_KERNEL
);
1117 kfree(tty
->write_buf
);
1118 tty
->write_cnt
= chunk
;
1119 tty
->write_buf
= buf_chunk
;
1122 /* Do the write .. */
1124 size_t size
= count
;
1128 if (copy_from_user(tty
->write_buf
, buf
, size
))
1130 ret
= write(tty
, file
, tty
->write_buf
, size
);
1139 if (signal_pending(current
))
1144 tty_update_time(&file_inode(file
)->i_mtime
);
1148 tty_write_unlock(tty
);
1153 * tty_write_message - write a message to a certain tty, not just the console.
1154 * @tty: the destination tty_struct
1155 * @msg: the message to write
1157 * This is used for messages that need to be redirected to a specific tty.
1158 * We don't put it into the syslog queue right now maybe in the future if
1161 * We must still hold the BTM and test the CLOSING flag for the moment.
1164 void tty_write_message(struct tty_struct
*tty
, char *msg
)
1167 mutex_lock(&tty
->atomic_write_lock
);
1169 if (tty
->ops
->write
&& !test_bit(TTY_CLOSING
, &tty
->flags
)) {
1171 tty
->ops
->write(tty
, msg
, strlen(msg
));
1174 tty_write_unlock(tty
);
1181 * tty_write - write method for tty device file
1182 * @file: tty file pointer
1183 * @buf: user data to write
1184 * @count: bytes to write
1187 * Write data to a tty device via the line discipline.
1190 * Locks the line discipline as required
1191 * Writes to the tty driver are serialized by the atomic_write_lock
1192 * and are then processed in chunks to the device. The line discipline
1193 * write method will not be invoked in parallel for each device.
1196 static ssize_t
tty_write(struct file
*file
, const char __user
*buf
,
1197 size_t count
, loff_t
*ppos
)
1199 struct tty_struct
*tty
= file_tty(file
);
1200 struct tty_ldisc
*ld
;
1203 if (tty_paranoia_check(tty
, file_inode(file
), "tty_write"))
1205 if (!tty
|| !tty
->ops
->write
||
1206 (test_bit(TTY_IO_ERROR
, &tty
->flags
)))
1208 /* Short term debug to catch buggy drivers */
1209 if (tty
->ops
->write_room
== NULL
)
1210 printk(KERN_ERR
"tty driver %s lacks a write_room method.\n",
1212 ld
= tty_ldisc_ref_wait(tty
);
1213 if (!ld
->ops
->write
)
1216 ret
= do_tty_write(ld
->ops
->write
, tty
, file
, buf
, count
);
1217 tty_ldisc_deref(ld
);
1221 ssize_t
redirected_tty_write(struct file
*file
, const char __user
*buf
,
1222 size_t count
, loff_t
*ppos
)
1224 struct file
*p
= NULL
;
1226 spin_lock(&redirect_lock
);
1228 p
= get_file(redirect
);
1229 spin_unlock(&redirect_lock
);
1233 res
= vfs_write(p
, buf
, count
, &p
->f_pos
);
1237 return tty_write(file
, buf
, count
, ppos
);
1240 static char ptychar
[] = "pqrstuvwxyzabcde";
1243 * pty_line_name - generate name for a pty
1244 * @driver: the tty driver in use
1245 * @index: the minor number
1246 * @p: output buffer of at least 6 bytes
1248 * Generate a name from a driver reference and write it to the output
1253 static void pty_line_name(struct tty_driver
*driver
, int index
, char *p
)
1255 int i
= index
+ driver
->name_base
;
1256 /* ->name is initialized to "ttyp", but "tty" is expected */
1257 sprintf(p
, "%s%c%x",
1258 driver
->subtype
== PTY_TYPE_SLAVE
? "tty" : driver
->name
,
1259 ptychar
[i
>> 4 & 0xf], i
& 0xf);
1263 * tty_line_name - generate name for a tty
1264 * @driver: the tty driver in use
1265 * @index: the minor number
1266 * @p: output buffer of at least 7 bytes
1268 * Generate a name from a driver reference and write it to the output
1273 static void tty_line_name(struct tty_driver
*driver
, int index
, char *p
)
1275 if (driver
->flags
& TTY_DRIVER_UNNUMBERED_NODE
)
1276 strcpy(p
, driver
->name
);
1278 sprintf(p
, "%s%d", driver
->name
, index
+ driver
->name_base
);
1282 * tty_driver_lookup_tty() - find an existing tty, if any
1283 * @driver: the driver for the tty
1284 * @idx: the minor number
1286 * Return the tty, if found or ERR_PTR() otherwise.
1288 * Locking: tty_mutex must be held. If tty is found, the mutex must
1289 * be held until the 'fast-open' is also done. Will change once we
1290 * have refcounting in the driver and per driver locking
1292 static struct tty_struct
*tty_driver_lookup_tty(struct tty_driver
*driver
,
1293 struct inode
*inode
, int idx
)
1295 if (driver
->ops
->lookup
)
1296 return driver
->ops
->lookup(driver
, inode
, idx
);
1298 return driver
->ttys
[idx
];
1302 * tty_init_termios - helper for termios setup
1303 * @tty: the tty to set up
1305 * Initialise the termios structures for this tty. Thus runs under
1306 * the tty_mutex currently so we can be relaxed about ordering.
1309 int tty_init_termios(struct tty_struct
*tty
)
1311 struct ktermios
*tp
;
1312 int idx
= tty
->index
;
1314 if (tty
->driver
->flags
& TTY_DRIVER_RESET_TERMIOS
)
1315 tty
->termios
= tty
->driver
->init_termios
;
1317 /* Check for lazy saved data */
1318 tp
= tty
->driver
->termios
[idx
];
1322 tty
->termios
= tty
->driver
->init_termios
;
1324 /* Compatibility until drivers always set this */
1325 tty
->termios
.c_ispeed
= tty_termios_input_baud_rate(&tty
->termios
);
1326 tty
->termios
.c_ospeed
= tty_termios_baud_rate(&tty
->termios
);
1329 EXPORT_SYMBOL_GPL(tty_init_termios
);
1331 int tty_standard_install(struct tty_driver
*driver
, struct tty_struct
*tty
)
1333 int ret
= tty_init_termios(tty
);
1337 tty_driver_kref_get(driver
);
1339 driver
->ttys
[tty
->index
] = tty
;
1342 EXPORT_SYMBOL_GPL(tty_standard_install
);
1345 * tty_driver_install_tty() - install a tty entry in the driver
1346 * @driver: the driver for the tty
1349 * Install a tty object into the driver tables. The tty->index field
1350 * will be set by the time this is called. This method is responsible
1351 * for ensuring any need additional structures are allocated and
1354 * Locking: tty_mutex for now
1356 static int tty_driver_install_tty(struct tty_driver
*driver
,
1357 struct tty_struct
*tty
)
1359 return driver
->ops
->install
? driver
->ops
->install(driver
, tty
) :
1360 tty_standard_install(driver
, tty
);
1364 * tty_driver_remove_tty() - remove a tty from the driver tables
1365 * @driver: the driver for the tty
1366 * @idx: the minor number
1368 * Remvoe a tty object from the driver tables. The tty->index field
1369 * will be set by the time this is called.
1371 * Locking: tty_mutex for now
1373 void tty_driver_remove_tty(struct tty_driver
*driver
, struct tty_struct
*tty
)
1375 if (driver
->ops
->remove
)
1376 driver
->ops
->remove(driver
, tty
);
1378 driver
->ttys
[tty
->index
] = NULL
;
1382 * tty_reopen() - fast re-open of an open tty
1383 * @tty - the tty to open
1385 * Return 0 on success, -errno on error.
1387 * Locking: tty_mutex must be held from the time the tty was found
1388 * till this open completes.
1390 static int tty_reopen(struct tty_struct
*tty
)
1392 struct tty_driver
*driver
= tty
->driver
;
1394 if (test_bit(TTY_CLOSING
, &tty
->flags
) ||
1395 test_bit(TTY_HUPPING
, &tty
->flags
))
1398 if (driver
->type
== TTY_DRIVER_TYPE_PTY
&&
1399 driver
->subtype
== PTY_TYPE_MASTER
) {
1401 * special case for PTY masters: only one open permitted,
1402 * and the slave side open count is incremented as well.
1411 WARN_ON(!tty
->ldisc
);
1417 * tty_init_dev - initialise a tty device
1418 * @driver: tty driver we are opening a device on
1419 * @idx: device index
1420 * @ret_tty: returned tty structure
1422 * Prepare a tty device. This may not be a "new" clean device but
1423 * could also be an active device. The pty drivers require special
1424 * handling because of this.
1427 * The function is called under the tty_mutex, which
1428 * protects us from the tty struct or driver itself going away.
1430 * On exit the tty device has the line discipline attached and
1431 * a reference count of 1. If a pair was created for pty/tty use
1432 * and the other was a pty master then it too has a reference count of 1.
1434 * WSH 06/09/97: Rewritten to remove races and properly clean up after a
1435 * failed open. The new code protects the open with a mutex, so it's
1436 * really quite straightforward. The mutex locking can probably be
1437 * relaxed for the (most common) case of reopening a tty.
1440 struct tty_struct
*tty_init_dev(struct tty_driver
*driver
, int idx
)
1442 struct tty_struct
*tty
;
1446 * First time open is complex, especially for PTY devices.
1447 * This code guarantees that either everything succeeds and the
1448 * TTY is ready for operation, or else the table slots are vacated
1449 * and the allocated memory released. (Except that the termios
1450 * and locked termios may be retained.)
1453 if (!try_module_get(driver
->owner
))
1454 return ERR_PTR(-ENODEV
);
1456 tty
= alloc_tty_struct();
1459 goto err_module_put
;
1461 initialize_tty_struct(tty
, driver
, idx
);
1464 retval
= tty_driver_install_tty(driver
, tty
);
1466 goto err_deinit_tty
;
1469 tty
->port
= driver
->ports
[idx
];
1471 WARN_RATELIMIT(!tty
->port
,
1472 "%s: %s driver does not set tty->port. This will crash the kernel later. Fix the driver!\n",
1473 __func__
, tty
->driver
->name
);
1475 tty
->port
->itty
= tty
;
1478 * Structures all installed ... call the ldisc open routines.
1479 * If we fail here just call release_tty to clean up. No need
1480 * to decrement the use counts, as release_tty doesn't care.
1482 retval
= tty_ldisc_setup(tty
, tty
->link
);
1484 goto err_release_tty
;
1485 /* Return the tty locked so that it cannot vanish under the caller */
1490 deinitialize_tty_struct(tty
);
1491 free_tty_struct(tty
);
1493 module_put(driver
->owner
);
1494 return ERR_PTR(retval
);
1496 /* call the tty release_tty routine to clean out this slot */
1499 printk_ratelimited(KERN_INFO
"tty_init_dev: ldisc open failed, "
1500 "clearing slot %d\n", idx
);
1501 release_tty(tty
, idx
);
1502 return ERR_PTR(retval
);
1505 void tty_free_termios(struct tty_struct
*tty
)
1507 struct ktermios
*tp
;
1508 int idx
= tty
->index
;
1510 /* If the port is going to reset then it has no termios to save */
1511 if (tty
->driver
->flags
& TTY_DRIVER_RESET_TERMIOS
)
1514 /* Stash the termios data */
1515 tp
= tty
->driver
->termios
[idx
];
1517 tp
= kmalloc(sizeof(struct ktermios
), GFP_KERNEL
);
1519 pr_warn("tty: no memory to save termios state.\n");
1522 tty
->driver
->termios
[idx
] = tp
;
1526 EXPORT_SYMBOL(tty_free_termios
);
1529 * tty_flush_works - flush all works of a tty
1530 * @tty: tty device to flush works for
1532 * Sync flush all works belonging to @tty.
1534 static void tty_flush_works(struct tty_struct
*tty
)
1536 flush_work(&tty
->SAK_work
);
1537 flush_work(&tty
->hangup_work
);
1541 * release_one_tty - release tty structure memory
1542 * @kref: kref of tty we are obliterating
1544 * Releases memory associated with a tty structure, and clears out the
1545 * driver table slots. This function is called when a device is no longer
1546 * in use. It also gets called when setup of a device fails.
1549 * takes the file list lock internally when working on the list
1550 * of ttys that the driver keeps.
1552 * This method gets called from a work queue so that the driver private
1553 * cleanup ops can sleep (needed for USB at least)
1555 static void release_one_tty(struct work_struct
*work
)
1557 struct tty_struct
*tty
=
1558 container_of(work
, struct tty_struct
, hangup_work
);
1559 struct tty_driver
*driver
= tty
->driver
;
1561 if (tty
->ops
->cleanup
)
1562 tty
->ops
->cleanup(tty
);
1565 tty_driver_kref_put(driver
);
1566 module_put(driver
->owner
);
1568 spin_lock(&tty_files_lock
);
1569 list_del_init(&tty
->tty_files
);
1570 spin_unlock(&tty_files_lock
);
1573 put_pid(tty
->session
);
1574 free_tty_struct(tty
);
1577 static void queue_release_one_tty(struct kref
*kref
)
1579 struct tty_struct
*tty
= container_of(kref
, struct tty_struct
, kref
);
1581 /* The hangup queue is now free so we can reuse it rather than
1582 waste a chunk of memory for each port */
1583 INIT_WORK(&tty
->hangup_work
, release_one_tty
);
1584 schedule_work(&tty
->hangup_work
);
1588 * tty_kref_put - release a tty kref
1591 * Release a reference to a tty device and if need be let the kref
1592 * layer destruct the object for us
1595 void tty_kref_put(struct tty_struct
*tty
)
1598 kref_put(&tty
->kref
, queue_release_one_tty
);
1600 EXPORT_SYMBOL(tty_kref_put
);
1603 * release_tty - release tty structure memory
1605 * Release both @tty and a possible linked partner (think pty pair),
1606 * and decrement the refcount of the backing module.
1610 * takes the file list lock internally when working on the list
1611 * of ttys that the driver keeps.
1614 static void release_tty(struct tty_struct
*tty
, int idx
)
1616 /* This should always be true but check for the moment */
1617 WARN_ON(tty
->index
!= idx
);
1618 WARN_ON(!mutex_is_locked(&tty_mutex
));
1619 if (tty
->ops
->shutdown
)
1620 tty
->ops
->shutdown(tty
);
1621 tty_free_termios(tty
);
1622 tty_driver_remove_tty(tty
->driver
, tty
);
1623 tty
->port
->itty
= NULL
;
1625 tty
->link
->port
->itty
= NULL
;
1626 cancel_work_sync(&tty
->port
->buf
.work
);
1629 tty_kref_put(tty
->link
);
1634 * tty_release_checks - check a tty before real release
1635 * @tty: tty to check
1636 * @o_tty: link of @tty (if any)
1637 * @idx: index of the tty
1639 * Performs some paranoid checking before true release of the @tty.
1640 * This is a no-op unless TTY_PARANOIA_CHECK is defined.
1642 static int tty_release_checks(struct tty_struct
*tty
, struct tty_struct
*o_tty
,
1645 #ifdef TTY_PARANOIA_CHECK
1646 if (idx
< 0 || idx
>= tty
->driver
->num
) {
1647 printk(KERN_DEBUG
"%s: bad idx when trying to free (%s)\n",
1648 __func__
, tty
->name
);
1652 /* not much to check for devpts */
1653 if (tty
->driver
->flags
& TTY_DRIVER_DEVPTS_MEM
)
1656 if (tty
!= tty
->driver
->ttys
[idx
]) {
1657 printk(KERN_DEBUG
"%s: driver.table[%d] not tty for (%s)\n",
1658 __func__
, idx
, tty
->name
);
1661 if (tty
->driver
->other
) {
1662 if (o_tty
!= tty
->driver
->other
->ttys
[idx
]) {
1663 printk(KERN_DEBUG
"%s: other->table[%d] not o_tty for (%s)\n",
1664 __func__
, idx
, tty
->name
);
1667 if (o_tty
->link
!= tty
) {
1668 printk(KERN_DEBUG
"%s: bad pty pointers\n", __func__
);
1677 * tty_release - vfs callback for close
1678 * @inode: inode of tty
1679 * @filp: file pointer for handle to tty
1681 * Called the last time each file handle is closed that references
1682 * this tty. There may however be several such references.
1685 * Takes bkl. See tty_release_dev
1687 * Even releasing the tty structures is a tricky business.. We have
1688 * to be very careful that the structures are all released at the
1689 * same time, as interrupts might otherwise get the wrong pointers.
1691 * WSH 09/09/97: rewritten to avoid some nasty race conditions that could
1692 * lead to double frees or releasing memory still in use.
1695 int tty_release(struct inode
*inode
, struct file
*filp
)
1697 struct tty_struct
*tty
= file_tty(filp
);
1698 struct tty_struct
*o_tty
;
1699 int pty_master
, tty_closing
, o_tty_closing
, do_sleep
;
1703 if (tty_paranoia_check(tty
, inode
, __func__
))
1707 check_tty_count(tty
, __func__
);
1709 __tty_fasync(-1, filp
, 0);
1712 pty_master
= (tty
->driver
->type
== TTY_DRIVER_TYPE_PTY
&&
1713 tty
->driver
->subtype
== PTY_TYPE_MASTER
);
1714 /* Review: parallel close */
1717 if (tty_release_checks(tty
, o_tty
, idx
)) {
1722 #ifdef TTY_DEBUG_HANGUP
1723 printk(KERN_DEBUG
"%s: %s (tty count=%d)...\n", __func__
,
1724 tty_name(tty
, buf
), tty
->count
);
1727 if (tty
->ops
->close
)
1728 tty
->ops
->close(tty
, filp
);
1732 * Sanity check: if tty->count is going to zero, there shouldn't be
1733 * any waiters on tty->read_wait or tty->write_wait. We test the
1734 * wait queues and kick everyone out _before_ actually starting to
1735 * close. This ensures that we won't block while releasing the tty
1738 * The test for the o_tty closing is necessary, since the master and
1739 * slave sides may close in any order. If the slave side closes out
1740 * first, its count will be one, since the master side holds an open.
1741 * Thus this test wouldn't be triggered at the time the slave closes,
1744 * Note that it's possible for the tty to be opened again while we're
1745 * flushing out waiters. By recalculating the closing flags before
1746 * each iteration we avoid any problems.
1749 /* Guard against races with tty->count changes elsewhere and
1750 opens on /dev/tty */
1752 mutex_lock(&tty_mutex
);
1753 tty_lock_pair(tty
, o_tty
);
1754 tty_closing
= tty
->count
<= 1;
1755 o_tty_closing
= o_tty
&&
1756 (o_tty
->count
<= (pty_master
? 1 : 0));
1760 if (waitqueue_active(&tty
->read_wait
)) {
1761 wake_up_poll(&tty
->read_wait
, POLLIN
);
1764 if (waitqueue_active(&tty
->write_wait
)) {
1765 wake_up_poll(&tty
->write_wait
, POLLOUT
);
1769 if (o_tty_closing
) {
1770 if (waitqueue_active(&o_tty
->read_wait
)) {
1771 wake_up_poll(&o_tty
->read_wait
, POLLIN
);
1774 if (waitqueue_active(&o_tty
->write_wait
)) {
1775 wake_up_poll(&o_tty
->write_wait
, POLLOUT
);
1782 printk(KERN_WARNING
"%s: %s: read/write wait queue active!\n",
1783 __func__
, tty_name(tty
, buf
));
1784 tty_unlock_pair(tty
, o_tty
);
1785 mutex_unlock(&tty_mutex
);
1790 * The closing flags are now consistent with the open counts on
1791 * both sides, and we've completed the last operation that could
1792 * block, so it's safe to proceed with closing.
1794 * We must *not* drop the tty_mutex until we ensure that a further
1795 * entry into tty_open can not pick up this tty.
1798 if (--o_tty
->count
< 0) {
1799 printk(KERN_WARNING
"%s: bad pty slave count (%d) for %s\n",
1800 __func__
, o_tty
->count
, tty_name(o_tty
, buf
));
1804 if (--tty
->count
< 0) {
1805 printk(KERN_WARNING
"%s: bad tty->count (%d) for %s\n",
1806 __func__
, tty
->count
, tty_name(tty
, buf
));
1811 * We've decremented tty->count, so we need to remove this file
1812 * descriptor off the tty->tty_files list; this serves two
1814 * - check_tty_count sees the correct number of file descriptors
1815 * associated with this tty.
1816 * - do_tty_hangup no longer sees this file descriptor as
1817 * something that needs to be handled for hangups.
1822 * Perform some housekeeping before deciding whether to return.
1824 * Set the TTY_CLOSING flag if this was the last open. In the
1825 * case of a pty we may have to wait around for the other side
1826 * to close, and TTY_CLOSING makes sure we can't be reopened.
1829 set_bit(TTY_CLOSING
, &tty
->flags
);
1831 set_bit(TTY_CLOSING
, &o_tty
->flags
);
1834 * If _either_ side is closing, make sure there aren't any
1835 * processes that still think tty or o_tty is their controlling
1838 if (tty_closing
|| o_tty_closing
) {
1839 read_lock(&tasklist_lock
);
1840 session_clear_tty(tty
->session
);
1842 session_clear_tty(o_tty
->session
);
1843 read_unlock(&tasklist_lock
);
1846 mutex_unlock(&tty_mutex
);
1847 tty_unlock_pair(tty
, o_tty
);
1848 /* At this point the TTY_CLOSING flag should ensure a dead tty
1849 cannot be re-opened by a racing opener */
1851 /* check whether both sides are closing ... */
1852 if (!tty_closing
|| (o_tty
&& !o_tty_closing
))
1855 #ifdef TTY_DEBUG_HANGUP
1856 printk(KERN_DEBUG
"%s: %s: final close\n", __func__
, tty_name(tty
, buf
));
1859 * Ask the line discipline code to release its structures
1861 tty_ldisc_release(tty
, o_tty
);
1863 /* Wait for pending work before tty destruction commmences */
1864 tty_flush_works(tty
);
1866 tty_flush_works(o_tty
);
1868 #ifdef TTY_DEBUG_HANGUP
1869 printk(KERN_DEBUG
"%s: %s: freeing structure...\n", __func__
, tty_name(tty
, buf
));
1872 * The release_tty function takes care of the details of clearing
1873 * the slots and preserving the termios structure. The tty_unlock_pair
1874 * should be safe as we keep a kref while the tty is locked (so the
1875 * unlock never unlocks a freed tty).
1877 mutex_lock(&tty_mutex
);
1878 release_tty(tty
, idx
);
1879 mutex_unlock(&tty_mutex
);
1885 * tty_open_current_tty - get tty of current task for open
1886 * @device: device number
1887 * @filp: file pointer to tty
1888 * @return: tty of the current task iff @device is /dev/tty
1890 * We cannot return driver and index like for the other nodes because
1891 * devpts will not work then. It expects inodes to be from devpts FS.
1893 * We need to move to returning a refcounted object from all the lookup
1894 * paths including this one.
1896 static struct tty_struct
*tty_open_current_tty(dev_t device
, struct file
*filp
)
1898 struct tty_struct
*tty
;
1900 if (device
!= MKDEV(TTYAUX_MAJOR
, 0))
1903 tty
= get_current_tty();
1905 return ERR_PTR(-ENXIO
);
1907 filp
->f_flags
|= O_NONBLOCK
; /* Don't let /dev/tty block */
1910 /* FIXME: we put a reference and return a TTY! */
1911 /* This is only safe because the caller holds tty_mutex */
1916 * tty_lookup_driver - lookup a tty driver for a given device file
1917 * @device: device number
1918 * @filp: file pointer to tty
1919 * @noctty: set if the device should not become a controlling tty
1920 * @index: index for the device in the @return driver
1921 * @return: driver for this inode (with increased refcount)
1923 * If @return is not erroneous, the caller is responsible to decrement the
1924 * refcount by tty_driver_kref_put.
1926 * Locking: tty_mutex protects get_tty_driver
1928 static struct tty_driver
*tty_lookup_driver(dev_t device
, struct file
*filp
,
1929 int *noctty
, int *index
)
1931 struct tty_driver
*driver
;
1935 case MKDEV(TTY_MAJOR
, 0): {
1936 extern struct tty_driver
*console_driver
;
1937 driver
= tty_driver_kref_get(console_driver
);
1938 *index
= fg_console
;
1943 case MKDEV(TTYAUX_MAJOR
, 1): {
1944 struct tty_driver
*console_driver
= console_device(index
);
1945 if (console_driver
) {
1946 driver
= tty_driver_kref_get(console_driver
);
1948 /* Don't let /dev/console block */
1949 filp
->f_flags
|= O_NONBLOCK
;
1954 return ERR_PTR(-ENODEV
);
1957 driver
= get_tty_driver(device
, index
);
1959 return ERR_PTR(-ENODEV
);
1966 * tty_open - open a tty device
1967 * @inode: inode of device file
1968 * @filp: file pointer to tty
1970 * tty_open and tty_release keep up the tty count that contains the
1971 * number of opens done on a tty. We cannot use the inode-count, as
1972 * different inodes might point to the same tty.
1974 * Open-counting is needed for pty masters, as well as for keeping
1975 * track of serial lines: DTR is dropped when the last close happens.
1976 * (This is not done solely through tty->count, now. - Ted 1/27/92)
1978 * The termios state of a pty is reset on first open so that
1979 * settings don't persist across reuse.
1981 * Locking: tty_mutex protects tty, tty_lookup_driver and tty_init_dev.
1982 * tty->count should protect the rest.
1983 * ->siglock protects ->signal/->sighand
1985 * Note: the tty_unlock/lock cases without a ref are only safe due to
1989 static int tty_open(struct inode
*inode
, struct file
*filp
)
1991 struct tty_struct
*tty
;
1993 struct tty_driver
*driver
= NULL
;
1995 dev_t device
= inode
->i_rdev
;
1996 unsigned saved_flags
= filp
->f_flags
;
1998 nonseekable_open(inode
, filp
);
2001 retval
= tty_alloc_file(filp
);
2005 noctty
= filp
->f_flags
& O_NOCTTY
;
2009 mutex_lock(&tty_mutex
);
2010 /* This is protected by the tty_mutex */
2011 tty
= tty_open_current_tty(device
, filp
);
2013 retval
= PTR_ERR(tty
);
2016 driver
= tty_lookup_driver(device
, filp
, &noctty
, &index
);
2017 if (IS_ERR(driver
)) {
2018 retval
= PTR_ERR(driver
);
2022 /* check whether we're reopening an existing tty */
2023 tty
= tty_driver_lookup_tty(driver
, inode
, index
);
2025 retval
= PTR_ERR(tty
);
2032 retval
= tty_reopen(tty
);
2035 tty
= ERR_PTR(retval
);
2037 } else /* Returns with the tty_lock held for now */
2038 tty
= tty_init_dev(driver
, index
);
2040 mutex_unlock(&tty_mutex
);
2042 tty_driver_kref_put(driver
);
2044 retval
= PTR_ERR(tty
);
2048 tty_add_file(tty
, filp
);
2050 check_tty_count(tty
, __func__
);
2051 if (tty
->driver
->type
== TTY_DRIVER_TYPE_PTY
&&
2052 tty
->driver
->subtype
== PTY_TYPE_MASTER
)
2054 #ifdef TTY_DEBUG_HANGUP
2055 printk(KERN_DEBUG
"%s: opening %s...\n", __func__
, tty
->name
);
2058 retval
= tty
->ops
->open(tty
, filp
);
2061 filp
->f_flags
= saved_flags
;
2063 if (!retval
&& test_bit(TTY_EXCLUSIVE
, &tty
->flags
) &&
2064 !capable(CAP_SYS_ADMIN
))
2068 #ifdef TTY_DEBUG_HANGUP
2069 printk(KERN_DEBUG
"%s: error %d in opening %s...\n", __func__
,
2072 tty_unlock(tty
); /* need to call tty_release without BTM */
2073 tty_release(inode
, filp
);
2074 if (retval
!= -ERESTARTSYS
)
2077 if (signal_pending(current
))
2082 * Need to reset f_op in case a hangup happened.
2084 if (filp
->f_op
== &hung_up_tty_fops
)
2085 filp
->f_op
= &tty_fops
;
2091 mutex_lock(&tty_mutex
);
2093 spin_lock_irq(¤t
->sighand
->siglock
);
2095 current
->signal
->leader
&&
2096 !current
->signal
->tty
&&
2097 tty
->session
== NULL
)
2098 __proc_set_tty(current
, tty
);
2099 spin_unlock_irq(¤t
->sighand
->siglock
);
2101 mutex_unlock(&tty_mutex
);
2104 mutex_unlock(&tty_mutex
);
2105 /* after locks to avoid deadlock */
2106 if (!IS_ERR_OR_NULL(driver
))
2107 tty_driver_kref_put(driver
);
2109 tty_free_file(filp
);
2116 * tty_poll - check tty status
2117 * @filp: file being polled
2118 * @wait: poll wait structures to update
2120 * Call the line discipline polling method to obtain the poll
2121 * status of the device.
2123 * Locking: locks called line discipline but ldisc poll method
2124 * may be re-entered freely by other callers.
2127 static unsigned int tty_poll(struct file
*filp
, poll_table
*wait
)
2129 struct tty_struct
*tty
= file_tty(filp
);
2130 struct tty_ldisc
*ld
;
2133 if (tty_paranoia_check(tty
, file_inode(filp
), "tty_poll"))
2136 ld
= tty_ldisc_ref_wait(tty
);
2138 ret
= (ld
->ops
->poll
)(tty
, filp
, wait
);
2139 tty_ldisc_deref(ld
);
2143 static int __tty_fasync(int fd
, struct file
*filp
, int on
)
2145 struct tty_struct
*tty
= file_tty(filp
);
2146 struct tty_ldisc
*ldisc
;
2147 unsigned long flags
;
2150 if (tty_paranoia_check(tty
, file_inode(filp
), "tty_fasync"))
2153 retval
= fasync_helper(fd
, filp
, on
, &tty
->fasync
);
2157 ldisc
= tty_ldisc_ref(tty
);
2159 if (ldisc
->ops
->fasync
)
2160 ldisc
->ops
->fasync(tty
, on
);
2161 tty_ldisc_deref(ldisc
);
2168 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
2171 type
= PIDTYPE_PGID
;
2173 pid
= task_pid(current
);
2177 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
2178 retval
= __f_setown(filp
, pid
, type
, 0);
2185 static int tty_fasync(int fd
, struct file
*filp
, int on
)
2187 struct tty_struct
*tty
= file_tty(filp
);
2191 retval
= __tty_fasync(fd
, filp
, on
);
2198 * tiocsti - fake input character
2199 * @tty: tty to fake input into
2200 * @p: pointer to character
2202 * Fake input to a tty device. Does the necessary locking and
2205 * FIXME: does not honour flow control ??
2208 * Called functions take tty_ldiscs_lock
2209 * current->signal->tty check is safe without locks
2211 * FIXME: may race normal receive processing
2214 static int tiocsti(struct tty_struct
*tty
, char __user
*p
)
2217 struct tty_ldisc
*ld
;
2219 if ((current
->signal
->tty
!= tty
) && !capable(CAP_SYS_ADMIN
))
2221 if (get_user(ch
, p
))
2223 tty_audit_tiocsti(tty
, ch
);
2224 ld
= tty_ldisc_ref_wait(tty
);
2225 ld
->ops
->receive_buf(tty
, &ch
, &mbz
, 1);
2226 tty_ldisc_deref(ld
);
2231 * tiocgwinsz - implement window query ioctl
2233 * @arg: user buffer for result
2235 * Copies the kernel idea of the window size into the user buffer.
2237 * Locking: tty->winsize_mutex is taken to ensure the winsize data
2241 static int tiocgwinsz(struct tty_struct
*tty
, struct winsize __user
*arg
)
2245 mutex_lock(&tty
->winsize_mutex
);
2246 err
= copy_to_user(arg
, &tty
->winsize
, sizeof(*arg
));
2247 mutex_unlock(&tty
->winsize_mutex
);
2249 return err
? -EFAULT
: 0;
2253 * tty_do_resize - resize event
2254 * @tty: tty being resized
2255 * @rows: rows (character)
2256 * @cols: cols (character)
2258 * Update the termios variables and send the necessary signals to
2259 * peform a terminal resize correctly
2262 int tty_do_resize(struct tty_struct
*tty
, struct winsize
*ws
)
2265 unsigned long flags
;
2268 mutex_lock(&tty
->winsize_mutex
);
2269 if (!memcmp(ws
, &tty
->winsize
, sizeof(*ws
)))
2271 /* Get the PID values and reference them so we can
2272 avoid holding the tty ctrl lock while sending signals */
2273 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
2274 pgrp
= get_pid(tty
->pgrp
);
2275 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
2278 kill_pgrp(pgrp
, SIGWINCH
, 1);
2283 mutex_unlock(&tty
->winsize_mutex
);
2286 EXPORT_SYMBOL(tty_do_resize
);
2289 * tiocswinsz - implement window size set ioctl
2290 * @tty; tty side of tty
2291 * @arg: user buffer for result
2293 * Copies the user idea of the window size to the kernel. Traditionally
2294 * this is just advisory information but for the Linux console it
2295 * actually has driver level meaning and triggers a VC resize.
2298 * Driver dependent. The default do_resize method takes the
2299 * tty termios mutex and ctrl_lock. The console takes its own lock
2300 * then calls into the default method.
2303 static int tiocswinsz(struct tty_struct
*tty
, struct winsize __user
*arg
)
2305 struct winsize tmp_ws
;
2306 if (copy_from_user(&tmp_ws
, arg
, sizeof(*arg
)))
2309 if (tty
->ops
->resize
)
2310 return tty
->ops
->resize(tty
, &tmp_ws
);
2312 return tty_do_resize(tty
, &tmp_ws
);
2316 * tioccons - allow admin to move logical console
2317 * @file: the file to become console
2319 * Allow the administrator to move the redirected console device
2321 * Locking: uses redirect_lock to guard the redirect information
2324 static int tioccons(struct file
*file
)
2326 if (!capable(CAP_SYS_ADMIN
))
2328 if (file
->f_op
->write
== redirected_tty_write
) {
2330 spin_lock(&redirect_lock
);
2333 spin_unlock(&redirect_lock
);
2338 spin_lock(&redirect_lock
);
2340 spin_unlock(&redirect_lock
);
2343 redirect
= get_file(file
);
2344 spin_unlock(&redirect_lock
);
2349 * fionbio - non blocking ioctl
2350 * @file: file to set blocking value
2351 * @p: user parameter
2353 * Historical tty interfaces had a blocking control ioctl before
2354 * the generic functionality existed. This piece of history is preserved
2355 * in the expected tty API of posix OS's.
2357 * Locking: none, the open file handle ensures it won't go away.
2360 static int fionbio(struct file
*file
, int __user
*p
)
2364 if (get_user(nonblock
, p
))
2367 spin_lock(&file
->f_lock
);
2369 file
->f_flags
|= O_NONBLOCK
;
2371 file
->f_flags
&= ~O_NONBLOCK
;
2372 spin_unlock(&file
->f_lock
);
2377 * tiocsctty - set controlling tty
2378 * @tty: tty structure
2379 * @arg: user argument
2381 * This ioctl is used to manage job control. It permits a session
2382 * leader to set this tty as the controlling tty for the session.
2385 * Takes tty_mutex() to protect tty instance
2386 * Takes tasklist_lock internally to walk sessions
2387 * Takes ->siglock() when updating signal->tty
2390 static int tiocsctty(struct tty_struct
*tty
, int arg
)
2393 if (current
->signal
->leader
&& (task_session(current
) == tty
->session
))
2396 mutex_lock(&tty_mutex
);
2398 * The process must be a session leader and
2399 * not have a controlling tty already.
2401 if (!current
->signal
->leader
|| current
->signal
->tty
) {
2408 * This tty is already the controlling
2409 * tty for another session group!
2411 if (arg
== 1 && capable(CAP_SYS_ADMIN
)) {
2415 read_lock(&tasklist_lock
);
2416 session_clear_tty(tty
->session
);
2417 read_unlock(&tasklist_lock
);
2423 proc_set_tty(current
, tty
);
2425 mutex_unlock(&tty_mutex
);
2430 * tty_get_pgrp - return a ref counted pgrp pid
2433 * Returns a refcounted instance of the pid struct for the process
2434 * group controlling the tty.
2437 struct pid
*tty_get_pgrp(struct tty_struct
*tty
)
2439 unsigned long flags
;
2442 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
2443 pgrp
= get_pid(tty
->pgrp
);
2444 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
2448 EXPORT_SYMBOL_GPL(tty_get_pgrp
);
2451 * tiocgpgrp - get process group
2452 * @tty: tty passed by user
2453 * @real_tty: tty side of the tty passed by the user if a pty else the tty
2456 * Obtain the process group of the tty. If there is no process group
2459 * Locking: none. Reference to current->signal->tty is safe.
2462 static int tiocgpgrp(struct tty_struct
*tty
, struct tty_struct
*real_tty
, pid_t __user
*p
)
2467 * (tty == real_tty) is a cheap way of
2468 * testing if the tty is NOT a master pty.
2470 if (tty
== real_tty
&& current
->signal
->tty
!= real_tty
)
2472 pid
= tty_get_pgrp(real_tty
);
2473 ret
= put_user(pid_vnr(pid
), p
);
2479 * tiocspgrp - attempt to set process group
2480 * @tty: tty passed by user
2481 * @real_tty: tty side device matching tty passed by user
2484 * Set the process group of the tty to the session passed. Only
2485 * permitted where the tty session is our session.
2487 * Locking: RCU, ctrl lock
2490 static int tiocspgrp(struct tty_struct
*tty
, struct tty_struct
*real_tty
, pid_t __user
*p
)
2494 int retval
= tty_check_change(real_tty
);
2495 unsigned long flags
;
2501 if (!current
->signal
->tty
||
2502 (current
->signal
->tty
!= real_tty
) ||
2503 (real_tty
->session
!= task_session(current
)))
2505 if (get_user(pgrp_nr
, p
))
2510 pgrp
= find_vpid(pgrp_nr
);
2515 if (session_of_pgrp(pgrp
) != task_session(current
))
2518 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
2519 put_pid(real_tty
->pgrp
);
2520 real_tty
->pgrp
= get_pid(pgrp
);
2521 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
2528 * tiocgsid - get session id
2529 * @tty: tty passed by user
2530 * @real_tty: tty side of the tty passed by the user if a pty else the tty
2531 * @p: pointer to returned session id
2533 * Obtain the session id of the tty. If there is no session
2536 * Locking: none. Reference to current->signal->tty is safe.
2539 static int tiocgsid(struct tty_struct
*tty
, struct tty_struct
*real_tty
, pid_t __user
*p
)
2542 * (tty == real_tty) is a cheap way of
2543 * testing if the tty is NOT a master pty.
2545 if (tty
== real_tty
&& current
->signal
->tty
!= real_tty
)
2547 if (!real_tty
->session
)
2549 return put_user(pid_vnr(real_tty
->session
), p
);
2553 * tiocsetd - set line discipline
2555 * @p: pointer to user data
2557 * Set the line discipline according to user request.
2559 * Locking: see tty_set_ldisc, this function is just a helper
2562 static int tiocsetd(struct tty_struct
*tty
, int __user
*p
)
2567 if (get_user(ldisc
, p
))
2570 ret
= tty_set_ldisc(tty
, ldisc
);
2576 * send_break - performed time break
2577 * @tty: device to break on
2578 * @duration: timeout in mS
2580 * Perform a timed break on hardware that lacks its own driver level
2581 * timed break functionality.
2584 * atomic_write_lock serializes
2588 static int send_break(struct tty_struct
*tty
, unsigned int duration
)
2592 if (tty
->ops
->break_ctl
== NULL
)
2595 if (tty
->driver
->flags
& TTY_DRIVER_HARDWARE_BREAK
)
2596 retval
= tty
->ops
->break_ctl(tty
, duration
);
2598 /* Do the work ourselves */
2599 if (tty_write_lock(tty
, 0) < 0)
2601 retval
= tty
->ops
->break_ctl(tty
, -1);
2604 if (!signal_pending(current
))
2605 msleep_interruptible(duration
);
2606 retval
= tty
->ops
->break_ctl(tty
, 0);
2608 tty_write_unlock(tty
);
2609 if (signal_pending(current
))
2616 * tty_tiocmget - get modem status
2618 * @file: user file pointer
2619 * @p: pointer to result
2621 * Obtain the modem status bits from the tty driver if the feature
2622 * is supported. Return -EINVAL if it is not available.
2624 * Locking: none (up to the driver)
2627 static int tty_tiocmget(struct tty_struct
*tty
, int __user
*p
)
2629 int retval
= -EINVAL
;
2631 if (tty
->ops
->tiocmget
) {
2632 retval
= tty
->ops
->tiocmget(tty
);
2635 retval
= put_user(retval
, p
);
2641 * tty_tiocmset - set modem status
2643 * @cmd: command - clear bits, set bits or set all
2644 * @p: pointer to desired bits
2646 * Set the modem status bits from the tty driver if the feature
2647 * is supported. Return -EINVAL if it is not available.
2649 * Locking: none (up to the driver)
2652 static int tty_tiocmset(struct tty_struct
*tty
, unsigned int cmd
,
2656 unsigned int set
, clear
, val
;
2658 if (tty
->ops
->tiocmset
== NULL
)
2661 retval
= get_user(val
, p
);
2677 set
&= TIOCM_DTR
|TIOCM_RTS
|TIOCM_OUT1
|TIOCM_OUT2
|TIOCM_LOOP
;
2678 clear
&= TIOCM_DTR
|TIOCM_RTS
|TIOCM_OUT1
|TIOCM_OUT2
|TIOCM_LOOP
;
2679 return tty
->ops
->tiocmset(tty
, set
, clear
);
2682 static int tty_tiocgicount(struct tty_struct
*tty
, void __user
*arg
)
2684 int retval
= -EINVAL
;
2685 struct serial_icounter_struct icount
;
2686 memset(&icount
, 0, sizeof(icount
));
2687 if (tty
->ops
->get_icount
)
2688 retval
= tty
->ops
->get_icount(tty
, &icount
);
2691 if (copy_to_user(arg
, &icount
, sizeof(icount
)))
2696 struct tty_struct
*tty_pair_get_tty(struct tty_struct
*tty
)
2698 if (tty
->driver
->type
== TTY_DRIVER_TYPE_PTY
&&
2699 tty
->driver
->subtype
== PTY_TYPE_MASTER
)
2703 EXPORT_SYMBOL(tty_pair_get_tty
);
2705 struct tty_struct
*tty_pair_get_pty(struct tty_struct
*tty
)
2707 if (tty
->driver
->type
== TTY_DRIVER_TYPE_PTY
&&
2708 tty
->driver
->subtype
== PTY_TYPE_MASTER
)
2712 EXPORT_SYMBOL(tty_pair_get_pty
);
2715 * Split this up, as gcc can choke on it otherwise..
2717 long tty_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
2719 struct tty_struct
*tty
= file_tty(file
);
2720 struct tty_struct
*real_tty
;
2721 void __user
*p
= (void __user
*)arg
;
2723 struct tty_ldisc
*ld
;
2725 if (tty_paranoia_check(tty
, file_inode(file
), "tty_ioctl"))
2728 real_tty
= tty_pair_get_tty(tty
);
2731 * Factor out some common prep work
2739 retval
= tty_check_change(tty
);
2742 if (cmd
!= TIOCCBRK
) {
2743 tty_wait_until_sent(tty
, 0);
2744 if (signal_pending(current
))
2755 return tiocsti(tty
, p
);
2757 return tiocgwinsz(real_tty
, p
);
2759 return tiocswinsz(real_tty
, p
);
2761 return real_tty
!= tty
? -EINVAL
: tioccons(file
);
2763 return fionbio(file
, p
);
2765 set_bit(TTY_EXCLUSIVE
, &tty
->flags
);
2768 clear_bit(TTY_EXCLUSIVE
, &tty
->flags
);
2772 int excl
= test_bit(TTY_EXCLUSIVE
, &tty
->flags
);
2773 return put_user(excl
, (int __user
*)p
);
2776 if (current
->signal
->tty
!= tty
)
2781 return tiocsctty(tty
, arg
);
2783 return tiocgpgrp(tty
, real_tty
, p
);
2785 return tiocspgrp(tty
, real_tty
, p
);
2787 return tiocgsid(tty
, real_tty
, p
);
2789 return put_user(tty
->ldisc
->ops
->num
, (int __user
*)p
);
2791 return tiocsetd(tty
, p
);
2793 if (!capable(CAP_SYS_ADMIN
))
2799 unsigned int ret
= new_encode_dev(tty_devnum(real_tty
));
2800 return put_user(ret
, (unsigned int __user
*)p
);
2805 case TIOCSBRK
: /* Turn break on, unconditionally */
2806 if (tty
->ops
->break_ctl
)
2807 return tty
->ops
->break_ctl(tty
, -1);
2809 case TIOCCBRK
: /* Turn break off, unconditionally */
2810 if (tty
->ops
->break_ctl
)
2811 return tty
->ops
->break_ctl(tty
, 0);
2813 case TCSBRK
: /* SVID version: non-zero arg --> no break */
2814 /* non-zero arg means wait for all output data
2815 * to be sent (performed above) but don't send break.
2816 * This is used by the tcdrain() termios function.
2819 return send_break(tty
, 250);
2821 case TCSBRKP
: /* support for POSIX tcsendbreak() */
2822 return send_break(tty
, arg
? arg
*100 : 250);
2825 return tty_tiocmget(tty
, p
);
2829 return tty_tiocmset(tty
, cmd
, p
);
2831 retval
= tty_tiocgicount(tty
, p
);
2832 /* For the moment allow fall through to the old method */
2833 if (retval
!= -EINVAL
)
2840 /* flush tty buffer and allow ldisc to process ioctl */
2841 tty_buffer_flush(tty
);
2846 if (tty
->ops
->ioctl
) {
2847 retval
= (tty
->ops
->ioctl
)(tty
, cmd
, arg
);
2848 if (retval
!= -ENOIOCTLCMD
)
2851 ld
= tty_ldisc_ref_wait(tty
);
2853 if (ld
->ops
->ioctl
) {
2854 retval
= ld
->ops
->ioctl(tty
, file
, cmd
, arg
);
2855 if (retval
== -ENOIOCTLCMD
)
2858 tty_ldisc_deref(ld
);
2862 #ifdef CONFIG_COMPAT
2863 static long tty_compat_ioctl(struct file
*file
, unsigned int cmd
,
2866 struct tty_struct
*tty
= file_tty(file
);
2867 struct tty_ldisc
*ld
;
2868 int retval
= -ENOIOCTLCMD
;
2870 if (tty_paranoia_check(tty
, file_inode(file
), "tty_ioctl"))
2873 if (tty
->ops
->compat_ioctl
) {
2874 retval
= (tty
->ops
->compat_ioctl
)(tty
, cmd
, arg
);
2875 if (retval
!= -ENOIOCTLCMD
)
2879 ld
= tty_ldisc_ref_wait(tty
);
2880 if (ld
->ops
->compat_ioctl
)
2881 retval
= ld
->ops
->compat_ioctl(tty
, file
, cmd
, arg
);
2883 retval
= n_tty_compat_ioctl_helper(tty
, file
, cmd
, arg
);
2884 tty_ldisc_deref(ld
);
2890 static int this_tty(const void *t
, struct file
*file
, unsigned fd
)
2892 if (likely(file
->f_op
->read
!= tty_read
))
2894 return file_tty(file
) != t
? 0 : fd
+ 1;
2898 * This implements the "Secure Attention Key" --- the idea is to
2899 * prevent trojan horses by killing all processes associated with this
2900 * tty when the user hits the "Secure Attention Key". Required for
2901 * super-paranoid applications --- see the Orange Book for more details.
2903 * This code could be nicer; ideally it should send a HUP, wait a few
2904 * seconds, then send a INT, and then a KILL signal. But you then
2905 * have to coordinate with the init process, since all processes associated
2906 * with the current tty must be dead before the new getty is allowed
2909 * Now, if it would be correct ;-/ The current code has a nasty hole -
2910 * it doesn't catch files in flight. We may send the descriptor to ourselves
2911 * via AF_UNIX socket, close it and later fetch from socket. FIXME.
2913 * Nasty bug: do_SAK is being called in interrupt context. This can
2914 * deadlock. We punt it up to process context. AKPM - 16Mar2001
2916 void __do_SAK(struct tty_struct
*tty
)
2921 struct task_struct
*g
, *p
;
2922 struct pid
*session
;
2927 session
= tty
->session
;
2929 tty_ldisc_flush(tty
);
2931 tty_driver_flush_buffer(tty
);
2933 read_lock(&tasklist_lock
);
2934 /* Kill the entire session */
2935 do_each_pid_task(session
, PIDTYPE_SID
, p
) {
2936 printk(KERN_NOTICE
"SAK: killed process %d"
2937 " (%s): task_session(p)==tty->session\n",
2938 task_pid_nr(p
), p
->comm
);
2939 send_sig(SIGKILL
, p
, 1);
2940 } while_each_pid_task(session
, PIDTYPE_SID
, p
);
2941 /* Now kill any processes that happen to have the
2944 do_each_thread(g
, p
) {
2945 if (p
->signal
->tty
== tty
) {
2946 printk(KERN_NOTICE
"SAK: killed process %d"
2947 " (%s): task_session(p)==tty->session\n",
2948 task_pid_nr(p
), p
->comm
);
2949 send_sig(SIGKILL
, p
, 1);
2953 i
= iterate_fd(p
->files
, 0, this_tty
, tty
);
2955 printk(KERN_NOTICE
"SAK: killed process %d"
2956 " (%s): fd#%d opened to the tty\n",
2957 task_pid_nr(p
), p
->comm
, i
- 1);
2958 force_sig(SIGKILL
, p
);
2961 } while_each_thread(g
, p
);
2962 read_unlock(&tasklist_lock
);
2966 static void do_SAK_work(struct work_struct
*work
)
2968 struct tty_struct
*tty
=
2969 container_of(work
, struct tty_struct
, SAK_work
);
2974 * The tq handling here is a little racy - tty->SAK_work may already be queued.
2975 * Fortunately we don't need to worry, because if ->SAK_work is already queued,
2976 * the values which we write to it will be identical to the values which it
2977 * already has. --akpm
2979 void do_SAK(struct tty_struct
*tty
)
2983 schedule_work(&tty
->SAK_work
);
2986 EXPORT_SYMBOL(do_SAK
);
2988 static int dev_match_devt(struct device
*dev
, const void *data
)
2990 const dev_t
*devt
= data
;
2991 return dev
->devt
== *devt
;
2994 /* Must put_device() after it's unused! */
2995 static struct device
*tty_get_device(struct tty_struct
*tty
)
2997 dev_t devt
= tty_devnum(tty
);
2998 return class_find_device(tty_class
, NULL
, &devt
, dev_match_devt
);
3003 * initialize_tty_struct
3004 * @tty: tty to initialize
3006 * This subroutine initializes a tty structure that has been newly
3009 * Locking: none - tty in question must not be exposed at this point
3012 void initialize_tty_struct(struct tty_struct
*tty
,
3013 struct tty_driver
*driver
, int idx
)
3015 memset(tty
, 0, sizeof(struct tty_struct
));
3016 kref_init(&tty
->kref
);
3017 tty
->magic
= TTY_MAGIC
;
3018 tty_ldisc_init(tty
);
3019 tty
->session
= NULL
;
3021 mutex_init(&tty
->legacy_mutex
);
3022 mutex_init(&tty
->throttle_mutex
);
3023 init_rwsem(&tty
->termios_rwsem
);
3024 mutex_init(&tty
->winsize_mutex
);
3025 init_ldsem(&tty
->ldisc_sem
);
3026 init_waitqueue_head(&tty
->write_wait
);
3027 init_waitqueue_head(&tty
->read_wait
);
3028 INIT_WORK(&tty
->hangup_work
, do_tty_hangup
);
3029 mutex_init(&tty
->atomic_write_lock
);
3030 spin_lock_init(&tty
->ctrl_lock
);
3031 INIT_LIST_HEAD(&tty
->tty_files
);
3032 INIT_WORK(&tty
->SAK_work
, do_SAK_work
);
3034 tty
->driver
= driver
;
3035 tty
->ops
= driver
->ops
;
3037 tty_line_name(driver
, idx
, tty
->name
);
3038 tty
->dev
= tty_get_device(tty
);
3042 * deinitialize_tty_struct
3043 * @tty: tty to deinitialize
3045 * This subroutine deinitializes a tty structure that has been newly
3046 * allocated but tty_release cannot be called on that yet.
3048 * Locking: none - tty in question must not be exposed at this point
3050 void deinitialize_tty_struct(struct tty_struct
*tty
)
3052 tty_ldisc_deinit(tty
);
3056 * tty_put_char - write one character to a tty
3060 * Write one byte to the tty using the provided put_char method
3061 * if present. Returns the number of characters successfully output.
3063 * Note: the specific put_char operation in the driver layer may go
3064 * away soon. Don't call it directly, use this method
3067 int tty_put_char(struct tty_struct
*tty
, unsigned char ch
)
3069 if (tty
->ops
->put_char
)
3070 return tty
->ops
->put_char(tty
, ch
);
3071 return tty
->ops
->write(tty
, &ch
, 1);
3073 EXPORT_SYMBOL_GPL(tty_put_char
);
3075 struct class *tty_class
;
3077 static int tty_cdev_add(struct tty_driver
*driver
, dev_t dev
,
3078 unsigned int index
, unsigned int count
)
3080 /* init here, since reused cdevs cause crashes */
3081 cdev_init(&driver
->cdevs
[index
], &tty_fops
);
3082 driver
->cdevs
[index
].owner
= driver
->owner
;
3083 return cdev_add(&driver
->cdevs
[index
], dev
, count
);
3087 * tty_register_device - register a tty device
3088 * @driver: the tty driver that describes the tty device
3089 * @index: the index in the tty driver for this tty device
3090 * @device: a struct device that is associated with this tty device.
3091 * This field is optional, if there is no known struct device
3092 * for this tty device it can be set to NULL safely.
3094 * Returns a pointer to the struct device for this tty device
3095 * (or ERR_PTR(-EFOO) on error).
3097 * This call is required to be made to register an individual tty device
3098 * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If
3099 * that bit is not set, this function should not be called by a tty
3105 struct device
*tty_register_device(struct tty_driver
*driver
, unsigned index
,
3106 struct device
*device
)
3108 return tty_register_device_attr(driver
, index
, device
, NULL
, NULL
);
3110 EXPORT_SYMBOL(tty_register_device
);
3112 static void tty_device_create_release(struct device
*dev
)
3114 pr_debug("device: '%s': %s\n", dev_name(dev
), __func__
);
3119 * tty_register_device_attr - register a tty device
3120 * @driver: the tty driver that describes the tty device
3121 * @index: the index in the tty driver for this tty device
3122 * @device: a struct device that is associated with this tty device.
3123 * This field is optional, if there is no known struct device
3124 * for this tty device it can be set to NULL safely.
3125 * @drvdata: Driver data to be set to device.
3126 * @attr_grp: Attribute group to be set on device.
3128 * Returns a pointer to the struct device for this tty device
3129 * (or ERR_PTR(-EFOO) on error).
3131 * This call is required to be made to register an individual tty device
3132 * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If
3133 * that bit is not set, this function should not be called by a tty
3138 struct device
*tty_register_device_attr(struct tty_driver
*driver
,
3139 unsigned index
, struct device
*device
,
3141 const struct attribute_group
**attr_grp
)
3144 dev_t devt
= MKDEV(driver
->major
, driver
->minor_start
) + index
;
3145 struct device
*dev
= NULL
;
3146 int retval
= -ENODEV
;
3149 if (index
>= driver
->num
) {
3150 printk(KERN_ERR
"Attempt to register invalid tty line number "
3152 return ERR_PTR(-EINVAL
);
3155 if (driver
->type
== TTY_DRIVER_TYPE_PTY
)
3156 pty_line_name(driver
, index
, name
);
3158 tty_line_name(driver
, index
, name
);
3160 if (!(driver
->flags
& TTY_DRIVER_DYNAMIC_ALLOC
)) {
3161 retval
= tty_cdev_add(driver
, devt
, index
, 1);
3167 dev
= kzalloc(sizeof(*dev
), GFP_KERNEL
);
3174 dev
->class = tty_class
;
3175 dev
->parent
= device
;
3176 dev
->release
= tty_device_create_release
;
3177 dev_set_name(dev
, "%s", name
);
3178 dev
->groups
= attr_grp
;
3179 dev_set_drvdata(dev
, drvdata
);
3181 retval
= device_register(dev
);
3190 cdev_del(&driver
->cdevs
[index
]);
3191 return ERR_PTR(retval
);
3193 EXPORT_SYMBOL_GPL(tty_register_device_attr
);
3196 * tty_unregister_device - unregister a tty device
3197 * @driver: the tty driver that describes the tty device
3198 * @index: the index in the tty driver for this tty device
3200 * If a tty device is registered with a call to tty_register_device() then
3201 * this function must be called when the tty device is gone.
3206 void tty_unregister_device(struct tty_driver
*driver
, unsigned index
)
3208 device_destroy(tty_class
,
3209 MKDEV(driver
->major
, driver
->minor_start
) + index
);
3210 if (!(driver
->flags
& TTY_DRIVER_DYNAMIC_ALLOC
))
3211 cdev_del(&driver
->cdevs
[index
]);
3213 EXPORT_SYMBOL(tty_unregister_device
);
3216 * __tty_alloc_driver -- allocate tty driver
3217 * @lines: count of lines this driver can handle at most
3218 * @owner: module which is repsonsible for this driver
3219 * @flags: some of TTY_DRIVER_* flags, will be set in driver->flags
3221 * This should not be called directly, some of the provided macros should be
3222 * used instead. Use IS_ERR and friends on @retval.
3224 struct tty_driver
*__tty_alloc_driver(unsigned int lines
, struct module
*owner
,
3225 unsigned long flags
)
3227 struct tty_driver
*driver
;
3228 unsigned int cdevs
= 1;
3231 if (!lines
|| (flags
& TTY_DRIVER_UNNUMBERED_NODE
&& lines
> 1))
3232 return ERR_PTR(-EINVAL
);
3234 driver
= kzalloc(sizeof(struct tty_driver
), GFP_KERNEL
);
3236 return ERR_PTR(-ENOMEM
);
3238 kref_init(&driver
->kref
);
3239 driver
->magic
= TTY_DRIVER_MAGIC
;
3240 driver
->num
= lines
;
3241 driver
->owner
= owner
;
3242 driver
->flags
= flags
;
3244 if (!(flags
& TTY_DRIVER_DEVPTS_MEM
)) {
3245 driver
->ttys
= kcalloc(lines
, sizeof(*driver
->ttys
),
3247 driver
->termios
= kcalloc(lines
, sizeof(*driver
->termios
),
3249 if (!driver
->ttys
|| !driver
->termios
) {
3255 if (!(flags
& TTY_DRIVER_DYNAMIC_ALLOC
)) {
3256 driver
->ports
= kcalloc(lines
, sizeof(*driver
->ports
),
3258 if (!driver
->ports
) {
3265 driver
->cdevs
= kcalloc(cdevs
, sizeof(*driver
->cdevs
), GFP_KERNEL
);
3266 if (!driver
->cdevs
) {
3273 kfree(driver
->ports
);
3274 kfree(driver
->ttys
);
3275 kfree(driver
->termios
);
3277 return ERR_PTR(err
);
3279 EXPORT_SYMBOL(__tty_alloc_driver
);
3281 static void destruct_tty_driver(struct kref
*kref
)
3283 struct tty_driver
*driver
= container_of(kref
, struct tty_driver
, kref
);
3285 struct ktermios
*tp
;
3287 if (driver
->flags
& TTY_DRIVER_INSTALLED
) {
3289 * Free the termios and termios_locked structures because
3290 * we don't want to get memory leaks when modular tty
3291 * drivers are removed from the kernel.
3293 for (i
= 0; i
< driver
->num
; i
++) {
3294 tp
= driver
->termios
[i
];
3296 driver
->termios
[i
] = NULL
;
3299 if (!(driver
->flags
& TTY_DRIVER_DYNAMIC_DEV
))
3300 tty_unregister_device(driver
, i
);
3302 proc_tty_unregister_driver(driver
);
3303 if (driver
->flags
& TTY_DRIVER_DYNAMIC_ALLOC
)
3304 cdev_del(&driver
->cdevs
[0]);
3306 kfree(driver
->cdevs
);
3307 kfree(driver
->ports
);
3308 kfree(driver
->termios
);
3309 kfree(driver
->ttys
);
3313 void tty_driver_kref_put(struct tty_driver
*driver
)
3315 kref_put(&driver
->kref
, destruct_tty_driver
);
3317 EXPORT_SYMBOL(tty_driver_kref_put
);
3319 void tty_set_operations(struct tty_driver
*driver
,
3320 const struct tty_operations
*op
)
3324 EXPORT_SYMBOL(tty_set_operations
);
3326 void put_tty_driver(struct tty_driver
*d
)
3328 tty_driver_kref_put(d
);
3330 EXPORT_SYMBOL(put_tty_driver
);
3333 * Called by a tty driver to register itself.
3335 int tty_register_driver(struct tty_driver
*driver
)
3342 if (!driver
->major
) {
3343 error
= alloc_chrdev_region(&dev
, driver
->minor_start
,
3344 driver
->num
, driver
->name
);
3346 driver
->major
= MAJOR(dev
);
3347 driver
->minor_start
= MINOR(dev
);
3350 dev
= MKDEV(driver
->major
, driver
->minor_start
);
3351 error
= register_chrdev_region(dev
, driver
->num
, driver
->name
);
3356 if (driver
->flags
& TTY_DRIVER_DYNAMIC_ALLOC
) {
3357 error
= tty_cdev_add(driver
, dev
, 0, driver
->num
);
3359 goto err_unreg_char
;
3362 mutex_lock(&tty_mutex
);
3363 list_add(&driver
->tty_drivers
, &tty_drivers
);
3364 mutex_unlock(&tty_mutex
);
3366 if (!(driver
->flags
& TTY_DRIVER_DYNAMIC_DEV
)) {
3367 for (i
= 0; i
< driver
->num
; i
++) {
3368 d
= tty_register_device(driver
, i
, NULL
);
3371 goto err_unreg_devs
;
3375 proc_tty_register_driver(driver
);
3376 driver
->flags
|= TTY_DRIVER_INSTALLED
;
3380 for (i
--; i
>= 0; i
--)
3381 tty_unregister_device(driver
, i
);
3383 mutex_lock(&tty_mutex
);
3384 list_del(&driver
->tty_drivers
);
3385 mutex_unlock(&tty_mutex
);
3388 unregister_chrdev_region(dev
, driver
->num
);
3392 EXPORT_SYMBOL(tty_register_driver
);
3395 * Called by a tty driver to unregister itself.
3397 int tty_unregister_driver(struct tty_driver
*driver
)
3401 if (driver
->refcount
)
3404 unregister_chrdev_region(MKDEV(driver
->major
, driver
->minor_start
),
3406 mutex_lock(&tty_mutex
);
3407 list_del(&driver
->tty_drivers
);
3408 mutex_unlock(&tty_mutex
);
3412 EXPORT_SYMBOL(tty_unregister_driver
);
3414 dev_t
tty_devnum(struct tty_struct
*tty
)
3416 return MKDEV(tty
->driver
->major
, tty
->driver
->minor_start
) + tty
->index
;
3418 EXPORT_SYMBOL(tty_devnum
);
3420 void proc_clear_tty(struct task_struct
*p
)
3422 unsigned long flags
;
3423 struct tty_struct
*tty
;
3424 spin_lock_irqsave(&p
->sighand
->siglock
, flags
);
3425 tty
= p
->signal
->tty
;
3426 p
->signal
->tty
= NULL
;
3427 spin_unlock_irqrestore(&p
->sighand
->siglock
, flags
);
3431 /* Called under the sighand lock */
3433 static void __proc_set_tty(struct task_struct
*tsk
, struct tty_struct
*tty
)
3436 unsigned long flags
;
3437 /* We should not have a session or pgrp to put here but.... */
3438 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
3439 put_pid(tty
->session
);
3441 tty
->pgrp
= get_pid(task_pgrp(tsk
));
3442 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
3443 tty
->session
= get_pid(task_session(tsk
));
3444 if (tsk
->signal
->tty
) {
3445 printk(KERN_DEBUG
"tty not NULL!!\n");
3446 tty_kref_put(tsk
->signal
->tty
);
3449 put_pid(tsk
->signal
->tty_old_pgrp
);
3450 tsk
->signal
->tty
= tty_kref_get(tty
);
3451 tsk
->signal
->tty_old_pgrp
= NULL
;
3454 static void proc_set_tty(struct task_struct
*tsk
, struct tty_struct
*tty
)
3456 spin_lock_irq(&tsk
->sighand
->siglock
);
3457 __proc_set_tty(tsk
, tty
);
3458 spin_unlock_irq(&tsk
->sighand
->siglock
);
3461 struct tty_struct
*get_current_tty(void)
3463 struct tty_struct
*tty
;
3464 unsigned long flags
;
3466 spin_lock_irqsave(¤t
->sighand
->siglock
, flags
);
3467 tty
= tty_kref_get(current
->signal
->tty
);
3468 spin_unlock_irqrestore(¤t
->sighand
->siglock
, flags
);
3471 EXPORT_SYMBOL_GPL(get_current_tty
);
3473 void tty_default_fops(struct file_operations
*fops
)
3479 * Initialize the console device. This is called *early*, so
3480 * we can't necessarily depend on lots of kernel help here.
3481 * Just do some early initializations, and do the complex setup
3484 void __init
console_init(void)
3488 /* Setup the default TTY line discipline. */
3492 * set up the console device so that later boot sequences can
3493 * inform about problems etc..
3495 call
= __con_initcall_start
;
3496 while (call
< __con_initcall_end
) {
3502 static char *tty_devnode(struct device
*dev
, umode_t
*mode
)
3506 if (dev
->devt
== MKDEV(TTYAUX_MAJOR
, 0) ||
3507 dev
->devt
== MKDEV(TTYAUX_MAJOR
, 2))
3512 static int __init
tty_class_init(void)
3514 tty_class
= class_create(THIS_MODULE
, "tty");
3515 if (IS_ERR(tty_class
))
3516 return PTR_ERR(tty_class
);
3517 tty_class
->devnode
= tty_devnode
;
3521 postcore_initcall(tty_class_init
);
3523 /* 3/2004 jmc: why do these devices exist? */
3524 static struct cdev tty_cdev
, console_cdev
;
3526 static ssize_t
show_cons_active(struct device
*dev
,
3527 struct device_attribute
*attr
, char *buf
)
3529 struct console
*cs
[16];
3535 for_each_console(c
) {
3540 if ((c
->flags
& CON_ENABLED
) == 0)
3543 if (i
>= ARRAY_SIZE(cs
))
3547 count
+= sprintf(buf
+ count
, "%s%d%c",
3548 cs
[i
]->name
, cs
[i
]->index
, i
? ' ':'\n');
3553 static DEVICE_ATTR(active
, S_IRUGO
, show_cons_active
, NULL
);
3555 static struct device
*consdev
;
3557 void console_sysfs_notify(void)
3560 sysfs_notify(&consdev
->kobj
, NULL
, "active");
3564 * Ok, now we can initialize the rest of the tty devices and can count
3565 * on memory allocations, interrupts etc..
3567 int __init
tty_init(void)
3569 cdev_init(&tty_cdev
, &tty_fops
);
3570 if (cdev_add(&tty_cdev
, MKDEV(TTYAUX_MAJOR
, 0), 1) ||
3571 register_chrdev_region(MKDEV(TTYAUX_MAJOR
, 0), 1, "/dev/tty") < 0)
3572 panic("Couldn't register /dev/tty driver\n");
3573 device_create(tty_class
, NULL
, MKDEV(TTYAUX_MAJOR
, 0), NULL
, "tty");
3575 cdev_init(&console_cdev
, &console_fops
);
3576 if (cdev_add(&console_cdev
, MKDEV(TTYAUX_MAJOR
, 1), 1) ||
3577 register_chrdev_region(MKDEV(TTYAUX_MAJOR
, 1), 1, "/dev/console") < 0)
3578 panic("Couldn't register /dev/console driver\n");
3579 consdev
= device_create(tty_class
, NULL
, MKDEV(TTYAUX_MAJOR
, 1), NULL
,
3581 if (IS_ERR(consdev
))
3584 WARN_ON(device_create_file(consdev
, &dev_attr_active
) < 0);
3587 vty_init(&console_fops
);