2 * linux/drivers/char/tty_io.c
4 * Copyright (C) 1991, 1992 Linus Torvalds
8 * 'tty_io.c' gives an orthogonal feeling to tty's, be they consoles
9 * or rs-channels. It also implements echoing, cooked mode etc.
11 * Kill-line thanks to John T Kohl, who also corrected VMIN = VTIME = 0.
13 * Modified by Theodore Ts'o, 9/14/92, to dynamically allocate the
14 * tty_struct and tty_queue structures. Previously there was an array
15 * of 256 tty_struct's which was statically allocated, and the
16 * tty_queue structures were allocated at boot time. Both are now
17 * dynamically allocated only when the tty is open.
19 * Also restructured routines so that there is more of a separation
20 * between the high-level tty routines (tty_io.c and tty_ioctl.c) and
21 * the low-level tty routines (serial.c, pty.c, console.c). This
22 * makes for cleaner and more compact code. -TYT, 9/17/92
24 * Modified by Fred N. van Kempen, 01/29/93, to add line disciplines
25 * which can be dynamically activated and de-activated by the line
26 * discipline handling modules (like SLIP).
28 * NOTE: pay no attention to the line discipline code (yet); its
29 * interface is still subject to change in this version...
32 * Added functionality to the OPOST tty handling. No delays, but all
33 * other bits should be there.
34 * -- Nick Holloway <alfie@dcs.warwick.ac.uk>, 27th May 1993.
36 * Rewrote canonical mode and added more termios flags.
37 * -- julian@uhunix.uhcc.hawaii.edu (J. Cowley), 13Jan94
39 * Reorganized FASYNC support so mouse code can share it.
40 * -- ctm@ardi.com, 9Sep95
42 * New TIOCLINUX variants added.
43 * -- mj@k332.feld.cvut.cz, 19-Nov-95
45 * Restrict vt switching via ioctl()
46 * -- grif@cs.ucr.edu, 5-Dec-95
48 * Move console and virtual terminal code to more appropriate files,
49 * implement CONFIG_VT and generalize console device interface.
50 * -- Marko Kohtala <Marko.Kohtala@hut.fi>, March 97
52 * Rewrote init_dev and release_dev to eliminate races.
53 * -- Bill Hawes <whawes@star.net>, June 97
55 * Added devfs support.
56 * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 13-Jan-1998
58 * Added support for a Unix98-style ptmx device.
59 * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 14-Jan-1998
61 * Reduced memory usage for older ARM systems
62 * -- Russell King <rmk@arm.linux.org.uk>
64 * Move do_SAK() into process context. Less stack use in devfs functions.
65 * alloc_tty_struct() always uses kmalloc()
66 * -- Andrew Morton <andrewm@uow.edu.eu> 17Mar01
69 #include <linux/types.h>
70 #include <linux/major.h>
71 #include <linux/errno.h>
72 #include <linux/signal.h>
73 #include <linux/fcntl.h>
74 #include <linux/sched.h>
75 #include <linux/interrupt.h>
76 #include <linux/tty.h>
77 #include <linux/tty_driver.h>
78 #include <linux/tty_flip.h>
79 #include <linux/devpts_fs.h>
80 #include <linux/file.h>
81 #include <linux/fdtable.h>
82 #include <linux/console.h>
83 #include <linux/timer.h>
84 #include <linux/ctype.h>
87 #include <linux/string.h>
88 #include <linux/slab.h>
89 #include <linux/poll.h>
90 #include <linux/proc_fs.h>
91 #include <linux/init.h>
92 #include <linux/module.h>
93 #include <linux/smp_lock.h>
94 #include <linux/device.h>
95 #include <linux/wait.h>
96 #include <linux/bitops.h>
97 #include <linux/delay.h>
98 #include <linux/seq_file.h>
100 #include <linux/uaccess.h>
101 #include <asm/system.h>
103 #include <linux/kbd_kern.h>
104 #include <linux/vt_kern.h>
105 #include <linux/selection.h>
107 #include <linux/kmod.h>
108 #include <linux/nsproxy.h>
110 #undef TTY_DEBUG_HANGUP
112 #define TTY_PARANOIA_CHECK 1
113 #define CHECK_TTY_COUNT 1
115 struct ktermios tty_std_termios
= { /* for the benefit of tty drivers */
116 .c_iflag
= ICRNL
| IXON
,
117 .c_oflag
= OPOST
| ONLCR
,
118 .c_cflag
= B38400
| CS8
| CREAD
| HUPCL
,
119 .c_lflag
= ISIG
| ICANON
| ECHO
| ECHOE
| ECHOK
|
120 ECHOCTL
| ECHOKE
| IEXTEN
,
126 EXPORT_SYMBOL(tty_std_termios
);
128 /* This list gets poked at by procfs and various bits of boot up code. This
129 could do with some rationalisation such as pulling the tty proc function
132 LIST_HEAD(tty_drivers
); /* linked list of tty drivers */
134 /* Mutex to protect creating and releasing a tty. This is shared with
135 vt.c for deeply disgusting hack reasons */
136 DEFINE_MUTEX(tty_mutex
);
137 EXPORT_SYMBOL(tty_mutex
);
139 #ifdef CONFIG_UNIX98_PTYS
140 extern struct tty_driver
*ptm_driver
; /* Unix98 pty masters; for /dev/ptmx */
141 static int ptmx_open(struct inode
*, struct file
*);
144 static void initialize_tty_struct(struct tty_struct
*tty
);
146 static ssize_t
tty_read(struct file
*, char __user
*, size_t, loff_t
*);
147 static ssize_t
tty_write(struct file
*, const char __user
*, size_t, loff_t
*);
148 ssize_t
redirected_tty_write(struct file
*, const char __user
*,
150 static unsigned int tty_poll(struct file
*, poll_table
*);
151 static int tty_open(struct inode
*, struct file
*);
152 static int tty_release(struct inode
*, struct file
*);
153 long tty_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
);
155 static long tty_compat_ioctl(struct file
*file
, unsigned int cmd
,
158 #define tty_compat_ioctl NULL
160 static int tty_fasync(int fd
, struct file
*filp
, int on
);
161 static void release_tty(struct tty_struct
*tty
, int idx
);
162 static void __proc_set_tty(struct task_struct
*tsk
, struct tty_struct
*tty
);
163 static void proc_set_tty(struct task_struct
*tsk
, struct tty_struct
*tty
);
166 * alloc_tty_struct - allocate a tty object
168 * Return a new empty tty structure. The data fields have not
169 * been initialized in any way but has been zeroed
174 static struct tty_struct
*alloc_tty_struct(void)
176 return kzalloc(sizeof(struct tty_struct
), GFP_KERNEL
);
179 static void tty_buffer_free_all(struct tty_struct
*);
182 * free_tty_struct - free a disused tty
183 * @tty: tty struct to free
185 * Free the write buffers, tty queue and tty memory itself.
187 * Locking: none. Must be called after tty is definitely unused
190 static inline void free_tty_struct(struct tty_struct
*tty
)
192 kfree(tty
->write_buf
);
193 tty_buffer_free_all(tty
);
197 #define TTY_NUMBER(tty) ((tty)->index + (tty)->driver->name_base)
200 * tty_name - return tty naming
201 * @tty: tty structure
202 * @buf: buffer for output
204 * Convert a tty structure into a name. The name reflects the kernel
205 * naming policy and if udev is in use may not reflect user space
210 char *tty_name(struct tty_struct
*tty
, char *buf
)
212 if (!tty
) /* Hmm. NULL pointer. That's fun. */
213 strcpy(buf
, "NULL tty");
215 strcpy(buf
, tty
->name
);
219 EXPORT_SYMBOL(tty_name
);
221 int tty_paranoia_check(struct tty_struct
*tty
, struct inode
*inode
,
224 #ifdef TTY_PARANOIA_CHECK
227 "null TTY for (%d:%d) in %s\n",
228 imajor(inode
), iminor(inode
), routine
);
231 if (tty
->magic
!= TTY_MAGIC
) {
233 "bad magic number for tty struct (%d:%d) in %s\n",
234 imajor(inode
), iminor(inode
), routine
);
241 static int check_tty_count(struct tty_struct
*tty
, const char *routine
)
243 #ifdef CHECK_TTY_COUNT
248 list_for_each(p
, &tty
->tty_files
) {
252 if (tty
->driver
->type
== TTY_DRIVER_TYPE_PTY
&&
253 tty
->driver
->subtype
== PTY_TYPE_SLAVE
&&
254 tty
->link
&& tty
->link
->count
)
256 if (tty
->count
!= count
) {
257 printk(KERN_WARNING
"Warning: dev (%s) tty->count(%d) "
258 "!= #fd's(%d) in %s\n",
259 tty
->name
, tty
->count
, count
, routine
);
267 * Tty buffer allocation management
271 * tty_buffer_free_all - free buffers used by a tty
272 * @tty: tty to free from
274 * Remove all the buffers pending on a tty whether queued with data
275 * or in the free ring. Must be called when the tty is no longer in use
280 static void tty_buffer_free_all(struct tty_struct
*tty
)
282 struct tty_buffer
*thead
;
283 while ((thead
= tty
->buf
.head
) != NULL
) {
284 tty
->buf
.head
= thead
->next
;
287 while ((thead
= tty
->buf
.free
) != NULL
) {
288 tty
->buf
.free
= thead
->next
;
291 tty
->buf
.tail
= NULL
;
292 tty
->buf
.memory_used
= 0;
296 * tty_buffer_init - prepare a tty buffer structure
297 * @tty: tty to initialise
299 * Set up the initial state of the buffer management for a tty device.
300 * Must be called before the other tty buffer functions are used.
305 static void tty_buffer_init(struct tty_struct
*tty
)
307 spin_lock_init(&tty
->buf
.lock
);
308 tty
->buf
.head
= NULL
;
309 tty
->buf
.tail
= NULL
;
310 tty
->buf
.free
= NULL
;
311 tty
->buf
.memory_used
= 0;
315 * tty_buffer_alloc - allocate a tty buffer
317 * @size: desired size (characters)
319 * Allocate a new tty buffer to hold the desired number of characters.
320 * Return NULL if out of memory or the allocation would exceed the
323 * Locking: Caller must hold tty->buf.lock
326 static struct tty_buffer
*tty_buffer_alloc(struct tty_struct
*tty
, size_t size
)
328 struct tty_buffer
*p
;
330 if (tty
->buf
.memory_used
+ size
> 65536)
332 p
= kmalloc(sizeof(struct tty_buffer
) + 2 * size
, GFP_ATOMIC
);
340 p
->char_buf_ptr
= (char *)(p
->data
);
341 p
->flag_buf_ptr
= (unsigned char *)p
->char_buf_ptr
+ size
;
342 tty
->buf
.memory_used
+= size
;
347 * tty_buffer_free - free a tty buffer
348 * @tty: tty owning the buffer
349 * @b: the buffer to free
351 * Free a tty buffer, or add it to the free list according to our
354 * Locking: Caller must hold tty->buf.lock
357 static void tty_buffer_free(struct tty_struct
*tty
, struct tty_buffer
*b
)
359 /* Dumb strategy for now - should keep some stats */
360 tty
->buf
.memory_used
-= b
->size
;
361 WARN_ON(tty
->buf
.memory_used
< 0);
366 b
->next
= tty
->buf
.free
;
372 * __tty_buffer_flush - flush full tty buffers
375 * flush all the buffers containing receive data. Caller must
376 * hold the buffer lock and must have ensured no parallel flush to
379 * Locking: Caller must hold tty->buf.lock
382 static void __tty_buffer_flush(struct tty_struct
*tty
)
384 struct tty_buffer
*thead
;
386 while ((thead
= tty
->buf
.head
) != NULL
) {
387 tty
->buf
.head
= thead
->next
;
388 tty_buffer_free(tty
, thead
);
390 tty
->buf
.tail
= NULL
;
394 * tty_buffer_flush - flush full tty buffers
397 * flush all the buffers containing receive data. If the buffer is
398 * being processed by flush_to_ldisc then we defer the processing
404 static void tty_buffer_flush(struct tty_struct
*tty
)
407 spin_lock_irqsave(&tty
->buf
.lock
, flags
);
409 /* If the data is being pushed to the tty layer then we can't
410 process it here. Instead set a flag and the flush_to_ldisc
411 path will process the flush request before it exits */
412 if (test_bit(TTY_FLUSHING
, &tty
->flags
)) {
413 set_bit(TTY_FLUSHPENDING
, &tty
->flags
);
414 spin_unlock_irqrestore(&tty
->buf
.lock
, flags
);
415 wait_event(tty
->read_wait
,
416 test_bit(TTY_FLUSHPENDING
, &tty
->flags
) == 0);
419 __tty_buffer_flush(tty
);
420 spin_unlock_irqrestore(&tty
->buf
.lock
, flags
);
424 * tty_buffer_find - find a free tty buffer
425 * @tty: tty owning the buffer
426 * @size: characters wanted
428 * Locate an existing suitable tty buffer or if we are lacking one then
429 * allocate a new one. We round our buffers off in 256 character chunks
430 * to get better allocation behaviour.
432 * Locking: Caller must hold tty->buf.lock
435 static struct tty_buffer
*tty_buffer_find(struct tty_struct
*tty
, size_t size
)
437 struct tty_buffer
**tbh
= &tty
->buf
.free
;
438 while ((*tbh
) != NULL
) {
439 struct tty_buffer
*t
= *tbh
;
440 if (t
->size
>= size
) {
446 tty
->buf
.memory_used
+= t
->size
;
449 tbh
= &((*tbh
)->next
);
451 /* Round the buffer size out */
452 size
= (size
+ 0xFF) & ~0xFF;
453 return tty_buffer_alloc(tty
, size
);
454 /* Should possibly check if this fails for the largest buffer we
455 have queued and recycle that ? */
459 * tty_buffer_request_room - grow tty buffer if needed
460 * @tty: tty structure
461 * @size: size desired
463 * Make at least size bytes of linear space available for the tty
464 * buffer. If we fail return the size we managed to find.
466 * Locking: Takes tty->buf.lock
468 int tty_buffer_request_room(struct tty_struct
*tty
, size_t size
)
470 struct tty_buffer
*b
, *n
;
474 spin_lock_irqsave(&tty
->buf
.lock
, flags
);
476 /* OPTIMISATION: We could keep a per tty "zero" sized buffer to
477 remove this conditional if its worth it. This would be invisible
479 if ((b
= tty
->buf
.tail
) != NULL
)
480 left
= b
->size
- b
->used
;
485 /* This is the slow path - looking for new buffers to use */
486 if ((n
= tty_buffer_find(tty
, size
)) != NULL
) {
497 spin_unlock_irqrestore(&tty
->buf
.lock
, flags
);
500 EXPORT_SYMBOL_GPL(tty_buffer_request_room
);
503 * tty_insert_flip_string - Add characters to the tty buffer
504 * @tty: tty structure
508 * Queue a series of bytes to the tty buffering. All the characters
509 * passed are marked as without error. Returns the number added.
511 * Locking: Called functions may take tty->buf.lock
514 int tty_insert_flip_string(struct tty_struct
*tty
, const unsigned char *chars
,
519 int space
= tty_buffer_request_room(tty
, size
- copied
);
520 struct tty_buffer
*tb
= tty
->buf
.tail
;
521 /* If there is no space then tb may be NULL */
522 if (unlikely(space
== 0))
524 memcpy(tb
->char_buf_ptr
+ tb
->used
, chars
, space
);
525 memset(tb
->flag_buf_ptr
+ tb
->used
, TTY_NORMAL
, space
);
529 /* There is a small chance that we need to split the data over
530 several buffers. If this is the case we must loop */
531 } while (unlikely(size
> copied
));
534 EXPORT_SYMBOL(tty_insert_flip_string
);
537 * tty_insert_flip_string_flags - Add characters to the tty buffer
538 * @tty: tty structure
543 * Queue a series of bytes to the tty buffering. For each character
544 * the flags array indicates the status of the character. Returns the
547 * Locking: Called functions may take tty->buf.lock
550 int tty_insert_flip_string_flags(struct tty_struct
*tty
,
551 const unsigned char *chars
, const char *flags
, size_t size
)
555 int space
= tty_buffer_request_room(tty
, size
- copied
);
556 struct tty_buffer
*tb
= tty
->buf
.tail
;
557 /* If there is no space then tb may be NULL */
558 if (unlikely(space
== 0))
560 memcpy(tb
->char_buf_ptr
+ tb
->used
, chars
, space
);
561 memcpy(tb
->flag_buf_ptr
+ tb
->used
, flags
, space
);
566 /* There is a small chance that we need to split the data over
567 several buffers. If this is the case we must loop */
568 } while (unlikely(size
> copied
));
571 EXPORT_SYMBOL(tty_insert_flip_string_flags
);
574 * tty_schedule_flip - push characters to ldisc
575 * @tty: tty to push from
577 * Takes any pending buffers and transfers their ownership to the
578 * ldisc side of the queue. It then schedules those characters for
579 * processing by the line discipline.
581 * Locking: Takes tty->buf.lock
584 void tty_schedule_flip(struct tty_struct
*tty
)
587 spin_lock_irqsave(&tty
->buf
.lock
, flags
);
588 if (tty
->buf
.tail
!= NULL
)
589 tty
->buf
.tail
->commit
= tty
->buf
.tail
->used
;
590 spin_unlock_irqrestore(&tty
->buf
.lock
, flags
);
591 schedule_delayed_work(&tty
->buf
.work
, 1);
593 EXPORT_SYMBOL(tty_schedule_flip
);
596 * tty_prepare_flip_string - make room for characters
598 * @chars: return pointer for character write area
599 * @size: desired size
601 * Prepare a block of space in the buffer for data. Returns the length
602 * available and buffer pointer to the space which is now allocated and
603 * accounted for as ready for normal characters. This is used for drivers
604 * that need their own block copy routines into the buffer. There is no
605 * guarantee the buffer is a DMA target!
607 * Locking: May call functions taking tty->buf.lock
610 int tty_prepare_flip_string(struct tty_struct
*tty
, unsigned char **chars
,
613 int space
= tty_buffer_request_room(tty
, size
);
615 struct tty_buffer
*tb
= tty
->buf
.tail
;
616 *chars
= tb
->char_buf_ptr
+ tb
->used
;
617 memset(tb
->flag_buf_ptr
+ tb
->used
, TTY_NORMAL
, space
);
623 EXPORT_SYMBOL_GPL(tty_prepare_flip_string
);
626 * tty_prepare_flip_string_flags - make room for characters
628 * @chars: return pointer for character write area
629 * @flags: return pointer for status flag write area
630 * @size: desired size
632 * Prepare a block of space in the buffer for data. Returns the length
633 * available and buffer pointer to the space which is now allocated and
634 * accounted for as ready for characters. This is used for drivers
635 * that need their own block copy routines into the buffer. There is no
636 * guarantee the buffer is a DMA target!
638 * Locking: May call functions taking tty->buf.lock
641 int tty_prepare_flip_string_flags(struct tty_struct
*tty
,
642 unsigned char **chars
, char **flags
, size_t size
)
644 int space
= tty_buffer_request_room(tty
, size
);
646 struct tty_buffer
*tb
= tty
->buf
.tail
;
647 *chars
= tb
->char_buf_ptr
+ tb
->used
;
648 *flags
= tb
->flag_buf_ptr
+ tb
->used
;
654 EXPORT_SYMBOL_GPL(tty_prepare_flip_string_flags
);
659 * get_tty_driver - find device of a tty
660 * @dev_t: device identifier
661 * @index: returns the index of the tty
663 * This routine returns a tty driver structure, given a device number
664 * and also passes back the index number.
666 * Locking: caller must hold tty_mutex
669 static struct tty_driver
*get_tty_driver(dev_t device
, int *index
)
671 struct tty_driver
*p
;
673 list_for_each_entry(p
, &tty_drivers
, tty_drivers
) {
674 dev_t base
= MKDEV(p
->major
, p
->minor_start
);
675 if (device
< base
|| device
>= base
+ p
->num
)
677 *index
= device
- base
;
683 #ifdef CONFIG_CONSOLE_POLL
686 * tty_find_polling_driver - find device of a polled tty
687 * @name: name string to match
688 * @line: pointer to resulting tty line nr
690 * This routine returns a tty driver structure, given a name
691 * and the condition that the tty driver is capable of polled
694 struct tty_driver
*tty_find_polling_driver(char *name
, int *line
)
696 struct tty_driver
*p
, *res
= NULL
;
700 mutex_lock(&tty_mutex
);
701 /* Search through the tty devices to look for a match */
702 list_for_each_entry(p
, &tty_drivers
, tty_drivers
) {
703 str
= name
+ strlen(p
->name
);
704 tty_line
= simple_strtoul(str
, &str
, 10);
710 if (tty_line
>= 0 && tty_line
<= p
->num
&& p
->ops
&&
711 p
->ops
->poll_init
&& !p
->ops
->poll_init(p
, tty_line
, str
)) {
717 mutex_unlock(&tty_mutex
);
721 EXPORT_SYMBOL_GPL(tty_find_polling_driver
);
725 * tty_check_change - check for POSIX terminal changes
728 * If we try to write to, or set the state of, a terminal and we're
729 * not in the foreground, send a SIGTTOU. If the signal is blocked or
730 * ignored, go ahead and perform the operation. (POSIX 7.2)
735 int tty_check_change(struct tty_struct
*tty
)
740 if (current
->signal
->tty
!= tty
)
743 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
746 printk(KERN_WARNING
"tty_check_change: tty->pgrp == NULL!\n");
749 if (task_pgrp(current
) == tty
->pgrp
)
751 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
752 if (is_ignored(SIGTTOU
))
754 if (is_current_pgrp_orphaned()) {
758 kill_pgrp(task_pgrp(current
), SIGTTOU
, 1);
759 set_thread_flag(TIF_SIGPENDING
);
764 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
768 EXPORT_SYMBOL(tty_check_change
);
770 static ssize_t
hung_up_tty_read(struct file
*file
, char __user
*buf
,
771 size_t count
, loff_t
*ppos
)
776 static ssize_t
hung_up_tty_write(struct file
*file
, const char __user
*buf
,
777 size_t count
, loff_t
*ppos
)
782 /* No kernel lock held - none needed ;) */
783 static unsigned int hung_up_tty_poll(struct file
*filp
, poll_table
*wait
)
785 return POLLIN
| POLLOUT
| POLLERR
| POLLHUP
| POLLRDNORM
| POLLWRNORM
;
788 static long hung_up_tty_ioctl(struct file
*file
, unsigned int cmd
,
791 return cmd
== TIOCSPGRP
? -ENOTTY
: -EIO
;
794 static long hung_up_tty_compat_ioctl(struct file
*file
,
795 unsigned int cmd
, unsigned long arg
)
797 return cmd
== TIOCSPGRP
? -ENOTTY
: -EIO
;
800 static const struct file_operations tty_fops
= {
805 .unlocked_ioctl
= tty_ioctl
,
806 .compat_ioctl
= tty_compat_ioctl
,
808 .release
= tty_release
,
809 .fasync
= tty_fasync
,
812 #ifdef CONFIG_UNIX98_PTYS
813 static const struct file_operations ptmx_fops
= {
818 .unlocked_ioctl
= tty_ioctl
,
819 .compat_ioctl
= tty_compat_ioctl
,
821 .release
= tty_release
,
822 .fasync
= tty_fasync
,
826 static const struct file_operations console_fops
= {
829 .write
= redirected_tty_write
,
831 .unlocked_ioctl
= tty_ioctl
,
832 .compat_ioctl
= tty_compat_ioctl
,
834 .release
= tty_release
,
835 .fasync
= tty_fasync
,
838 static const struct file_operations hung_up_tty_fops
= {
840 .read
= hung_up_tty_read
,
841 .write
= hung_up_tty_write
,
842 .poll
= hung_up_tty_poll
,
843 .unlocked_ioctl
= hung_up_tty_ioctl
,
844 .compat_ioctl
= hung_up_tty_compat_ioctl
,
845 .release
= tty_release
,
848 static DEFINE_SPINLOCK(redirect_lock
);
849 static struct file
*redirect
;
852 * tty_wakeup - request more data
855 * Internal and external helper for wakeups of tty. This function
856 * informs the line discipline if present that the driver is ready
857 * to receive more output data.
860 void tty_wakeup(struct tty_struct
*tty
)
862 struct tty_ldisc
*ld
;
864 if (test_bit(TTY_DO_WRITE_WAKEUP
, &tty
->flags
)) {
865 ld
= tty_ldisc_ref(tty
);
867 if (ld
->ops
->write_wakeup
)
868 ld
->ops
->write_wakeup(tty
);
872 wake_up_interruptible(&tty
->write_wait
);
875 EXPORT_SYMBOL_GPL(tty_wakeup
);
878 * tty_ldisc_flush - flush line discipline queue
881 * Flush the line discipline queue (if any) for this tty. If there
882 * is no line discipline active this is a no-op.
885 void tty_ldisc_flush(struct tty_struct
*tty
)
887 struct tty_ldisc
*ld
= tty_ldisc_ref(tty
);
889 if (ld
->ops
->flush_buffer
)
890 ld
->ops
->flush_buffer(tty
);
893 tty_buffer_flush(tty
);
896 EXPORT_SYMBOL_GPL(tty_ldisc_flush
);
899 * tty_reset_termios - reset terminal state
902 * Restore a terminal to the driver default state
905 static void tty_reset_termios(struct tty_struct
*tty
)
907 mutex_lock(&tty
->termios_mutex
);
908 *tty
->termios
= tty
->driver
->init_termios
;
909 tty
->termios
->c_ispeed
= tty_termios_input_baud_rate(tty
->termios
);
910 tty
->termios
->c_ospeed
= tty_termios_baud_rate(tty
->termios
);
911 mutex_unlock(&tty
->termios_mutex
);
915 * do_tty_hangup - actual handler for hangup events
918 k * This can be called by the "eventd" kernel thread. That is process
919 * synchronous but doesn't hold any locks, so we need to make sure we
920 * have the appropriate locks for what we're doing.
922 * The hangup event clears any pending redirections onto the hung up
923 * device. It ensures future writes will error and it does the needed
924 * line discipline hangup and signal delivery. The tty object itself
929 * redirect lock for undoing redirection
930 * file list lock for manipulating list of ttys
931 * tty_ldisc_lock from called functions
932 * termios_mutex resetting termios data
933 * tasklist_lock to walk task list for hangup event
934 * ->siglock to protect ->signal/->sighand
936 static void do_tty_hangup(struct work_struct
*work
)
938 struct tty_struct
*tty
=
939 container_of(work
, struct tty_struct
, hangup_work
);
940 struct file
*cons_filp
= NULL
;
941 struct file
*filp
, *f
= NULL
;
942 struct task_struct
*p
;
943 struct tty_ldisc
*ld
;
944 int closecount
= 0, n
;
950 /* inuse_filps is protected by the single kernel lock */
953 spin_lock(&redirect_lock
);
954 if (redirect
&& redirect
->private_data
== tty
) {
958 spin_unlock(&redirect_lock
);
960 check_tty_count(tty
, "do_tty_hangup");
962 /* This breaks for file handles being sent over AF_UNIX sockets ? */
963 list_for_each_entry(filp
, &tty
->tty_files
, f_u
.fu_list
) {
964 if (filp
->f_op
->write
== redirected_tty_write
)
966 if (filp
->f_op
->write
!= tty_write
)
969 tty_fasync(-1, filp
, 0); /* can't block */
970 filp
->f_op
= &hung_up_tty_fops
;
974 * FIXME! What are the locking issues here? This may me overdoing
975 * things... This question is especially important now that we've
976 * removed the irqlock.
978 ld
= tty_ldisc_ref(tty
);
980 /* We may have no line discipline at this point */
981 if (ld
->ops
->flush_buffer
)
982 ld
->ops
->flush_buffer(tty
);
983 tty_driver_flush_buffer(tty
);
984 if ((test_bit(TTY_DO_WRITE_WAKEUP
, &tty
->flags
)) &&
985 ld
->ops
->write_wakeup
)
986 ld
->ops
->write_wakeup(tty
);
988 ld
->ops
->hangup(tty
);
991 * FIXME: Once we trust the LDISC code better we can wait here for
992 * ldisc completion and fix the driver call race
994 wake_up_interruptible(&tty
->write_wait
);
995 wake_up_interruptible(&tty
->read_wait
);
997 * Shutdown the current line discipline, and reset it to
1000 if (tty
->driver
->flags
& TTY_DRIVER_RESET_TERMIOS
)
1001 tty_reset_termios(tty
);
1002 /* Defer ldisc switch */
1003 /* tty_deferred_ldisc_switch(N_TTY);
1005 This should get done automatically when the port closes and
1006 tty_release is called */
1008 read_lock(&tasklist_lock
);
1010 do_each_pid_task(tty
->session
, PIDTYPE_SID
, p
) {
1011 spin_lock_irq(&p
->sighand
->siglock
);
1012 if (p
->signal
->tty
== tty
)
1013 p
->signal
->tty
= NULL
;
1014 if (!p
->signal
->leader
) {
1015 spin_unlock_irq(&p
->sighand
->siglock
);
1018 __group_send_sig_info(SIGHUP
, SEND_SIG_PRIV
, p
);
1019 __group_send_sig_info(SIGCONT
, SEND_SIG_PRIV
, p
);
1020 put_pid(p
->signal
->tty_old_pgrp
); /* A noop */
1021 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
1023 p
->signal
->tty_old_pgrp
= get_pid(tty
->pgrp
);
1024 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
1025 spin_unlock_irq(&p
->sighand
->siglock
);
1026 } while_each_pid_task(tty
->session
, PIDTYPE_SID
, p
);
1028 read_unlock(&tasklist_lock
);
1030 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
1032 put_pid(tty
->session
);
1034 tty
->session
= NULL
;
1036 tty
->ctrl_status
= 0;
1037 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
1040 * If one of the devices matches a console pointer, we
1041 * cannot just call hangup() because that will cause
1042 * tty->count and state->count to go out of sync.
1043 * So we just call close() the right number of times.
1046 if (tty
->ops
->close
)
1047 for (n
= 0; n
< closecount
; n
++)
1048 tty
->ops
->close(tty
, cons_filp
);
1049 } else if (tty
->ops
->hangup
)
1050 (tty
->ops
->hangup
)(tty
);
1052 * We don't want to have driver/ldisc interactions beyond
1053 * the ones we did here. The driver layer expects no
1054 * calls after ->hangup() from the ldisc side. However we
1055 * can't yet guarantee all that.
1057 set_bit(TTY_HUPPED
, &tty
->flags
);
1059 tty_ldisc_enable(tty
);
1060 tty_ldisc_deref(ld
);
1068 * tty_hangup - trigger a hangup event
1069 * @tty: tty to hangup
1071 * A carrier loss (virtual or otherwise) has occurred on this like
1072 * schedule a hangup sequence to run after this event.
1075 void tty_hangup(struct tty_struct
*tty
)
1077 #ifdef TTY_DEBUG_HANGUP
1079 printk(KERN_DEBUG
"%s hangup...\n", tty_name(tty
, buf
));
1081 schedule_work(&tty
->hangup_work
);
1084 EXPORT_SYMBOL(tty_hangup
);
1087 * tty_vhangup - process vhangup
1088 * @tty: tty to hangup
1090 * The user has asked via system call for the terminal to be hung up.
1091 * We do this synchronously so that when the syscall returns the process
1092 * is complete. That guarantee is necessary for security reasons.
1095 void tty_vhangup(struct tty_struct
*tty
)
1097 #ifdef TTY_DEBUG_HANGUP
1100 printk(KERN_DEBUG
"%s vhangup...\n", tty_name(tty
, buf
));
1102 do_tty_hangup(&tty
->hangup_work
);
1105 EXPORT_SYMBOL(tty_vhangup
);
1108 * tty_hung_up_p - was tty hung up
1109 * @filp: file pointer of tty
1111 * Return true if the tty has been subject to a vhangup or a carrier
1115 int tty_hung_up_p(struct file
*filp
)
1117 return (filp
->f_op
== &hung_up_tty_fops
);
1120 EXPORT_SYMBOL(tty_hung_up_p
);
1123 * is_tty - checker whether file is a TTY
1124 * @filp: file handle that may be a tty
1126 * Check if the file handle is a tty handle.
1129 int is_tty(struct file
*filp
)
1131 return filp
->f_op
->read
== tty_read
1132 || filp
->f_op
->read
== hung_up_tty_read
;
1135 static void session_clear_tty(struct pid
*session
)
1137 struct task_struct
*p
;
1138 do_each_pid_task(session
, PIDTYPE_SID
, p
) {
1140 } while_each_pid_task(session
, PIDTYPE_SID
, p
);
1144 * disassociate_ctty - disconnect controlling tty
1145 * @on_exit: true if exiting so need to "hang up" the session
1147 * This function is typically called only by the session leader, when
1148 * it wants to disassociate itself from its controlling tty.
1150 * It performs the following functions:
1151 * (1) Sends a SIGHUP and SIGCONT to the foreground process group
1152 * (2) Clears the tty from being controlling the session
1153 * (3) Clears the controlling tty for all processes in the
1156 * The argument on_exit is set to 1 if called when a process is
1157 * exiting; it is 0 if called by the ioctl TIOCNOTTY.
1160 * BKL is taken for hysterical raisins
1161 * tty_mutex is taken to protect tty
1162 * ->siglock is taken to protect ->signal/->sighand
1163 * tasklist_lock is taken to walk process list for sessions
1164 * ->siglock is taken to protect ->signal/->sighand
1167 void disassociate_ctty(int on_exit
)
1169 struct tty_struct
*tty
;
1170 struct pid
*tty_pgrp
= NULL
;
1173 mutex_lock(&tty_mutex
);
1174 tty
= get_current_tty();
1176 tty_pgrp
= get_pid(tty
->pgrp
);
1177 mutex_unlock(&tty_mutex
);
1179 /* XXX: here we race, there is nothing protecting tty */
1180 if (on_exit
&& tty
->driver
->type
!= TTY_DRIVER_TYPE_PTY
)
1183 } else if (on_exit
) {
1184 struct pid
*old_pgrp
;
1185 spin_lock_irq(¤t
->sighand
->siglock
);
1186 old_pgrp
= current
->signal
->tty_old_pgrp
;
1187 current
->signal
->tty_old_pgrp
= NULL
;
1188 spin_unlock_irq(¤t
->sighand
->siglock
);
1190 kill_pgrp(old_pgrp
, SIGHUP
, on_exit
);
1191 kill_pgrp(old_pgrp
, SIGCONT
, on_exit
);
1194 mutex_unlock(&tty_mutex
);
1198 kill_pgrp(tty_pgrp
, SIGHUP
, on_exit
);
1200 kill_pgrp(tty_pgrp
, SIGCONT
, on_exit
);
1204 spin_lock_irq(¤t
->sighand
->siglock
);
1205 put_pid(current
->signal
->tty_old_pgrp
);
1206 current
->signal
->tty_old_pgrp
= NULL
;
1207 spin_unlock_irq(¤t
->sighand
->siglock
);
1209 mutex_lock(&tty_mutex
);
1210 /* It is possible that do_tty_hangup has free'd this tty */
1211 tty
= get_current_tty();
1213 unsigned long flags
;
1214 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
1215 put_pid(tty
->session
);
1217 tty
->session
= NULL
;
1219 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
1221 #ifdef TTY_DEBUG_HANGUP
1222 printk(KERN_DEBUG
"error attempted to write to tty [0x%p]"
1226 mutex_unlock(&tty_mutex
);
1228 /* Now clear signal->tty under the lock */
1229 read_lock(&tasklist_lock
);
1230 session_clear_tty(task_session(current
));
1231 read_unlock(&tasklist_lock
);
1236 * no_tty - Ensure the current process does not have a controlling tty
1240 struct task_struct
*tsk
= current
;
1242 if (tsk
->signal
->leader
)
1243 disassociate_ctty(0);
1245 proc_clear_tty(tsk
);
1250 * stop_tty - propagate flow control
1253 * Perform flow control to the driver. For PTY/TTY pairs we
1254 * must also propagate the TIOCKPKT status. May be called
1255 * on an already stopped device and will not re-call the driver
1258 * This functionality is used by both the line disciplines for
1259 * halting incoming flow and by the driver. It may therefore be
1260 * called from any context, may be under the tty atomic_write_lock
1264 * Uses the tty control lock internally
1267 void stop_tty(struct tty_struct
*tty
)
1269 unsigned long flags
;
1270 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
1272 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
1276 if (tty
->link
&& tty
->link
->packet
) {
1277 tty
->ctrl_status
&= ~TIOCPKT_START
;
1278 tty
->ctrl_status
|= TIOCPKT_STOP
;
1279 wake_up_interruptible(&tty
->link
->read_wait
);
1281 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
1283 (tty
->ops
->stop
)(tty
);
1286 EXPORT_SYMBOL(stop_tty
);
1289 * start_tty - propagate flow control
1290 * @tty: tty to start
1292 * Start a tty that has been stopped if at all possible. Perform
1293 * any necessary wakeups and propagate the TIOCPKT status. If this
1294 * is the tty was previous stopped and is being started then the
1295 * driver start method is invoked and the line discipline woken.
1301 void start_tty(struct tty_struct
*tty
)
1303 unsigned long flags
;
1304 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
1305 if (!tty
->stopped
|| tty
->flow_stopped
) {
1306 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
1310 if (tty
->link
&& tty
->link
->packet
) {
1311 tty
->ctrl_status
&= ~TIOCPKT_STOP
;
1312 tty
->ctrl_status
|= TIOCPKT_START
;
1313 wake_up_interruptible(&tty
->link
->read_wait
);
1315 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
1316 if (tty
->ops
->start
)
1317 (tty
->ops
->start
)(tty
);
1318 /* If we have a running line discipline it may need kicking */
1322 EXPORT_SYMBOL(start_tty
);
1325 * tty_read - read method for tty device files
1326 * @file: pointer to tty file
1328 * @count: size of user buffer
1331 * Perform the read system call function on this terminal device. Checks
1332 * for hung up devices before calling the line discipline method.
1335 * Locks the line discipline internally while needed. Multiple
1336 * read calls may be outstanding in parallel.
1339 static ssize_t
tty_read(struct file
*file
, char __user
*buf
, size_t count
,
1343 struct tty_struct
*tty
;
1344 struct inode
*inode
;
1345 struct tty_ldisc
*ld
;
1347 tty
= (struct tty_struct
*)file
->private_data
;
1348 inode
= file
->f_path
.dentry
->d_inode
;
1349 if (tty_paranoia_check(tty
, inode
, "tty_read"))
1351 if (!tty
|| (test_bit(TTY_IO_ERROR
, &tty
->flags
)))
1354 /* We want to wait for the line discipline to sort out in this
1356 ld
= tty_ldisc_ref_wait(tty
);
1358 i
= (ld
->ops
->read
)(tty
, file
, buf
, count
);
1361 tty_ldisc_deref(ld
);
1363 inode
->i_atime
= current_fs_time(inode
->i_sb
);
1367 void tty_write_unlock(struct tty_struct
*tty
)
1369 mutex_unlock(&tty
->atomic_write_lock
);
1370 wake_up_interruptible(&tty
->write_wait
);
1373 int tty_write_lock(struct tty_struct
*tty
, int ndelay
)
1375 if (!mutex_trylock(&tty
->atomic_write_lock
)) {
1378 if (mutex_lock_interruptible(&tty
->atomic_write_lock
))
1379 return -ERESTARTSYS
;
1385 * Split writes up in sane blocksizes to avoid
1386 * denial-of-service type attacks
1388 static inline ssize_t
do_tty_write(
1389 ssize_t (*write
)(struct tty_struct
*, struct file
*, const unsigned char *, size_t),
1390 struct tty_struct
*tty
,
1392 const char __user
*buf
,
1395 ssize_t ret
, written
= 0;
1398 ret
= tty_write_lock(tty
, file
->f_flags
& O_NDELAY
);
1403 * We chunk up writes into a temporary buffer. This
1404 * simplifies low-level drivers immensely, since they
1405 * don't have locking issues and user mode accesses.
1407 * But if TTY_NO_WRITE_SPLIT is set, we should use a
1410 * The default chunk-size is 2kB, because the NTTY
1411 * layer has problems with bigger chunks. It will
1412 * claim to be able to handle more characters than
1415 * FIXME: This can probably go away now except that 64K chunks
1416 * are too likely to fail unless switched to vmalloc...
1419 if (test_bit(TTY_NO_WRITE_SPLIT
, &tty
->flags
))
1424 /* write_buf/write_cnt is protected by the atomic_write_lock mutex */
1425 if (tty
->write_cnt
< chunk
) {
1431 buf
= kmalloc(chunk
, GFP_KERNEL
);
1436 kfree(tty
->write_buf
);
1437 tty
->write_cnt
= chunk
;
1438 tty
->write_buf
= buf
;
1441 /* Do the write .. */
1443 size_t size
= count
;
1447 if (copy_from_user(tty
->write_buf
, buf
, size
))
1449 ret
= write(tty
, file
, tty
->write_buf
, size
);
1458 if (signal_pending(current
))
1463 struct inode
*inode
= file
->f_path
.dentry
->d_inode
;
1464 inode
->i_mtime
= current_fs_time(inode
->i_sb
);
1468 tty_write_unlock(tty
);
1474 * tty_write - write method for tty device file
1475 * @file: tty file pointer
1476 * @buf: user data to write
1477 * @count: bytes to write
1480 * Write data to a tty device via the line discipline.
1483 * Locks the line discipline as required
1484 * Writes to the tty driver are serialized by the atomic_write_lock
1485 * and are then processed in chunks to the device. The line discipline
1486 * write method will not be involked in parallel for each device
1487 * The line discipline write method is called under the big
1488 * kernel lock for historical reasons. New code should not rely on this.
1491 static ssize_t
tty_write(struct file
*file
, const char __user
*buf
,
1492 size_t count
, loff_t
*ppos
)
1494 struct tty_struct
*tty
;
1495 struct inode
*inode
= file
->f_path
.dentry
->d_inode
;
1497 struct tty_ldisc
*ld
;
1499 tty
= (struct tty_struct
*)file
->private_data
;
1500 if (tty_paranoia_check(tty
, inode
, "tty_write"))
1502 if (!tty
|| !tty
->ops
->write
||
1503 (test_bit(TTY_IO_ERROR
, &tty
->flags
)))
1505 /* Short term debug to catch buggy drivers */
1506 if (tty
->ops
->write_room
== NULL
)
1507 printk(KERN_ERR
"tty driver %s lacks a write_room method.\n",
1509 ld
= tty_ldisc_ref_wait(tty
);
1510 if (!ld
->ops
->write
)
1513 ret
= do_tty_write(ld
->ops
->write
, tty
, file
, buf
, count
);
1514 tty_ldisc_deref(ld
);
1518 ssize_t
redirected_tty_write(struct file
*file
, const char __user
*buf
,
1519 size_t count
, loff_t
*ppos
)
1521 struct file
*p
= NULL
;
1523 spin_lock(&redirect_lock
);
1528 spin_unlock(&redirect_lock
);
1532 res
= vfs_write(p
, buf
, count
, &p
->f_pos
);
1536 return tty_write(file
, buf
, count
, ppos
);
1539 void tty_port_init(struct tty_port
*port
)
1541 memset(port
, 0, sizeof(*port
));
1542 init_waitqueue_head(&port
->open_wait
);
1543 init_waitqueue_head(&port
->close_wait
);
1544 mutex_init(&port
->mutex
);
1545 port
->close_delay
= (50 * HZ
) / 100;
1546 port
->closing_wait
= (3000 * HZ
) / 100;
1548 EXPORT_SYMBOL(tty_port_init
);
1550 int tty_port_alloc_xmit_buf(struct tty_port
*port
)
1552 /* We may sleep in get_zeroed_page() */
1553 mutex_lock(&port
->mutex
);
1554 if (port
->xmit_buf
== NULL
)
1555 port
->xmit_buf
= (unsigned char *)get_zeroed_page(GFP_KERNEL
);
1556 mutex_unlock(&port
->mutex
);
1557 if (port
->xmit_buf
== NULL
)
1561 EXPORT_SYMBOL(tty_port_alloc_xmit_buf
);
1563 void tty_port_free_xmit_buf(struct tty_port
*port
)
1565 mutex_lock(&port
->mutex
);
1566 if (port
->xmit_buf
!= NULL
) {
1567 free_page((unsigned long)port
->xmit_buf
);
1568 port
->xmit_buf
= NULL
;
1570 mutex_unlock(&port
->mutex
);
1572 EXPORT_SYMBOL(tty_port_free_xmit_buf
);
1575 static char ptychar
[] = "pqrstuvwxyzabcde";
1578 * pty_line_name - generate name for a pty
1579 * @driver: the tty driver in use
1580 * @index: the minor number
1581 * @p: output buffer of at least 6 bytes
1583 * Generate a name from a driver reference and write it to the output
1588 static void pty_line_name(struct tty_driver
*driver
, int index
, char *p
)
1590 int i
= index
+ driver
->name_base
;
1591 /* ->name is initialized to "ttyp", but "tty" is expected */
1592 sprintf(p
, "%s%c%x",
1593 driver
->subtype
== PTY_TYPE_SLAVE
? "tty" : driver
->name
,
1594 ptychar
[i
>> 4 & 0xf], i
& 0xf);
1598 * pty_line_name - generate name for a tty
1599 * @driver: the tty driver in use
1600 * @index: the minor number
1601 * @p: output buffer of at least 7 bytes
1603 * Generate a name from a driver reference and write it to the output
1608 static void tty_line_name(struct tty_driver
*driver
, int index
, char *p
)
1610 sprintf(p
, "%s%d", driver
->name
, index
+ driver
->name_base
);
1614 * init_dev - initialise a tty device
1615 * @driver: tty driver we are opening a device on
1616 * @idx: device index
1617 * @tty: returned tty structure
1619 * Prepare a tty device. This may not be a "new" clean device but
1620 * could also be an active device. The pty drivers require special
1621 * handling because of this.
1624 * The function is called under the tty_mutex, which
1625 * protects us from the tty struct or driver itself going away.
1627 * On exit the tty device has the line discipline attached and
1628 * a reference count of 1. If a pair was created for pty/tty use
1629 * and the other was a pty master then it too has a reference count of 1.
1631 * WSH 06/09/97: Rewritten to remove races and properly clean up after a
1632 * failed open. The new code protects the open with a mutex, so it's
1633 * really quite straightforward. The mutex locking can probably be
1634 * relaxed for the (most common) case of reopening a tty.
1637 static int init_dev(struct tty_driver
*driver
, int idx
,
1638 struct tty_struct
**ret_tty
)
1640 struct tty_struct
*tty
, *o_tty
;
1641 struct ktermios
*tp
, **tp_loc
, *o_tp
, **o_tp_loc
;
1642 struct ktermios
*ltp
, **ltp_loc
, *o_ltp
, **o_ltp_loc
;
1645 /* check whether we're reopening an existing tty */
1646 if (driver
->flags
& TTY_DRIVER_DEVPTS_MEM
) {
1647 tty
= devpts_get_tty(idx
);
1649 * If we don't have a tty here on a slave open, it's because
1650 * the master already started the close process and there's
1651 * no relation between devpts file and tty anymore.
1653 if (!tty
&& driver
->subtype
== PTY_TYPE_SLAVE
) {
1658 * It's safe from now on because init_dev() is called with
1659 * tty_mutex held and release_dev() won't change tty->count
1660 * or tty->flags without having to grab tty_mutex
1662 if (tty
&& driver
->subtype
== PTY_TYPE_MASTER
)
1665 tty
= driver
->ttys
[idx
];
1667 if (tty
) goto fast_track
;
1670 * First time open is complex, especially for PTY devices.
1671 * This code guarantees that either everything succeeds and the
1672 * TTY is ready for operation, or else the table slots are vacated
1673 * and the allocated memory released. (Except that the termios
1674 * and locked termios may be retained.)
1677 if (!try_module_get(driver
->owner
)) {
1686 tty
= alloc_tty_struct();
1689 initialize_tty_struct(tty
);
1690 tty
->driver
= driver
;
1691 tty
->ops
= driver
->ops
;
1693 tty_line_name(driver
, idx
, tty
->name
);
1695 if (driver
->flags
& TTY_DRIVER_DEVPTS_MEM
) {
1696 tp_loc
= &tty
->termios
;
1697 ltp_loc
= &tty
->termios_locked
;
1699 tp_loc
= &driver
->termios
[idx
];
1700 ltp_loc
= &driver
->termios_locked
[idx
];
1704 tp
= kmalloc(sizeof(struct ktermios
), GFP_KERNEL
);
1707 *tp
= driver
->init_termios
;
1711 ltp
= kzalloc(sizeof(struct ktermios
), GFP_KERNEL
);
1716 if (driver
->type
== TTY_DRIVER_TYPE_PTY
) {
1717 o_tty
= alloc_tty_struct();
1720 initialize_tty_struct(o_tty
);
1721 o_tty
->driver
= driver
->other
;
1722 o_tty
->ops
= driver
->ops
;
1724 tty_line_name(driver
->other
, idx
, o_tty
->name
);
1726 if (driver
->flags
& TTY_DRIVER_DEVPTS_MEM
) {
1727 o_tp_loc
= &o_tty
->termios
;
1728 o_ltp_loc
= &o_tty
->termios_locked
;
1730 o_tp_loc
= &driver
->other
->termios
[idx
];
1731 o_ltp_loc
= &driver
->other
->termios_locked
[idx
];
1735 o_tp
= kmalloc(sizeof(struct ktermios
), GFP_KERNEL
);
1738 *o_tp
= driver
->other
->init_termios
;
1742 o_ltp
= kzalloc(sizeof(struct ktermios
), GFP_KERNEL
);
1748 * Everything allocated ... set up the o_tty structure.
1750 if (!(driver
->other
->flags
& TTY_DRIVER_DEVPTS_MEM
))
1751 driver
->other
->ttys
[idx
] = o_tty
;
1756 o_tty
->termios
= *o_tp_loc
;
1757 o_tty
->termios_locked
= *o_ltp_loc
;
1758 driver
->other
->refcount
++;
1759 if (driver
->subtype
== PTY_TYPE_MASTER
)
1762 /* Establish the links in both directions */
1768 * All structures have been allocated, so now we install them.
1769 * Failures after this point use release_tty to clean up, so
1770 * there's no need to null out the local pointers.
1772 if (!(driver
->flags
& TTY_DRIVER_DEVPTS_MEM
))
1773 driver
->ttys
[idx
] = tty
;
1779 tty
->termios
= *tp_loc
;
1780 tty
->termios_locked
= *ltp_loc
;
1781 /* Compatibility until drivers always set this */
1782 tty
->termios
->c_ispeed
= tty_termios_input_baud_rate(tty
->termios
);
1783 tty
->termios
->c_ospeed
= tty_termios_baud_rate(tty
->termios
);
1788 * Structures all installed ... call the ldisc open routines.
1789 * If we fail here just call release_tty to clean up. No need
1790 * to decrement the use counts, as release_tty doesn't care.
1793 retval
= tty_ldisc_setup(tty
, o_tty
);
1796 goto release_mem_out
;
1800 * This fast open can be used if the tty is already open.
1801 * No memory is allocated, and the only failures are from
1802 * attempting to open a closing tty or attempting multiple
1803 * opens on a pty master.
1806 if (test_bit(TTY_CLOSING
, &tty
->flags
)) {
1810 if (driver
->type
== TTY_DRIVER_TYPE_PTY
&&
1811 driver
->subtype
== PTY_TYPE_MASTER
) {
1813 * special case for PTY masters: only one open permitted,
1814 * and the slave side open count is incremented as well.
1823 tty
->driver
= driver
; /* N.B. why do this every time?? */
1826 if (!test_bit(TTY_LDISC
, &tty
->flags
))
1827 printk(KERN_ERR
"init_dev but no ldisc\n");
1831 /* All paths come through here to release the mutex */
1835 /* Release locally allocated memory ... nothing placed in slots */
1839 free_tty_struct(o_tty
);
1842 free_tty_struct(tty
);
1845 module_put(driver
->owner
);
1849 /* call the tty release_tty routine to clean out this slot */
1851 if (printk_ratelimit())
1852 printk(KERN_INFO
"init_dev: ldisc open failed, "
1853 "clearing slot %d\n", idx
);
1854 release_tty(tty
, idx
);
1859 * release_one_tty - release tty structure memory
1861 * Releases memory associated with a tty structure, and clears out the
1862 * driver table slots. This function is called when a device is no longer
1863 * in use. It also gets called when setup of a device fails.
1866 * tty_mutex - sometimes only
1867 * takes the file list lock internally when working on the list
1868 * of ttys that the driver keeps.
1869 * FIXME: should we require tty_mutex is held here ??
1871 static void release_one_tty(struct tty_struct
*tty
, int idx
)
1873 int devpts
= tty
->driver
->flags
& TTY_DRIVER_DEVPTS_MEM
;
1874 struct ktermios
*tp
;
1877 tty
->driver
->ttys
[idx
] = NULL
;
1879 if (tty
->driver
->flags
& TTY_DRIVER_RESET_TERMIOS
) {
1882 tty
->driver
->termios
[idx
] = NULL
;
1885 tp
= tty
->termios_locked
;
1887 tty
->driver
->termios_locked
[idx
] = NULL
;
1893 tty
->driver
->refcount
--;
1896 list_del_init(&tty
->tty_files
);
1899 free_tty_struct(tty
);
1903 * release_tty - release tty structure memory
1905 * Release both @tty and a possible linked partner (think pty pair),
1906 * and decrement the refcount of the backing module.
1909 * tty_mutex - sometimes only
1910 * takes the file list lock internally when working on the list
1911 * of ttys that the driver keeps.
1912 * FIXME: should we require tty_mutex is held here ??
1914 static void release_tty(struct tty_struct
*tty
, int idx
)
1916 struct tty_driver
*driver
= tty
->driver
;
1919 release_one_tty(tty
->link
, idx
);
1920 release_one_tty(tty
, idx
);
1921 module_put(driver
->owner
);
1925 * Even releasing the tty structures is a tricky business.. We have
1926 * to be very careful that the structures are all released at the
1927 * same time, as interrupts might otherwise get the wrong pointers.
1929 * WSH 09/09/97: rewritten to avoid some nasty race conditions that could
1930 * lead to double frees or releasing memory still in use.
1932 static void release_dev(struct file
*filp
)
1934 struct tty_struct
*tty
, *o_tty
;
1935 int pty_master
, tty_closing
, o_tty_closing
, do_sleep
;
1940 tty
= (struct tty_struct
*)filp
->private_data
;
1941 if (tty_paranoia_check(tty
, filp
->f_path
.dentry
->d_inode
,
1945 check_tty_count(tty
, "release_dev");
1947 tty_fasync(-1, filp
, 0);
1950 pty_master
= (tty
->driver
->type
== TTY_DRIVER_TYPE_PTY
&&
1951 tty
->driver
->subtype
== PTY_TYPE_MASTER
);
1952 devpts
= (tty
->driver
->flags
& TTY_DRIVER_DEVPTS_MEM
) != 0;
1955 #ifdef TTY_PARANOIA_CHECK
1956 if (idx
< 0 || idx
>= tty
->driver
->num
) {
1957 printk(KERN_DEBUG
"release_dev: bad idx when trying to "
1958 "free (%s)\n", tty
->name
);
1961 if (!(tty
->driver
->flags
& TTY_DRIVER_DEVPTS_MEM
)) {
1962 if (tty
!= tty
->driver
->ttys
[idx
]) {
1963 printk(KERN_DEBUG
"release_dev: driver.table[%d] not tty "
1964 "for (%s)\n", idx
, tty
->name
);
1967 if (tty
->termios
!= tty
->driver
->termios
[idx
]) {
1968 printk(KERN_DEBUG
"release_dev: driver.termios[%d] not termios "
1973 if (tty
->termios_locked
!= tty
->driver
->termios_locked
[idx
]) {
1974 printk(KERN_DEBUG
"release_dev: driver.termios_locked[%d] not "
1975 "termios_locked for (%s)\n",
1982 #ifdef TTY_DEBUG_HANGUP
1983 printk(KERN_DEBUG
"release_dev of %s (tty count=%d)...",
1984 tty_name(tty
, buf
), tty
->count
);
1987 #ifdef TTY_PARANOIA_CHECK
1988 if (tty
->driver
->other
&&
1989 !(tty
->driver
->flags
& TTY_DRIVER_DEVPTS_MEM
)) {
1990 if (o_tty
!= tty
->driver
->other
->ttys
[idx
]) {
1991 printk(KERN_DEBUG
"release_dev: other->table[%d] "
1992 "not o_tty for (%s)\n",
1996 if (o_tty
->termios
!= tty
->driver
->other
->termios
[idx
]) {
1997 printk(KERN_DEBUG
"release_dev: other->termios[%d] "
1998 "not o_termios for (%s)\n",
2002 if (o_tty
->termios_locked
!=
2003 tty
->driver
->other
->termios_locked
[idx
]) {
2004 printk(KERN_DEBUG
"release_dev: other->termios_locked["
2005 "%d] not o_termios_locked for (%s)\n",
2009 if (o_tty
->link
!= tty
) {
2010 printk(KERN_DEBUG
"release_dev: bad pty pointers\n");
2015 if (tty
->ops
->close
)
2016 tty
->ops
->close(tty
, filp
);
2019 * Sanity check: if tty->count is going to zero, there shouldn't be
2020 * any waiters on tty->read_wait or tty->write_wait. We test the
2021 * wait queues and kick everyone out _before_ actually starting to
2022 * close. This ensures that we won't block while releasing the tty
2025 * The test for the o_tty closing is necessary, since the master and
2026 * slave sides may close in any order. If the slave side closes out
2027 * first, its count will be one, since the master side holds an open.
2028 * Thus this test wouldn't be triggered at the time the slave closes,
2031 * Note that it's possible for the tty to be opened again while we're
2032 * flushing out waiters. By recalculating the closing flags before
2033 * each iteration we avoid any problems.
2036 /* Guard against races with tty->count changes elsewhere and
2037 opens on /dev/tty */
2039 mutex_lock(&tty_mutex
);
2040 tty_closing
= tty
->count
<= 1;
2041 o_tty_closing
= o_tty
&&
2042 (o_tty
->count
<= (pty_master
? 1 : 0));
2046 if (waitqueue_active(&tty
->read_wait
)) {
2047 wake_up(&tty
->read_wait
);
2050 if (waitqueue_active(&tty
->write_wait
)) {
2051 wake_up(&tty
->write_wait
);
2055 if (o_tty_closing
) {
2056 if (waitqueue_active(&o_tty
->read_wait
)) {
2057 wake_up(&o_tty
->read_wait
);
2060 if (waitqueue_active(&o_tty
->write_wait
)) {
2061 wake_up(&o_tty
->write_wait
);
2068 printk(KERN_WARNING
"release_dev: %s: read/write wait queue "
2069 "active!\n", tty_name(tty
, buf
));
2070 mutex_unlock(&tty_mutex
);
2075 * The closing flags are now consistent with the open counts on
2076 * both sides, and we've completed the last operation that could
2077 * block, so it's safe to proceed with closing.
2080 if (--o_tty
->count
< 0) {
2081 printk(KERN_WARNING
"release_dev: bad pty slave count "
2083 o_tty
->count
, tty_name(o_tty
, buf
));
2087 if (--tty
->count
< 0) {
2088 printk(KERN_WARNING
"release_dev: bad tty->count (%d) for %s\n",
2089 tty
->count
, tty_name(tty
, buf
));
2094 * We've decremented tty->count, so we need to remove this file
2095 * descriptor off the tty->tty_files list; this serves two
2097 * - check_tty_count sees the correct number of file descriptors
2098 * associated with this tty.
2099 * - do_tty_hangup no longer sees this file descriptor as
2100 * something that needs to be handled for hangups.
2103 filp
->private_data
= NULL
;
2106 * Perform some housekeeping before deciding whether to return.
2108 * Set the TTY_CLOSING flag if this was the last open. In the
2109 * case of a pty we may have to wait around for the other side
2110 * to close, and TTY_CLOSING makes sure we can't be reopened.
2113 set_bit(TTY_CLOSING
, &tty
->flags
);
2115 set_bit(TTY_CLOSING
, &o_tty
->flags
);
2118 * If _either_ side is closing, make sure there aren't any
2119 * processes that still think tty or o_tty is their controlling
2122 if (tty_closing
|| o_tty_closing
) {
2123 read_lock(&tasklist_lock
);
2124 session_clear_tty(tty
->session
);
2126 session_clear_tty(o_tty
->session
);
2127 read_unlock(&tasklist_lock
);
2130 mutex_unlock(&tty_mutex
);
2132 /* check whether both sides are closing ... */
2133 if (!tty_closing
|| (o_tty
&& !o_tty_closing
))
2136 #ifdef TTY_DEBUG_HANGUP
2137 printk(KERN_DEBUG
"freeing tty structure...");
2140 * Ask the line discipline code to release its structures
2142 tty_ldisc_release(tty
, o_tty
);
2144 * The release_tty function takes care of the details of clearing
2145 * the slots and preserving the termios structure.
2147 release_tty(tty
, idx
);
2149 /* Make this pty number available for reallocation */
2151 devpts_kill_index(idx
);
2155 * tty_open - open a tty device
2156 * @inode: inode of device file
2157 * @filp: file pointer to tty
2159 * tty_open and tty_release keep up the tty count that contains the
2160 * number of opens done on a tty. We cannot use the inode-count, as
2161 * different inodes might point to the same tty.
2163 * Open-counting is needed for pty masters, as well as for keeping
2164 * track of serial lines: DTR is dropped when the last close happens.
2165 * (This is not done solely through tty->count, now. - Ted 1/27/92)
2167 * The termios state of a pty is reset on first open so that
2168 * settings don't persist across reuse.
2170 * Locking: tty_mutex protects tty, get_tty_driver and init_dev work.
2171 * tty->count should protect the rest.
2172 * ->siglock protects ->signal/->sighand
2175 static int __tty_open(struct inode
*inode
, struct file
*filp
)
2177 struct tty_struct
*tty
;
2179 struct tty_driver
*driver
;
2181 dev_t device
= inode
->i_rdev
;
2182 unsigned short saved_flags
= filp
->f_flags
;
2184 nonseekable_open(inode
, filp
);
2187 noctty
= filp
->f_flags
& O_NOCTTY
;
2191 mutex_lock(&tty_mutex
);
2193 if (device
== MKDEV(TTYAUX_MAJOR
, 0)) {
2194 tty
= get_current_tty();
2196 mutex_unlock(&tty_mutex
);
2199 driver
= tty
->driver
;
2201 filp
->f_flags
|= O_NONBLOCK
; /* Don't let /dev/tty block */
2206 if (device
== MKDEV(TTY_MAJOR
, 0)) {
2207 extern struct tty_driver
*console_driver
;
2208 driver
= console_driver
;
2214 if (device
== MKDEV(TTYAUX_MAJOR
, 1)) {
2215 driver
= console_device(&index
);
2217 /* Don't let /dev/console block */
2218 filp
->f_flags
|= O_NONBLOCK
;
2222 mutex_unlock(&tty_mutex
);
2226 driver
= get_tty_driver(device
, &index
);
2228 mutex_unlock(&tty_mutex
);
2232 retval
= init_dev(driver
, index
, &tty
);
2233 mutex_unlock(&tty_mutex
);
2237 filp
->private_data
= tty
;
2238 file_move(filp
, &tty
->tty_files
);
2239 check_tty_count(tty
, "tty_open");
2240 if (tty
->driver
->type
== TTY_DRIVER_TYPE_PTY
&&
2241 tty
->driver
->subtype
== PTY_TYPE_MASTER
)
2243 #ifdef TTY_DEBUG_HANGUP
2244 printk(KERN_DEBUG
"opening %s...", tty
->name
);
2248 retval
= tty
->ops
->open(tty
, filp
);
2252 filp
->f_flags
= saved_flags
;
2254 if (!retval
&& test_bit(TTY_EXCLUSIVE
, &tty
->flags
) &&
2255 !capable(CAP_SYS_ADMIN
))
2259 #ifdef TTY_DEBUG_HANGUP
2260 printk(KERN_DEBUG
"error %d in opening %s...", retval
,
2264 if (retval
!= -ERESTARTSYS
)
2266 if (signal_pending(current
))
2270 * Need to reset f_op in case a hangup happened.
2272 if (filp
->f_op
== &hung_up_tty_fops
)
2273 filp
->f_op
= &tty_fops
;
2277 mutex_lock(&tty_mutex
);
2278 spin_lock_irq(¤t
->sighand
->siglock
);
2280 current
->signal
->leader
&&
2281 !current
->signal
->tty
&&
2282 tty
->session
== NULL
)
2283 __proc_set_tty(current
, tty
);
2284 spin_unlock_irq(¤t
->sighand
->siglock
);
2285 mutex_unlock(&tty_mutex
);
2289 /* BKL pushdown: scary code avoidance wrapper */
2290 static int tty_open(struct inode
*inode
, struct file
*filp
)
2295 ret
= __tty_open(inode
, filp
);
2302 #ifdef CONFIG_UNIX98_PTYS
2304 * ptmx_open - open a unix 98 pty master
2305 * @inode: inode of device file
2306 * @filp: file pointer to tty
2308 * Allocate a unix98 pty master device from the ptmx driver.
2310 * Locking: tty_mutex protects theinit_dev work. tty->count should
2312 * allocated_ptys_lock handles the list of free pty numbers
2315 static int __ptmx_open(struct inode
*inode
, struct file
*filp
)
2317 struct tty_struct
*tty
;
2321 nonseekable_open(inode
, filp
);
2323 /* find a device that is not in use. */
2324 index
= devpts_new_index();
2328 mutex_lock(&tty_mutex
);
2329 retval
= init_dev(ptm_driver
, index
, &tty
);
2330 mutex_unlock(&tty_mutex
);
2335 set_bit(TTY_PTY_LOCK
, &tty
->flags
); /* LOCK THE SLAVE */
2336 filp
->private_data
= tty
;
2337 file_move(filp
, &tty
->tty_files
);
2339 retval
= devpts_pty_new(tty
->link
);
2343 check_tty_count(tty
, "ptmx_open");
2344 retval
= ptm_driver
->ops
->open(tty
, filp
);
2351 devpts_kill_index(index
);
2355 static int ptmx_open(struct inode
*inode
, struct file
*filp
)
2360 ret
= __ptmx_open(inode
, filp
);
2367 * tty_release - vfs callback for close
2368 * @inode: inode of tty
2369 * @filp: file pointer for handle to tty
2371 * Called the last time each file handle is closed that references
2372 * this tty. There may however be several such references.
2375 * Takes bkl. See release_dev
2378 static int tty_release(struct inode
*inode
, struct file
*filp
)
2387 * tty_poll - check tty status
2388 * @filp: file being polled
2389 * @wait: poll wait structures to update
2391 * Call the line discipline polling method to obtain the poll
2392 * status of the device.
2394 * Locking: locks called line discipline but ldisc poll method
2395 * may be re-entered freely by other callers.
2398 static unsigned int tty_poll(struct file
*filp
, poll_table
*wait
)
2400 struct tty_struct
*tty
;
2401 struct tty_ldisc
*ld
;
2404 tty
= (struct tty_struct
*)filp
->private_data
;
2405 if (tty_paranoia_check(tty
, filp
->f_path
.dentry
->d_inode
, "tty_poll"))
2408 ld
= tty_ldisc_ref_wait(tty
);
2410 ret
= (ld
->ops
->poll
)(tty
, filp
, wait
);
2411 tty_ldisc_deref(ld
);
2415 static int tty_fasync(int fd
, struct file
*filp
, int on
)
2417 struct tty_struct
*tty
;
2418 unsigned long flags
;
2422 tty
= (struct tty_struct
*)filp
->private_data
;
2423 if (tty_paranoia_check(tty
, filp
->f_path
.dentry
->d_inode
, "tty_fasync"))
2426 retval
= fasync_helper(fd
, filp
, on
, &tty
->fasync
);
2433 if (!waitqueue_active(&tty
->read_wait
))
2434 tty
->minimum_to_wake
= 1;
2435 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
2438 type
= PIDTYPE_PGID
;
2440 pid
= task_pid(current
);
2443 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
2444 retval
= __f_setown(filp
, pid
, type
, 0);
2448 if (!tty
->fasync
&& !waitqueue_active(&tty
->read_wait
))
2449 tty
->minimum_to_wake
= N_TTY_BUF_SIZE
;
2458 * tiocsti - fake input character
2459 * @tty: tty to fake input into
2460 * @p: pointer to character
2462 * Fake input to a tty device. Does the necessary locking and
2465 * FIXME: does not honour flow control ??
2468 * Called functions take tty_ldisc_lock
2469 * current->signal->tty check is safe without locks
2471 * FIXME: may race normal receive processing
2474 static int tiocsti(struct tty_struct
*tty
, char __user
*p
)
2477 struct tty_ldisc
*ld
;
2479 if ((current
->signal
->tty
!= tty
) && !capable(CAP_SYS_ADMIN
))
2481 if (get_user(ch
, p
))
2483 ld
= tty_ldisc_ref_wait(tty
);
2484 ld
->ops
->receive_buf(tty
, &ch
, &mbz
, 1);
2485 tty_ldisc_deref(ld
);
2490 * tiocgwinsz - implement window query ioctl
2492 * @arg: user buffer for result
2494 * Copies the kernel idea of the window size into the user buffer.
2496 * Locking: tty->termios_mutex is taken to ensure the winsize data
2500 static int tiocgwinsz(struct tty_struct
*tty
, struct winsize __user
*arg
)
2504 mutex_lock(&tty
->termios_mutex
);
2505 err
= copy_to_user(arg
, &tty
->winsize
, sizeof(*arg
));
2506 mutex_unlock(&tty
->termios_mutex
);
2508 return err
? -EFAULT
: 0;
2512 * tiocswinsz - implement window size set ioctl
2514 * @arg: user buffer for result
2516 * Copies the user idea of the window size to the kernel. Traditionally
2517 * this is just advisory information but for the Linux console it
2518 * actually has driver level meaning and triggers a VC resize.
2521 * Called function use the console_sem is used to ensure we do
2522 * not try and resize the console twice at once.
2523 * The tty->termios_mutex is used to ensure we don't double
2524 * resize and get confused. Lock order - tty->termios_mutex before
2528 static int tiocswinsz(struct tty_struct
*tty
, struct tty_struct
*real_tty
,
2529 struct winsize __user
*arg
)
2531 struct winsize tmp_ws
;
2532 struct pid
*pgrp
, *rpgrp
;
2533 unsigned long flags
;
2535 if (copy_from_user(&tmp_ws
, arg
, sizeof(*arg
)))
2538 mutex_lock(&tty
->termios_mutex
);
2539 if (!memcmp(&tmp_ws
, &tty
->winsize
, sizeof(*arg
)))
2543 if (tty
->driver
->type
== TTY_DRIVER_TYPE_CONSOLE
) {
2544 if (vc_lock_resize(tty
->driver_data
, tmp_ws
.ws_col
,
2546 mutex_unlock(&tty
->termios_mutex
);
2551 /* Get the PID values and reference them so we can
2552 avoid holding the tty ctrl lock while sending signals */
2553 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
2554 pgrp
= get_pid(tty
->pgrp
);
2555 rpgrp
= get_pid(real_tty
->pgrp
);
2556 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
2559 kill_pgrp(pgrp
, SIGWINCH
, 1);
2560 if (rpgrp
!= pgrp
&& rpgrp
)
2561 kill_pgrp(rpgrp
, SIGWINCH
, 1);
2566 tty
->winsize
= tmp_ws
;
2567 real_tty
->winsize
= tmp_ws
;
2569 mutex_unlock(&tty
->termios_mutex
);
2574 * tioccons - allow admin to move logical console
2575 * @file: the file to become console
2577 * Allow the adminstrator to move the redirected console device
2579 * Locking: uses redirect_lock to guard the redirect information
2582 static int tioccons(struct file
*file
)
2584 if (!capable(CAP_SYS_ADMIN
))
2586 if (file
->f_op
->write
== redirected_tty_write
) {
2588 spin_lock(&redirect_lock
);
2591 spin_unlock(&redirect_lock
);
2596 spin_lock(&redirect_lock
);
2598 spin_unlock(&redirect_lock
);
2603 spin_unlock(&redirect_lock
);
2608 * fionbio - non blocking ioctl
2609 * @file: file to set blocking value
2610 * @p: user parameter
2612 * Historical tty interfaces had a blocking control ioctl before
2613 * the generic functionality existed. This piece of history is preserved
2614 * in the expected tty API of posix OS's.
2616 * Locking: none, the open fle handle ensures it won't go away.
2619 static int fionbio(struct file
*file
, int __user
*p
)
2623 if (get_user(nonblock
, p
))
2626 /* file->f_flags is still BKL protected in the fs layer - vomit */
2629 file
->f_flags
|= O_NONBLOCK
;
2631 file
->f_flags
&= ~O_NONBLOCK
;
2637 * tiocsctty - set controlling tty
2638 * @tty: tty structure
2639 * @arg: user argument
2641 * This ioctl is used to manage job control. It permits a session
2642 * leader to set this tty as the controlling tty for the session.
2645 * Takes tty_mutex() to protect tty instance
2646 * Takes tasklist_lock internally to walk sessions
2647 * Takes ->siglock() when updating signal->tty
2650 static int tiocsctty(struct tty_struct
*tty
, int arg
)
2653 if (current
->signal
->leader
&& (task_session(current
) == tty
->session
))
2656 mutex_lock(&tty_mutex
);
2658 * The process must be a session leader and
2659 * not have a controlling tty already.
2661 if (!current
->signal
->leader
|| current
->signal
->tty
) {
2668 * This tty is already the controlling
2669 * tty for another session group!
2671 if (arg
== 1 && capable(CAP_SYS_ADMIN
)) {
2675 read_lock(&tasklist_lock
);
2676 session_clear_tty(tty
->session
);
2677 read_unlock(&tasklist_lock
);
2683 proc_set_tty(current
, tty
);
2685 mutex_unlock(&tty_mutex
);
2690 * tty_get_pgrp - return a ref counted pgrp pid
2693 * Returns a refcounted instance of the pid struct for the process
2694 * group controlling the tty.
2697 struct pid
*tty_get_pgrp(struct tty_struct
*tty
)
2699 unsigned long flags
;
2702 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
2703 pgrp
= get_pid(tty
->pgrp
);
2704 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
2708 EXPORT_SYMBOL_GPL(tty_get_pgrp
);
2711 * tiocgpgrp - get process group
2712 * @tty: tty passed by user
2713 * @real_tty: tty side of the tty pased by the user if a pty else the tty
2716 * Obtain the process group of the tty. If there is no process group
2719 * Locking: none. Reference to current->signal->tty is safe.
2722 static int tiocgpgrp(struct tty_struct
*tty
, struct tty_struct
*real_tty
, pid_t __user
*p
)
2727 * (tty == real_tty) is a cheap way of
2728 * testing if the tty is NOT a master pty.
2730 if (tty
== real_tty
&& current
->signal
->tty
!= real_tty
)
2732 pid
= tty_get_pgrp(real_tty
);
2733 ret
= put_user(pid_vnr(pid
), p
);
2739 * tiocspgrp - attempt to set process group
2740 * @tty: tty passed by user
2741 * @real_tty: tty side device matching tty passed by user
2744 * Set the process group of the tty to the session passed. Only
2745 * permitted where the tty session is our session.
2747 * Locking: RCU, ctrl lock
2750 static int tiocspgrp(struct tty_struct
*tty
, struct tty_struct
*real_tty
, pid_t __user
*p
)
2754 int retval
= tty_check_change(real_tty
);
2755 unsigned long flags
;
2761 if (!current
->signal
->tty
||
2762 (current
->signal
->tty
!= real_tty
) ||
2763 (real_tty
->session
!= task_session(current
)))
2765 if (get_user(pgrp_nr
, p
))
2770 pgrp
= find_vpid(pgrp_nr
);
2775 if (session_of_pgrp(pgrp
) != task_session(current
))
2778 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
2779 put_pid(real_tty
->pgrp
);
2780 real_tty
->pgrp
= get_pid(pgrp
);
2781 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
2788 * tiocgsid - get session id
2789 * @tty: tty passed by user
2790 * @real_tty: tty side of the tty pased by the user if a pty else the tty
2791 * @p: pointer to returned session id
2793 * Obtain the session id of the tty. If there is no session
2796 * Locking: none. Reference to current->signal->tty is safe.
2799 static int tiocgsid(struct tty_struct
*tty
, struct tty_struct
*real_tty
, pid_t __user
*p
)
2802 * (tty == real_tty) is a cheap way of
2803 * testing if the tty is NOT a master pty.
2805 if (tty
== real_tty
&& current
->signal
->tty
!= real_tty
)
2807 if (!real_tty
->session
)
2809 return put_user(pid_vnr(real_tty
->session
), p
);
2813 * tiocsetd - set line discipline
2815 * @p: pointer to user data
2817 * Set the line discipline according to user request.
2819 * Locking: see tty_set_ldisc, this function is just a helper
2822 static int tiocsetd(struct tty_struct
*tty
, int __user
*p
)
2827 if (get_user(ldisc
, p
))
2831 ret
= tty_set_ldisc(tty
, ldisc
);
2838 * send_break - performed time break
2839 * @tty: device to break on
2840 * @duration: timeout in mS
2842 * Perform a timed break on hardware that lacks its own driver level
2843 * timed break functionality.
2846 * atomic_write_lock serializes
2850 static int send_break(struct tty_struct
*tty
, unsigned int duration
)
2854 if (tty
->ops
->break_ctl
== NULL
)
2857 if (tty
->driver
->flags
& TTY_DRIVER_HARDWARE_BREAK
)
2858 retval
= tty
->ops
->break_ctl(tty
, duration
);
2860 /* Do the work ourselves */
2861 if (tty_write_lock(tty
, 0) < 0)
2863 retval
= tty
->ops
->break_ctl(tty
, -1);
2866 if (!signal_pending(current
))
2867 msleep_interruptible(duration
);
2868 retval
= tty
->ops
->break_ctl(tty
, 0);
2870 tty_write_unlock(tty
);
2871 if (signal_pending(current
))
2878 * tty_tiocmget - get modem status
2880 * @file: user file pointer
2881 * @p: pointer to result
2883 * Obtain the modem status bits from the tty driver if the feature
2884 * is supported. Return -EINVAL if it is not available.
2886 * Locking: none (up to the driver)
2889 static int tty_tiocmget(struct tty_struct
*tty
, struct file
*file
, int __user
*p
)
2891 int retval
= -EINVAL
;
2893 if (tty
->ops
->tiocmget
) {
2894 retval
= tty
->ops
->tiocmget(tty
, file
);
2897 retval
= put_user(retval
, p
);
2903 * tty_tiocmset - set modem status
2905 * @file: user file pointer
2906 * @cmd: command - clear bits, set bits or set all
2907 * @p: pointer to desired bits
2909 * Set the modem status bits from the tty driver if the feature
2910 * is supported. Return -EINVAL if it is not available.
2912 * Locking: none (up to the driver)
2915 static int tty_tiocmset(struct tty_struct
*tty
, struct file
*file
, unsigned int cmd
,
2919 unsigned int set
, clear
, val
;
2921 if (tty
->ops
->tiocmset
== NULL
)
2924 retval
= get_user(val
, p
);
2940 set
&= TIOCM_DTR
|TIOCM_RTS
|TIOCM_OUT1
|TIOCM_OUT2
|TIOCM_LOOP
;
2941 clear
&= TIOCM_DTR
|TIOCM_RTS
|TIOCM_OUT1
|TIOCM_OUT2
|TIOCM_LOOP
;
2942 return tty
->ops
->tiocmset(tty
, file
, set
, clear
);
2946 * Split this up, as gcc can choke on it otherwise..
2948 long tty_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
2950 struct tty_struct
*tty
, *real_tty
;
2951 void __user
*p
= (void __user
*)arg
;
2953 struct tty_ldisc
*ld
;
2954 struct inode
*inode
= file
->f_dentry
->d_inode
;
2956 tty
= (struct tty_struct
*)file
->private_data
;
2957 if (tty_paranoia_check(tty
, inode
, "tty_ioctl"))
2961 if (tty
->driver
->type
== TTY_DRIVER_TYPE_PTY
&&
2962 tty
->driver
->subtype
== PTY_TYPE_MASTER
)
2963 real_tty
= tty
->link
;
2967 * Factor out some common prep work
2975 retval
= tty_check_change(tty
);
2978 if (cmd
!= TIOCCBRK
) {
2979 tty_wait_until_sent(tty
, 0);
2980 if (signal_pending(current
))
2991 return tiocsti(tty
, p
);
2993 return tiocgwinsz(tty
, p
);
2995 return tiocswinsz(tty
, real_tty
, p
);
2997 return real_tty
!= tty
? -EINVAL
: tioccons(file
);
2999 return fionbio(file
, p
);
3001 set_bit(TTY_EXCLUSIVE
, &tty
->flags
);
3004 clear_bit(TTY_EXCLUSIVE
, &tty
->flags
);
3007 if (current
->signal
->tty
!= tty
)
3012 return tiocsctty(tty
, arg
);
3014 return tiocgpgrp(tty
, real_tty
, p
);
3016 return tiocspgrp(tty
, real_tty
, p
);
3018 return tiocgsid(tty
, real_tty
, p
);
3020 return put_user(tty
->ldisc
.ops
->num
, (int __user
*)p
);
3022 return tiocsetd(tty
, p
);
3025 return tioclinux(tty
, arg
);
3030 case TIOCSBRK
: /* Turn break on, unconditionally */
3031 if (tty
->ops
->break_ctl
)
3032 return tty
->ops
->break_ctl(tty
, -1);
3034 case TIOCCBRK
: /* Turn break off, unconditionally */
3035 if (tty
->ops
->break_ctl
)
3036 return tty
->ops
->break_ctl(tty
, 0);
3038 case TCSBRK
: /* SVID version: non-zero arg --> no break */
3039 /* non-zero arg means wait for all output data
3040 * to be sent (performed above) but don't send break.
3041 * This is used by the tcdrain() termios function.
3044 return send_break(tty
, 250);
3046 case TCSBRKP
: /* support for POSIX tcsendbreak() */
3047 return send_break(tty
, arg
? arg
*100 : 250);
3050 return tty_tiocmget(tty
, file
, p
);
3054 return tty_tiocmset(tty
, file
, cmd
, p
);
3059 /* flush tty buffer and allow ldisc to process ioctl */
3060 tty_buffer_flush(tty
);
3065 if (tty
->ops
->ioctl
) {
3066 retval
= (tty
->ops
->ioctl
)(tty
, file
, cmd
, arg
);
3067 if (retval
!= -ENOIOCTLCMD
)
3070 ld
= tty_ldisc_ref_wait(tty
);
3072 if (ld
->ops
->ioctl
) {
3073 retval
= ld
->ops
->ioctl(tty
, file
, cmd
, arg
);
3074 if (retval
== -ENOIOCTLCMD
)
3077 tty_ldisc_deref(ld
);
3081 #ifdef CONFIG_COMPAT
3082 static long tty_compat_ioctl(struct file
*file
, unsigned int cmd
,
3085 struct inode
*inode
= file
->f_dentry
->d_inode
;
3086 struct tty_struct
*tty
= file
->private_data
;
3087 struct tty_ldisc
*ld
;
3088 int retval
= -ENOIOCTLCMD
;
3090 if (tty_paranoia_check(tty
, inode
, "tty_ioctl"))
3093 if (tty
->ops
->compat_ioctl
) {
3094 retval
= (tty
->ops
->compat_ioctl
)(tty
, file
, cmd
, arg
);
3095 if (retval
!= -ENOIOCTLCMD
)
3099 ld
= tty_ldisc_ref_wait(tty
);
3100 if (ld
->ops
->compat_ioctl
)
3101 retval
= ld
->ops
->compat_ioctl(tty
, file
, cmd
, arg
);
3102 tty_ldisc_deref(ld
);
3109 * This implements the "Secure Attention Key" --- the idea is to
3110 * prevent trojan horses by killing all processes associated with this
3111 * tty when the user hits the "Secure Attention Key". Required for
3112 * super-paranoid applications --- see the Orange Book for more details.
3114 * This code could be nicer; ideally it should send a HUP, wait a few
3115 * seconds, then send a INT, and then a KILL signal. But you then
3116 * have to coordinate with the init process, since all processes associated
3117 * with the current tty must be dead before the new getty is allowed
3120 * Now, if it would be correct ;-/ The current code has a nasty hole -
3121 * it doesn't catch files in flight. We may send the descriptor to ourselves
3122 * via AF_UNIX socket, close it and later fetch from socket. FIXME.
3124 * Nasty bug: do_SAK is being called in interrupt context. This can
3125 * deadlock. We punt it up to process context. AKPM - 16Mar2001
3127 void __do_SAK(struct tty_struct
*tty
)
3132 struct task_struct
*g
, *p
;
3133 struct pid
*session
;
3136 struct fdtable
*fdt
;
3140 session
= tty
->session
;
3142 tty_ldisc_flush(tty
);
3144 tty_driver_flush_buffer(tty
);
3146 read_lock(&tasklist_lock
);
3147 /* Kill the entire session */
3148 do_each_pid_task(session
, PIDTYPE_SID
, p
) {
3149 printk(KERN_NOTICE
"SAK: killed process %d"
3150 " (%s): task_session_nr(p)==tty->session\n",
3151 task_pid_nr(p
), p
->comm
);
3152 send_sig(SIGKILL
, p
, 1);
3153 } while_each_pid_task(session
, PIDTYPE_SID
, p
);
3154 /* Now kill any processes that happen to have the
3157 do_each_thread(g
, p
) {
3158 if (p
->signal
->tty
== tty
) {
3159 printk(KERN_NOTICE
"SAK: killed process %d"
3160 " (%s): task_session_nr(p)==tty->session\n",
3161 task_pid_nr(p
), p
->comm
);
3162 send_sig(SIGKILL
, p
, 1);
3168 * We don't take a ref to the file, so we must
3169 * hold ->file_lock instead.
3171 spin_lock(&p
->files
->file_lock
);
3172 fdt
= files_fdtable(p
->files
);
3173 for (i
= 0; i
< fdt
->max_fds
; i
++) {
3174 filp
= fcheck_files(p
->files
, i
);
3177 if (filp
->f_op
->read
== tty_read
&&
3178 filp
->private_data
== tty
) {
3179 printk(KERN_NOTICE
"SAK: killed process %d"
3180 " (%s): fd#%d opened to the tty\n",
3181 task_pid_nr(p
), p
->comm
, i
);
3182 force_sig(SIGKILL
, p
);
3186 spin_unlock(&p
->files
->file_lock
);
3189 } while_each_thread(g
, p
);
3190 read_unlock(&tasklist_lock
);
3194 static void do_SAK_work(struct work_struct
*work
)
3196 struct tty_struct
*tty
=
3197 container_of(work
, struct tty_struct
, SAK_work
);
3202 * The tq handling here is a little racy - tty->SAK_work may already be queued.
3203 * Fortunately we don't need to worry, because if ->SAK_work is already queued,
3204 * the values which we write to it will be identical to the values which it
3205 * already has. --akpm
3207 void do_SAK(struct tty_struct
*tty
)
3211 schedule_work(&tty
->SAK_work
);
3214 EXPORT_SYMBOL(do_SAK
);
3218 * @work: tty structure passed from work queue.
3220 * This routine is called out of the software interrupt to flush data
3221 * from the buffer chain to the line discipline.
3223 * Locking: holds tty->buf.lock to guard buffer list. Drops the lock
3224 * while invoking the line discipline receive_buf method. The
3225 * receive_buf method is single threaded for each tty instance.
3228 static void flush_to_ldisc(struct work_struct
*work
)
3230 struct tty_struct
*tty
=
3231 container_of(work
, struct tty_struct
, buf
.work
.work
);
3232 unsigned long flags
;
3233 struct tty_ldisc
*disc
;
3234 struct tty_buffer
*tbuf
, *head
;
3236 unsigned char *flag_buf
;
3238 disc
= tty_ldisc_ref(tty
);
3239 if (disc
== NULL
) /* !TTY_LDISC */
3242 spin_lock_irqsave(&tty
->buf
.lock
, flags
);
3243 /* So we know a flush is running */
3244 set_bit(TTY_FLUSHING
, &tty
->flags
);
3245 head
= tty
->buf
.head
;
3247 tty
->buf
.head
= NULL
;
3249 int count
= head
->commit
- head
->read
;
3251 if (head
->next
== NULL
)
3255 tty_buffer_free(tty
, tbuf
);
3258 /* Ldisc or user is trying to flush the buffers
3259 we are feeding to the ldisc, stop feeding the
3260 line discipline as we want to empty the queue */
3261 if (test_bit(TTY_FLUSHPENDING
, &tty
->flags
))
3263 if (!tty
->receive_room
) {
3264 schedule_delayed_work(&tty
->buf
.work
, 1);
3267 if (count
> tty
->receive_room
)
3268 count
= tty
->receive_room
;
3269 char_buf
= head
->char_buf_ptr
+ head
->read
;
3270 flag_buf
= head
->flag_buf_ptr
+ head
->read
;
3271 head
->read
+= count
;
3272 spin_unlock_irqrestore(&tty
->buf
.lock
, flags
);
3273 disc
->ops
->receive_buf(tty
, char_buf
,
3275 spin_lock_irqsave(&tty
->buf
.lock
, flags
);
3277 /* Restore the queue head */
3278 tty
->buf
.head
= head
;
3280 /* We may have a deferred request to flush the input buffer,
3281 if so pull the chain under the lock and empty the queue */
3282 if (test_bit(TTY_FLUSHPENDING
, &tty
->flags
)) {
3283 __tty_buffer_flush(tty
);
3284 clear_bit(TTY_FLUSHPENDING
, &tty
->flags
);
3285 wake_up(&tty
->read_wait
);
3287 clear_bit(TTY_FLUSHING
, &tty
->flags
);
3288 spin_unlock_irqrestore(&tty
->buf
.lock
, flags
);
3290 tty_ldisc_deref(disc
);
3294 * tty_flip_buffer_push - terminal
3297 * Queue a push of the terminal flip buffers to the line discipline. This
3298 * function must not be called from IRQ context if tty->low_latency is set.
3300 * In the event of the queue being busy for flipping the work will be
3301 * held off and retried later.
3303 * Locking: tty buffer lock. Driver locks in low latency mode.
3306 void tty_flip_buffer_push(struct tty_struct
*tty
)
3308 unsigned long flags
;
3309 spin_lock_irqsave(&tty
->buf
.lock
, flags
);
3310 if (tty
->buf
.tail
!= NULL
)
3311 tty
->buf
.tail
->commit
= tty
->buf
.tail
->used
;
3312 spin_unlock_irqrestore(&tty
->buf
.lock
, flags
);
3314 if (tty
->low_latency
)
3315 flush_to_ldisc(&tty
->buf
.work
.work
);
3317 schedule_delayed_work(&tty
->buf
.work
, 1);
3320 EXPORT_SYMBOL(tty_flip_buffer_push
);
3324 * initialize_tty_struct
3325 * @tty: tty to initialize
3327 * This subroutine initializes a tty structure that has been newly
3330 * Locking: none - tty in question must not be exposed at this point
3333 static void initialize_tty_struct(struct tty_struct
*tty
)
3335 memset(tty
, 0, sizeof(struct tty_struct
));
3336 tty
->magic
= TTY_MAGIC
;
3337 tty_ldisc_init(tty
);
3338 tty
->session
= NULL
;
3340 tty
->overrun_time
= jiffies
;
3341 tty
->buf
.head
= tty
->buf
.tail
= NULL
;
3342 tty_buffer_init(tty
);
3343 INIT_DELAYED_WORK(&tty
->buf
.work
, flush_to_ldisc
);
3344 mutex_init(&tty
->termios_mutex
);
3345 init_waitqueue_head(&tty
->write_wait
);
3346 init_waitqueue_head(&tty
->read_wait
);
3347 INIT_WORK(&tty
->hangup_work
, do_tty_hangup
);
3348 mutex_init(&tty
->atomic_read_lock
);
3349 mutex_init(&tty
->atomic_write_lock
);
3350 spin_lock_init(&tty
->read_lock
);
3351 spin_lock_init(&tty
->ctrl_lock
);
3352 INIT_LIST_HEAD(&tty
->tty_files
);
3353 INIT_WORK(&tty
->SAK_work
, do_SAK_work
);
3357 * tty_put_char - write one character to a tty
3361 * Write one byte to the tty using the provided put_char method
3362 * if present. Returns the number of characters successfully output.
3364 * Note: the specific put_char operation in the driver layer may go
3365 * away soon. Don't call it directly, use this method
3368 int tty_put_char(struct tty_struct
*tty
, unsigned char ch
)
3370 if (tty
->ops
->put_char
)
3371 return tty
->ops
->put_char(tty
, ch
);
3372 return tty
->ops
->write(tty
, &ch
, 1);
3375 EXPORT_SYMBOL_GPL(tty_put_char
);
3377 static struct class *tty_class
;
3380 * tty_register_device - register a tty device
3381 * @driver: the tty driver that describes the tty device
3382 * @index: the index in the tty driver for this tty device
3383 * @device: a struct device that is associated with this tty device.
3384 * This field is optional, if there is no known struct device
3385 * for this tty device it can be set to NULL safely.
3387 * Returns a pointer to the struct device for this tty device
3388 * (or ERR_PTR(-EFOO) on error).
3390 * This call is required to be made to register an individual tty device
3391 * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If
3392 * that bit is not set, this function should not be called by a tty
3398 struct device
*tty_register_device(struct tty_driver
*driver
, unsigned index
,
3399 struct device
*device
)
3402 dev_t dev
= MKDEV(driver
->major
, driver
->minor_start
) + index
;
3404 if (index
>= driver
->num
) {
3405 printk(KERN_ERR
"Attempt to register invalid tty line number "
3407 return ERR_PTR(-EINVAL
);
3410 if (driver
->type
== TTY_DRIVER_TYPE_PTY
)
3411 pty_line_name(driver
, index
, name
);
3413 tty_line_name(driver
, index
, name
);
3415 return device_create(tty_class
, device
, dev
, name
);
3419 * tty_unregister_device - unregister a tty device
3420 * @driver: the tty driver that describes the tty device
3421 * @index: the index in the tty driver for this tty device
3423 * If a tty device is registered with a call to tty_register_device() then
3424 * this function must be called when the tty device is gone.
3429 void tty_unregister_device(struct tty_driver
*driver
, unsigned index
)
3431 device_destroy(tty_class
,
3432 MKDEV(driver
->major
, driver
->minor_start
) + index
);
3435 EXPORT_SYMBOL(tty_register_device
);
3436 EXPORT_SYMBOL(tty_unregister_device
);
3438 struct tty_driver
*alloc_tty_driver(int lines
)
3440 struct tty_driver
*driver
;
3442 driver
= kzalloc(sizeof(struct tty_driver
), GFP_KERNEL
);
3444 driver
->magic
= TTY_DRIVER_MAGIC
;
3445 driver
->num
= lines
;
3446 /* later we'll move allocation of tables here */
3451 void put_tty_driver(struct tty_driver
*driver
)
3456 void tty_set_operations(struct tty_driver
*driver
,
3457 const struct tty_operations
*op
)
3462 EXPORT_SYMBOL(alloc_tty_driver
);
3463 EXPORT_SYMBOL(put_tty_driver
);
3464 EXPORT_SYMBOL(tty_set_operations
);
3467 * Called by a tty driver to register itself.
3469 int tty_register_driver(struct tty_driver
*driver
)
3476 if (driver
->flags
& TTY_DRIVER_INSTALLED
)
3479 if (!(driver
->flags
& TTY_DRIVER_DEVPTS_MEM
) && driver
->num
) {
3480 p
= kzalloc(driver
->num
* 3 * sizeof(void *), GFP_KERNEL
);
3485 if (!driver
->major
) {
3486 error
= alloc_chrdev_region(&dev
, driver
->minor_start
,
3487 driver
->num
, driver
->name
);
3489 driver
->major
= MAJOR(dev
);
3490 driver
->minor_start
= MINOR(dev
);
3493 dev
= MKDEV(driver
->major
, driver
->minor_start
);
3494 error
= register_chrdev_region(dev
, driver
->num
, driver
->name
);
3502 driver
->ttys
= (struct tty_struct
**)p
;
3503 driver
->termios
= (struct ktermios
**)(p
+ driver
->num
);
3504 driver
->termios_locked
= (struct ktermios
**)
3505 (p
+ driver
->num
* 2);
3507 driver
->ttys
= NULL
;
3508 driver
->termios
= NULL
;
3509 driver
->termios_locked
= NULL
;
3512 cdev_init(&driver
->cdev
, &tty_fops
);
3513 driver
->cdev
.owner
= driver
->owner
;
3514 error
= cdev_add(&driver
->cdev
, dev
, driver
->num
);
3516 unregister_chrdev_region(dev
, driver
->num
);
3517 driver
->ttys
= NULL
;
3518 driver
->termios
= driver
->termios_locked
= NULL
;
3523 mutex_lock(&tty_mutex
);
3524 list_add(&driver
->tty_drivers
, &tty_drivers
);
3525 mutex_unlock(&tty_mutex
);
3527 if (!(driver
->flags
& TTY_DRIVER_DYNAMIC_DEV
)) {
3528 for (i
= 0; i
< driver
->num
; i
++)
3529 tty_register_device(driver
, i
, NULL
);
3531 proc_tty_register_driver(driver
);
3535 EXPORT_SYMBOL(tty_register_driver
);
3538 * Called by a tty driver to unregister itself.
3540 int tty_unregister_driver(struct tty_driver
*driver
)
3543 struct ktermios
*tp
;
3546 if (driver
->refcount
)
3549 unregister_chrdev_region(MKDEV(driver
->major
, driver
->minor_start
),
3551 mutex_lock(&tty_mutex
);
3552 list_del(&driver
->tty_drivers
);
3553 mutex_unlock(&tty_mutex
);
3556 * Free the termios and termios_locked structures because
3557 * we don't want to get memory leaks when modular tty
3558 * drivers are removed from the kernel.
3560 for (i
= 0; i
< driver
->num
; i
++) {
3561 tp
= driver
->termios
[i
];
3563 driver
->termios
[i
] = NULL
;
3566 tp
= driver
->termios_locked
[i
];
3568 driver
->termios_locked
[i
] = NULL
;
3571 if (!(driver
->flags
& TTY_DRIVER_DYNAMIC_DEV
))
3572 tty_unregister_device(driver
, i
);
3575 proc_tty_unregister_driver(driver
);
3576 driver
->ttys
= NULL
;
3577 driver
->termios
= driver
->termios_locked
= NULL
;
3579 cdev_del(&driver
->cdev
);
3582 EXPORT_SYMBOL(tty_unregister_driver
);
3584 dev_t
tty_devnum(struct tty_struct
*tty
)
3586 return MKDEV(tty
->driver
->major
, tty
->driver
->minor_start
) + tty
->index
;
3588 EXPORT_SYMBOL(tty_devnum
);
3590 void proc_clear_tty(struct task_struct
*p
)
3592 spin_lock_irq(&p
->sighand
->siglock
);
3593 p
->signal
->tty
= NULL
;
3594 spin_unlock_irq(&p
->sighand
->siglock
);
3596 EXPORT_SYMBOL(proc_clear_tty
);
3598 /* Called under the sighand lock */
3600 static void __proc_set_tty(struct task_struct
*tsk
, struct tty_struct
*tty
)
3603 unsigned long flags
;
3604 /* We should not have a session or pgrp to put here but.... */
3605 spin_lock_irqsave(&tty
->ctrl_lock
, flags
);
3606 put_pid(tty
->session
);
3608 tty
->pgrp
= get_pid(task_pgrp(tsk
));
3609 spin_unlock_irqrestore(&tty
->ctrl_lock
, flags
);
3610 tty
->session
= get_pid(task_session(tsk
));
3612 put_pid(tsk
->signal
->tty_old_pgrp
);
3613 tsk
->signal
->tty
= tty
;
3614 tsk
->signal
->tty_old_pgrp
= NULL
;
3617 static void proc_set_tty(struct task_struct
*tsk
, struct tty_struct
*tty
)
3619 spin_lock_irq(&tsk
->sighand
->siglock
);
3620 __proc_set_tty(tsk
, tty
);
3621 spin_unlock_irq(&tsk
->sighand
->siglock
);
3624 struct tty_struct
*get_current_tty(void)
3626 struct tty_struct
*tty
;
3627 WARN_ON_ONCE(!mutex_is_locked(&tty_mutex
));
3628 tty
= current
->signal
->tty
;
3630 * session->tty can be changed/cleared from under us, make sure we
3631 * issue the load. The obtained pointer, when not NULL, is valid as
3632 * long as we hold tty_mutex.
3637 EXPORT_SYMBOL_GPL(get_current_tty
);
3640 * Initialize the console device. This is called *early*, so
3641 * we can't necessarily depend on lots of kernel help here.
3642 * Just do some early initializations, and do the complex setup
3645 void __init
console_init(void)
3649 /* Setup the default TTY line discipline. */
3653 * set up the console device so that later boot sequences can
3654 * inform about problems etc..
3656 call
= __con_initcall_start
;
3657 while (call
< __con_initcall_end
) {
3663 static int __init
tty_class_init(void)
3665 tty_class
= class_create(THIS_MODULE
, "tty");
3666 if (IS_ERR(tty_class
))
3667 return PTR_ERR(tty_class
);
3671 postcore_initcall(tty_class_init
);
3673 /* 3/2004 jmc: why do these devices exist? */
3675 static struct cdev tty_cdev
, console_cdev
;
3676 #ifdef CONFIG_UNIX98_PTYS
3677 static struct cdev ptmx_cdev
;
3680 static struct cdev vc0_cdev
;
3684 * Ok, now we can initialize the rest of the tty devices and can count
3685 * on memory allocations, interrupts etc..
3687 static int __init
tty_init(void)
3689 cdev_init(&tty_cdev
, &tty_fops
);
3690 if (cdev_add(&tty_cdev
, MKDEV(TTYAUX_MAJOR
, 0), 1) ||
3691 register_chrdev_region(MKDEV(TTYAUX_MAJOR
, 0), 1, "/dev/tty") < 0)
3692 panic("Couldn't register /dev/tty driver\n");
3693 device_create(tty_class
, NULL
, MKDEV(TTYAUX_MAJOR
, 0), "tty");
3695 cdev_init(&console_cdev
, &console_fops
);
3696 if (cdev_add(&console_cdev
, MKDEV(TTYAUX_MAJOR
, 1), 1) ||
3697 register_chrdev_region(MKDEV(TTYAUX_MAJOR
, 1), 1, "/dev/console") < 0)
3698 panic("Couldn't register /dev/console driver\n");
3699 device_create(tty_class
, NULL
, MKDEV(TTYAUX_MAJOR
, 1), "console");
3701 #ifdef CONFIG_UNIX98_PTYS
3702 cdev_init(&ptmx_cdev
, &ptmx_fops
);
3703 if (cdev_add(&ptmx_cdev
, MKDEV(TTYAUX_MAJOR
, 2), 1) ||
3704 register_chrdev_region(MKDEV(TTYAUX_MAJOR
, 2), 1, "/dev/ptmx") < 0)
3705 panic("Couldn't register /dev/ptmx driver\n");
3706 device_create(tty_class
, NULL
, MKDEV(TTYAUX_MAJOR
, 2), "ptmx");
3710 cdev_init(&vc0_cdev
, &console_fops
);
3711 if (cdev_add(&vc0_cdev
, MKDEV(TTY_MAJOR
, 0), 1) ||
3712 register_chrdev_region(MKDEV(TTY_MAJOR
, 0), 1, "/dev/vc/0") < 0)
3713 panic("Couldn't register /dev/tty0 driver\n");
3714 device_create(tty_class
, NULL
, MKDEV(TTY_MAJOR
, 0), "tty0");
3720 module_init(tty_init
);