1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 1991, 1992 Linus Torvalds
5 * Added support for a Unix98-style ptmx device.
6 * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 14-Jan-1998
10 #include <linux/module.h>
11 #include <linux/errno.h>
12 #include <linux/interrupt.h>
13 #include <linux/tty.h>
14 #include <linux/tty_flip.h>
15 #include <linux/fcntl.h>
16 #include <linux/sched/signal.h>
17 #include <linux/string.h>
18 #include <linux/major.h>
20 #include <linux/init.h>
21 #include <linux/device.h>
22 #include <linux/uaccess.h>
23 #include <linux/bitops.h>
24 #include <linux/devpts_fs.h>
25 #include <linux/slab.h>
26 #include <linux/mutex.h>
27 #include <linux/poll.h>
28 #include <linux/mount.h>
29 #include <linux/file.h>
30 #include <linux/ioctl.h>
31 #include <linux/compat.h>
34 #undef TTY_DEBUG_HANGUP
35 #ifdef TTY_DEBUG_HANGUP
36 # define tty_debug_hangup(tty, f, args...) tty_debug(tty, f, ##args)
38 # define tty_debug_hangup(tty, f, args...) do {} while (0)
41 #ifdef CONFIG_UNIX98_PTYS
42 static struct tty_driver *ptm_driver;
43 static struct tty_driver *pts_driver;
44 static DEFINE_MUTEX(devpts_mutex);
47 static void pty_close(struct tty_struct *tty, struct file *filp)
49 if (tty->driver->subtype == PTY_TYPE_MASTER)
50 WARN_ON(tty->count > 1);
52 if (tty_io_error(tty))
57 set_bit(TTY_IO_ERROR, &tty->flags);
58 wake_up_interruptible(&tty->read_wait);
59 wake_up_interruptible(&tty->write_wait);
60 spin_lock_irq(&tty->ctrl.lock);
61 tty->ctrl.packet = false;
62 spin_unlock_irq(&tty->ctrl.lock);
63 /* Review - krefs on tty_link ?? */
66 set_bit(TTY_OTHER_CLOSED, &tty->link->flags);
67 wake_up_interruptible(&tty->link->read_wait);
68 wake_up_interruptible(&tty->link->write_wait);
69 if (tty->driver->subtype == PTY_TYPE_MASTER) {
70 set_bit(TTY_OTHER_CLOSED, &tty->flags);
71 #ifdef CONFIG_UNIX98_PTYS
72 if (tty->driver == ptm_driver) {
73 mutex_lock(&devpts_mutex);
74 if (tty->link->driver_data)
75 devpts_pty_kill(tty->link->driver_data);
76 mutex_unlock(&devpts_mutex);
79 tty_vhangup(tty->link);
84 * The unthrottle routine is called by the line discipline to signal
85 * that it can receive more characters. For PTY's, the TTY_THROTTLED
86 * flag is always set, to force the line discipline to always call the
87 * unthrottle routine when there are fewer than TTY_THRESHOLD_UNTHROTTLE
88 * characters in the queue. This is necessary since each time this
89 * happens, we need to wake up any sleeping processes that could be
90 * (1) trying to send data to the pty, or (2) waiting in wait_until_sent()
91 * for the pty buffer to be drained.
93 static void pty_unthrottle(struct tty_struct *tty)
95 tty_wakeup(tty->link);
96 set_bit(TTY_THROTTLED, &tty->flags);
100 * pty_write - write to a pty
101 * @tty: the tty we write from
102 * @buf: kernel buffer of data
105 * Our "hardware" write method. Data is coming from the ldisc which
106 * may be in a non sleeping state. We simply throw this at the other
107 * end of the link as if we were an IRQ handler receiving stuff for
108 * the other side of the pty/tty pair.
111 static int pty_write(struct tty_struct *tty, const unsigned char *buf, int c)
113 struct tty_struct *to = tty->link;
116 if (tty->flow.stopped)
120 spin_lock_irqsave(&to->port->lock, flags);
121 /* Stuff the data into the input queue of the other end */
122 c = tty_insert_flip_string(to->port, buf, c);
123 spin_unlock_irqrestore(&to->port->lock, flags);
126 tty_flip_buffer_push(to->port);
132 * pty_write_room - write space
133 * @tty: tty we are writing from
135 * Report how many bytes the ldisc can send into the queue for
139 static unsigned int pty_write_room(struct tty_struct *tty)
141 if (tty->flow.stopped)
143 return tty_buffer_space_avail(tty->link->port);
146 /* Set the lock flag on a pty */
147 static int pty_set_lock(struct tty_struct *tty, int __user *arg)
151 if (get_user(val, arg))
154 set_bit(TTY_PTY_LOCK, &tty->flags);
156 clear_bit(TTY_PTY_LOCK, &tty->flags);
160 static int pty_get_lock(struct tty_struct *tty, int __user *arg)
162 int locked = test_bit(TTY_PTY_LOCK, &tty->flags);
164 return put_user(locked, arg);
167 /* Set the packet mode on a pty */
168 static int pty_set_pktmode(struct tty_struct *tty, int __user *arg)
172 if (get_user(pktmode, arg))
175 spin_lock_irq(&tty->ctrl.lock);
177 if (!tty->ctrl.packet) {
178 tty->link->ctrl.pktstatus = 0;
180 tty->ctrl.packet = true;
183 tty->ctrl.packet = false;
184 spin_unlock_irq(&tty->ctrl.lock);
189 /* Get the packet mode of a pty */
190 static int pty_get_pktmode(struct tty_struct *tty, int __user *arg)
192 int pktmode = tty->ctrl.packet;
194 return put_user(pktmode, arg);
197 /* Send a signal to the slave */
198 static int pty_signal(struct tty_struct *tty, int sig)
202 if (sig != SIGINT && sig != SIGQUIT && sig != SIGTSTP)
206 pgrp = tty_get_pgrp(tty->link);
208 kill_pgrp(pgrp, sig, 1);
214 static void pty_flush_buffer(struct tty_struct *tty)
216 struct tty_struct *to = tty->link;
221 tty_buffer_flush(to, NULL);
222 if (to->ctrl.packet) {
223 spin_lock_irq(&tty->ctrl.lock);
224 tty->ctrl.pktstatus |= TIOCPKT_FLUSHWRITE;
225 wake_up_interruptible(&to->read_wait);
226 spin_unlock_irq(&tty->ctrl.lock);
230 static int pty_open(struct tty_struct *tty, struct file *filp)
232 if (!tty || !tty->link)
235 if (test_bit(TTY_OTHER_CLOSED, &tty->flags))
237 if (test_bit(TTY_PTY_LOCK, &tty->link->flags))
239 if (tty->driver->subtype == PTY_TYPE_SLAVE && tty->link->count != 1)
242 clear_bit(TTY_IO_ERROR, &tty->flags);
243 clear_bit(TTY_OTHER_CLOSED, &tty->link->flags);
244 set_bit(TTY_THROTTLED, &tty->flags);
248 set_bit(TTY_IO_ERROR, &tty->flags);
252 static void pty_set_termios(struct tty_struct *tty,
253 struct ktermios *old_termios)
255 /* See if packet mode change of state. */
256 if (tty->link && tty->link->ctrl.packet) {
257 int extproc = (old_termios->c_lflag & EXTPROC) | L_EXTPROC(tty);
258 int old_flow = ((old_termios->c_iflag & IXON) &&
259 (old_termios->c_cc[VSTOP] == '\023') &&
260 (old_termios->c_cc[VSTART] == '\021'));
261 int new_flow = (I_IXON(tty) &&
262 STOP_CHAR(tty) == '\023' &&
263 START_CHAR(tty) == '\021');
264 if ((old_flow != new_flow) || extproc) {
265 spin_lock_irq(&tty->ctrl.lock);
266 if (old_flow != new_flow) {
267 tty->ctrl.pktstatus &= ~(TIOCPKT_DOSTOP | TIOCPKT_NOSTOP);
269 tty->ctrl.pktstatus |= TIOCPKT_DOSTOP;
271 tty->ctrl.pktstatus |= TIOCPKT_NOSTOP;
274 tty->ctrl.pktstatus |= TIOCPKT_IOCTL;
275 spin_unlock_irq(&tty->ctrl.lock);
276 wake_up_interruptible(&tty->link->read_wait);
280 tty->termios.c_cflag &= ~(CSIZE | PARENB);
281 tty->termios.c_cflag |= (CS8 | CREAD);
285 * pty_resize - resize event
286 * @tty: tty being resized
287 * @ws: window size being set.
289 * Update the termios variables and send the necessary signals to
290 * peform a terminal resize correctly
293 static int pty_resize(struct tty_struct *tty, struct winsize *ws)
295 struct pid *pgrp, *rpgrp;
296 struct tty_struct *pty = tty->link;
298 /* For a PTY we need to lock the tty side */
299 mutex_lock(&tty->winsize_mutex);
300 if (!memcmp(ws, &tty->winsize, sizeof(*ws)))
303 /* Signal the foreground process group of both ptys */
304 pgrp = tty_get_pgrp(tty);
305 rpgrp = tty_get_pgrp(pty);
308 kill_pgrp(pgrp, SIGWINCH, 1);
309 if (rpgrp != pgrp && rpgrp)
310 kill_pgrp(rpgrp, SIGWINCH, 1);
316 pty->winsize = *ws; /* Never used so will go away soon */
318 mutex_unlock(&tty->winsize_mutex);
323 * pty_start - start() handler
324 * pty_stop - stop() handler
325 * @tty: tty being flow-controlled
327 * Propagates the TIOCPKT status to the master pty.
329 * NB: only the master pty can be in packet mode so only the slave
330 * needs start()/stop() handlers
332 static void pty_start(struct tty_struct *tty)
336 if (tty->link && tty->link->ctrl.packet) {
337 spin_lock_irqsave(&tty->ctrl.lock, flags);
338 tty->ctrl.pktstatus &= ~TIOCPKT_STOP;
339 tty->ctrl.pktstatus |= TIOCPKT_START;
340 spin_unlock_irqrestore(&tty->ctrl.lock, flags);
341 wake_up_interruptible_poll(&tty->link->read_wait, EPOLLIN);
345 static void pty_stop(struct tty_struct *tty)
349 if (tty->link && tty->link->ctrl.packet) {
350 spin_lock_irqsave(&tty->ctrl.lock, flags);
351 tty->ctrl.pktstatus &= ~TIOCPKT_START;
352 tty->ctrl.pktstatus |= TIOCPKT_STOP;
353 spin_unlock_irqrestore(&tty->ctrl.lock, flags);
354 wake_up_interruptible_poll(&tty->link->read_wait, EPOLLIN);
359 * pty_common_install - set up the pty pair
360 * @driver: the pty driver
361 * @tty: the tty being instantiated
362 * @legacy: true if this is BSD style
364 * Perform the initial set up for the tty/pty pair. Called from the
365 * tty layer when the port is first opened.
367 * Locking: the caller must hold the tty_mutex
369 static int pty_common_install(struct tty_driver *driver, struct tty_struct *tty,
372 struct tty_struct *o_tty;
373 struct tty_port *ports[2];
374 int idx = tty->index;
375 int retval = -ENOMEM;
377 /* Opening the slave first has always returned -EIO */
378 if (driver->subtype != PTY_TYPE_MASTER)
381 ports[0] = kmalloc(sizeof **ports, GFP_KERNEL);
382 ports[1] = kmalloc(sizeof **ports, GFP_KERNEL);
383 if (!ports[0] || !ports[1])
385 if (!try_module_get(driver->other->owner)) {
386 /* This cannot in fact currently happen */
389 o_tty = alloc_tty_struct(driver->other, idx);
393 tty_set_lock_subclass(o_tty);
394 lockdep_set_subclass(&o_tty->termios_rwsem, TTY_LOCK_SLAVE);
397 /* We always use new tty termios data so we can do this
399 tty_init_termios(tty);
400 tty_init_termios(o_tty);
402 driver->other->ttys[idx] = o_tty;
403 driver->ttys[idx] = tty;
405 memset(&tty->termios_locked, 0, sizeof(tty->termios_locked));
406 tty->termios = driver->init_termios;
407 memset(&o_tty->termios_locked, 0, sizeof(tty->termios_locked));
408 o_tty->termios = driver->other->init_termios;
412 * Everything allocated ... set up the o_tty structure.
414 tty_driver_kref_get(driver->other);
415 /* Establish the links in both directions */
418 tty_port_init(ports[0]);
419 tty_port_init(ports[1]);
420 tty_buffer_set_limit(ports[0], 8192);
421 tty_buffer_set_limit(ports[1], 8192);
422 o_tty->port = ports[0];
423 tty->port = ports[1];
424 o_tty->port->itty = o_tty;
426 tty_buffer_set_lock_subclass(o_tty->port);
428 tty_driver_kref_get(driver);
434 module_put(driver->other->owner);
441 static void pty_cleanup(struct tty_struct *tty)
443 tty_port_put(tty->port);
446 /* Traditional BSD devices */
447 #ifdef CONFIG_LEGACY_PTYS
449 static int pty_install(struct tty_driver *driver, struct tty_struct *tty)
451 return pty_common_install(driver, tty, true);
454 static void pty_remove(struct tty_driver *driver, struct tty_struct *tty)
456 struct tty_struct *pair = tty->link;
458 driver->ttys[tty->index] = NULL;
460 pair->driver->ttys[pair->index] = NULL;
463 static int pty_bsd_ioctl(struct tty_struct *tty,
464 unsigned int cmd, unsigned long arg)
467 case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */
468 return pty_set_lock(tty, (int __user *) arg);
469 case TIOCGPTLCK: /* Get PT Lock status */
470 return pty_get_lock(tty, (int __user *)arg);
471 case TIOCPKT: /* Set PT packet mode */
472 return pty_set_pktmode(tty, (int __user *)arg);
473 case TIOCGPKT: /* Get PT packet mode */
474 return pty_get_pktmode(tty, (int __user *)arg);
475 case TIOCSIG: /* Send signal to other side of pty */
476 return pty_signal(tty, (int) arg);
477 case TIOCGPTN: /* TTY returns ENOTTY, but glibc expects EINVAL here */
484 static long pty_bsd_compat_ioctl(struct tty_struct *tty,
485 unsigned int cmd, unsigned long arg)
488 * PTY ioctls don't require any special translation between 32-bit and
489 * 64-bit userspace, they are already compatible.
491 return pty_bsd_ioctl(tty, cmd, (unsigned long)compat_ptr(arg));
494 #define pty_bsd_compat_ioctl NULL
497 static int legacy_count = CONFIG_LEGACY_PTY_COUNT;
499 * not really modular, but the easiest way to keep compat with existing
500 * bootargs behaviour is to continue using module_param here.
502 module_param(legacy_count, int, 0);
505 * The master side of a pty can do TIOCSPTLCK and thus
508 static const struct tty_operations master_pty_ops_bsd = {
509 .install = pty_install,
513 .write_room = pty_write_room,
514 .flush_buffer = pty_flush_buffer,
515 .unthrottle = pty_unthrottle,
516 .ioctl = pty_bsd_ioctl,
517 .compat_ioctl = pty_bsd_compat_ioctl,
518 .cleanup = pty_cleanup,
519 .resize = pty_resize,
523 static const struct tty_operations slave_pty_ops_bsd = {
524 .install = pty_install,
528 .write_room = pty_write_room,
529 .flush_buffer = pty_flush_buffer,
530 .unthrottle = pty_unthrottle,
531 .set_termios = pty_set_termios,
532 .cleanup = pty_cleanup,
533 .resize = pty_resize,
539 static void __init legacy_pty_init(void)
541 struct tty_driver *pty_driver, *pty_slave_driver;
543 if (legacy_count <= 0)
546 pty_driver = tty_alloc_driver(legacy_count,
547 TTY_DRIVER_RESET_TERMIOS |
548 TTY_DRIVER_REAL_RAW |
549 TTY_DRIVER_DYNAMIC_ALLOC);
550 if (IS_ERR(pty_driver))
551 panic("Couldn't allocate pty driver");
553 pty_slave_driver = tty_alloc_driver(legacy_count,
554 TTY_DRIVER_RESET_TERMIOS |
555 TTY_DRIVER_REAL_RAW |
556 TTY_DRIVER_DYNAMIC_ALLOC);
557 if (IS_ERR(pty_slave_driver))
558 panic("Couldn't allocate pty slave driver");
560 pty_driver->driver_name = "pty_master";
561 pty_driver->name = "pty";
562 pty_driver->major = PTY_MASTER_MAJOR;
563 pty_driver->minor_start = 0;
564 pty_driver->type = TTY_DRIVER_TYPE_PTY;
565 pty_driver->subtype = PTY_TYPE_MASTER;
566 pty_driver->init_termios = tty_std_termios;
567 pty_driver->init_termios.c_iflag = 0;
568 pty_driver->init_termios.c_oflag = 0;
569 pty_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
570 pty_driver->init_termios.c_lflag = 0;
571 pty_driver->init_termios.c_ispeed = 38400;
572 pty_driver->init_termios.c_ospeed = 38400;
573 pty_driver->other = pty_slave_driver;
574 tty_set_operations(pty_driver, &master_pty_ops_bsd);
576 pty_slave_driver->driver_name = "pty_slave";
577 pty_slave_driver->name = "ttyp";
578 pty_slave_driver->major = PTY_SLAVE_MAJOR;
579 pty_slave_driver->minor_start = 0;
580 pty_slave_driver->type = TTY_DRIVER_TYPE_PTY;
581 pty_slave_driver->subtype = PTY_TYPE_SLAVE;
582 pty_slave_driver->init_termios = tty_std_termios;
583 pty_slave_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
584 pty_slave_driver->init_termios.c_ispeed = 38400;
585 pty_slave_driver->init_termios.c_ospeed = 38400;
586 pty_slave_driver->other = pty_driver;
587 tty_set_operations(pty_slave_driver, &slave_pty_ops_bsd);
589 if (tty_register_driver(pty_driver))
590 panic("Couldn't register pty driver");
591 if (tty_register_driver(pty_slave_driver))
592 panic("Couldn't register pty slave driver");
595 static inline void legacy_pty_init(void) { }
599 #ifdef CONFIG_UNIX98_PTYS
600 static struct cdev ptmx_cdev;
603 * ptm_open_peer - open the peer of a pty
604 * @master: the open struct file of the ptmx device node
605 * @tty: the master of the pty being opened
606 * @flags: the flags for open
608 * Provide a race free way for userspace to open the slave end of a pty
609 * (where they have the master fd and cannot access or trust the mount
610 * namespace /dev/pts was mounted inside).
612 int ptm_open_peer(struct file *master, struct tty_struct *tty, int flags)
616 int retval = -EINVAL;
619 if (tty->driver != ptm_driver)
622 fd = get_unused_fd_flags(flags);
628 /* Compute the slave's path */
629 path.mnt = devpts_mntget(master, tty->driver_data);
630 if (IS_ERR(path.mnt)) {
631 retval = PTR_ERR(path.mnt);
634 path.dentry = tty->link->driver_data;
636 filp = dentry_open(&path, flags, current_cred());
639 retval = PTR_ERR(filp);
643 fd_install(fd, filp);
652 static int pty_unix98_ioctl(struct tty_struct *tty,
653 unsigned int cmd, unsigned long arg)
656 case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */
657 return pty_set_lock(tty, (int __user *)arg);
658 case TIOCGPTLCK: /* Get PT Lock status */
659 return pty_get_lock(tty, (int __user *)arg);
660 case TIOCPKT: /* Set PT packet mode */
661 return pty_set_pktmode(tty, (int __user *)arg);
662 case TIOCGPKT: /* Get PT packet mode */
663 return pty_get_pktmode(tty, (int __user *)arg);
664 case TIOCGPTN: /* Get PT Number */
665 return put_user(tty->index, (unsigned int __user *)arg);
666 case TIOCSIG: /* Send signal to other side of pty */
667 return pty_signal(tty, (int) arg);
674 static long pty_unix98_compat_ioctl(struct tty_struct *tty,
675 unsigned int cmd, unsigned long arg)
678 * PTY ioctls don't require any special translation between 32-bit and
679 * 64-bit userspace, they are already compatible.
681 return pty_unix98_ioctl(tty, cmd,
682 cmd == TIOCSIG ? arg : (unsigned long)compat_ptr(arg));
685 #define pty_unix98_compat_ioctl NULL
689 * ptm_unix98_lookup - find a pty master
690 * @driver: ptm driver
694 * Look up a pty master device. Called under the tty_mutex for now.
695 * This provides our locking.
698 static struct tty_struct *ptm_unix98_lookup(struct tty_driver *driver,
699 struct file *file, int idx)
701 /* Master must be open via /dev/ptmx */
702 return ERR_PTR(-EIO);
706 * pts_unix98_lookup - find a pty slave
707 * @driver: pts driver
708 * @file: file pointer to tty
711 * Look up a pty master device. Called under the tty_mutex for now.
712 * This provides our locking for the tty pointer.
715 static struct tty_struct *pts_unix98_lookup(struct tty_driver *driver,
716 struct file *file, int idx)
718 struct tty_struct *tty;
720 mutex_lock(&devpts_mutex);
721 tty = devpts_get_priv(file->f_path.dentry);
722 mutex_unlock(&devpts_mutex);
723 /* Master must be open before slave */
725 return ERR_PTR(-EIO);
729 static int pty_unix98_install(struct tty_driver *driver, struct tty_struct *tty)
731 return pty_common_install(driver, tty, false);
734 /* this is called once with whichever end is closed last */
735 static void pty_unix98_remove(struct tty_driver *driver, struct tty_struct *tty)
737 struct pts_fs_info *fsi;
739 if (tty->driver->subtype == PTY_TYPE_MASTER)
740 fsi = tty->driver_data;
742 fsi = tty->link->driver_data;
745 devpts_kill_index(fsi, tty->index);
750 static void pty_show_fdinfo(struct tty_struct *tty, struct seq_file *m)
752 seq_printf(m, "tty-index:\t%d\n", tty->index);
755 static const struct tty_operations ptm_unix98_ops = {
756 .lookup = ptm_unix98_lookup,
757 .install = pty_unix98_install,
758 .remove = pty_unix98_remove,
762 .write_room = pty_write_room,
763 .flush_buffer = pty_flush_buffer,
764 .unthrottle = pty_unthrottle,
765 .ioctl = pty_unix98_ioctl,
766 .compat_ioctl = pty_unix98_compat_ioctl,
767 .resize = pty_resize,
768 .cleanup = pty_cleanup,
769 .show_fdinfo = pty_show_fdinfo,
772 static const struct tty_operations pty_unix98_ops = {
773 .lookup = pts_unix98_lookup,
774 .install = pty_unix98_install,
775 .remove = pty_unix98_remove,
779 .write_room = pty_write_room,
780 .flush_buffer = pty_flush_buffer,
781 .unthrottle = pty_unthrottle,
782 .set_termios = pty_set_termios,
785 .cleanup = pty_cleanup,
789 * ptmx_open - open a unix 98 pty master
790 * @inode: inode of device file
791 * @filp: file pointer to tty
793 * Allocate a unix98 pty master device from the ptmx driver.
795 * Locking: tty_mutex protects the init_dev work. tty->count should
797 * allocated_ptys_lock handles the list of free pty numbers
800 static int ptmx_open(struct inode *inode, struct file *filp)
802 struct pts_fs_info *fsi;
803 struct tty_struct *tty;
804 struct dentry *dentry;
808 nonseekable_open(inode, filp);
810 /* We refuse fsnotify events on ptmx, since it's a shared resource */
811 filp->f_mode |= FMODE_NONOTIFY;
813 retval = tty_alloc_file(filp);
817 fsi = devpts_acquire(filp);
819 retval = PTR_ERR(fsi);
823 /* find a device that is not in use. */
824 mutex_lock(&devpts_mutex);
825 index = devpts_new_index(fsi);
826 mutex_unlock(&devpts_mutex);
833 mutex_lock(&tty_mutex);
834 tty = tty_init_dev(ptm_driver, index);
835 /* The tty returned here is locked so we can safely
837 mutex_unlock(&tty_mutex);
839 retval = PTR_ERR(tty);
844 * From here on out, the tty is "live", and the index and
845 * fsi will be killed/put by the tty_release()
847 set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */
848 tty->driver_data = fsi;
850 tty_add_file(tty, filp);
852 dentry = devpts_pty_new(fsi, index, tty->link);
853 if (IS_ERR(dentry)) {
854 retval = PTR_ERR(dentry);
857 tty->link->driver_data = dentry;
859 retval = ptm_driver->ops->open(tty, filp);
863 tty_debug_hangup(tty, "opening (count=%d)\n", tty->count);
869 // This will also put-ref the fsi
870 tty_release(inode, filp);
873 devpts_kill_index(fsi, index);
881 static struct file_operations ptmx_fops __ro_after_init;
883 static void __init unix98_pty_init(void)
885 ptm_driver = tty_alloc_driver(NR_UNIX98_PTY_MAX,
886 TTY_DRIVER_RESET_TERMIOS |
887 TTY_DRIVER_REAL_RAW |
888 TTY_DRIVER_DYNAMIC_DEV |
889 TTY_DRIVER_DEVPTS_MEM |
890 TTY_DRIVER_DYNAMIC_ALLOC);
891 if (IS_ERR(ptm_driver))
892 panic("Couldn't allocate Unix98 ptm driver");
893 pts_driver = tty_alloc_driver(NR_UNIX98_PTY_MAX,
894 TTY_DRIVER_RESET_TERMIOS |
895 TTY_DRIVER_REAL_RAW |
896 TTY_DRIVER_DYNAMIC_DEV |
897 TTY_DRIVER_DEVPTS_MEM |
898 TTY_DRIVER_DYNAMIC_ALLOC);
899 if (IS_ERR(pts_driver))
900 panic("Couldn't allocate Unix98 pts driver");
902 ptm_driver->driver_name = "pty_master";
903 ptm_driver->name = "ptm";
904 ptm_driver->major = UNIX98_PTY_MASTER_MAJOR;
905 ptm_driver->minor_start = 0;
906 ptm_driver->type = TTY_DRIVER_TYPE_PTY;
907 ptm_driver->subtype = PTY_TYPE_MASTER;
908 ptm_driver->init_termios = tty_std_termios;
909 ptm_driver->init_termios.c_iflag = 0;
910 ptm_driver->init_termios.c_oflag = 0;
911 ptm_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
912 ptm_driver->init_termios.c_lflag = 0;
913 ptm_driver->init_termios.c_ispeed = 38400;
914 ptm_driver->init_termios.c_ospeed = 38400;
915 ptm_driver->other = pts_driver;
916 tty_set_operations(ptm_driver, &ptm_unix98_ops);
918 pts_driver->driver_name = "pty_slave";
919 pts_driver->name = "pts";
920 pts_driver->major = UNIX98_PTY_SLAVE_MAJOR;
921 pts_driver->minor_start = 0;
922 pts_driver->type = TTY_DRIVER_TYPE_PTY;
923 pts_driver->subtype = PTY_TYPE_SLAVE;
924 pts_driver->init_termios = tty_std_termios;
925 pts_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
926 pts_driver->init_termios.c_ispeed = 38400;
927 pts_driver->init_termios.c_ospeed = 38400;
928 pts_driver->other = ptm_driver;
929 tty_set_operations(pts_driver, &pty_unix98_ops);
931 if (tty_register_driver(ptm_driver))
932 panic("Couldn't register Unix98 ptm driver");
933 if (tty_register_driver(pts_driver))
934 panic("Couldn't register Unix98 pts driver");
936 /* Now create the /dev/ptmx special device */
937 tty_default_fops(&ptmx_fops);
938 ptmx_fops.open = ptmx_open;
940 cdev_init(&ptmx_cdev, &ptmx_fops);
941 if (cdev_add(&ptmx_cdev, MKDEV(TTYAUX_MAJOR, 2), 1) ||
942 register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0)
943 panic("Couldn't register /dev/ptmx driver");
944 device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx");
948 static inline void unix98_pty_init(void) { }
951 static int __init pty_init(void)
957 device_initcall(pty_init);