13 #include <linux/tty.h>
32 #include "tty.h"
36 # define tty_debug_hangup(tty, f, args...)	tty_debug(tty, f, ##args)  argument
38 # define tty_debug_hangup(tty, f, args...)	do {} while (0)  argument
47 static void pty_close(struct tty_struct *tty, struct file *filp)  in pty_close()  argument
49 	if (tty->driver->subtype == PTY_TYPE_MASTER)  in pty_close()
50 		WARN_ON(tty->count > 1);  in pty_close()
52 		if (tty_io_error(tty))  in pty_close()
54 		if (tty->count > 2)  in pty_close()
57 	set_bit(TTY_IO_ERROR, &tty->flags);  in pty_close()
58 	wake_up_interruptible(&tty->read_wait);  in pty_close()
59 	wake_up_interruptible(&tty->write_wait);  in pty_close()
60 	scoped_guard(spinlock_irq, &tty->ctrl.lock)  in pty_close()
61 		tty->ctrl.packet = false;  in pty_close()
63 	if (!tty->link)  in pty_close()
65 	set_bit(TTY_OTHER_CLOSED, &tty->link->flags);  in pty_close()
66 	wake_up_interruptible(&tty->link->read_wait);  in pty_close()
67 	wake_up_interruptible(&tty->link->write_wait);  in pty_close()
68 	if (tty->driver->subtype == PTY_TYPE_MASTER) {  in pty_close()
69 		set_bit(TTY_OTHER_CLOSED, &tty->flags);  in pty_close()
71 		if (tty->driver == ptm_driver) {  in pty_close()
73 			if (tty->link->driver_data)  in pty_close()
74 				devpts_pty_kill(tty->link->driver_data);  in pty_close()
77 		tty_vhangup(tty->link);  in pty_close()
91 static void pty_unthrottle(struct tty_struct *tty)  in pty_unthrottle()  argument
93 	tty_wakeup(tty->link);  in pty_unthrottle()
94 	set_bit(TTY_THROTTLED, &tty->flags);  in pty_unthrottle()
99  *	@tty: the tty we write from
106  *	the other side of the pty/tty pair.
109 static ssize_t pty_write(struct tty_struct *tty, const u8 *buf, size_t c)  in pty_write()  argument
111 	struct tty_struct *to = tty->link;  in pty_write()
113 	if (tty->flow.stopped || !c)  in pty_write()
121  *	@tty: tty we are writing from
127 static unsigned int pty_write_room(struct tty_struct *tty)  in pty_write_room()  argument
129 	if (tty->flow.stopped)  in pty_write_room()
131 	return tty_buffer_space_avail(tty->link->port);  in pty_write_room()
135 static int pty_set_lock(struct tty_struct *tty, int __user *arg)  in pty_set_lock()  argument
142 		set_bit(TTY_PTY_LOCK, &tty->flags);  in pty_set_lock()
144 		clear_bit(TTY_PTY_LOCK, &tty->flags);  in pty_set_lock()
148 static int pty_get_lock(struct tty_struct *tty, int __user *arg)  in pty_get_lock()  argument
150 	int locked = test_bit(TTY_PTY_LOCK, &tty->flags);  in pty_get_lock()
156 static int pty_set_pktmode(struct tty_struct *tty, int __user *arg)  in pty_set_pktmode()  argument
163 	guard(spinlock_irq)(&tty->ctrl.lock);  in pty_set_pktmode()
165 		tty->ctrl.packet = false;  in pty_set_pktmode()
169 	if (tty->ctrl.packet)  in pty_set_pktmode()
172 	tty->link->ctrl.pktstatus = 0;  in pty_set_pktmode()
174 	tty->ctrl.packet = true;  in pty_set_pktmode()
180 static int pty_get_pktmode(struct tty_struct *tty, int __user *arg)  in pty_get_pktmode()  argument
182 	int pktmode = tty->ctrl.packet;  in pty_get_pktmode()
188 static int pty_signal(struct tty_struct *tty, int sig)  in pty_signal()  argument
195 	if (tty->link) {  in pty_signal()
196 		pgrp = tty_get_pgrp(tty->link);  in pty_signal()
204 static void pty_flush_buffer(struct tty_struct *tty)  in pty_flush_buffer()  argument
206 	struct tty_struct *to = tty->link;  in pty_flush_buffer()
213 		guard(spinlock_irq)(&tty->ctrl.lock);  in pty_flush_buffer()
214 		tty->ctrl.pktstatus |= TIOCPKT_FLUSHWRITE;  in pty_flush_buffer()
219 static int pty_open(struct tty_struct *tty, struct file *filp)  in pty_open()  argument
221 	if (!tty || !tty->link)  in pty_open()
224 	if (test_bit(TTY_OTHER_CLOSED, &tty->flags))  in pty_open()
226 	if (test_bit(TTY_PTY_LOCK, &tty->link->flags))  in pty_open()
228 	if (tty->driver->subtype == PTY_TYPE_SLAVE && tty->link->count != 1)  in pty_open()
231 	clear_bit(TTY_IO_ERROR, &tty->flags);  in pty_open()
232 	clear_bit(TTY_OTHER_CLOSED, &tty->link->flags);  in pty_open()
233 	set_bit(TTY_THROTTLED, &tty->flags);  in pty_open()
237 	set_bit(TTY_IO_ERROR, &tty->flags);  in pty_open()
241 static void pty_set_termios(struct tty_struct *tty,  in pty_set_termios()  argument
245 	if (tty->link && tty->link->ctrl.packet) {  in pty_set_termios()
246 		int extproc = (old_termios->c_lflag & EXTPROC) | L_EXTPROC(tty);  in pty_set_termios()
250 		int new_flow = (I_IXON(tty) &&  in pty_set_termios()
251 				STOP_CHAR(tty) == '\023' &&  in pty_set_termios()
252 				START_CHAR(tty) == '\021');  in pty_set_termios()
254 			scoped_guard(spinlock_irq, &tty->ctrl.lock) {  in pty_set_termios()
256 					tty->ctrl.pktstatus &= ~(TIOCPKT_DOSTOP | TIOCPKT_NOSTOP);  in pty_set_termios()
258 						tty->ctrl.pktstatus |= TIOCPKT_DOSTOP;  in pty_set_termios()
260 						tty->ctrl.pktstatus |= TIOCPKT_NOSTOP;  in pty_set_termios()
263 					tty->ctrl.pktstatus |= TIOCPKT_IOCTL;  in pty_set_termios()
265 			wake_up_interruptible(&tty->link->read_wait);  in pty_set_termios()
269 	tty->termios.c_cflag &= ~(CSIZE | PARENB);  in pty_set_termios()
270 	tty->termios.c_cflag |= (CS8 | CREAD);  in pty_set_termios()
275  *	@tty: tty being resized
282 static int pty_resize(struct tty_struct *tty,  struct winsize *ws)  in pty_resize()  argument
285 	struct tty_struct *pty = tty->link;  in pty_resize()
287 	/* For a PTY we need to lock the tty side */  in pty_resize()
288 	guard(mutex)(&tty->winsize_mutex);  in pty_resize()
289 	if (!memcmp(ws, &tty->winsize, sizeof(*ws)))  in pty_resize()
293 	pgrp = tty_get_pgrp(tty);  in pty_resize()
304 	tty->winsize = *ws;  in pty_resize()
313  *	@tty: tty being flow-controlled
320 static void pty_start(struct tty_struct *tty)  in pty_start()  argument
322 	if (!tty->link || !tty->link->ctrl.packet)  in pty_start()
325 	scoped_guard(spinlock_irqsave, &tty->ctrl.lock) {  in pty_start()
326 		tty->ctrl.pktstatus &= ~TIOCPKT_STOP;  in pty_start()
327 		tty->ctrl.pktstatus |= TIOCPKT_START;  in pty_start()
329 	wake_up_interruptible_poll(&tty->link->read_wait, EPOLLIN);  in pty_start()
332 static void pty_stop(struct tty_struct *tty)  in pty_stop()  argument
334 	if (!tty->link || !tty->link->ctrl.packet)  in pty_stop()
337 	scoped_guard(spinlock_irqsave, &tty->ctrl.lock) {  in pty_stop()
338 		tty->ctrl.pktstatus &= ~TIOCPKT_START;  in pty_stop()
339 		tty->ctrl.pktstatus |= TIOCPKT_STOP;  in pty_stop()
341 	wake_up_interruptible_poll(&tty->link->read_wait, EPOLLIN);  in pty_stop()
347  *	@tty: the tty being instantiated
350  *	Perform the initial set up for the tty/pty pair. Called from the
351  *	tty layer when the port is first opened.
355 static int pty_common_install(struct tty_driver *driver, struct tty_struct *tty,  in pty_common_install()  argument
360 	int idx = tty->index;  in pty_common_install()
383 		/* We always use new tty termios data so we can do this  in pty_common_install()
385 		tty_init_termios(tty);  in pty_common_install()
389 		driver->ttys[idx] = tty;  in pty_common_install()
391 		memset(&tty->termios_locked, 0, sizeof(tty->termios_locked));  in pty_common_install()
392 		tty->termios = driver->init_termios;  in pty_common_install()
393 		memset(&o_tty->termios_locked, 0, sizeof(tty->termios_locked));  in pty_common_install()
402 	tty->link   = o_tty;  in pty_common_install()
403 	o_tty->link = tty;  in pty_common_install()
409 	tty->port = ports[1];  in pty_common_install()
415 	tty->count++;  in pty_common_install()
427 static void pty_cleanup(struct tty_struct *tty)  in pty_cleanup()  argument
429 	tty_port_put(tty->port);  in pty_cleanup()
435 static int pty_install(struct tty_driver *driver, struct tty_struct *tty)  in pty_install()  argument
437 	return pty_common_install(driver, tty, true);  in pty_install()
440 static void pty_remove(struct tty_driver *driver, struct tty_struct *tty)  in pty_remove()  argument
442 	struct tty_struct *pair = tty->link;  in pty_remove()
444 	driver->ttys[tty->index] = NULL;  in pty_remove()
449 static int pty_bsd_ioctl(struct tty_struct *tty,  in pty_bsd_ioctl()  argument
454 		return pty_set_lock(tty, (int __user *) arg);  in pty_bsd_ioctl()
456 		return pty_get_lock(tty, (int __user *)arg);  in pty_bsd_ioctl()
458 		return pty_set_pktmode(tty, (int __user *)arg);  in pty_bsd_ioctl()
460 		return pty_get_pktmode(tty, (int __user *)arg);  in pty_bsd_ioctl()
462 		return pty_signal(tty, (int) arg);  in pty_bsd_ioctl()
463 	case TIOCGPTN: /* TTY returns ENOTTY, but glibc expects EINVAL here */  in pty_bsd_ioctl()
470 static long pty_bsd_compat_ioctl(struct tty_struct *tty,  in pty_bsd_compat_ioctl()  argument
477 	return pty_bsd_ioctl(tty, cmd, (unsigned long)compat_ptr(arg));  in pty_bsd_compat_ioctl()
589 				       struct tty_struct *tty, int flags)  in ptm_open_peer_file()  argument
595 	path.mnt = devpts_mntget(master, tty->driver_data);  in ptm_open_peer_file()
598 	path.dentry = tty->link->driver_data;  in ptm_open_peer_file()
608  *	@tty: the master of the pty being opened
615 int ptm_open_peer(struct file *master, struct tty_struct *tty, int flags)  in ptm_open_peer()  argument
617 	if (tty->driver != ptm_driver)  in ptm_open_peer()
620 	return FD_ADD(flags, ptm_open_peer_file(master, tty, flags));  in ptm_open_peer()
623 static int pty_unix98_ioctl(struct tty_struct *tty,  in pty_unix98_ioctl()  argument
628 		return pty_set_lock(tty, (int __user *)arg);  in pty_unix98_ioctl()
630 		return pty_get_lock(tty, (int __user *)arg);  in pty_unix98_ioctl()
632 		return pty_set_pktmode(tty, (int __user *)arg);  in pty_unix98_ioctl()
634 		return pty_get_pktmode(tty, (int __user *)arg);  in pty_unix98_ioctl()
636 		return put_user(tty->index, (unsigned int __user *)arg);  in pty_unix98_ioctl()
638 		return pty_signal(tty, (int) arg);  in pty_unix98_ioctl()
645 static long pty_unix98_compat_ioctl(struct tty_struct *tty,  in pty_unix98_compat_ioctl()  argument
652 	return pty_unix98_ioctl(tty, cmd,  in pty_unix98_compat_ioctl()
663  *	@idx: tty index
679  *	@file: file pointer to tty
680  *	@idx: tty index
683  *	This provides our locking for the tty pointer.
694 static int pty_unix98_install(struct tty_driver *driver, struct tty_struct *tty)  in pty_unix98_install()  argument
696 	return pty_common_install(driver, tty, false);  in pty_unix98_install()
700 static void pty_unix98_remove(struct tty_driver *driver, struct tty_struct *tty)  in pty_unix98_remove()  argument
704 	if (tty->driver->subtype == PTY_TYPE_MASTER)  in pty_unix98_remove()
705 		fsi = tty->driver_data;  in pty_unix98_remove()
707 		fsi = tty->link->driver_data;  in pty_unix98_remove()
710 		devpts_kill_index(fsi, tty->index);  in pty_unix98_remove()
715 static void pty_show_fdinfo(struct tty_struct *tty, struct seq_file *m)  in pty_show_fdinfo()  argument
717 	seq_printf(m, "tty-index:\t%d\n", tty->index);  in pty_show_fdinfo()
756  *	@filp: file pointer to tty
760  *	Locking: tty_mutex protects the init_dev work. tty->count should
768 	struct tty_struct *tty;  in ptmx_open()  local
797 	/* The tty returned here is locked so we can safely drop the mutex */  in ptmx_open()
799 		tty = tty_init_dev(ptm_driver, index);  in ptmx_open()
801 	retval = PTR_ERR(tty);  in ptmx_open()
802 	if (IS_ERR(tty))  in ptmx_open()
806 	 * From here on out, the tty is "live", and the index and  in ptmx_open()
809 	set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */  in ptmx_open()
810 	tty->driver_data = fsi;  in ptmx_open()
812 	tty_add_file(tty, filp);  in ptmx_open()
814 	dentry = devpts_pty_new(fsi, index, tty->link);  in ptmx_open()
819 	tty->link->driver_data = dentry;  in ptmx_open()
821 	retval = ptm_driver->ops->open(tty, filp);  in ptmx_open()
825 	tty_debug_hangup(tty, "opening (count=%d)\n", tty->count);  in ptmx_open()
827 	tty_unlock(tty);  in ptmx_open()
830 	tty_unlock(tty);  in ptmx_open()