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Commit 5785c95b authored by Arjan van de Ven's avatar Arjan van de Ven Committed by Linus Torvalds
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[PATCH] tty: make termios_sem a mutex 



[akpm@osdl.org: fix]
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 54306cf0

drivers/char/tty_io.c

+12 −11
Original line number Diff line number Diff line
@@ -618,9 +618,9 @@ EXPORT_SYMBOL_GPL(tty_prepare_flip_string_flags); 
 

static void tty_set_termios_ldisc(struct tty_struct *tty, int num)

{

	down(&tty->termios_sem);

	mutex_lock(&tty->termios_mutex);

	tty->termios->c_line = num;

	up(&tty->termios_sem);

	mutex_unlock(&tty->termios_mutex);

}



/*
@@ -1338,9 +1338,9 @@ static void do_tty_hangup(void *data) 
	 */

	if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS)

	{

		down(&tty->termios_sem);

		mutex_lock(&tty->termios_mutex);

		*tty->termios = tty->driver->init_termios;

		up(&tty->termios_sem);

		mutex_unlock(&tty->termios_mutex);

	}

	

	/* Defer ldisc switch */
@@ -2750,9 +2750,9 @@ static int tiocgwinsz(struct tty_struct *tty, struct winsize __user * arg) 
{

	int err;



	down(&tty->termios_sem);

	mutex_lock(&tty->termios_mutex);

	err = copy_to_user(arg, &tty->winsize, sizeof(*arg));

	up(&tty->termios_sem);

	mutex_unlock(&tty->termios_mutex);



	return err ? -EFAULT: 0;

}
@@ -2782,14 +2782,15 @@ static int tiocswinsz(struct tty_struct *tty, struct tty_struct *real_tty, 
	if (copy_from_user(&tmp_ws, arg, sizeof(*arg)))

		return -EFAULT;



	down(&tty->termios_sem);

	mutex_lock(&tty->termios_mutex);

	if (!memcmp(&tmp_ws, &tty->winsize, sizeof(*arg)))

		goto done;



#ifdef CONFIG_VT

	if (tty->driver->type == TTY_DRIVER_TYPE_CONSOLE) {

		if (vc_lock_resize(tty->driver_data, tmp_ws.ws_col, tmp_ws.ws_row)) {

			up(&tty->termios_sem);

		if (vc_lock_resize(tty->driver_data, tmp_ws.ws_col,

					tmp_ws.ws_row)) {

			mutex_unlock(&tty->termios_mutex);

 			return -ENXIO;

		}

	}
@@ -2801,7 +2802,7 @@ static int tiocswinsz(struct tty_struct *tty, struct tty_struct *real_tty, 
	tty->winsize = tmp_ws;

	real_tty->winsize = tmp_ws;

done:

	up(&tty->termios_sem);

	mutex_unlock(&tty->termios_mutex);

	return 0;

}
@@ -3576,7 +3577,7 @@ static void initialize_tty_struct(struct tty_struct *tty) 
	tty_buffer_init(tty);

	INIT_WORK(&tty->buf.work, flush_to_ldisc, tty);

	init_MUTEX(&tty->buf.pty_sem);

	init_MUTEX(&tty->termios_sem);

	mutex_init(&tty->termios_mutex);

	init_waitqueue_head(&tty->write_wait);

	init_waitqueue_head(&tty->read_wait);

	INIT_WORK(&tty->hangup_work, do_tty_hangup, tty);

drivers/char/tty_ioctl.c

+9 −8
Original line number Diff line number Diff line
@@ -20,6 +20,7 @@ 
#include <linux/mm.h>

#include <linux/module.h>

#include <linux/bitops.h>

#include <linux/mutex.h>



#include <asm/io.h>

#include <asm/uaccess.h>
@@ -131,7 +132,7 @@ static void change_termios(struct tty_struct * tty, struct termios * new_termios 


	/* FIXME: we need to decide on some locking/ordering semantics

	   for the set_termios notification eventually */

	down(&tty->termios_sem);

	mutex_lock(&tty->termios_mutex);



	*tty->termios = *new_termios;

	unset_locked_termios(tty->termios, &old_termios, tty->termios_locked);
@@ -176,7 +177,7 @@ static void change_termios(struct tty_struct * tty, struct termios * new_termios 
			(ld->set_termios)(tty, &old_termios);

		tty_ldisc_deref(ld);

	}

	up(&tty->termios_sem);

	mutex_unlock(&tty->termios_mutex);

}



/**
@@ -284,13 +285,13 @@ static int get_sgttyb(struct tty_struct * tty, struct sgttyb __user * sgttyb) 
{

	struct sgttyb tmp;



	down(&tty->termios_sem);

	mutex_lock(&tty->termios_mutex);

	tmp.sg_ispeed = 0;

	tmp.sg_ospeed = 0;

	tmp.sg_erase = tty->termios->c_cc[VERASE];

	tmp.sg_kill = tty->termios->c_cc[VKILL];

	tmp.sg_flags = get_sgflags(tty);

	up(&tty->termios_sem);

	mutex_unlock(&tty->termios_mutex);

	

	return copy_to_user(sgttyb, &tmp, sizeof(tmp)) ? -EFAULT : 0;

}
@@ -345,12 +346,12 @@ static int set_sgttyb(struct tty_struct * tty, struct sgttyb __user * sgttyb) 
	if (copy_from_user(&tmp, sgttyb, sizeof(tmp)))

		return -EFAULT;



	down(&tty->termios_sem);		

	mutex_lock(&tty->termios_mutex);

	termios =  *tty->termios;

	termios.c_cc[VERASE] = tmp.sg_erase;

	termios.c_cc[VKILL] = tmp.sg_kill;

	set_sgflags(&termios, tmp.sg_flags);

	up(&tty->termios_sem);

	mutex_unlock(&tty->termios_mutex);

	change_termios(tty, &termios);

	return 0;

}
@@ -592,11 +593,11 @@ int n_tty_ioctl(struct tty_struct * tty, struct file * file, 
		case TIOCSSOFTCAR:

			if (get_user(arg, (unsigned int __user *) arg))

				return -EFAULT;

			down(&tty->termios_sem);

			mutex_lock(&tty->termios_mutex);

			tty->termios->c_cflag =

				((tty->termios->c_cflag & ~CLOCAL) |

				 (arg ? CLOCAL : 0));

			up(&tty->termios_sem);

			mutex_unlock(&tty->termios_mutex);

			return 0;

		default:

			return -ENOIOCTLCMD;

include/linux/tty.h

+1 −1
Original line number Diff line number Diff line
@@ -174,7 +174,7 @@ struct tty_struct { 
	struct tty_driver *driver;

	int index;

	struct tty_ldisc ldisc;

	struct semaphore termios_sem;

	struct mutex termios_mutex;

	struct termios *termios, *termios_locked;

	char name[64];

	int pgrp;