Commit 8f520021 authored by Alan Cox's avatar Alan Cox Committed by Linus Torvalds
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tty: Termios locking - sort out real_tty confusions and lock reads 



This moves us towards sanity and should mean our termios locking is now
complete and comprehensive.

Signed-off-by: default avatarAlan Cox <alan@redhat.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 1d65b4a0

drivers/char/tty_io.c

+1 −1
Original line number Diff line number Diff line
@@ -2605,7 +2605,7 @@ long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 
	case TIOCSTI:

		return tiocsti(tty, p);

	case TIOCGWINSZ:

		return tiocgwinsz(tty, p);

		return tiocgwinsz(real_tty, p);

	case TIOCSWINSZ:

		return tiocswinsz(tty, real_tty, p);

	case TIOCCONS:

drivers/char/tty_ioctl.c

+38 −20
Original line number Diff line number Diff line
@@ -893,6 +893,7 @@ int tty_mode_ioctl(struct tty_struct *tty, struct file *file, 
{

	struct tty_struct *real_tty;

	void __user *p = (void __user *)arg;

	int ret = 0;



	if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&

	    tty->driver->subtype == PTY_TYPE_MASTER)
@@ -928,18 +929,24 @@ int tty_mode_ioctl(struct tty_struct *tty, struct file *file, 
		return set_termios(real_tty, p, TERMIOS_OLD);

#ifndef TCGETS2

	case TCGETS:

		mutex_lock(&real_tty->termios_mutex);

		if (kernel_termios_to_user_termios((struct termios __user *)arg, real_tty->termios))

			return -EFAULT;

		return 0;

			ret = -EFAULT;

		mutex_unlock(&real_tty->termios_mutex);

		return ret;

#else

	case TCGETS:

		mutex_lock(&real_tty->termios_mutex);

		if (kernel_termios_to_user_termios_1((struct termios __user *)arg, real_tty->termios))

			return -EFAULT;

		return 0;

			ret = -EFAULT;

		mutex_unlock(&real_tty->termios_mutex);

		return ret;

	case TCGETS2:

		mutex_lock(&real_tty->termios_mutex);

		if (kernel_termios_to_user_termios((struct termios2 __user *)arg, real_tty->termios))

			return -EFAULT;

		return 0;

			ret = -EFAULT;

		mutex_unlock(&real_tty->termios_mutex);

		return ret;

	case TCSETSF2:

		return set_termios(real_tty, p,  TERMIOS_FLUSH | TERMIOS_WAIT);

	case TCSETSW2:
@@ -957,36 +964,46 @@ int tty_mode_ioctl(struct tty_struct *tty, struct file *file, 
		return set_termios(real_tty, p, TERMIOS_TERMIO);

#ifndef TCGETS2

	case TIOCGLCKTRMIOS:

		mutex_lock(&real_tty->termios_mutex);

		if (kernel_termios_to_user_termios((struct termios __user *)arg, real_tty->termios_locked))

			return -EFAULT;

		return 0;

			ret = -EFAULT;

		mutex_unlock(&real_tty->termios_mutex);

		return ret;

	case TIOCSLCKTRMIOS:

		if (!capable(CAP_SYS_ADMIN))

			return -EPERM;

		mutex_lock(&real_tty->termios_mutex);

		if (user_termios_to_kernel_termios(real_tty->termios_locked,

					       (struct termios __user *) arg))

			return -EFAULT;

		return 0;

			ret = -EFAULT;

		mutex_unlock(&real_tty->termios_mutex);

		return ret;

#else

	case TIOCGLCKTRMIOS:

		mutex_lock(&real_tty->termios_mutex);

		if (kernel_termios_to_user_termios_1((struct termios __user *)arg, real_tty->termios_locked))

			return -EFAULT;

		return 0;

			ret = -EFAULT;

		mutex_unlock(&real_tty->termios_mutex);

		return ret;

	case TIOCSLCKTRMIOS:

		if (!capable(CAP_SYS_ADMIN))

			return -EPERM;

			ret = -EPERM;

		mutex_lock(&real_tty->termios_mutex);

		if (user_termios_to_kernel_termios_1(real_tty->termios_locked,

					       (struct termios __user *) arg))

			return -EFAULT;

			return 0;

			ret = -EFAULT;

		mutex_unlock(&real_tty->termios_mutex);

		return ret;

#endif

#ifdef TCGETX

	case TCGETX:

		if (real_tty->termiox == NULL)

			return -EINVAL;

		mutex_lock(&real_tty->termios_mutex);

		if (copy_to_user(p, real_tty->termiox, sizeof(struct termiox)))

			return -EFAULT;

		return 0;

			ret = -EFAULT;

		mutex_unlock(&real_tty->termios_mutex);

		return ret;

	case TCSETX:

		return set_termiox(real_tty, p, 0);

	case TCSETXW:
@@ -995,10 +1012,11 @@ int tty_mode_ioctl(struct tty_struct *tty, struct file *file, 
		return set_termiox(real_tty, p, TERMIOS_FLUSH);

#endif		

	case TIOCGSOFTCAR:

		/* FIXME: for correctness we may need to take the termios

		   lock here - review */

		return put_user(C_CLOCAL(real_tty) ? 1 : 0,

		mutex_lock(&real_tty->termios_mutex);

		ret = put_user(C_CLOCAL(real_tty) ? 1 : 0,

						(int __user *)arg);

		mutex_unlock(&real_tty->termios_mutex);

		return ret;

	case TIOCSSOFTCAR:

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

			return -EFAULT;