tty: Untangle termios and mm mutex dependencies

[deliverable/linux.git] / drivers / char / tty_ioctl.c

diff --git a/drivers/char/tty_ioctl.c b/drivers/char/tty_ioctl.c
index 2401dbcbee9c170e2efdfe2bfbf474c61fbe2acc..8116bb1c8f801c505816b0eec531bed441ff0842 100644 (file)
--- a/drivers/char/tty_ioctl.c
+++ b/drivers/char/tty_ioctl.c
@@ -626,9 +626,25 @@ static int set_termios(struct tty_struct *tty, void __user *arg, int opt)
        return 0;
 }
 
+static void copy_termios(struct tty_struct *tty, struct ktermios *kterm)
+{
+       mutex_lock(&tty->termios_mutex);
+       memcpy(kterm, tty->termios, sizeof(struct ktermios));
+       mutex_unlock(&tty->termios_mutex);
+}
+
+static void copy_termios_locked(struct tty_struct *tty, struct ktermios *kterm)
+{
+       mutex_lock(&tty->termios_mutex);
+       memcpy(kterm, tty->termios_locked, sizeof(struct ktermios));
+       mutex_unlock(&tty->termios_mutex);
+}
+
 static int get_termio(struct tty_struct *tty, struct termio __user *termio)
 {
-       if (kernel_termios_to_user_termio(termio, tty->termios))
+       struct ktermios kterm;
+       copy_termios(tty, &kterm);
+       if (kernel_termios_to_user_termio(termio, &kterm))
                return -EFAULT;
        return 0;
 }
@@ -930,6 +946,8 @@ 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;
+       struct ktermios kterm;
+       struct termiox ktermx;
 
        if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
            tty->driver->subtype == PTY_TYPE_MASTER)
@@ -965,23 +983,20 @@ 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))
+               copy_termios(real_tty, &kterm);
+               if (kernel_termios_to_user_termios((struct termios __user *)arg, &kterm))
                        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))
+               copy_termios(real_tty, &kterm);
+               if (kernel_termios_to_user_termios_1((struct termios __user *)arg, &kterm))
                        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))
+               copy_termios(real_tty, &kterm);
+               if (kernel_termios_to_user_termios((struct termios2 __user *)arg, &kterm))
                        ret = -EFAULT;
-               mutex_unlock(&real_tty->termios_mutex);
                return ret;
        case TCSETSF2:
                return set_termios(real_tty, p,  TERMIOS_FLUSH | TERMIOS_WAIT);
@@ -1000,34 +1015,36 @@ 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))
+               copy_termios_locked(real_tty, &kterm);
+               if (kernel_termios_to_user_termios((struct termios __user *)arg, &kterm))
                        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,
+               copy_termios_locked(real_tty, &kterm);
+               if (user_termios_to_kernel_termios(&kterm,
                                               (struct termios __user *) arg))
-                       ret = -EFAULT;
+                       return -EFAULT;
+               mutex_lock(&real_tty->termios_mutex);
+               memcpy(real_tty->termios_locked, &kterm, sizeof(struct ktermios));
                mutex_unlock(&real_tty->termios_mutex);
-               return ret;
+               return 0;
 #else
        case TIOCGLCKTRMIOS:
-               mutex_lock(&real_tty->termios_mutex);
-               if (kernel_termios_to_user_termios_1((struct termios __user *)arg, real_tty->termios_locked))
+               copy_termios_locked(real_tty, &kterm);
+               if (kernel_termios_to_user_termios_1((struct termios __user *)arg, &kterm))
                        ret = -EFAULT;
-               mutex_unlock(&real_tty->termios_mutex);
                return ret;
        case TIOCSLCKTRMIOS:
                if (!capable(CAP_SYS_ADMIN))
-                       ret = -EPERM;
-               mutex_lock(&real_tty->termios_mutex);
-               if (user_termios_to_kernel_termios_1(real_tty->termios_locked,
+                       return -EPERM;
+               copy_termios_locked(real_tty, &kterm);
+               if (user_termios_to_kernel_termios_1(&kterm,
                                               (struct termios __user *) arg))
-                       ret = -EFAULT;
+                       return -EFAULT;
+               mutex_lock(&real_tty->termios_mutex);
+               memcpy(real_tty->termios_locked, &kterm, sizeof(struct ktermios));
                mutex_unlock(&real_tty->termios_mutex);
                return ret;
 #endif
@@ -1036,9 +1053,10 @@ int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
                if (real_tty->termiox == NULL)
                        return -EINVAL;
                mutex_lock(&real_tty->termios_mutex);
-               if (copy_to_user(p, real_tty->termiox, sizeof(struct termiox)))
-                       ret = -EFAULT;
+               memcpy(&ktermx, real_tty->termiox, sizeof(struct termiox));
                mutex_unlock(&real_tty->termios_mutex);
+               if (copy_to_user(p, &ktermx, sizeof(struct termiox)))
+                       ret = -EFAULT;
                return ret;
        case TCSETX:
                return set_termiox(real_tty, p, 0);
@@ -1048,10 +1066,9 @@ int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
                return set_termiox(real_tty, p, TERMIOS_FLUSH);
 #endif         
        case TIOCGSOFTCAR:
-               mutex_lock(&real_tty->termios_mutex);
-               ret = put_user(C_CLOCAL(real_tty) ? 1 : 0,
+               copy_termios(real_tty, &kterm);
+               ret = put_user((kterm.c_cflag & CLOCAL) ? 1 : 0,
                                                (int __user *)arg);
-               mutex_unlock(&real_tty->termios_mutex);
                return ret;
        case TIOCSSOFTCAR:
                if (get_user(arg, (unsigned int __user *) arg))