Merge to Fedora kernel-2.6.18-1.2239_FC5 patched with stable patch-2.6.18.2-vs2.0...

[linux-2.6.git] / drivers / char / tty_ioctl.c

diff --git a/drivers/char/tty_ioctl.c b/drivers/char/tty_ioctl.c
index 4ad47d3..3b6fa7b 100644 (file)
--- a/drivers/char/tty_ioctl.c
+++ b/drivers/char/tty_ioctl.c
@@ -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;
 }
@@ -422,24 +423,28 @@ static int set_ltchars(struct tty_struct * tty, struct ltchars __user * ltchars)
  *
  *     Send a high priority character to the tty even if stopped
  *
- *     Locking: none
- *
- *     FIXME: overlapping calls with start/stop tty lose state of tty
+ *     Locking: none for xchar method, write ordering for write method.
  */
 
-static void send_prio_char(struct tty_struct *tty, char ch)
+static int send_prio_char(struct tty_struct *tty, char ch)
 {
        int     was_stopped = tty->stopped;
 
        if (tty->driver->send_xchar) {
                tty->driver->send_xchar(tty, ch);
-               return;
+               return 0;
        }
+
+       if (mutex_lock_interruptible(&tty->atomic_write_lock))
+               return -ERESTARTSYS;
+
        if (was_stopped)
                start_tty(tty);
        tty->driver->write(tty, &ch, 1);
        if (was_stopped)
                stop_tty(tty);
+       mutex_unlock(&tty->atomic_write_lock);
+       return 0;
 }
 
 int n_tty_ioctl(struct tty_struct * tty, struct file * file,
@@ -513,11 +518,11 @@ int n_tty_ioctl(struct tty_struct * tty, struct file * file,
                                break;
                        case TCIOFF:
                                if (STOP_CHAR(tty) != __DISABLED_CHAR)
-                                       send_prio_char(tty, STOP_CHAR(tty));
+                                       return send_prio_char(tty, STOP_CHAR(tty));
                                break;
                        case TCION:
                                if (START_CHAR(tty) != __DISABLED_CHAR)
-                                       send_prio_char(tty, START_CHAR(tty));
+                                       return send_prio_char(tty, START_CHAR(tty));
                                break;
                        default:
                                return -EINVAL;
@@ -592,11 +597,11 @@ 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;