patch-2.0.21-2.1.0 linux/drivers/char/pty.c

• Lines: 81
• Date: Sat Sep 28 22:58:22 1996
• Orig file: lx2.0/v2.0.21/linux/drivers/char/pty.c
• Orig date: Wed Jul 17 15:10:03 1996

diff -u --recursive --new-file lx2.0/v2.0.21/linux/drivers/char/pty.c linux/drivers/char/pty.c
@@ -181,66 +181,41 @@
 
 int pty_open(struct tty_struct *tty, struct file * filp)
 {
-#if PTY_SLAVE_WAITS_ON_OPEN
-	struct wait_queue wait = { current, NULL };
-#endif
 	int	retval;
 	int	line;
 	struct	pty_struct *pty;
-	
+
+	retval = -ENODEV;
 	if (!tty || !tty->link)
-		return -ENODEV;
+		goto out;
 	line = MINOR(tty->device) - tty->driver.minor_start;
 	if ((line < 0) || (line >= NR_PTYS))
-		return -ENODEV;
+		goto out;
 	pty = pty_state + line;
 	tty->driver_data = pty;
 
 	if (!tmp_buf) {
-		unsigned long page = get_free_page(GFP_KERNEL);
+		unsigned long page = __get_free_page(GFP_KERNEL);
 		if (!tmp_buf) {
+			retval = -ENOMEM;
 			if (!page)
-				return -ENOMEM;
+				goto out;
 			tmp_buf = (unsigned char *) page;
+			memset((void *) page, 0, PAGE_SIZE);
 		} else
 			free_page(page);
 	}
+	retval = -EIO;
+	if (test_bit(TTY_OTHER_CLOSED, &tty->flags))
+		goto out;
+	if (tty->link->count != 1)
+		goto out;
 
 	clear_bit(TTY_OTHER_CLOSED, &tty->link->flags);
 	wake_up_interruptible(&pty->open_wait);
 	set_bit(TTY_THROTTLED, &tty->flags);
-	if (filp->f_flags & O_NDELAY)
-		return 0;
-	/*
-	 * If we're opening the master pty, just return.  If we're
-	 * trying to open the slave pty, then we have to wait for the
-	 * master pty to open.
-	 */
-	if (tty->driver.subtype == PTY_TYPE_MASTER)
-		return 0;
 	retval = 0;
-#if PTY_SLAVE_WAITS_ON_OPEN
-	add_wait_queue(&pty->open_wait, &wait);
-	while (1) {
-		if (current->signal & ~current->blocked) {
-			retval = -ERESTARTSYS;
-			break;
-		}
-		/*
-		 * Block until the master is open...
-		 */
-		current->state = TASK_INTERRUPTIBLE;
-		if (tty->link->count &&
-		    !test_bit(TTY_OTHER_CLOSED, &tty->flags))
-			break;
-		schedule();
-	}
-	current->state = TASK_RUNNING;
-	remove_wait_queue(&pty->open_wait, &wait);
-#else
-	if (!tty->link->count || test_bit(TTY_OTHER_CLOSED, &tty->flags))
-		retval = -EPERM;
-#endif
+out:
 	return retval;
 }