Re: [PATCH] 2.5.68-bk1 crash in devfs_remove() for defpts files

[Christoph Hellwig <hch@lst.de>]

On Mon, Apr 21, 2003 at 04:35:21PM -0400, Pavel Roskin wrote:
> > Oh, I see now.  There's a longstanding bug in the handling of
> > TTY_DRIVER_NO_DEVFS that got exposed by this.
> >
> > Please try this patch additionally:
> 
> Applied.  Now I can log in by ssh and there are no problems with
> pseudoterminals.  However, all local terminals are gone:

The devfs <-> tty interaction are going to drive me nuts.

TTY_DRIVER_NO_DEVFS actually means don't call tty_register_device
in tty_register_driver, not don't register with devfs.

Updated patch (replaces the last one):


--- 1.78/drivers/char/tty_io.c	Sat Apr 19 19:24:04 2003
+++ edited/drivers/char/tty_io.c	Mon Apr 21 21:28:01 2003
@@ -2173,9 +2173,9 @@
 	
 	list_add(&driver->tty_drivers, &tty_drivers);
 	
-	if ( !(driver->flags & TTY_DRIVER_NO_DEVFS) ) {
-		for(i = 0; i < driver->num; i++)
-		    tty_register_device(driver, driver->minor_start + i);
+	if (!(driver->flags & TTY_DRIVER_NO_DEVFS)) {
+		for (i = 0; i < driver->num; i++)
+			tty_register_device(driver, driver->minor_start + i);
 	}
 	proc_tty_register_driver(driver);
 	return error;
@@ -2215,7 +2215,8 @@
 			driver->termios_locked[i] = NULL;
 			kfree(tp);
 		}
-		tty_unregister_device(driver, driver->minor_start + i);
+		if (!(driver->flags & TTY_DRIVER_NO_DEVFS))
+			tty_unregister_device(driver, driver->minor_start + i);
 	}
 	proc_tty_unregister_driver(driver);
 	return 0;