Re: tty_struct curruption

[Aivils S. <Aiv...@un...>]

>ok, some more research, but i still do not understand what really
>happens.
>
>the tty_struct which later is found from kdb_keycode and causes
>the oops in tty_insert_flip_char() is correctly kfree()d much
>earlier, when the tty is shut down at some point. (they seem to
>be opened and released all the time for different purposes.)
>
>But in the vc->vc_tty pointer keeps pointing to the old, freed
>tty_struct.
>where should that pointer be reset, if a tty is released?
>
>Shouldnt this happen in tty_io.c in release_dev()? this is not
>the case in ruby or in Aivils backport to 2.4.

Now understand.

--- drivers/char/vt.c.orig    Mon Sep 23 21:19:26 2002
+++ drivers/char/vt.c    Mon Oct 21 18:46:36 2002
@@ -1277,11 +1277,14 @@ static int vt_open(struct tty_struct *tt

 static void vt_close(struct tty_struct *tty, struct file *filp)
 {
+        struct vc_data *vc;
     if (!tty)
          return;
     if (tty->count != 1)
          return;
     vcs_make_devfs(minor(tty->device), 1);
+    vc = (struct vc_data *) tty->driver_data;
+    vc->vc_tty = NULL;
     tty->driver_data = 0;
 }

James Simons
Current ruby CVS call vt_map_input() vt.c any time when keyboard pluged
into box.
If user plug USB keyboard multiple times in vt_map_input() vty_driver
allocated
again and again, called from kbd_connect() keyboard.c.

Your sugestion?
1) Free vty_driver in the kbd_disconnect()
or
2) ignore vt_map_input() second call from kbd_connect() if vty_driver
already
allocated for this VT.
Me like 2) because VT never released.

Aivils Stoss