Re: kern/37915: vt100 + wscons + tty vmlocking changes = panic

[David Holland <dholland-bugs%netbsd.org@localhost>]

The following reply was made to PR kern/37915; it has been noted by GNATS.

From: David Holland <dholland-bugs%netbsd.org@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: kern-bug-people%netbsd.org@localhost, gnats-admin%netbsd.org@localhost,
        netbsd-bugs%netbsd.org@localhost
Subject: Re: kern/37915: vt100 + wscons + tty vmlocking changes = panic
Date: Mon, 8 Dec 2008 17:36:47 +0000

 On Wed, Jan 30, 2008 at 01:30:00AM +0000, dholland%eecs.harvard.edu@localhost 
wrote:
  > >Synopsis:       vt100 + wscons + tty vmlocking changes = panic
  >
  > Sending some VT100 control sequences to wscons will panic the kernel.
  > 
  > The problem is that ttwrite() holds tty_lock while calling ttstart();
  > this makes its way down to wsemul_vt100_handle_csi(), which for
  > several sequences that report stuff back calls wsdisplay_emulinput(),
  > which calls ttyinput(), which tries to get tty_lock again.
 
 This still happens with up-to-the-minute current.
 
 -- 
 David A. Holland
 dholland%netbsd.org@localhost