tcsh backtick hang info

[Steve Kargl]

On Wed, Jul 11, 2007 at 07:28:55PM -0700, Doug White wrote:
> 
> In this case it appears to be an improperly placed bump to the SIGCHLD 
> disable count that is held over a call to pjwait(). I haven't yet 
> determined the call stack (and gdb cannot debug tcsh at the moment) so I 
> need to continue instrumenting the code to figure out what higher level 
> function is disabling SIGCHLD and then calling something that eventually 
> calls pjwait().
> 

Signal handling is completely and utterly messed up in
tcsh 6.15.0.  I've asked more than once to have the 6.15.0
import reverted in the FreeBSD tree.  Having broken signal
handling for the default shell of root suggests that there
is a likely exploit waiting in the wings.

-- 
Steve