hang on exit bug under Linux

[Jani Jaakkola]

On Thu, 21 Feb 2002, Michael wrote:

> > On Thu, Feb 21, 2002 at 11:34:06AM -0800, Michael wrote:
> > > Just thought I'd mention that when you restart "init"
> > > 
> > > kill -HUP 1
> > > 
> > > ssh 3.02p1 hangs as expected. What data would I expect back from 
> > > that??
> > 
> > I don't see that behaviour.  I assume you are talking about an sshd
> > patched with the "AllowDataLossOnPty" patch.
> > 
> >     ssh localhost -t "sleep 20 & exit"
> > 
> > returns immediately before and after 'kill -HUP 1'.  Perhaps you
> > aren't requesting a pty in your test?
> > 
> 
> simpler than that....
> unpatched 3.02.p1
> 
> local:~# ssh some.remotehost.com
> some:~# kill -HUP 1
> some:~# exit
> hangs......

You must have some login script which starts something in the 
background. Or a shell which does not actually exit on command 
exit. Or kill is not /bin/kill but is something else (weird shell alias?) 
instead.

Or then it is a completely different problem than the usual 
'hang on exit' one. I certainly do not see any behaviour like that
(but I get the hang on exit when I leave processes which are not 
properly daemonized in the background. Which, IMHO, is as things should 
be).

- Jani