Re: [uml-user] random guest processes segfault

[Allen C. <al...@us...>]

On Tuesday 31 January 2006 22:23, uml@s.rhythm.cx wrote:
> I tried upgrading my UML running 2.4.28-1um to 2.6.15.2-bs1. After
> bringing the UML up under the later kernel, I noticed random
> processes within the UML would segfault. For instance, I tried
> SSHing to it over and over and in about 1 in 5 attempts my shell or
> something else during the login procedure would segfault before
> getting to a prompt.

I've had similar problems in every UML guest kernel starting with 
2.6.11.  The initial ssh login would segfault every now and then, but 
the UML appears to run fine otherwise.  The same setup would work 
fine in a 2.4.* guest kernel and in 2.6.* guest kernels up to 2.6.10.

After a little experimentation, it appears that the problem only 
occurs in a tcsh shell and the segfault occurs on command lines 
containing backquotes, and even then, the segfault only occurs 
roughly 10% of the time.  The problem can be reproduced by repeatedly 
executing the following command inside the UML guest:
	tcsh -c 'echo `hostname`'

Unfortunately, I have not found a solution other than to avoid tcsh 
and/or backquoted commands from inside tcsh scripts.