Segfaults as non-root user

[john@cs.hmc.edu (John C. McCullough)]

I recently installed the amd64 port onto an intel EM64t SMP machine.  I
am running the 2.6.12.6 kernel.  The same issue occurs using the
debian-packaged 2.6.11-em64t-p4-smp kernel.  I cannot test on the 2.6.13
kernel due to a driver issue in the raid controler.

The system was installed using a slightly modified unstable cd image and
then packages from the testing branch were installed.  The raid board on
the machine is not supported until the 2.6.11 kernel and I was having
difficulty getting a kernel satisfying that onto a testing installation
cd.

So far, I have found a few programs that segfault, particularly zsh and
dpkg-buildpkg when run as a non-root user.  They behave normally when
run as root.

In zsh the problem appears as:
~ % cd /tmp/test
/tmp/test % ls -la
/tmp/test
total 12
drwx--x--x  3 john john 4096 2005-09-20 09:55 .
drwxrwxrwt  7 root root     4096 2005-09-20 09:54 ..
drwx-----x  3 john john 4096 2005-09-20 09:55 pkgs
/tmp/test %

/tmp/test %  cd pkgs
/tmp/test/pkgs % ls
zsh: 4707 segmentation fault  ls
/tmp/test/pkgs %

And any attempts to execute commands elsewhere results in a segmentation
fault.  However, if the full path is used, the segfault does not occur:

~ % cd /tmp/test/pkgs
/tmp/test/pkgs % ls -la
total 6516
drwx-----x   3 john john    4096 2005-09-20 09:55 .
drwx--x--x   3 john john    4096 2005-09-20 09:55 ..
drwx--x--x  18 john john    4096 2005-09-20 09:54 zsh-4.2.5
-rw-------   1 john john    1468 2005-09-20 09:54 zsh_4.2.5-19_amd64.changes
-rw-------   1 john john 2119662 2005-09-20 09:54 zsh_4.2.5-19_amd64.deb
-rw-------   1 john john  338405 2005-09-20 09:54 zsh_4.2.5-19.diff.gz
-rw-------   1 john john     675 2005-09-20 09:54 zsh_4.2.5-19.dsc
-rw-------   1 john john 2624122 2005-09-20 09:54 zsh_4.2.5.orig.tar.gz
-rw-------   1 john john  672170 2005-09-20 09:54 zsh-doc_4.2.5-19_all.deb
-rw-------   1 john john  865214 2005-09-20 09:54 zsh-static_4.2.5-19_amd64.deb
/tmp/test/pkgs %

This only seems to occur in specific directories, though I have not yet
determined whath distinguishes them from others (/usr/local/bin is fine though
/usr/local/lib/site_perl isn't).

The problem is not limited to zsh, though I haven't done a complete test
of all programs for example (running from tcsh):
/tmp/test/pkgs/zsh-4.2.5 > dpkg-buildpackage 
dpkg-parsechangelog: failure: tail of debian/changelog died from signal 11
dpkg-buildpackage: unable to determine source package is

Running as root, or through sudo, is sucessful.  The same with zsh and
the change directory issue.  

Has anyone experienced this before who can offer some help?

The likely course of action for me is to go back to the 32-bit debian or
to try another 64bit distribution.  However, I am willing to try to
diagnose this for a little while.

Thanks,
John