Re: Re: Upgrading expat for apache question

A segmentation fault can occur for other reasons. If it is happening
when you use LDAP, it could be a conflict in versions of LDAP
libraries being used by Apache or PHP and Python LDAP module.

You should use the 'ldd' command to determine what LDAP shared library
is used by mod_authnz_ldap and compare that to the LDAP library being
used by the C extension module component of the Python module you are
using to access LDAP. Similarly find any PHP extension modules which
use LDAP and look at those.

If mod_authnz_ldap is loaded into Apache and you don't need it, then
don't load it and see if problem goes away. Also try not loading PHP
if it is being loaded. Narrow down which is in conflict.

As far as I remember, Apache itself doesn't link to LDAP library and
even possible that mod_authnz_ldap uses an internal LDAP library
rather than linking external library. All the same even use ldd on
Apache binary itself to see which LDAP library may be linked.

Graham

On 10 March 2010 04:18, wayne collier <[email protected]> wrote:
> Okay I guess I will look else where. However, I keep getting segmentati=
on
> faults when try an execute the ldap command
>
> t=3Dl.simple_bind_s(dn,pw). It is only line of code that crashes. If th=
e have
> the classic expat problem, would that mean I would get a segmentation
> fault problem from the start.  Also, ldap script works okay as a stand =
alone
> script. Thanks.
>
> Wayne
>
>
> Graham Dumpleton wrote:
>
> That is not your problem, quoting:
>
> http://code.google.com/p/modwsgi/wiki/IssuesWithExpatLibrary
>
> which is more up to date in respect of this issue, even if the
> mod_wsgi variant of that document:
>
> """Note that this only applies to Python versions prior to Python 2.5.
> >From Python 2.5 onwards, the copy of the "expat" library bundled in
> with Python is name space prefixed, thereby avoid name clashes with an
> "expat" library which has previously been loaded."""
>
> You are using Python 2.6, so you cannot be affected by this problem.
>
> Graham
>
> On 9 March 2010 05:54, wayne collier <[email protected]> wrote:
>
>
> Hello all. I need some help solving the dreaded segmentation fault that=
 has
> cropped several time on this board. I have read the link
> http://www.dscpl.com.au/wiki/ModPython/Articles/ExpatCausingApacheCrash=
 and
> followed the step and have uncovered the following.
>
>
>
>
> ldd=A0=A0=A0 /usr/local/httpd-2.2.11/bin/httpd | grep expat
>
>
> =A0=A0=A0 libexpat.so.0 =3D> /lib/libexpat.so.0 (0x00d70000)
>
>
>
> strings /lib/libexpat.so.0=A0 | grep expat_
>
>
> expat_1.95.8
>
>
>
> =A0 ps aux | grep http | head -3
>
>
> webuser=A0 14986=A0 0.0=A0 2.1=A0 54236 19048 ?=A0=A0=A0=A0=A0=A0=A0 S=A0=
=A0=A0 Mar04=A0=A0 0:01
> /usr/local/httpd-2.2.11/bin/httpd -d /usr/local/httpd-2.2.11 -f
> /usr/local/httpd-2.2.11/conf/httpd.conf
> webuser=A0 14987=A0 0.0=A0 3.2 144128 29540 ?=A0=A0=A0=A0=A0=A0=A0 S=A0=
=A0=A0 Mar04=A0=A0 0:01
> /usr/local/httpd-2.2.11/bin/httpd -d /usr/local/httpd-2.2.11 -f
> /usr/local/httpd-2.2.11/conf/httpd.conf
> webuser=A0 14998=A0 0.0=A0 3.2 144212 29660 ?=A0=A0=A0=A0=A0=A0=A0 S=A0=
=A0=A0 Mar04=A0=A0 0:01
> /usr/local/httpd-2.2.11/bin/httpd -d /usr/local/httpd-2.2.11 -f
> /usr/local/httpd-2.2.11/conf/httpd.conf
>
>
>
> =A0 /usr/sbin/lsof -p 14986 | grep expat
>
>
> httpd=A0=A0 14986 webuser=A0 mem=A0=A0=A0 REG=A0=A0=A0=A0 3,5=A0=A0 572=
313=A0 972637
> /opt/Python/lib/python2.6/lib-dynload/pyexpat.so
> httpd=A0=A0 14986 webuser=A0 mem=A0=A0=A0 REG=A0=A0=A0=A0 3,5=A0=A0 133=
120 1883791
> /lib/libexpat.so.0.5.0
>
> I am not sure why I get 2 shared libaries here.
>
>
>
> =A0 strings=A0 /lib/libexpat.so.0.5.0 | grep expat_
>
>
> expat_1.95.8
>
>
>
>
> strings /opt/Python/lib/python2.6/lib-dynload/pyexpat.so | grep expat_
>
>
> pyexpat.expat_CAPI 1.0
> expat_CAPI
> expat_2.0.0
>
>
>
>
> import pyexpat
> pyexpat.version_info
>
>
> (2, 0, 0)
>
>
> So it seems like I need get expat_1.95.8 apache is using up to expat_2.=
0.0.
> Can I simply try replacing the 1.95.8 library with 2.0.0. Or do I have
> recompile with Apache? If I do recompile I need to recompile apache wit=
h
> mod_python as well?
>
>
>
>
>
>
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