Re: Apache2, mod_python and nss_ldap: Coredump...

From: Johan Ström (johan_at_stromnet.org)
Date: 11/10/05

  • Next message: Will Saxon: "RE: Anyone having problems with xorg 6.8.2 on 6.0-R" 
    Date: Thu, 10 Nov 2005 14:51:23 +0100
To: freebsd-stable@freebsd.org, users@httpd.apache.org, mod_python@modpython.org

    On 10 nov 2005, at 12.54, Johan Ström wrote:

    > On 10 nov 2005, at 00.25, Brian Fundakowski Feldman wrote:
    >
    >> On Wed, Nov 09, 2005 at 10:20:26AM +0100, Johan Ström wrote:
    >>> Hi
    >>>
    >>> I got a new 6.0-STABLE box. Rebuilt kernel and world 2 hours ago
    >>> (against RELENG_6), so it should be pretty new.
    >>>
    >>> Im trying to have apache 2.0.55, mod_python 3.1.4 and nss_ldap 239,
    >>> all the latest from ports.
    >>> The problem I have is this: If i have LoadModule python_module
    >>> libexec/apache2/mod_python.so in my httpd.conf, and at the same time
    >>> have either
    >>> "group: files ldap" and/or "passwd: files ldap" in my nsswitch.conf,
    >>> i get Segfaults. Example:
    >>>
    >>> root@elfi2:~$ apachectl configtest
    >>> Syntax OK
    >>> Segmentation fault (core dumped)
    >>> root@elfi2:~$
    >>>
    >>> However, apache itself is running fine, even using mod_python.
    >>> If i remove either the LoadModule or both the ldap-entrys in
    >>> nsswitch, the segfaults dissappear. I've compiled httpd with debug
    >>> symbols, and this is what I found with gdb (httpd -t is same as
    >>> apachectl configtest):
    >>> [...]
    >>> (gdb) where
    >>> #0 0x00000000 in ?? ()
    >>> #1 0x28be6744 in ?? () from /usr/local/lib/nss_ldap.so.1
    >>> #2 0x28bf2200 in ?? () from /usr/local/lib/nss_ldap.so.1
    >>
    >> Can you try making sure that nss_ldap gets built and linked with -g,
    >> and is not stripped, so that all symbols and debug info are preserved
    >> as well? Looks to be atexit(3)-related, from here, but the symbols
    >> should clear things up.
    >
    > Hi, thanks for the answer!
    > I *think* i got the nss_ldap.so to not be strip'd, at least I cant
    > find any call in the port Makefile or the sources makefile/
    > configure stuff that would strip it. Same result as before, no new
    > symbols.. Strange? I'm compiling with -g and -O0..
    >
    > However, I've noticed one thing, if I run gdb httpd and then run -
    > t, I get this:
    >
    > root@elfi2:~$ gdb httpd
    > GNU gdb 6.1.1 [FreeBSD]
    > Copyright 2004 Free Software Foundation, Inc.
    > GDB is free software, covered by the GNU General Public License,
    > and you are
    > welcome to change it and/or distribute copies of it under certain
    > conditions.
    > Type "show copying" to see the conditions.
    > There is absolutely no warranty for GDB. Type "show warranty" for
    > details.
    > This GDB was configured as "i386-marcel-freebsd"...
    > (gdb) run -t
    > Starting program: /usr/local/sbin/httpd -t
    > warning: Unable to get location for thread creation breakpoint:
    > generic error
    > [New LWP 100128]
    > [New Thread 0x80fa000 (LWP 100128)]
    > wWarning: DocumentRoot [/usr/local/nagios/share] does not exist
    > Syntax OK
    > [New LWP 100128]
    >
    > Program received signal SIGTRAP, Trace/breakpoint trap.
    > [Switching to LWP 100128]
    > 0x28bce277 in pthread_testcancel () from /usr/lib/libpthread.so.2
    > (gdb) where
    > #0 0x28bce277 in pthread_testcancel () from /usr/lib/libpthread.so.2
    > Error accessing memory address 0x28bcd7a8: Bad address.
    > (gdb)
    >
    >
    > Thats the pthread_cancel thing I was talking about before...
    > However, if I do run httpd -t and then check the dump with gdb
    > httpd -c httpd.core, I get the same as first posted.
    >
    > Did the test over and over again, got the same pthread_cancel
    > error, reading the same memory address, re-ran httpd -t a couple of
    > times and seems I only get these pthread_cancel calls...
    >
    > Is there any way to check if a lib is strip'd/got debug symbols or
    > not?
    >
    > Thanks
    > Johan

    Okay, some news here then.. Thanks to David Adam I used file to
    determine if it was striped or not, seems it was.. So now I've fixed
    it, not striped anymore (the install command striped it, i missed
    that)..
    New debug output then:

    (gdb) where
    #0 0x00000000 in ?? ()
    #1 0x28bd9730 in __do_global_dtors_aux () from /usr/local/lib/
    nss_ldap.so.1
    #2 0x28be2984 in _fini () from /usr/local/lib/nss_ldap.so.1
    #3 0x280b5018 in tls_dtv_generation () from /libexec/ld-elf.so.1
    #4 0x280b63d8 in ?? () from /libexec/ld-elf.so.1
    #5 0xbfbfe628 in ?? ()
    #6 0x2809d076 in elf_hash () from /libexec/ld-elf.so.1
    #7 0x2809f958 in dlclose () from /libexec/ld-elf.so.1
    #8 0x284b064c in _nsdbtaddsrc () from /lib/libc.so.6
    #9 0x284b020f in endhostent () from /lib/libc.so.6
    #10 0x284b06cc in _nsdbtaddsrc () from /lib/libc.so.6
    #11 0x284cf35f in __cxa_finalize () from /lib/libc.so.6
    #12 0x284cef9a in exit () from /lib/libc.so.6
    #13 0x0806b746 in destroy_and_exit_process (process=0x80a4090,
    process_exit_value=0) at main.c:216
    #14 0x0806c0fe in main (argc=2, argv=0xbfbfe838) at main.c:565

    (Also sent this to the other lists this thread is discussed in).

    Johan

    _______________________________________________
    freebsd-stable@freebsd.org mailing list
    http://lists.freebsd.org/mailman/listinfo/freebsd-stable
    To unsubscribe, send any mail to "freebsd-stable-unsubscribe@freebsd.org"

  • Next message: Will Saxon: "RE: Anyone having problems with xorg 6.8.2 on 6.0-R"

    Relevant Pages