[mod_python] Help about apache mod_python Segmentation fault

auther_bin auther_bin at 21cn.com
Mon Mar 3 23:42:01 EST 2008


Hi, Graham Dumpleton!

¡¡¡¡For I am in an embeded system with chroot. And I don't know clearly why python looking for the libs in /bin/lib ( find in strace, it first looking into /bin/lib/python2.5 ) so I placed it there. Let me try if I move it into /usr/local/lib ....

======= 2008-03-04 wrote =======

>On 04/03/2008, auther_bin <auther_bin at 21cn.com> wrote:
>> Hi, Graham Dumpleton!
>>
>>  Thanks for your help first, but the problem is still there. here is my testing steps:
>>
>>  I read carefully of the URL you give me: http://code.google.com/p/modwsgi/wiki/InstallationIssues
>>  and re-compiling the python2.5 --enable-shared, and get python libpython2.5.so install, when I testing python like:
>>
>>  =====================================================================
>>  # python
>>  Python 2.5 (r25:51908, Mar  4 2008, 08:56:31)
>>  [GCC 3.4.4] on linux2
>>  Type "help", "copyright", "credits" or "license" for more information.
>>  >>> testi=1
>>  >>> if testi==1:
>>  ...  print "hello test"
>>  ...
>>  hello test
>>  >>> <ctl-d>
>>  # ldd python
>>                 libpython2.5.so.1.0 => not found
>
>Where is your libpython2.5.so installed? Not your sylimk, but what the
>symlink points at.
>
>>         libpthread.so.0 => /lib/libpthread.so.0 (0x40023000)
>>         libdl.so.0 => not found
>>         libutil.so.0 => not found
>>         libm.so.0 => not found
>>         libc.so.0 => not found
>
>Your operating system installation is severely crippled or broken if
>these standard libraries cannot be found. Are you stuck with using
>uClibc or can you use something else?
>
>>         libc.so.6 => /lib/libc.so.6 (0x40076000)
>>         /lib/ld-linux.so.2 => /lib/ld-linux.so.2 (0x40000000)
>>  # ## for the libs is installed in an embeded path so some of them could not be found
>>  # ls -F /bin/lib/python2.5/config
>
>Why is this under /bin/lib? That isn't the standard location for this
>sort off stuff and if libpython2.5.so is in /bin/lib it will not be
>found.
>
>Graham
>
>>  Makefile         config.c         libpython2.5.a   python.o
>>  Setup            config.c.in      [email protected]
>>  Setup.local      install-sh*      makesetup*
>>  =====================================================================
>>
>>  when I run "httpd -X" it's still gives an Segmentation fault :(
>>  anything else could be found about this crash?
>>  or I give you an ssh login to my host :)
>>
>>  ======= 2008-03-03 wrote =======
>>
>>
>>  >In gdb, instead of 'where', try:
>>  >
>>  >  thread apply all bt
>>  >
>>  >in case gdb isn't throwing you into the correct thread context.
>>  >
>>  >BTW, does the Python on the environment that crashes provide a shared
>>  >library? For what I am talking about see:
>>  >
>>  >  http://code.google.com/p/modwsgi/wiki/InstallationIssues
>>  >
>>  >This is documentation from mod_wsgi but same problems apply to mod_python.
>>  >
>>  >Graham
>>  >
>>  >On 03/03/2008, auther_bin <auther_bin at 21cn.com> wrote:
>>  >>
>>  >>
>>  >> Hi Graham Dumpleton,
>>  >>
>>  >> And, when I debug in RedHat9 and my embeded
>>  >> envirenment, the main process goes
>>  >> different!?
>>  >>
>>  >> in Redhat9, run like:
>>  >>
>>  >>
>>  >> (gdb) b main
>>  >> Breakpoint 1 at 0x8067a40: file main.c, line 438.
>>  >> (gdb) run -X
>>  >> Starting program: /usr/local/apache2/bin/httpd -X
>>  >> [New Thread 1076592288 (LWP 1049)]
>>  >> [Switching to Thread 1076592288 (LWP 1049)]
>>  >>
>>  >> Breakpoint 1, main (argc=134642240, argv=0x2) at main.c:438
>>  >> 438     {
>>  >> (gdb) n
>>  >> 272         stat = apr_app_initialize(argc, argv, NULL);
>>  >>
>>  >> and in my embeded system runs like:
>>  >>
>>  >>
>>  >>
>>  >> Breakpoint 1, main (argc=2, argv=0xbffff294)
>>  >>     at
>>  >> /usr/src/build/snapgear/user/apache/server/main.c:441
>>  >> 441         int configtestonly = 0;
>>  >> (gdb) n
>>  >> 442         const char *confname = SERVER_CONFIG_FILE;
>>  >>
>>  >>
>>  >>
>>  >> it seems that, the hosting system doing something for init before the main
>>  >> function run, but embeded system do not?
>>  >>
>>  >> I thinks is here somthing wrong? or there should be some compiling
>>  >> parameters I missed?
>>  >>
>>  >> ======= 2008-02-27 wrote: =======
>>  >>
>>  >>
>>  >> >On 27/02/2008, auther_bin  <auther_bin at 21cn.com > wrote:
>>  >> > > Dear friends,
>>  >> > >
>>  >> > >         When I compiling the apache python mod_python
>>  >> and install it into my uClibc
>>  >> envirentment,
>>  >> but when I
>>  >> > >  runing httpd -X, send a very little request with
>>  >> index.html it crashed. after some debuging work,
>>  >> I find there should be something wrong in mod_python.c
>>  >> line(about 1561) which looks like:
>>  >> > >  --------------------------------- with my debug
>>  >> printing :) ------------------------
>>  >> > >  printf("JJJJJJJJ %s - > python_handler\n", phase);
>>  >> > >  printf("JJJJJJJJ %x[%d]\n", &req- >per_dir_config,
>>  >> (&python_module)- >module_index);
>>  >> > >     /* get configuration */
>>  >> > >     conf = (py_config *) ap_get_module_config(req-
>>  >> >per_dir_config,
>>  >> > >
>>  >> &python_module);
>>  >> > >  printf("JJJJJJJJ a %s conf=%x - > python_handler\n",
>>  >> phase,conf);
>>  >> > >  .............
>>  >> > >  ------------------------------ end source
>>  >> --------------------------------------
>>  >> > >
>>  >> > >  I guess that, there should be a regester error in
>>  >> it. with some debug message I print:
>>  >> > >  ------------- printing -------------------------------
>>  >> > >  JJJJJJJJJ PythonPostReadRequestHandler
>>  >> > >  JJJJJJJJ PythonInitHandler - > python_handler
>>  >> > >  JJJJJJJJ 820a544[29]
>>  >> > >  Segmentation fault
>>  >> > >  ------------- end printing ---------------------------
>>  >> > >
>>  >> > >  any advices pls?
>>  >> >
>>  >> >Unfortunately that doesn't help much.
>>  >> >
>>  >> >You need a stack trace to show the true location
>>  >> in code.
>>  >> >
>>  >> >Use procedure documented in section 'Debugging
>>  >> Crashes With GDB' of:
>>  >> >
>>  >> >
>>  >> http://code.google.com/p/modwsgi/wiki/DebuggingTechniques
>>  >> >
>>  >> >to run up httpd inside of gdb and get a stack trace
>>  >> of where crash is occurring.
>>  >> >
>>  >> >This documentation is for mod_wgsi, but same procedure
>>  >> used for mod_python.
>>  >> >
>>  >> >There is a similar procedure documented on Apache
>>  >> site, but can't
>>  >> >remember where.
>>  >> >
>>  >> >Graham
>>  >> >
>>  >> >
>>  >> >__________ NOD32 2906 (20080227) Information
>>  >> __________
>>  >> >
>>  >> >This message was checked by NOD32 antivirus system.
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>>  >> >
>>  >> >
>>  >>
>>  >> = = = = = = = = = = = = = = = = = = = =
>>  >>
>>  >>
>>  >>                     ÖÂ
>>  >> Àñ£¡
>>  >> 2008-03-03
>>  >>
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>>
>>                     ÖÂ
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>>                 2008-03-04
>>
>>
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		2008-03-04 



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