[ZOO-Discuss] ZOO and segfaults

[James.Sewell at lisasoft.com]

Hey all,

After having worked out my previous problem (segfaults caused by an older version of CURL) I am faced with a new problem. I am now getting segfaults caused by  calls to free(). I get these problems when trying to run an Execute (I am testing with the python hello world at the moment).

A portion of the backtrace when debugging with gdb is below. It looks like calling free on python_path is the culprit.

*** glibc detected *** ./zoo_loader_capture: free(): invalid pointer: 0x000000000042515b ***
..
#4  0x00007ffff4c5be53 in free () from /lib/libc.so.6
No symbol table info available.
#5  0x00000000004117a3 in zoo_python_support (main_conf=<value optimised out>, request=0x631830, s=0x642150,
    real_inputs=<value optimised out>, real_outputs=0x7fffffff0820) at service_internal_python.c:178
        m = 0x632e30
        inputs = 0x651a60
        outputs = <value optimised out>
        tmp = <value optimised out>
        python_path = 0x42515b "."
        pModule = <value optimised out>
        pFunc = <value optimised out>
...

I have replicated this behavior on a CentOS 64bit machine and a Ubuntu 32bit machine.  The Java hello world runs fine, although it looks like some of the other processes (Distance etc..) have other problems causing segfaults for other reasons (a call to xmlNewText which seems to be in the libxml2 library in the case of Distance).

I can stop the free errors by setting MALLOC_CHECK_ =0, but that doesn't seem like a very good solution.

Can anyone shed any light on why this is happening? Has anyone managed a successful install of the subversion head which can process python? I can run all these requests from shilpa.media.osaka-cu.ac.jp/zoo/?, so I am also curious about what version this is running. I can see some differences on this box to the head (the Distance process only requires one Input as an example).

I am more than happy to provide more debugging output if anyone would like some.

Cheers,
James Sewell
LISAsoft Developer
+61 (3) 8680 3200 / +61 414 688 892


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