[Python-Dev] Newly Built Python3 Binary Throws Segfault

[Cyd Haselton]

Absolutely.  Good thing I have addr2line on device

/bld/python/Python-3.4.2 $ addr2line -C -f -e /lib/libpython3.4m.so.1.0 0008bbc8
_PyMem_RawStrdup
/bld/python/Python-3.4.2/Objects/obmalloc.c:323
/bld/python/Python-3.4.2 $



On Thu, Jan 29, 2015 at 8:26 PM, Ryan <rymg19 at gmail.com> wrote:
> Could you try the steps at http://stackoverflow.com/a/11369475/2097780? They
> allow you to get a better idea of where libc is crashing.
>
> Cyd Haselton <chaselton at gmail.com> wrote:
>>
>> Managed to get this out of logcat:
>> F(11914) Fatal signal 11 (SIGSEGV) at 0x00000000 (code=1), thread
>> 11914 (python)  (libc)
>>
>> [ 01-29 19:30:55.855 23373:23373 F/libc     ]
>> Fatal signal 11 (SIGSEGV) at 0x00000000 (code=1), thread 23373 (python)
>>
>> Less detail than strace but it seems to be that python is segfaulting
>> libc...
>>
>> On Wed, Jan 28, 2015 at 11:23 AM, Ryan Gonzalez <rymg19 at gmail.com> wrote:
>>>
>>>  On Wed, Jan 28, 2015 at 10:43 AM, Guido van Rossum <guido at python.org>
>>> wrote:
>>>>
>>>>
>>>>  What I see in the strace:
>>>>
>>>>  ... load libpython3.4m.so.1.0
>>>>  ... load libm
>>>>  ... open /dev/__properties__ and do something to it
>>>> (what?)
>>>>  ... get current time
>>>>  ... allocate memory
>>>>  ... getuid
>>>>  ... segfault
>>>>
>>>>  That's not a lot to go on, but it doesn't look as if it has started to
>>>>  load modules yet.
>>>>
>>>>  Does /dev/__properties__ ring a bell? Not to me.
>>>
>>>
>>>
>>>
>>> https://android.googlesource.com/platform/system/core/+/tools_r22/init/property_service.c
>>>  is the code that works with that file.
>>>
>>>  This explains it a bit (slides 24-29). Looks like something to do with
>>>  interprocess communication. Likely has nothing to do with Python itself.
>>>
>>>  Maybe this would be useful?
>>>
>>>>
>>>>  That stack trace would be really helpful.
>>>>
>>>>  On Wed, Jan 28, 2015 at 8:34 AM, Cyd Haselton <chaselton at gmail.com>
>>>> wrote:
>>>>>
>>>>>
>>>>>  Apologies...I'm not sure what a stack track is, but I do have the
>>>>>  strace.  Nearest I can tell, it happens due to an open call, though I
>>>>>  am probably wrong.
>>>>>  Attaching the strace output to this email.  I'm going to head back to
>>>>>  the documentation and to back out of some Android-related changes in
>>>>>  _localemodule.c
>>>>>
>>>>>  On Wed, Jan 28, 2015 at 9:43 AM, Guido van Rossum <guido at python.org>
>>>>>  wrote:
>>>>>>
>>>>>>  There could be a million differences relevant (unicode, ints, ...).
>>>>>>  Perhaps
>>>>>>  the importlib bootstrap is failing. Perhaps the dynamic loading code
>>>>>>  changed. Did you get a stack track? (IIRC strace shows a syscall
>>>>>> trace
>>>>>>  --
>>>>>>  also useful, but doesn't tell you precisely how
>>>>>> it segfaulted.)
>>>>>>
>>>>>>  On Wed, Jan 28, 2015 at 6:43 AM, Cyd Haselton <chaselton at gmail.com>
>>>>>>  wrote:
>>>>>>>
>>>>>>>
>>>>>>>  All,
>>>>>>>  I recently ditched my attempts to port Python 2.7.8 to Android in
>>>>>>>  favor of Python 3.4.2.  Unfortunately, after using the same
>>>>>>> configure
>>>>>>>  options in the same environment, and modifying the setup.py as
>>>>>>> needed,
>>>>>>>  the newly built binary throws a segfault when the
>>>>>>> generate-posix-vars
>>>>>>>  portion of the build is reached...and when it is run as well (i.e.
>>>>>>>  ./python --help, ./python -E -S -m sysconfig, or similar)
>>>>>>>
>>>>>>>  I took a strace of ./python, however I'm a bit lost when reviewing
>>>>>>> it.
>>>>>>>  Any ideas as to what may be going on...i.e. why Python 2.7 works but
>>>>>>>  3.x throws a segfault?
>>>>>>>
>>>>>>>  Thanks in advance,
>>>>>>>  Cyd
>>>>>>> ________________________________
>>>>>>>
>>>>>>>  Python-Dev mailing list
>>>>>>>
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>>>>>>>
>>>>>>> https://mail.python.org/mailman/options/python-dev/guido%40python.org
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>  --
>>>>>>  --Guido van Rossum (python.org/~guido)
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>  --
>>>>  --Guido van Rossum (python.org/~guido)
>>>>
>>>> ________________________________
>>>>
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>>>
>>>
>>>
>>>
>>>
>>>  --
>>>  Ryan
>>>  If anybody ever asks me why I prefer C++ to C, my answer will be simple:
>>>  "It's becauseslejfp23(@#Q*(E*EIdc-SEGFAULT. Wait, I don't think that was
>>>  nul-terminated."
>>>  Personal reality distortion fields are immune to contradictory evidence.
>>> -
>>>  srean
>>>  Check out my website: http://kirbyfan64.github.io/
>
>
> --
> Sent from my Android phone with K-9 Mail. Please excuse my brevity.
> Check out my website: http://kirbyfan64.github.io/