[Stackless] Python25.dll crashing on Windows 7

Richard Tew richard.m.tew at gmail.com
Fri Aug 7 10:28:49 CEST 2009


On Fri, Aug 7, 2009 at 9:38 AM, Colleen Williams (Smart Marketing &
Events)<v-collw at microsoft.com> wrote:
> Python25.dll is crashing consistently on all Windows 7 builds. You may
> already be aware of the issue but it appears the crash is related to a
> manipulation of stacks. The app manipulates the C stack directly for its own
> implementation of lightweight threads. This means a Stack Buffer Overrrun
> could be coming from almost anything it’s doing. This is causing almost 4000
> crashes per day since mid-June. The version we’re seeing crashing the most
> is 2.5.4150.1013.

I've been working on Stackless Python 2.5.3 today, and interestingly,
I get a stack overflow crash with it.  This crash exists in the
released Python 2.5.3 code I am working from.  It is pretty much a
variant of an old Python bug (http://bugs.python.org/issue2286).

The call stack looks something like this:
>	python25_d.dll!_PyObject_GC_New(_typeobject * tp=0x104833e0)  Line 1345 + 0x9 bytes	C
 	python25_d.dll!PyDict_New()  Line 220 + 0xa bytes	C
 	python25_d.dll!r_object(WFILE * p=0x0021360c)  Line 835 + 0x5 bytes	C
 	python25_d.dll!r_object(WFILE * p=0x0021360c)  Line 842 + 0x9 bytes	C
        .........

Now, this was encountered with VC 2008 express.  The official compiler
for the 2.5 branches of Python in order to maintain compatibility with
built extensions is actually Visual Studio.NET 2003, which I only have
the free toolkit of, and under that the crash is not encountered.

Again, this is not a Stackless problem, but going by my experience
with the crash today, if I had to guess where the thousands of
failures for Python 2.5.4 were coming from, I would assume someone had
compiled it with VS 2008.  Perhaps a buildbot that was constantly
rerunning the unit tests, or snakebite (http://snakebite.org).

Anyway, just some further thoughts.

Cheers,
Richard.




More information about the Stackless mailing list