As of 2.5.3, calling accept() on an AF_UNIX socket fails on arm. The
following exception occurs:

SystemError: Negative size passed to PyString_FromStringAndSize

I have attached a test program that creates a socket and connects to it.
It works on x86-64 but fails on armeb (gcc 4.1.2).

This failure has been noted a few times by the arm buildbot too:
http://archives.free.net.ph/message/20081012.121034.89069ea2.en.html

It's already fixed in 2.6.x in rev 60214. I applied the same change to
2.5.4 and the problem was resolved.