[Python-Dev] cpython: threading.RLock._acquire_restore() now raises a TypeError instead of a

[Victor Stinner]

2014/1/3 Victor Stinner <victor.stinner at gmail.com>:
> 2014/1/3 Serhiy Storchaka <storchaka at gmail.com>:
>>> -    if (!PyArg_ParseTuple(arg, "kl:_acquire_restore", &count, &owner))
>>> +    if (!PyArg_ParseTuple(args, "(kl):_acquire_restore", &count, &owner))
>>>           return NULL;
>>
>> Please don't use "(...)" in PyArg_ParseTuple, it is dangerous (see issue6083
>> [1]).
>>
>> [1] http://bugs.python.org/issue6083
>
> ...
>
> Would it be possible to handle this issue in Argument Clinic, split
> the function in two parts: a function to parse arguments and keep
> references, and the implementation function?

Oh, I found a similiar issue but different issue:

>>> import resource
>>> resource.prlimit(0, resource.RLIMIT_CORE, "\u0100\u0101")
Erreur de segmentation (core dumped)

This new function uses the following code to parse arguments:

    if (!PyArg_ParseTuple(args, _Py_PARSE_PID "i|(OO):prlimit",
                          &pid, &resource, &curobj, &maxobj))
        return NULL;

"\u0100\u0101" is seen as a sequence. Getting an item of this sequence
creates a new substring of 1 character, but the substring has only 1
reference, and the only reference is immediatly removed, so the
borrowed reference (curobj and maxobj) become immediatly dangling
pointers...

Victor