New submission from STINNER Victor <vstin...@python.org>:
In bpo-38392, I modified PyObject_GC_Track() to ensure that the object newly tracked is valid: call its traverse function. => commit 1b1845569539db5c1a6948a5d32daea381f1e35f I propose to now also attempt to implement the same check in _PyObject_GC_TRACK() which is part of the internal C API. PyType_GenericAlloc() allocates memory for a type allocated on the heap... and then immediately track it in the GC. Problem: this type is not initialized yet, all fields are set to zero. Calling type_traverse() at this point fails with an assertion error: --- Objects/typeobject.c:3570: type_traverse: Assertion failed: type_traverse() called on non-heap type '(null)' Enable tracemalloc to get the memory block allocation traceback object address : 0x840860 object refcount : 1 object type : 0x7e0900 object type name: type object repr : --- By the way, Python crash in _PyObject_Dump() on PyObject_Repr() call: type_repr() crash when accessing type->tp_name which is NULL. type_call() should only track the newly created type when it's fully initialized. Try attached track.patch to reproduce the crash. ---------- components: Interpreter Core files: track.patch keywords: patch messages: 365515 nosy: vstinner priority: normal severity: normal status: open title: Modify _PyObject_GC_TRACK() to ensure that newly tracked object is valid type: enhancement versions: Python 3.9 Added file: https://bugs.python.org/file49021/track.patch _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue40142> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
