[3.6] bpo-9263: _PyObject_Dump() detects freed memory (GH-10061) (GH-10662) by vstinner · Pull Request #10663 · python/cpython (original) (raw)

_PyObject_Dump() now uses an heuristic to check if the object memory
has been freed: log "" in that case.

The heuristic rely on the debug hooks on Python memory allocators
which fills the memory with DEADBYTE (0xDB) when memory is
deallocated. Use PYTHONMALLOC=debug to always enable these debug
hooks.

(cherry picked from commit 82af0b6)

If _PyObject_Dump() detects that the object is freed, don't try to
dump it (exit immediately).

Enhance also _PyObject_IsFreed(): it now detects if the pointer
itself looks like freed memory.

(cherry picked from commit 2cf5d32)
(cherry picked from commit 95036ea)

https://bugs.python.org/issue9263