bpo-9263: _PyObject_Dump() detects freed memory #10061
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_PyObject_Dump() now uses an heuristic to check if the object memory has been freed: log "<freed object>" 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.
matrixise
reviewed
Oct 23, 2018
The heuristic is not reliable and it shouldn't be used directly. I chose to not expose it. It's very new, I would prefer to use it during one release to see if it's reliable enough or not, to decide to make it more visible. Note: Private functions are not documented (currently). |
vstinner
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Nov 22, 2018
…10662) * bpo-9263: _PyObject_Dump() detects freed memory (GH-10061) _PyObject_Dump() now uses an heuristic to check if the object memory has been freed: log "<freed object>" 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) * bpo-9263: Fix _PyObject_Dump() for freed object (#10661) 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)
vstinner
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Nov 22, 2018
…GH-10663) * bpo-9263: _PyObject_Dump() detects freed memory (GH-10061) _PyObject_Dump() now uses an heuristic to check if the object memory has been freed: log "<freed object>" 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) * bpo-9263: Fix _PyObject_Dump() for freed object (#10661) 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)
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That's my old friend https://bugs.python.org/issue34513 |
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_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.
https://bugs.python.org/issue9263