gh-101430: Update tracemalloc to handle presize properly.

python · Feb 9, 2023 · f3808bf · f3808bf
1 parent ecfd2d3
commit f3808bf
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Showing 2 changed files with 7 additions and 2 deletions.
diff --git a/Misc/NEWS.d/next/Core and Builtins/2023-02-10-01-15-57.gh-issue-101430.T3Gegb.rst b/Misc/NEWS.d/next/Core and Builtins/2023-02-10-01-15-57.gh-issue-101430.T3Gegb.rst
@@ -0,0 +1,2 @@
+Update :mod:`tracemalloc` to handle presize of object properly. Patch by
+Dong-hee Na.
diff --git a/Modules/_tracemalloc.c b/Modules/_tracemalloc.c
@@ -2,6 +2,7 @@
 #include "pycore_fileutils.h" // _Py_write_noraise()
 #include "pycore_gc.h" // PyGC_Head
 #include "pycore_hashtable.h" // _Py_hashtable_t
+#include "pycore_object.h" // _PyType_PreHeaderSize
 #include "pycore_pymem.h" // _Py_tracemalloc_config
 #include "pycore_runtime.h" // _Py_ID()
 #include "pycore_traceback.h"
@@ -1404,8 +1405,9 @@ _tracemalloc__get_object_traceback(PyObject *module, PyObject *obj)
  traceback_t *traceback;
 
  type = Py_TYPE(obj);
+ const size_t presize = _PyType_PreHeaderSize(type);
  if (PyType_IS_GC(type)) {
- ptr = (void *)((char *)obj - sizeof(PyGC_Head));
+ ptr = (void *)((char *)obj - presize);
  }
  else {
  ptr = (void *)obj;
@@ -1725,8 +1727,9 @@ _PyTraceMalloc_NewReference(PyObject *op)
 
  uintptr_t ptr;
  PyTypeObject *type = Py_TYPE(op);
+ const size_t presize = _PyType_PreHeaderSize(type);
  if (PyType_IS_GC(type)) {
- ptr = (uintptr_t)((char *)op - sizeof(PyGC_Head));
+ ptr = (uintptr_t)((char *)op - presize);
  }
  else {
  ptr = (uintptr_t)op;