Make cold exits immortal safely

Author: markshannon

Include/internal/pycore_object.h

@@ -126,6 +126,7 @@ static inline void _Py_RefcntAdd(PyObject* op, Py_ssize_t n)
 #define _Py_RefcntAdd(op, n) _Py_RefcntAdd(_PyObject_CAST(op), n)
 
 extern void _Py_SetImmortal(PyObject *op);
+extern void _Py_SetImmortalUntracked(PyObject *op);
 
 // Makes an immortal object mortal again with the specified refcnt. Should only
 // be used during runtime finalization.

Objects/object.c

@@ -2402,11 +2402,8 @@ _Py_NewReferenceNoTotal(PyObject *op)
 }
 
 void
-_Py_SetImmortal(PyObject *op)
+_Py_SetImmortalUntracked(PyObject *op)
 {
-    if (PyObject_IS_GC(op) && _PyObject_GC_IS_TRACKED(op)) {
-        _PyObject_GC_UNTRACK(op);
-    }
 #ifdef Py_GIL_DISABLED
     op->ob_tid = _Py_UNOWNED_TID;
     op->ob_ref_local = _Py_IMMORTAL_REFCNT_LOCAL;
@@ -2416,6 +2413,15 @@ _Py_SetImmortal(PyObject *op)
 #endif
 }
 
+void
+_Py_SetImmortal(PyObject *op)
+{
+    if (PyObject_IS_GC(op) && _PyObject_GC_IS_TRACKED(op)) {
+        _PyObject_GC_UNTRACK(op);
+    }
+    _Py_SetImmortalUntracked(op);
+}
+
 void
 _Py_ResurrectReference(PyObject *op)
 {

Python/optimizer.c

@@ -969,7 +969,7 @@ make_executor_from_uops(_PyUOpInstruction *buffer, const _PyBloomFilter *depende
 static int
 init_cold_exit_executor(_PyExecutorObject *executor, int oparg)
 {
-    _Py_SetImmortal((PyObject *)executor);
+    _Py_SetImmortalUntracked((PyObject *)executor);
     Py_SET_TYPE(executor, &_PyUOpExecutor_Type);
     executor->trace = (_PyUOpInstruction *)executor->exits;
     executor->code_size = 1;