From f14e9f91544b526a920724dd2b3e2d88d1e28463 Mon Sep 17 00:00:00 2001 From: mpage Date: Thu, 25 Apr 2024 08:31:57 -0700 Subject: [PATCH] gh-117657: Fix data race in `_Py_IsImmortal` (#118261) The load of `ob_ref_local races with stores. Using a relaxed load is sufficient; stores to the field are relaxed. --- Include/object.h | 3 ++- Tools/tsan/suppressions_free_threading.txt | 1 - 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/Include/object.h b/Include/object.h index ffcacf1a3ef..5aaf11c5194 100644 --- a/Include/object.h +++ b/Include/object.h @@ -349,7 +349,8 @@ static inline Py_ssize_t Py_SIZE(PyObject *ob) { static inline Py_ALWAYS_INLINE int _Py_IsImmortal(PyObject *op) { #if defined(Py_GIL_DISABLED) - return (op->ob_ref_local == _Py_IMMORTAL_REFCNT_LOCAL); + return (_Py_atomic_load_uint32_relaxed(&op->ob_ref_local) == + _Py_IMMORTAL_REFCNT_LOCAL); #elif SIZEOF_VOID_P > 4 return (_Py_CAST(PY_INT32_T, op->ob_refcnt) < 0); #else diff --git a/Tools/tsan/suppressions_free_threading.txt b/Tools/tsan/suppressions_free_threading.txt index 1408103ba80..6ceb275925c 100644 --- a/Tools/tsan/suppressions_free_threading.txt +++ b/Tools/tsan/suppressions_free_threading.txt @@ -14,7 +14,6 @@ race:set_allocator_unlocked race:_add_to_weak_set race:_in_weak_set race:_mi_heap_delayed_free_partial -race:_Py_IsImmortal race:_Py_IsOwnedByCurrentThread race:_PyEval_EvalFrameDefault race:_PyFunction_SetVersion