From 0bcb1c25f7ba254bea9b744c7c5423cfebade3b3 Mon Sep 17 00:00:00 2001 From: Peter Bierma Date: Tue, 14 Oct 2025 21:46:43 -0400 Subject: [PATCH] Revert "gh-140067: Fix memory leak in sub-interpreter creation (#140111)" (#140140) This reverts commit 59547a251f7069dc6e08cb6082dd21872671e381. --- Include/internal/pycore_interp_structs.h | 6 ++++++ ...2025-10-14-17-07-37.gh-issue-140067.ID2gOm.rst | 1 - Python/pystate.c | 15 ++++++--------- 3 files changed, 12 insertions(+), 10 deletions(-) delete mode 100644 Misc/NEWS.d/next/Core_and_Builtins/2025-10-14-17-07-37.gh-issue-140067.ID2gOm.rst diff --git a/Include/internal/pycore_interp_structs.h b/Include/internal/pycore_interp_structs.h index badc97808c61..2124e76514f1 100644 --- a/Include/internal/pycore_interp_structs.h +++ b/Include/internal/pycore_interp_structs.h @@ -769,6 +769,12 @@ struct _is { * and should be placed at the beginning. */ struct _ceval_state ceval; + /* This structure is carefully allocated so that it's correctly aligned + * to avoid undefined behaviors during LOAD and STORE. The '_malloced' + * field stores the allocated pointer address that will later be freed. + */ + void *_malloced; + PyInterpreterState *next; int64_t id; diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2025-10-14-17-07-37.gh-issue-140067.ID2gOm.rst b/Misc/NEWS.d/next/Core_and_Builtins/2025-10-14-17-07-37.gh-issue-140067.ID2gOm.rst deleted file mode 100644 index 3c5a828101d9..000000000000 --- a/Misc/NEWS.d/next/Core_and_Builtins/2025-10-14-17-07-37.gh-issue-140067.ID2gOm.rst +++ /dev/null @@ -1 +0,0 @@ -Fix memory leak in sub-interpreter creation. diff --git a/Python/pystate.c b/Python/pystate.c index bf6e4e56e6df..dbed609f29aa 100644 --- a/Python/pystate.c +++ b/Python/pystate.c @@ -457,19 +457,16 @@ _PyInterpreterState_Enable(_PyRuntimeState *runtime) static PyInterpreterState * alloc_interpreter(void) { - // Aligned allocation for PyInterpreterState. - // the first word of the memory block is used to store - // the original pointer to be used later to free the memory. size_t alignment = _Alignof(PyInterpreterState); - size_t allocsize = sizeof(PyInterpreterState) + sizeof(void *) + alignment - 1; + size_t allocsize = sizeof(PyInterpreterState) + alignment - 1; void *mem = PyMem_RawCalloc(1, allocsize); if (mem == NULL) { return NULL; } - void *ptr = _Py_ALIGN_UP((char *)mem + sizeof(void *), alignment); - ((void **)ptr)[-1] = mem; - assert(_Py_IS_ALIGNED(ptr, alignment)); - return ptr; + PyInterpreterState *interp = _Py_ALIGN_UP(mem, alignment); + assert(_Py_IS_ALIGNED(interp, alignment)); + interp->_malloced = mem; + return interp; } static void @@ -484,7 +481,7 @@ free_interpreter(PyInterpreterState *interp) interp->obmalloc = NULL; } assert(_Py_IS_ALIGNED(interp, _Alignof(PyInterpreterState))); - PyMem_RawFree(((void **)interp)[-1]); + PyMem_RawFree(interp->_malloced); } } -- 2.47.3