From: Serhiy Storchaka Date: Mon, 1 Jan 2024 16:46:07 +0000 (+0200) Subject: [3.11] gh-62260: Fix ctypes.Structure subclassing with multiple layers (GH-13374... X-Git-Tag: v3.11.8~201 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=36153494f1fe3182bb1fdef89839b594a70d570d;p=thirdparty%2FPython%2Fcpython.git [3.11] gh-62260: Fix ctypes.Structure subclassing with multiple layers (GH-13374) (GH-113624) The length field of StgDictObject for Structure class contains now the total number of items in ffi_type_pointer.elements (excluding the trailing null). The old behavior of using the number of elements in the parent class can cause the array to be truncated when it is copied, especially when there are multiple layers of subclassing. (cherry picked from commit 5f3cc90a12d6df404fd6f48a0df1334902e271f2) Co-authored-by: Jeffrey Kintscher <49998481+websurfer5@users.noreply.github.com> --- diff --git a/Lib/ctypes/test/test_structures.py b/Lib/ctypes/test/test_structures.py index f57bb2b5c178..c4fc6092c45e 100644 --- a/Lib/ctypes/test/test_structures.py +++ b/Lib/ctypes/test/test_structures.py @@ -1,4 +1,6 @@ import platform +from platform import architecture as _architecture +import struct import sys import unittest from ctypes.test import need_symbol @@ -7,6 +9,7 @@ from ctypes import (CDLL, Array, Structure, Union, POINTER, sizeof, byref, align c_uint8, c_uint16, c_uint32, c_short, c_ushort, c_int, c_uint, c_long, c_ulong, c_longlong, c_ulonglong, c_float, c_double) +from ctypes.util import find_library from struct import calcsize import _ctypes_test from test import support @@ -479,6 +482,66 @@ class StructureTestCase(unittest.TestCase): self.assertEqual(s.first, got.first) self.assertEqual(s.second, got.second) + def _test_issue18060(self, Vector): + # The call to atan2() should succeed if the + # class fields were correctly cloned in the + # subclasses. Otherwise, it will segfault. + if sys.platform == 'win32': + libm = CDLL(find_library('msvcrt.dll')) + else: + libm = CDLL(find_library('m')) + + libm.atan2.argtypes = [Vector] + libm.atan2.restype = c_double + + arg = Vector(y=0.0, x=-1.0) + self.assertAlmostEqual(libm.atan2(arg), 3.141592653589793) + + @unittest.skipIf(_architecture() == ('64bit', 'WindowsPE'), "can't test Windows x64 build") + @unittest.skipUnless(sys.byteorder == 'little', "can't test on this platform") + def test_issue18060_a(self): + # This test case calls + # PyCStructUnionType_update_stgdict() for each + # _fields_ assignment, and PyCStgDict_clone() + # for the Mid and Vector class definitions. + class Base(Structure): + _fields_ = [('y', c_double), + ('x', c_double)] + class Mid(Base): + pass + Mid._fields_ = [] + class Vector(Mid): pass + self._test_issue18060(Vector) + + @unittest.skipIf(_architecture() == ('64bit', 'WindowsPE'), "can't test Windows x64 build") + @unittest.skipUnless(sys.byteorder == 'little', "can't test on this platform") + def test_issue18060_b(self): + # This test case calls + # PyCStructUnionType_update_stgdict() for each + # _fields_ assignment. + class Base(Structure): + _fields_ = [('y', c_double), + ('x', c_double)] + class Mid(Base): + _fields_ = [] + class Vector(Mid): + _fields_ = [] + self._test_issue18060(Vector) + + @unittest.skipIf(_architecture() == ('64bit', 'WindowsPE'), "can't test Windows x64 build") + @unittest.skipUnless(sys.byteorder == 'little', "can't test on this platform") + def test_issue18060_c(self): + # This test case calls + # PyCStructUnionType_update_stgdict() for each + # _fields_ assignment. + class Base(Structure): + _fields_ = [('y', c_double)] + class Mid(Base): + _fields_ = [] + class Vector(Mid): + _fields_ = [('x', c_double)] + self._test_issue18060(Vector) + def test_array_in_struct(self): # See bpo-22273 diff --git a/Misc/NEWS.d/next/Library/2019-05-17-07-22-33.bpo-18060.5mqTQM.rst b/Misc/NEWS.d/next/Library/2019-05-17-07-22-33.bpo-18060.5mqTQM.rst new file mode 100644 index 000000000000..3fefbc3efb63 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2019-05-17-07-22-33.bpo-18060.5mqTQM.rst @@ -0,0 +1,2 @@ +Fixed a class inheritance issue that can cause segfaults when deriving two or more levels of subclasses from a base class of Structure or Union. + diff --git a/Modules/_ctypes/_ctypes.c b/Modules/_ctypes/_ctypes.c index fc73264ff5a3..50cad3075b2f 100644 --- a/Modules/_ctypes/_ctypes.c +++ b/Modules/_ctypes/_ctypes.c @@ -4387,10 +4387,10 @@ _init_pos_args(PyObject *self, PyTypeObject *type, return index; } - for (i = 0; - i < dict->length && (i+index) < PyTuple_GET_SIZE(args); + for (i = index; + i < dict->length && i < PyTuple_GET_SIZE(args); ++i) { - PyObject *pair = PySequence_GetItem(fields, i); + PyObject *pair = PySequence_GetItem(fields, i - index); PyObject *name, *val; int res; if (!pair) @@ -4400,7 +4400,7 @@ _init_pos_args(PyObject *self, PyTypeObject *type, Py_DECREF(pair); return -1; } - val = PyTuple_GET_ITEM(args, i + index); + val = PyTuple_GET_ITEM(args, i); if (kwds) { res = PyDict_Contains(kwds, name); if (res != 0) { @@ -4421,7 +4421,7 @@ _init_pos_args(PyObject *self, PyTypeObject *type, if (res == -1) return -1; } - return index + dict->length; + return dict->length; } static int diff --git a/Modules/_ctypes/stgdict.c b/Modules/_ctypes/stgdict.c index 7746f95692f3..cbd705d49221 100644 --- a/Modules/_ctypes/stgdict.c +++ b/Modules/_ctypes/stgdict.c @@ -660,7 +660,7 @@ PyCStructUnionType_update_stgdict(PyObject *type, PyObject *fields, int isStruct stgdict->size = size; stgdict->align = total_align; - stgdict->length = len; /* ADD ffi_ofs? */ + stgdict->length = ffi_ofs + len; /* * On Arm platforms, structs with at most 4 elements of any floating point