diff options
| -rw-r--r-- | Lib/test/test_type_cache.py | 158 | ||||
| -rw-r--r-- | Misc/NEWS.d/next/Core and Builtins/2024-01-03-12-19-37.gh-issue-89811.cZOj6d.rst | 2 | ||||
| -rw-r--r-- | Modules/_testcapimodule.c | 29 | ||||
| -rw-r--r-- | Python/specialize.c | 28 |
4 files changed, 216 insertions, 1 deletions
diff --git a/Lib/test/test_type_cache.py b/Lib/test/test_type_cache.py index 9dc91dc..11158f9 100644 --- a/Lib/test/test_type_cache.py +++ b/Lib/test/test_type_cache.py @@ -1,5 +1,6 @@ """ Tests for the internal type cache in CPython. """ import unittest +import dis from test import support from test.support import import_helper try: @@ -8,7 +9,17 @@ except ImportError: _clear_type_cache = None # Skip this test if the _testcapi module isn't available. -type_get_version = import_helper.import_module('_testcapi').type_get_version +_testcapi = import_helper.import_module("_testcapi") +type_get_version = _testcapi.type_get_version +type_assign_specific_version_unsafe = _testcapi.type_assign_specific_version_unsafe +type_modified = _testcapi.type_modified + + +def type_assign_version(type_): + try: + type_.x + except AttributeError: + pass @support.cpython_only @@ -42,6 +53,151 @@ class TypeCacheTests(unittest.TestCase): self.assertEqual(len(set(all_version_tags)), 30, msg=f"{all_version_tags} contains non-unique versions") + def test_type_assign_specific_version(self): + """meta-test for type_assign_specific_version_unsafe""" + class C: + pass + + type_assign_version(C) + orig_version = type_get_version(C) + if orig_version == 0: + self.skipTest("Could not assign a valid type version") + + type_modified(C) + type_assign_specific_version_unsafe(C, orig_version + 5) + type_assign_version(C) # this should do nothing + + new_version = type_get_version(C) + self.assertEqual(new_version, orig_version + 5) + + _clear_type_cache() + + +@support.cpython_only +class TypeCacheWithSpecializationTests(unittest.TestCase): + def tearDown(self): + _clear_type_cache() + + def _assign_valid_version_or_skip(self, type_): + type_modified(type_) + type_assign_version(type_) + if type_get_version(type_) == 0: + self.skipTest("Could not assign valid type version") + + def _assign_and_check_version_0(self, user_type): + type_modified(user_type) + type_assign_specific_version_unsafe(user_type, 0) + self.assertEqual(type_get_version(user_type), 0) + + def _all_opnames(self, func): + return set(instr.opname for instr in dis.Bytecode(func, adaptive=True)) + + def _check_specialization(self, func, arg, opname, *, should_specialize): + for _ in range(100): + func(arg) + + if should_specialize: + self.assertNotIn(opname, self._all_opnames(func)) + else: + self.assertIn(opname, self._all_opnames(func)) + + def test_load_method_specialization_user_type(self): + class A: + def foo(self): + pass + + self._assign_valid_version_or_skip(A) + + def load_foo_1(instance): + instance.foo() + + self._check_specialization( + load_foo_1, A(), "LOAD_METHOD_ADAPTIVE", should_specialize=True + ) + del load_foo_1 + + self._assign_and_check_version_0(A) + + def load_foo_2(instance): + instance.foo() + + self._check_specialization( + load_foo_2, A(), "LOAD_METHOD_ADAPTIVE", should_specialize=False + ) + + def test_store_attr_specialization_user_type(self): + class B: + __slots__ = ("bar",) + + self._assign_valid_version_or_skip(B) + + def store_bar_1(instance): + instance.bar = 10 + + self._check_specialization( + store_bar_1, B(), "STORE_ATTR_ADAPTIVE", should_specialize=True + ) + del store_bar_1 + + self._assign_and_check_version_0(B) + + def store_bar_2(instance): + instance.bar = 10 + + self._check_specialization( + store_bar_2, B(), "STORE_ATTR_ADAPTIVE", should_specialize=False + ) + + def test_load_attr_specialization_user_type(self): + class C: + __slots__ = ("biz",) + def __init__(self): + self.biz = 8 + + self._assign_valid_version_or_skip(C) + + def load_biz_1(type_): + type_.biz + + self._check_specialization( + load_biz_1, C(), "LOAD_ATTR_ADAPTIVE", should_specialize=True + ) + del load_biz_1 + + self._assign_and_check_version_0(C) + + def load_biz_2(type_): + type_.biz + + self._check_specialization( + load_biz_2, C(), "LOAD_ATTR_ADAPTIVE", should_specialize=False + ) + + def test_binary_subscript_specialization_user_type(self): + class D: + def __getitem__(self, _): + return 1 + + self._assign_valid_version_or_skip(D) + + def subscript_1(instance): + instance[6] + + self._check_specialization( + subscript_1, D(), "BINARY_SUBSCR_ADAPTIVE", should_specialize=True + ) + del subscript_1 + + self._assign_and_check_version_0(D) + + def subscript_2(instance): + instance[6] + + self._check_specialization( + subscript_2, D(), "BINARY_SUBSCR_ADAPTIVE", should_specialize=False + ) + + if __name__ == "__main__": unittest.main() diff --git a/Misc/NEWS.d/next/Core and Builtins/2024-01-03-12-19-37.gh-issue-89811.cZOj6d.rst b/Misc/NEWS.d/next/Core and Builtins/2024-01-03-12-19-37.gh-issue-89811.cZOj6d.rst new file mode 100644 index 0000000..90bd981 --- /dev/null +++ b/Misc/NEWS.d/next/Core and Builtins/2024-01-03-12-19-37.gh-issue-89811.cZOj6d.rst @@ -0,0 +1,2 @@ +Check for a valid ``tp_version_tag`` before performing bytecode specializations that +rely on this value being usable. diff --git a/Modules/_testcapimodule.c b/Modules/_testcapimodule.c index 2f1801f..a4411d1 100644 --- a/Modules/_testcapimodule.c +++ b/Modules/_testcapimodule.c @@ -5899,6 +5899,32 @@ type_get_version(PyObject *self, PyObject *type) return res; } +static PyObject * +type_modified(PyObject *self, PyObject *type) +{ + if (!PyType_Check(type)) { + PyErr_SetString(PyExc_TypeError, "argument must be a type"); + return NULL; + } + PyType_Modified((PyTypeObject *)type); + Py_RETURN_NONE; +} + +// Circumvents standard version assignment machinery - use with caution and only on +// short-lived heap types +static PyObject * +type_assign_specific_version_unsafe(PyObject *self, PyObject *args) +{ + PyTypeObject *type; + unsigned int version; + if (!PyArg_ParseTuple(args, "Oi:type_assign_specific_version_unsafe", &type, &version)) { + return NULL; + } + assert(!PyType_HasFeature(type, Py_TPFLAGS_IMMUTABLETYPE)); + type->tp_version_tag = version; + type->tp_flags |= Py_TPFLAGS_VALID_VERSION_TAG; + Py_RETURN_NONE; +} // Test PyThreadState C API static PyObject * @@ -6782,6 +6808,9 @@ static PyMethodDef TestMethods[] = { {"fatal_error", test_fatal_error, METH_VARARGS, PyDoc_STR("fatal_error(message, release_gil=False): call Py_FatalError(message)")}, {"type_get_version", type_get_version, METH_O, PyDoc_STR("type->tp_version_tag")}, + {"type_modified", type_modified, METH_O, PyDoc_STR("PyType_Modified")}, + {"type_assign_specific_version_unsafe", type_assign_specific_version_unsafe, METH_VARARGS, + PyDoc_STR("forcefully assign type->tp_version_tag")}, {"test_tstate_capi", test_tstate_capi, METH_NOARGS, NULL}, {"float_pack", test_float_pack, METH_VARARGS, NULL}, {"float_unpack", test_float_unpack, METH_VARARGS, NULL}, diff --git a/Python/specialize.c b/Python/specialize.c index 4a5213c..3441e84 100644 --- a/Python/specialize.c +++ b/Python/specialize.c @@ -481,6 +481,7 @@ miss_counter_start(void) { #define SPEC_FAIL_UNPACK_SEQUENCE_ITERATOR 8 #define SPEC_FAIL_UNPACK_SEQUENCE_SEQUENCE 9 +static uint32_t type_get_version(PyTypeObject *t, int opcode); static int specialize_module_load_attr(PyObject *owner, _Py_CODEUNIT *instr, @@ -673,6 +674,9 @@ _Py_Specialize_LoadAttr(PyObject *owner, _Py_CODEUNIT *instr, PyObject *name) } PyObject *descr; DescriptorClassification kind = analyze_descriptor(type, name, &descr, 0); + if (type_get_version(type, LOAD_ATTR) == 0) { + goto fail; + } switch(kind) { case OVERRIDING: SPECIALIZATION_FAIL(LOAD_ATTR, SPEC_FAIL_ATTR_OVERRIDING_DESCRIPTOR); @@ -766,6 +770,9 @@ _Py_Specialize_StoreAttr(PyObject *owner, _Py_CODEUNIT *instr, PyObject *name) } PyObject *descr; DescriptorClassification kind = analyze_descriptor(type, name, &descr, 1); + if (type_get_version(type, STORE_ATTR) == 0) { + goto fail; + } switch(kind) { case OVERRIDING: SPECIALIZATION_FAIL(STORE_ATTR, SPEC_FAIL_ATTR_OVERRIDING_DESCRIPTOR); @@ -889,6 +896,9 @@ specialize_class_load_method(PyObject *owner, _Py_CODEUNIT *instr, PyObject *descr = NULL; DescriptorClassification kind = 0; kind = analyze_descriptor((PyTypeObject *)owner, name, &descr, 0); + if (type_get_version((PyTypeObject *)owner, LOAD_METHOD) == 0) { + return -1; + } switch (kind) { case METHOD: case NON_DESCRIPTOR: @@ -950,6 +960,9 @@ _Py_Specialize_LoadMethod(PyObject *owner, _Py_CODEUNIT *instr, PyObject *name) PyObject *descr = NULL; DescriptorClassification kind = 0; kind = analyze_descriptor(owner_cls, name, &descr, 0); + if (type_get_version(owner_cls, LOAD_METHOD) == 0) { + goto fail; + } assert(descr != NULL || kind == ABSENT || kind == GETSET_OVERRIDDEN); if (kind != METHOD) { SPECIALIZATION_FAIL(LOAD_METHOD, load_method_fail_kind(kind)); @@ -1183,6 +1196,18 @@ function_kind(PyCodeObject *code) { return SIMPLE_FUNCTION; } +/* Returning 0 indicates a failure. */ +static uint32_t +type_get_version(PyTypeObject *t, int opcode) +{ + uint32_t version = t->tp_version_tag; + if (version == 0) { + SPECIALIZATION_FAIL(opcode, SPEC_FAIL_OUT_OF_VERSIONS); + return 0; + } + return version; +} + int _Py_Specialize_BinarySubscr( PyObject *container, PyObject *sub, _Py_CODEUNIT *instr) @@ -1231,6 +1256,9 @@ _Py_Specialize_BinarySubscr( SPECIALIZATION_FAIL(BINARY_SUBSCR, SPEC_FAIL_WRONG_NUMBER_ARGUMENTS); goto fail; } + if (type_get_version(cls, BINARY_SUBSCR) == 0) { + goto fail; + } assert(cls->tp_version_tag != 0); write_u32(cache->type_version, cls->tp_version_tag); int version = _PyFunction_GetVersionForCurrentState(func); |