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GH-121459: Streamline PyObject* to PyStackRef conversions by disallowing NULL pointers. (GH-124894)

This commit is contained in:
Mark Shannon 2024-10-07 18:13:04 +01:00 committed by GitHub
parent 10094a533a
commit d1453f60c2
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GPG Key ID: B5690EEEBB952194
4 changed files with 63 additions and 57 deletions
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14
Include/internal/pycore_stackref.h
View File

@ -111,7 +111,8 @@ PyStackRef_AsPyObjectBorrow(_PyStackRef stackref)
static inline PyObject *
PyStackRef_AsPyObjectSteal(_PyStackRef stackref)
{
if (!PyStackRef_IsNull(stackref) && PyStackRef_IsDeferred(stackref)) {
assert(!PyStackRef_IsNull(stackref));
if (PyStackRef_IsDeferred(stackref)) {
return Py_NewRef(PyStackRef_AsPyObjectBorrow(stackref));
}
return PyStackRef_AsPyObjectBorrow(stackref);
@ -131,9 +132,10 @@ PyStackRef_AsPyObjectSteal(_PyStackRef stackref)
static inline _PyStackRef
_PyStackRef_FromPyObjectSteal(PyObject *obj)
{
assert(obj != NULL);
// Make sure we don't take an already tagged value.
assert(((uintptr_t)obj & Py_TAG_BITS) == 0);
unsigned int tag = (obj == NULL || _Py_IsImmortal(obj)) ? (Py_TAG_DEFERRED) : Py_TAG_PTR;
unsigned int tag = _Py_IsImmortal(obj) ? (Py_TAG_DEFERRED) : Py_TAG_PTR;
return ((_PyStackRef){.bits = ((uintptr_t)(obj)) | tag});
}
# define PyStackRef_FromPyObjectSteal(obj) _PyStackRef_FromPyObjectSteal(_PyObject_CAST(obj))
@ -193,6 +195,7 @@ PyStackRef_FromPyObjectImmortal(PyObject *obj)
# define PyStackRef_CLOSE(REF) \
do { \
_PyStackRef _close_tmp = (REF); \
assert(!PyStackRef_IsNull(_close_tmp)); \
if (!PyStackRef_IsDeferred(_close_tmp)) { \
Py_DECREF(PyStackRef_AsPyObjectBorrow(_close_tmp)); \
} \
@ -214,10 +217,11 @@ PyStackRef_FromPyObjectImmortal(PyObject *obj)
static inline _PyStackRef
PyStackRef_DUP(_PyStackRef stackref)
{
assert(!PyStackRef_IsNull(stackref));
if (PyStackRef_IsDeferred(stackref)) {
assert(PyStackRef_IsNull(stackref) ||
_Py_IsImmortal(PyStackRef_AsPyObjectBorrow(stackref)) ||
_PyObject_HasDeferredRefcount(PyStackRef_AsPyObjectBorrow(stackref)));
assert(_Py_IsImmortal(PyStackRef_AsPyObjectBorrow(stackref)) ||
_PyObject_HasDeferredRefcount(PyStackRef_AsPyObjectBorrow(stackref))
);
return stackref;
}
Py_INCREF(PyStackRef_AsPyObjectBorrow(stackref));

32
Python/bytecodes.c
View File

@ -1922,9 +1922,10 @@ dummy_func(
DECREF_INPUTS();
ERROR_IF(super == NULL, error);
PyObject *name = GETITEM(FRAME_CO_NAMES, oparg >> 2);
attr = PyStackRef_FromPyObjectSteal(PyObject_GetAttr(super, name));
PyObject *attr_o = PyObject_GetAttr(super, name);
Py_DECREF(super);
ERROR_IF(PyStackRef_IsNull(attr), error);
ERROR_IF(attr_o == NULL, error);
attr = PyStackRef_FromPyObjectSteal(attr_o);
null = PyStackRef_NULL;
}
@ -2740,9 +2741,10 @@ dummy_func(
inst(GET_ITER, (iterable -- iter)) {
/* before: [obj]; after [getiter(obj)] */
iter = PyStackRef_FromPyObjectSteal(PyObject_GetIter(PyStackRef_AsPyObjectBorrow(iterable)));
PyObject *iter_o = PyObject_GetIter(PyStackRef_AsPyObjectBorrow(iterable));
DECREF_INPUTS();
ERROR_IF(PyStackRef_IsNull(iter), error);
ERROR_IF(iter_o == NULL, error);
iter = PyStackRef_FromPyObjectSteal(iter_o);
}
inst(GET_YIELD_FROM_ITER, (iterable -- iter)) {
@ -3052,16 +3054,18 @@ dummy_func(
PyObject *owner_o = PyStackRef_AsPyObjectSteal(owner);
PyObject *name = _Py_SpecialMethods[oparg].name;
PyObject *self_or_null_o;
attr = PyStackRef_FromPyObjectSteal(_PyObject_LookupSpecialMethod(owner_o, name, &self_or_null_o));
if (PyStackRef_IsNull(attr)) {
PyObject *attr_o = _PyObject_LookupSpecialMethod(owner_o, name, &self_or_null_o);
if (attr_o == NULL) {
if (!_PyErr_Occurred(tstate)) {
_PyErr_Format(tstate, PyExc_TypeError,
_Py_SpecialMethods[oparg].error,
Py_TYPE(owner_o)->tp_name);
}
ERROR_IF(true, error);
}
ERROR_IF(PyStackRef_IsNull(attr), error);
self_or_null = PyStackRef_FromPyObjectSteal(self_or_null_o);
attr = PyStackRef_FromPyObjectSteal(attr_o);
self_or_null = self_or_null_o == NULL ?
PyStackRef_NULL : PyStackRef_FromPyObjectSteal(self_or_null_o);
}
inst(WITH_EXCEPT_START, (exit_func, exit_self, lasti, unused, val -- exit_func, exit_self, lasti, unused, val, res)) {
@ -3092,9 +3096,10 @@ dummy_func(
(void)lasti; // Shut up compiler warning if asserts are off
PyObject *stack[5] = {NULL, PyStackRef_AsPyObjectBorrow(exit_self), exc, val_o, tb};
int has_self = !PyStackRef_IsNull(exit_self);
res = PyStackRef_FromPyObjectSteal(PyObject_Vectorcall(exit_func_o, stack + 2 - has_self,
(3 + has_self) | PY_VECTORCALL_ARGUMENTS_OFFSET, NULL));
ERROR_IF(PyStackRef_IsNull(res), error);
PyObject *res_o = PyObject_Vectorcall(exit_func_o, stack + 2 - has_self,
(3 + has_self) | PY_VECTORCALL_ARGUMENTS_OFFSET, NULL);
ERROR_IF(res_o == NULL, error);
res = PyStackRef_FromPyObjectSteal(res_o);
}
pseudo(SETUP_FINALLY, (-- unused), (HAS_ARG)) = {
@ -4539,9 +4544,10 @@ dummy_func(
/* If value is a unicode object, then we know the result
* of format(value) is value itself. */
if (!PyUnicode_CheckExact(value_o)) {
res = PyStackRef_FromPyObjectSteal(PyObject_Format(value_o, NULL));
PyObject *res_o = PyObject_Format(value_o, NULL);
PyStackRef_CLOSE(value);
ERROR_IF(PyStackRef_IsNull(res), error);
ERROR_IF(res_o == NULL, error);
res = PyStackRef_FromPyObjectSteal(res_o);
}
else {
res = value;

32
Python/executor_cases.c.h generated
View File

@ -3281,10 +3281,11 @@
iterable = stack_pointer[-1];
/* before: [obj]; after [getiter(obj)] */
_PyFrame_SetStackPointer(frame, stack_pointer);
iter = PyStackRef_FromPyObjectSteal(PyObject_GetIter(PyStackRef_AsPyObjectBorrow(iterable)));
PyObject *iter_o = PyObject_GetIter(PyStackRef_AsPyObjectBorrow(iterable));
stack_pointer = _PyFrame_GetStackPointer(frame);
PyStackRef_CLOSE(iterable);
if (PyStackRef_IsNull(iter)) JUMP_TO_ERROR();
if (iter_o == NULL) JUMP_TO_ERROR();
iter = PyStackRef_FromPyObjectSteal(iter_o);
stack_pointer[-1] = iter;
break;
}
@ -3552,24 +3553,21 @@
stack_pointer += -1;
assert(WITHIN_STACK_BOUNDS());
_PyFrame_SetStackPointer(frame, stack_pointer);
attr = PyStackRef_FromPyObjectSteal(_PyObject_LookupSpecialMethod(owner_o, name, &self_or_null_o));
PyObject *attr_o = _PyObject_LookupSpecialMethod(owner_o, name, &self_or_null_o);
stack_pointer = _PyFrame_GetStackPointer(frame);
if (PyStackRef_IsNull(attr)) {
if (attr_o == NULL) {
if (!_PyErr_Occurred(tstate)) {
stack_pointer[0] = attr;
stack_pointer += 1;
assert(WITHIN_STACK_BOUNDS());
_PyFrame_SetStackPointer(frame, stack_pointer);
_PyErr_Format(tstate, PyExc_TypeError,
_Py_SpecialMethods[oparg].error,
Py_TYPE(owner_o)->tp_name);
stack_pointer = _PyFrame_GetStackPointer(frame);
stack_pointer += -1;
assert(WITHIN_STACK_BOUNDS());
}
if (true) JUMP_TO_ERROR();
}
if (PyStackRef_IsNull(attr)) JUMP_TO_ERROR();
self_or_null = PyStackRef_FromPyObjectSteal(self_or_null_o);
attr = PyStackRef_FromPyObjectSteal(attr_o);
self_or_null = self_or_null_o == NULL ?
PyStackRef_NULL : PyStackRef_FromPyObjectSteal(self_or_null_o);
stack_pointer[0] = attr;
stack_pointer[1] = self_or_null;
stack_pointer += 2;
@ -3613,10 +3611,11 @@
PyObject *stack[5] = {NULL, PyStackRef_AsPyObjectBorrow(exit_self), exc, val_o, tb};
int has_self = !PyStackRef_IsNull(exit_self);
_PyFrame_SetStackPointer(frame, stack_pointer);
res = PyStackRef_FromPyObjectSteal(PyObject_Vectorcall(exit_func_o, stack + 2 - has_self,
(3 + has_self) | PY_VECTORCALL_ARGUMENTS_OFFSET, NULL));
PyObject *res_o = PyObject_Vectorcall(exit_func_o, stack + 2 - has_self,
(3 + has_self) | PY_VECTORCALL_ARGUMENTS_OFFSET, NULL);
stack_pointer = _PyFrame_GetStackPointer(frame);
if (PyStackRef_IsNull(res)) JUMP_TO_ERROR();
if (res_o == NULL) JUMP_TO_ERROR();
res = PyStackRef_FromPyObjectSteal(res_o);
stack_pointer[0] = res;
stack_pointer += 1;
assert(WITHIN_STACK_BOUNDS());
@ -5373,10 +5372,11 @@
* of format(value) is value itself. */
if (!PyUnicode_CheckExact(value_o)) {
_PyFrame_SetStackPointer(frame, stack_pointer);
res = PyStackRef_FromPyObjectSteal(PyObject_Format(value_o, NULL));
PyObject *res_o = PyObject_Format(value_o, NULL);
stack_pointer = _PyFrame_GetStackPointer(frame);
PyStackRef_CLOSE(value);
if (PyStackRef_IsNull(res)) JUMP_TO_ERROR();
if (res_o == NULL) JUMP_TO_ERROR();
res = PyStackRef_FromPyObjectSteal(res_o);
}
else {
res = value;

42
Python/generated_cases.c.h generated
View File

@ -3856,10 +3856,11 @@
* of format(value) is value itself. */
if (!PyUnicode_CheckExact(value_o)) {
_PyFrame_SetStackPointer(frame, stack_pointer);
res = PyStackRef_FromPyObjectSteal(PyObject_Format(value_o, NULL));
PyObject *res_o = PyObject_Format(value_o, NULL);
stack_pointer = _PyFrame_GetStackPointer(frame);
PyStackRef_CLOSE(value);
if (PyStackRef_IsNull(res)) goto pop_1_error;
if (res_o == NULL) goto pop_1_error;
res = PyStackRef_FromPyObjectSteal(res_o);
}
else {
res = value;
@ -4239,10 +4240,11 @@
iterable = stack_pointer[-1];
/* before: [obj]; after [getiter(obj)] */
_PyFrame_SetStackPointer(frame, stack_pointer);
iter = PyStackRef_FromPyObjectSteal(PyObject_GetIter(PyStackRef_AsPyObjectBorrow(iterable)));
PyObject *iter_o = PyObject_GetIter(PyStackRef_AsPyObjectBorrow(iterable));
stack_pointer = _PyFrame_GetStackPointer(frame);
PyStackRef_CLOSE(iterable);
if (PyStackRef_IsNull(iter)) goto pop_1_error;
if (iter_o == NULL) goto pop_1_error;
iter = PyStackRef_FromPyObjectSteal(iter_o);
stack_pointer[-1] = iter;
DISPATCH();
}
@ -6270,29 +6272,21 @@
stack_pointer += -1;
assert(WITHIN_STACK_BOUNDS());
_PyFrame_SetStackPointer(frame, stack_pointer);
attr = PyStackRef_FromPyObjectSteal(_PyObject_LookupSpecialMethod(owner_o, name, &self_or_null_o));
PyObject *attr_o = _PyObject_LookupSpecialMethod(owner_o, name, &self_or_null_o);
stack_pointer = _PyFrame_GetStackPointer(frame);
if (PyStackRef_IsNull(attr)) {
if (attr_o == NULL) {
if (!_PyErr_Occurred(tstate)) {
stack_pointer[0] = attr;
stack_pointer += 1;
assert(WITHIN_STACK_BOUNDS());
_PyFrame_SetStackPointer(frame, stack_pointer);
_PyErr_Format(tstate, PyExc_TypeError,
_Py_SpecialMethods[oparg].error,
Py_TYPE(owner_o)->tp_name);
stack_pointer = _PyFrame_GetStackPointer(frame);
stack_pointer += -1;
assert(WITHIN_STACK_BOUNDS());
}
if (true) goto error;
}
if (PyStackRef_IsNull(attr)) {
stack_pointer[0] = attr;
stack_pointer += 1;
assert(WITHIN_STACK_BOUNDS());
goto error;
}
self_or_null = PyStackRef_FromPyObjectSteal(self_or_null_o);
attr = PyStackRef_FromPyObjectSteal(attr_o);
self_or_null = self_or_null_o == NULL ?
PyStackRef_NULL : PyStackRef_FromPyObjectSteal(self_or_null_o);
stack_pointer[0] = attr;
stack_pointer[1] = self_or_null;
stack_pointer += 2;
@ -6385,10 +6379,11 @@
stack_pointer += -3;
assert(WITHIN_STACK_BOUNDS());
_PyFrame_SetStackPointer(frame, stack_pointer);
attr = PyStackRef_FromPyObjectSteal(PyObject_GetAttr(super, name));
PyObject *attr_o = PyObject_GetAttr(super, name);
stack_pointer = _PyFrame_GetStackPointer(frame);
Py_DECREF(super);
if (PyStackRef_IsNull(attr)) goto error;
if (attr_o == NULL) goto error;
attr = PyStackRef_FromPyObjectSteal(attr_o);
null = PyStackRef_NULL;
}
stack_pointer[0] = attr;
@ -8139,10 +8134,11 @@
PyObject *stack[5] = {NULL, PyStackRef_AsPyObjectBorrow(exit_self), exc, val_o, tb};
int has_self = !PyStackRef_IsNull(exit_self);
_PyFrame_SetStackPointer(frame, stack_pointer);
res = PyStackRef_FromPyObjectSteal(PyObject_Vectorcall(exit_func_o, stack + 2 - has_self,
(3 + has_self) | PY_VECTORCALL_ARGUMENTS_OFFSET, NULL));
PyObject *res_o = PyObject_Vectorcall(exit_func_o, stack + 2 - has_self,
(3 + has_self) | PY_VECTORCALL_ARGUMENTS_OFFSET, NULL);
stack_pointer = _PyFrame_GetStackPointer(frame);
if (PyStackRef_IsNull(res)) goto error;
if (res_o == NULL) goto error;
res = PyStackRef_FromPyObjectSteal(res_o);
stack_pointer[0] = res;
stack_pointer += 1;
assert(WITHIN_STACK_BOUNDS());