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GH-99298: Don't perform jumps before error handling (GH-99299)
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@brandtbucher
brandtbucher committed Nov 10, 2022
1 parent c41b13d commit 00ee6d5
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Showing 3 changed files with 40 additions and 30 deletions.
2 changes: 2 additions & 0 deletions Misc/NEWS.d/next/Core and Builtins/2022-11-09-12-07-24.gh-issue-99298.NeArAJ.rst
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@@ -0,0 +1,2 @@
Fix an issue that could potentially cause incorrect error handling for some
bytecode instructions.
34 changes: 19 additions & 15 deletions Python/bytecodes.c
View file
Expand Up @@ -1146,6 +1146,8 @@ dummy_func(
PyObject *name = GETITEM(names, oparg);
next_instr--;
if (_Py_Specialize_StoreAttr(owner, next_instr, name)) {
// "undo" the rewind so end up in the correct handler:
next_instr++;
goto error;
}
DISPATCH_SAME_OPARG();
Expand Down Expand Up @@ -1725,6 +1727,8 @@ dummy_func(
PyObject *name = GETITEM(names, oparg>>1);
next_instr--;
if (_Py_Specialize_LoadAttr(owner, next_instr, name)) {
// "undo" the rewind so end up in the correct handler:
next_instr++;
goto error;
}
DISPATCH_SAME_OPARG();
Expand Down Expand Up @@ -3113,7 +3117,6 @@ dummy_func(
PyObject *callable = PEEK(2);
DEOPT_IF(callable != (PyObject *)&PyUnicode_Type, CALL);
STAT_INC(CALL, hit);
JUMPBY(INLINE_CACHE_ENTRIES_CALL);
PyObject *arg = TOP();
PyObject *res = PyObject_Str(arg);
Py_DECREF(arg);
Expand All @@ -3123,6 +3126,7 @@ dummy_func(
if (res == NULL) {
goto error;
}
JUMPBY(INLINE_CACHE_ENTRIES_CALL);
CHECK_EVAL_BREAKER();
}

Expand All @@ -3134,7 +3138,6 @@ dummy_func(
PyObject *callable = PEEK(2);
DEOPT_IF(callable != (PyObject *)&PyTuple_Type, CALL);
STAT_INC(CALL, hit);
JUMPBY(INLINE_CACHE_ENTRIES_CALL);
PyObject *arg = TOP();
PyObject *res = PySequence_Tuple(arg);
Py_DECREF(arg);
Expand All @@ -3144,6 +3147,7 @@ dummy_func(
if (res == NULL) {
goto error;
}
JUMPBY(INLINE_CACHE_ENTRIES_CALL);
CHECK_EVAL_BREAKER();
}

Expand All @@ -3157,7 +3161,6 @@ dummy_func(
PyTypeObject *tp = (PyTypeObject *)callable;
DEOPT_IF(tp->tp_vectorcall == NULL, CALL);
STAT_INC(CALL, hit);
JUMPBY(INLINE_CACHE_ENTRIES_CALL);
STACK_SHRINK(total_args);
PyObject *res = tp->tp_vectorcall((PyObject *)tp, stack_pointer,
total_args-kwnames_len, kwnames);
Expand All @@ -3172,6 +3175,7 @@ dummy_func(
if (res == NULL) {
goto error;
}
JUMPBY(INLINE_CACHE_ENTRIES_CALL);
CHECK_EVAL_BREAKER();
}

Expand All @@ -3187,7 +3191,6 @@ dummy_func(
DEOPT_IF(!PyCFunction_CheckExact(callable), CALL);
DEOPT_IF(PyCFunction_GET_FLAGS(callable) != METH_O, CALL);
STAT_INC(CALL, hit);
JUMPBY(INLINE_CACHE_ENTRIES_CALL);
PyCFunction cfunc = PyCFunction_GET_FUNCTION(callable);
// This is slower but CPython promises to check all non-vectorcall
// function calls.
Expand All @@ -3206,6 +3209,7 @@ dummy_func(
if (res == NULL) {
goto error;
}
JUMPBY(INLINE_CACHE_ENTRIES_CALL);
CHECK_EVAL_BREAKER();
}

Expand All @@ -3221,7 +3225,6 @@ dummy_func(
DEOPT_IF(PyCFunction_GET_FLAGS(callable) != METH_FASTCALL,
CALL);
STAT_INC(CALL, hit);
JUMPBY(INLINE_CACHE_ENTRIES_CALL);
PyCFunction cfunc = PyCFunction_GET_FUNCTION(callable);
STACK_SHRINK(total_args);
/* res = func(self, args, nargs) */
Expand All @@ -3246,6 +3249,7 @@ dummy_func(
*/
goto error;
}
JUMPBY(INLINE_CACHE_ENTRIES_CALL);
CHECK_EVAL_BREAKER();
}

Expand All @@ -3260,7 +3264,6 @@ dummy_func(
DEOPT_IF(PyCFunction_GET_FLAGS(callable) !=
(METH_FASTCALL | METH_KEYWORDS), CALL);
STAT_INC(CALL, hit);
JUMPBY(INLINE_CACHE_ENTRIES_CALL);
STACK_SHRINK(total_args);
/* res = func(self, args, nargs, kwnames) */
_PyCFunctionFastWithKeywords cfunc =
Expand All @@ -3285,6 +3288,7 @@ dummy_func(
if (res == NULL) {
goto error;
}
JUMPBY(INLINE_CACHE_ENTRIES_CALL);
CHECK_EVAL_BREAKER();
}

Expand All @@ -3300,7 +3304,6 @@ dummy_func(
PyInterpreterState *interp = _PyInterpreterState_GET();
DEOPT_IF(callable != interp->callable_cache.len, CALL);
STAT_INC(CALL, hit);
JUMPBY(INLINE_CACHE_ENTRIES_CALL);
PyObject *arg = TOP();
Py_ssize_t len_i = PyObject_Length(arg);
if (len_i < 0) {
Expand All @@ -3316,6 +3319,7 @@ dummy_func(
if (res == NULL) {
goto error;
}
JUMPBY(INLINE_CACHE_ENTRIES_CALL);
}

// stack effect: (__0, __array[oparg] -- )
Expand All @@ -3330,7 +3334,6 @@ dummy_func(
PyInterpreterState *interp = _PyInterpreterState_GET();
DEOPT_IF(callable != interp->callable_cache.isinstance, CALL);
STAT_INC(CALL, hit);
JUMPBY(INLINE_CACHE_ENTRIES_CALL);
PyObject *cls = POP();
PyObject *inst = TOP();
int retval = PyObject_IsInstance(inst, cls);
Expand All @@ -3349,6 +3352,7 @@ dummy_func(
if (res == NULL) {
goto error;
}
JUMPBY(INLINE_CACHE_ENTRIES_CALL);
}

// stack effect: (__0, __array[oparg] -- )
Expand All @@ -3362,16 +3366,16 @@ dummy_func(
PyObject *list = SECOND();
DEOPT_IF(!PyList_Check(list), CALL);
STAT_INC(CALL, hit);
// CALL + POP_TOP
JUMPBY(INLINE_CACHE_ENTRIES_CALL + 1);
assert(_Py_OPCODE(next_instr[-1]) == POP_TOP);
PyObject *arg = POP();
if (_PyList_AppendTakeRef((PyListObject *)list, arg) < 0) {
goto error;
}
STACK_SHRINK(2);
Py_DECREF(list);
Py_DECREF(callable);
// CALL + POP_TOP
JUMPBY(INLINE_CACHE_ENTRIES_CALL + 1);
assert(_Py_OPCODE(next_instr[-1]) == POP_TOP);
}

// stack effect: (__0, __array[oparg] -- )
Expand All @@ -3389,7 +3393,6 @@ dummy_func(
PyObject *self = SECOND();
DEOPT_IF(!Py_IS_TYPE(self, callable->d_common.d_type), CALL);
STAT_INC(CALL, hit);
JUMPBY(INLINE_CACHE_ENTRIES_CALL);
PyCFunction cfunc = meth->ml_meth;
// This is slower but CPython promises to check all non-vectorcall
// function calls.
Expand All @@ -3407,6 +3410,7 @@ dummy_func(
if (res == NULL) {
goto error;
}
JUMPBY(INLINE_CACHE_ENTRIES_CALL);
CHECK_EVAL_BREAKER();
}

Expand All @@ -3423,7 +3427,6 @@ dummy_func(
PyObject *self = PEEK(total_args);
DEOPT_IF(!Py_IS_TYPE(self, d_type), CALL);
STAT_INC(CALL, hit);
JUMPBY(INLINE_CACHE_ENTRIES_CALL);
int nargs = total_args-1;
STACK_SHRINK(nargs);
_PyCFunctionFastWithKeywords cfunc =
Expand All @@ -3444,6 +3447,7 @@ dummy_func(
if (res == NULL) {
goto error;
}
JUMPBY(INLINE_CACHE_ENTRIES_CALL);
CHECK_EVAL_BREAKER();
}

Expand All @@ -3461,7 +3465,6 @@ dummy_func(
DEOPT_IF(!Py_IS_TYPE(self, callable->d_common.d_type), CALL);
DEOPT_IF(meth->ml_flags != METH_NOARGS, CALL);
STAT_INC(CALL, hit);
JUMPBY(INLINE_CACHE_ENTRIES_CALL);
PyCFunction cfunc = meth->ml_meth;
// This is slower but CPython promises to check all non-vectorcall
// function calls.
Expand All @@ -3478,6 +3481,7 @@ dummy_func(
if (res == NULL) {
goto error;
}
JUMPBY(INLINE_CACHE_ENTRIES_CALL);
CHECK_EVAL_BREAKER();
}

Expand All @@ -3495,7 +3499,6 @@ dummy_func(
PyObject *self = PEEK(total_args);
DEOPT_IF(!Py_IS_TYPE(self, callable->d_common.d_type), CALL);
STAT_INC(CALL, hit);
JUMPBY(INLINE_CACHE_ENTRIES_CALL);
_PyCFunctionFast cfunc =
(_PyCFunctionFast)(void(*)(void))meth->ml_meth;
int nargs = total_args-1;
Expand All @@ -3513,6 +3516,7 @@ dummy_func(
if (res == NULL) {
goto error;
}
JUMPBY(INLINE_CACHE_ENTRIES_CALL);
CHECK_EVAL_BREAKER();
}

Expand Down

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