GH-99298: Don't perform jumps before error handling (GH-99299)

3 files changed, 40 insertions, 30 deletions

diff --git a/Misc/NEWS.d/next/Core and Builtins/2022-11-09-12-07-24.gh-issue-99298.NeArAJ.rst b/Misc/NEWS.d/next/Core and Builtins/2022-11-09-12-07-24.gh-issue-99298.NeArAJ.rst
new file mode 100644
index 0000000..8908bfa
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2022-11-09-12-07-24.gh-issue-99298.NeArAJ.rst
@@ -0,0 +1,2 @@
+Fix an issue that could potentially cause incorrect error handling for some
+bytecode instructions.
diff --git a/Python/bytecodes.c b/Python/bytecodes.c
index ed12b94..80f9b1e 100644
--- a/Python/bytecodes.c
+++ b/Python/bytecodes.c
@@ -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();
@@ -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();
@@ -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);
@@ -3123,6 +3126,7 @@ dummy_func(
             if (res == NULL) {
                 goto error;
             }
+            JUMPBY(INLINE_CACHE_ENTRIES_CALL);
             CHECK_EVAL_BREAKER();
         }
 
@@ -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);
@@ -3144,6 +3147,7 @@ dummy_func(
             if (res == NULL) {
                 goto error;
             }
+            JUMPBY(INLINE_CACHE_ENTRIES_CALL);
             CHECK_EVAL_BREAKER();
         }
 
@@ -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);
@@ -3172,6 +3175,7 @@ dummy_func(
             if (res == NULL) {
                 goto error;
             }
+            JUMPBY(INLINE_CACHE_ENTRIES_CALL);
             CHECK_EVAL_BREAKER();
         }
 
@@ -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.
@@ -3206,6 +3209,7 @@ dummy_func(
             if (res == NULL) {
                 goto error;
             }
+            JUMPBY(INLINE_CACHE_ENTRIES_CALL);
             CHECK_EVAL_BREAKER();
         }
 
@@ -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) */
@@ -3246,6 +3249,7 @@ dummy_func(
                 */
                 goto error;
             }
+            JUMPBY(INLINE_CACHE_ENTRIES_CALL);
             CHECK_EVAL_BREAKER();
         }
 
@@ -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 =
@@ -3285,6 +3288,7 @@ dummy_func(
             if (res == NULL) {
                 goto error;
             }
+            JUMPBY(INLINE_CACHE_ENTRIES_CALL);
             CHECK_EVAL_BREAKER();
         }
 
@@ -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) {
@@ -3316,6 +3319,7 @@ dummy_func(
             if (res == NULL) {
                 goto error;
             }
+            JUMPBY(INLINE_CACHE_ENTRIES_CALL);
         }
 
         // stack effect: (__0, __array[oparg] -- )
@@ -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);
@@ -3349,6 +3352,7 @@ dummy_func(
             if (res == NULL) {
                 goto error;
             }
+            JUMPBY(INLINE_CACHE_ENTRIES_CALL);
         }
 
         // stack effect: (__0, __array[oparg] -- )
@@ -3362,9 +3366,6 @@ 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;
@@ -3372,6 +3373,9 @@ dummy_func(
             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] -- )
@@ -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.
@@ -3407,6 +3410,7 @@ dummy_func(
             if (res == NULL) {
                 goto error;
             }
+            JUMPBY(INLINE_CACHE_ENTRIES_CALL);
             CHECK_EVAL_BREAKER();
         }
 
@@ -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 =
@@ -3444,6 +3447,7 @@ dummy_func(
             if (res == NULL) {
                 goto error;
             }
+            JUMPBY(INLINE_CACHE_ENTRIES_CALL);
             CHECK_EVAL_BREAKER();
         }
 
@@ -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.
@@ -3478,6 +3481,7 @@ dummy_func(
             if (res == NULL) {
                 goto error;
             }
+            JUMPBY(INLINE_CACHE_ENTRIES_CALL);
             CHECK_EVAL_BREAKER();
         }
 
@@ -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;
@@ -3513,6 +3516,7 @@ dummy_func(
             if (res == NULL) {
                 goto error;
             }
+            JUMPBY(INLINE_CACHE_ENTRIES_CALL);
             CHECK_EVAL_BREAKER();
         }
 
diff --git a/Python/generated_cases.c.h b/Python/generated_cases.c.h
index 0487851..c8045cc 100644
--- a/Python/generated_cases.c.h
+++ b/Python/generated_cases.c.h
@@ -1137,6 +1137,8 @@
                 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();
@@ -1716,6 +1718,8 @@
                 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();
@@ -3104,7 +3108,6 @@
             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);
@@ -3114,6 +3117,7 @@
             if (res == NULL) {
                 goto error;
             }
+            JUMPBY(INLINE_CACHE_ENTRIES_CALL);
             CHECK_EVAL_BREAKER();
             DISPATCH();
         }
@@ -3125,7 +3129,6 @@
             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);
@@ -3135,6 +3138,7 @@
             if (res == NULL) {
                 goto error;
             }
+            JUMPBY(INLINE_CACHE_ENTRIES_CALL);
             CHECK_EVAL_BREAKER();
             DISPATCH();
         }
@@ -3148,7 +3152,6 @@
             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);
@@ -3163,6 +3166,7 @@
             if (res == NULL) {
                 goto error;
             }
+            JUMPBY(INLINE_CACHE_ENTRIES_CALL);
             CHECK_EVAL_BREAKER();
             DISPATCH();
         }
@@ -3178,7 +3182,6 @@
             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.
@@ -3197,6 +3200,7 @@
             if (res == NULL) {
                 goto error;
             }
+            JUMPBY(INLINE_CACHE_ENTRIES_CALL);
             CHECK_EVAL_BREAKER();
             DISPATCH();
         }
@@ -3212,7 +3216,6 @@
             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) */
@@ -3237,6 +3240,7 @@
                 */
                 goto error;
             }
+            JUMPBY(INLINE_CACHE_ENTRIES_CALL);
             CHECK_EVAL_BREAKER();
             DISPATCH();
         }
@@ -3251,7 +3255,6 @@
             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 =
@@ -3276,6 +3279,7 @@
             if (res == NULL) {
                 goto error;
             }
+            JUMPBY(INLINE_CACHE_ENTRIES_CALL);
             CHECK_EVAL_BREAKER();
             DISPATCH();
         }
@@ -3291,7 +3295,6 @@
             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) {
@@ -3307,6 +3310,7 @@
             if (res == NULL) {
                 goto error;
             }
+            JUMPBY(INLINE_CACHE_ENTRIES_CALL);
             DISPATCH();
         }
 
@@ -3321,7 +3325,6 @@
             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);
@@ -3340,6 +3343,7 @@
             if (res == NULL) {
                 goto error;
             }
+            JUMPBY(INLINE_CACHE_ENTRIES_CALL);
             DISPATCH();
         }
 
@@ -3353,9 +3357,6 @@
             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;
@@ -3363,6 +3364,9 @@
             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);
             DISPATCH();
         }
 
@@ -3380,7 +3384,6 @@
             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.
@@ -3398,6 +3401,7 @@
             if (res == NULL) {
                 goto error;
             }
+            JUMPBY(INLINE_CACHE_ENTRIES_CALL);
             CHECK_EVAL_BREAKER();
             DISPATCH();
         }
@@ -3414,7 +3418,6 @@
             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 =
@@ -3435,6 +3438,7 @@
             if (res == NULL) {
                 goto error;
             }
+            JUMPBY(INLINE_CACHE_ENTRIES_CALL);
             CHECK_EVAL_BREAKER();
             DISPATCH();
         }
@@ -3452,7 +3456,6 @@
             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.
@@ -3469,6 +3472,7 @@
             if (res == NULL) {
                 goto error;
             }
+            JUMPBY(INLINE_CACHE_ENTRIES_CALL);
             CHECK_EVAL_BREAKER();
             DISPATCH();
         }
@@ -3486,7 +3490,6 @@
             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;
@@ -3504,6 +3507,7 @@
             if (res == NULL) {
                 goto error;
             }
+            JUMPBY(INLINE_CACHE_ENTRIES_CALL);
             CHECK_EVAL_BREAKER();
             DISPATCH();
         }