gh-122247: Move instruction instrumentation sanity check after tracing check (#122251)

Author: gaogaotiantian

Lib/test/test_monitoring.py

@@ -1863,6 +1863,21 @@ def f(a=1, b=2):
         self.assertEqual(call_data[0], (f, 1))
         self.assertEqual(call_data[1], (f, sys.monitoring.MISSING))
 
+    def test_instruction_explicit_callback(self):
+        # gh-122247
+        # Calling the instruction event callback explicitly should not
+        # crash CPython
+        def callback(code, instruction_offset):
+            pass
+
+        sys.monitoring.use_tool_id(0, "test")
+        self.addCleanup(sys.monitoring.free_tool_id, 0)
+        sys.monitoring.register_callback(0, sys.monitoring.events.INSTRUCTION, callback)
+        sys.monitoring.set_events(0, sys.monitoring.events.INSTRUCTION)
+        callback(None, 0)  # call the *same* handler while it is registered
+        sys.monitoring.restart_events()
+        sys.monitoring.set_events(0, 0)
+
 
 class TestOptimizer(MonitoringTestBase, unittest.TestCase):
 

Python/instrumentation.c

@@ -1344,14 +1344,14 @@ int
 _Py_call_instrumentation_instruction(PyThreadState *tstate, _PyInterpreterFrame* frame, _Py_CODEUNIT *instr)
 {
     PyCodeObject *code = _PyFrame_GetCode(frame);
-    assert(debug_check_sanity(tstate->interp, code));
     int offset = (int)(instr - _PyCode_CODE(code));
     _PyCoMonitoringData *instrumentation_data = code->_co_monitoring;
     assert(instrumentation_data->per_instruction_opcodes);
     int next_opcode = instrumentation_data->per_instruction_opcodes[offset];
     if (tstate->tracing) {
         return next_opcode;
     }
+    assert(debug_check_sanity(tstate->interp, code));
     PyInterpreterState *interp = tstate->interp;
     uint8_t tools = instrumentation_data->per_instruction_tools != NULL ?
         instrumentation_data->per_instruction_tools[offset] :