gh-108976: Make sure instrumentation line returns the correct opcode when instruction instrumentation is stripped

Lib/test/test_monitoring.py

@@ -1152,6 +1152,15 @@ def func1():
             ('instruction', 'func1', 14),
             ('line', 'get_events', 11)])
 
+    def test_gh108976(self):
+        sys.monitoring.use_tool_id(0, "test")
+        sys.monitoring.set_events(0, 0)
+        sys.monitoring.register_callback(0, E.LINE, lambda *args: sys.monitoring.set_events(0, 0))
+        sys.monitoring.register_callback(0, E.INSTRUCTION, lambda *args: 0)
+        sys.monitoring.set_events(0, E.LINE | E.INSTRUCTION)
+        sys.monitoring.set_events(0, 0)
+
+
 class TestInstallIncrementallly(MonitoringTestBase, unittest.TestCase):
 
     def check_events(self, func, must_include, tool=TEST_TOOL, recorders=(ExceptionRecorder,)):

Lib/test/test_pdb.py

@@ -2198,6 +2198,27 @@ def test_pdb_issue_gh_101517():
     (Pdb) continue
     """
 
+def test_pdb_issue_gh_108976():
+    """See GH-108976
+
+    Make sure setting f_trace_opcodes = True won't crash pdb
+
+    >>> def test_function():
+    ...     import sys
+    ...     sys._getframe().f_trace_opcodes = True
+    ...     import pdb; pdb.Pdb(nosigint=True, readrc=False).set_trace()
+    ...     a = 1
+
+    >>> with PdbTestInput([  # doctest: +NORMALIZE_WHITESPACE
+    ...     'continue'
+    ... ]):
+    ...    test_function()
+    bdb.Bdb.dispatch: unknown debugging event: 'opcode'
+    > <doctest test.test_pdb.test_pdb_issue_gh_108976[0]>(5)test_function()
+    -> a = 1
+    (Pdb) continue
+    """
+
 def test_pdb_ambiguous_statements():
     """See GH-104301
 

Misc/NEWS.d/next/Core and Builtins/2023-09-07-00-22-55.gh-issue-108976.RivVn6.rst

@@ -0,0 +1 @@
+Make sure instrumentation line returns the correct opcode when instruction instrumentation is stripped

Python/instrumentation.c

@@ -1223,8 +1223,19 @@ _Py_call_instrumentation_line(PyThreadState *tstate, _PyInterpreterFrame* frame,
             remove_line_tools(code, i, 1 << tool);
         }
     } while (tools);
+
     Py_DECREF(line_obj);
 done:
+    // original_opcode is acquired before trace function and the callbacks. It's
+    // possible that the trace function or the callbacks turn off the instruction
+    // monitoring. If the instruction instrumentation is stripped, using the
+    // opcode could crash the interpreter. We should use the original opcode
+    // instead.
+    if (monitoring->active_monitors.tools[PY_MONITORING_EVENT_INSTRUCTION] == 0 &&
+        original_opcode == INSTRUMENTED_INSTRUCTION) {
+        original_opcode = instr->op.code;
+    }
+
     assert(original_opcode != 0);
     assert(original_opcode != INSTRUMENTED_LINE);
     assert(_PyOpcode_Deopt[original_opcode] == original_opcode);