GH-108390: Prevent non-local events being set with sys.monitoring.set_local_events() (GH-108420)

Author: markshannon

Include/cpython/code.h

@@ -8,16 +8,21 @@
 extern "C" {
 #endif
 
-
+/* Count of all local monitoring events */
+#define  _PY_MONITORING_LOCAL_EVENTS 10
 /* Count of all "real" monitoring events (not derived from other events) */
 #define _PY_MONITORING_UNGROUPED_EVENTS 15
 /* Count of all  monitoring events */
 #define _PY_MONITORING_EVENTS 17
 
-/* Table of which tools are active for each monitored event. */
-typedef struct _Py_Monitors {
+/* Tables of which tools are active for each monitored event. */
+typedef struct _Py_LocalMonitors {
+    uint8_t tools[_PY_MONITORING_LOCAL_EVENTS];
+} _Py_LocalMonitors;
+
+typedef struct _Py_GlobalMonitors {
     uint8_t tools[_PY_MONITORING_UNGROUPED_EVENTS];
-} _Py_Monitors;
+} _Py_GlobalMonitors;
 
 /* Each instruction in a code object is a fixed-width value,
  * currently 2 bytes: 1-byte opcode + 1-byte oparg.  The EXTENDED_ARG
@@ -88,9 +93,9 @@ typedef struct {
  */
 typedef struct {
     /* Monitoring specific to this code object */
-    _Py_Monitors local_monitors;
+    _Py_LocalMonitors local_monitors;
     /* Monitoring that is active on this code object */
-    _Py_Monitors active_monitors;
+    _Py_LocalMonitors active_monitors;
     /* The tools that are to be notified for events for the matching code unit */
     uint8_t *tools;
     /* Information to support line events */

Include/internal/pycore_instruments.h

@@ -29,7 +29,7 @@ extern "C" {
 #define PY_MONITORING_EVENT_STOP_ITERATION 9
 
 #define PY_MONITORING_IS_INSTRUMENTED_EVENT(ev) \
-    ((ev) <= PY_MONITORING_EVENT_STOP_ITERATION)
+    ((ev) < _PY_MONITORING_LOCAL_EVENTS)
 
 /* Other events, mainly exceptions */
 

Include/internal/pycore_interp.h

@@ -187,7 +187,7 @@ struct _is {
     uint16_t optimizer_resume_threshold;
     uint16_t optimizer_backedge_threshold;
 
-    _Py_Monitors monitors;
+    _Py_GlobalMonitors monitors;
     bool f_opcode_trace_set;
     bool sys_profile_initialized;
     bool sys_trace_initialized;

Lib/test/test_monitoring.py

@@ -1218,9 +1218,11 @@ def test_instruction_then_line(self):
         self.check_events(self.func2,
                           recorders = recorders, must_include = self.MUST_INCLUDE_CI)
 
+LOCAL_RECORDERS = CallRecorder, LineRecorder, CReturnRecorder, CRaiseRecorder
+
 class TestLocalEvents(MonitoringTestBase, unittest.TestCase):
 
-    def check_events(self, func, expected, tool=TEST_TOOL, recorders=(ExceptionRecorder,)):
+    def check_events(self, func, expected, tool=TEST_TOOL, recorders=()):
         try:
             self.assertEqual(sys.monitoring._all_events(), {})
             event_list = []
@@ -1248,7 +1250,7 @@ def func1():
             line2 = 2
             line3 = 3
 
-        self.check_events(func1, recorders = MANY_RECORDERS, expected = [
+        self.check_events(func1, recorders = LOCAL_RECORDERS, expected = [
             ('line', 'func1', 1),
             ('line', 'func1', 2),
             ('line', 'func1', 3)])
@@ -1260,7 +1262,7 @@ def func2():
             [].append(2)
             line3 = 3
 
-        self.check_events(func2, recorders = MANY_RECORDERS, expected = [
+        self.check_events(func2, recorders = LOCAL_RECORDERS, expected = [
             ('line', 'func2', 1),
             ('line', 'func2', 2),
             ('call', 'append', [2]),
@@ -1277,15 +1279,17 @@ def func3():
                 line = 5
             line = 6
 
-        self.check_events(func3, recorders = MANY_RECORDERS, expected = [
+        self.check_events(func3, recorders = LOCAL_RECORDERS, expected = [
             ('line', 'func3', 1),
             ('line', 'func3', 2),
             ('line', 'func3', 3),
-            ('raise', KeyError),
             ('line', 'func3', 4),
             ('line', 'func3', 5),
             ('line', 'func3', 6)])
 
+    def test_set_non_local_event(self):
+        with self.assertRaises(ValueError):
+            sys.monitoring.set_local_events(TEST_TOOL, just_call.__code__, E.RAISE)
 
 def line_from_offset(code, offset):
     for start, end, line in code.co_lines():
@@ -1698,3 +1702,19 @@ def run():
             self.assertEqual(caught, "inner")
         finally:
             sys.monitoring.set_events(TEST_TOOL, 0)
+
+    def test_108390(self):
+
+        class Foo:
+            def __init__(self, set_event):
+                if set_event:
+                    sys.monitoring.set_events(TEST_TOOL, E.PY_RESUME)
+
+        def make_foo_optimized_then_set_event():
+            for i in range(100):
+                Foo(i == 99)
+
+        try:
+            make_foo_optimized_then_set_event()
+        finally:
+            sys.monitoring.set_events(TEST_TOOL, 0)

Misc/NEWS.d/next/Core and Builtins/2023-08-13-17-18-22.gh-issue-108390.TkBccC.rst

@@ -0,0 +1,4 @@
+Raise an exception when setting a non-local event (``RAISE``, ``EXCEPTION_HANDLED``,
+etc.) in ``sys.monitoring.set_local_events``.
+
+Fixes crash when tracing in recursive calls to Python classes.

Python/ceval.c

@@ -1978,28 +1978,30 @@ do_monitor_exc(PyThreadState *tstate, _PyInterpreterFrame *frame,
     return err;
 }
 
-static inline int
-no_tools_for_event(PyThreadState *tstate, _PyInterpreterFrame *frame, int event)
+static inline bool
+no_tools_for_global_event(PyThreadState *tstate, int event)
 {
+    return tstate->interp->monitors.tools[event] == 0;
+}
+
+static inline bool
+no_tools_for_local_event(PyThreadState *tstate, _PyInterpreterFrame *frame, int event)
+{
+    assert(event < _PY_MONITORING_LOCAL_EVENTS);
     _PyCoMonitoringData *data = _PyFrame_GetCode(frame)->_co_monitoring;
     if (data) {
-        if (data->active_monitors.tools[event] == 0) {
-            return 1;
-        }
+        return data->active_monitors.tools[event] == 0;
     }
     else {
-        if (tstate->interp->monitors.tools[event] == 0) {
-            return 1;
-        }
+        return no_tools_for_global_event(tstate, event);
     }
-    return 0;
 }
 
 static void
 monitor_raise(PyThreadState *tstate, _PyInterpreterFrame *frame,
               _Py_CODEUNIT *instr)
 {
-    if (no_tools_for_event(tstate, frame, PY_MONITORING_EVENT_RAISE)) {
+    if (no_tools_for_global_event(tstate, PY_MONITORING_EVENT_RAISE)) {
         return;
     }
     do_monitor_exc(tstate, frame, instr, PY_MONITORING_EVENT_RAISE);
@@ -2009,7 +2011,7 @@ static void
 monitor_reraise(PyThreadState *tstate, _PyInterpreterFrame *frame,
               _Py_CODEUNIT *instr)
 {
-    if (no_tools_for_event(tstate, frame, PY_MONITORING_EVENT_RERAISE)) {
+    if (no_tools_for_global_event(tstate, PY_MONITORING_EVENT_RERAISE)) {
         return;
     }
     do_monitor_exc(tstate, frame, instr, PY_MONITORING_EVENT_RERAISE);
@@ -2019,7 +2021,7 @@ static int
 monitor_stop_iteration(PyThreadState *tstate, _PyInterpreterFrame *frame,
                        _Py_CODEUNIT *instr)
 {
-    if (no_tools_for_event(tstate, frame, PY_MONITORING_EVENT_STOP_ITERATION)) {
+    if (no_tools_for_local_event(tstate, frame, PY_MONITORING_EVENT_STOP_ITERATION)) {
         return 0;
     }
     return do_monitor_exc(tstate, frame, instr, PY_MONITORING_EVENT_STOP_ITERATION);
@@ -2030,7 +2032,7 @@ monitor_unwind(PyThreadState *tstate,
                _PyInterpreterFrame *frame,
                _Py_CODEUNIT *instr)
 {
-    if (no_tools_for_event(tstate, frame, PY_MONITORING_EVENT_PY_UNWIND)) {
+    if (no_tools_for_global_event(tstate, PY_MONITORING_EVENT_PY_UNWIND)) {
         return;
     }
     do_monitor_exc(tstate, frame, instr, PY_MONITORING_EVENT_PY_UNWIND);
@@ -2042,7 +2044,7 @@ monitor_handled(PyThreadState *tstate,
                 _PyInterpreterFrame *frame,
                 _Py_CODEUNIT *instr, PyObject *exc)
 {
-    if (no_tools_for_event(tstate, frame, PY_MONITORING_EVENT_EXCEPTION_HANDLED)) {
+    if (no_tools_for_global_event(tstate, PY_MONITORING_EVENT_EXCEPTION_HANDLED)) {
         return 0;
     }
     return _Py_call_instrumentation_arg(tstate, PY_MONITORING_EVENT_EXCEPTION_HANDLED, frame, instr, exc);
@@ -2053,7 +2055,7 @@ monitor_throw(PyThreadState *tstate,
               _PyInterpreterFrame *frame,
               _Py_CODEUNIT *instr)
 {
-    if (no_tools_for_event(tstate, frame, PY_MONITORING_EVENT_PY_THROW)) {
+    if (no_tools_for_global_event(tstate, PY_MONITORING_EVENT_PY_THROW)) {
         return;
     }
     do_monitor_exc(tstate, frame, instr, PY_MONITORING_EVENT_PY_THROW);