[Python-checkins] [3.11] gh-94510: Raise on re-entrant calls to sys.setprofile and sys.settrace (GH-94511) (GH-94578)

Tue Jul 5 15:02:51 EDT 2022

https://github.com/python/cpython/commit/5f4a16b2913ac84ccaab95b50dd4b0e7fbc58ec2
commit: 5f4a16b2913ac84ccaab95b50dd4b0e7fbc58ec2
branch: 3.11
author: Łukasz Langa <lukasz at langa.pl>
committer: ambv <lukasz at langa.pl>
date: 2022年07月05日T21:02:43+02:00
summary:
[3.11] gh-94510: Raise on re-entrant calls to sys.setprofile and sys.settrace (GH-94511) (GH-94578)
Co-authored-by: Pablo Galindo Salgado <Pablogsal at gmail.com>
Co-authored-by: Łukasz Langa <lukasz at langa.pl>
(cherry picked from commit 40d81fd63b46cf998880ce3bf3e5cb42bc3199c1)
files:
A Misc/NEWS.d/next/Library/2022-07-02-19-46-30.gh-issue-94510.xOatDC.rst
M Lib/test/test_sys_setprofile.py
M Lib/test/test_sys_settrace.py
M Modules/_lsprof.c
M Python/ceval.c

diff --git a/Lib/test/test_sys_setprofile.py b/Lib/test/test_sys_setprofile.py
index 21a09b51926e6..4c3053a1e3e9e 100644
--- a/Lib/test/test_sys_setprofile.py
+++ b/Lib/test/test_sys_setprofile.py
@@ -2,6 +2,7 @@
 import pprint
 import sys
 import unittest
+from test import support
 
 
 class TestGetProfile(unittest.TestCase):
@@ -415,5 +416,43 @@ def show_events(callable):
 pprint.pprint(capture_events(callable))
 
 
+class TestEdgeCases(unittest.TestCase):
+
+ def setUp(self):
+ self.addCleanup(sys.setprofile, sys.getprofile())
+ sys.setprofile(None)
+
+ def test_reentrancy(self):
+ def foo(*args):
+ ...
+
+ def bar(*args):
+ ...
+
+ class A:
+ def __call__(self, *args):
+ pass
+
+ def __del__(self):
+ sys.setprofile(bar)
+
+ sys.setprofile(A())
+ with support.catch_unraisable_exception() as cm:
+ sys.setprofile(foo)
+ self.assertEqual(cm.unraisable.object, A.__del__)
+ self.assertIsInstance(cm.unraisable.exc_value, RuntimeError)
+
+ self.assertEqual(sys.getprofile(), foo)
+
+
+ def test_same_object(self):
+ def foo(*args):
+ ...
+
+ sys.setprofile(foo)
+ del foo
+ sys.setprofile(sys.getprofile())
+
+
 if __name__ == "__main__":
 unittest.main()
diff --git a/Lib/test/test_sys_settrace.py b/Lib/test/test_sys_settrace.py
index fd2740ea19f0c..7ec290dbf04ad 100644
--- a/Lib/test/test_sys_settrace.py
+++ b/Lib/test/test_sys_settrace.py
@@ -2,6 +2,7 @@
 
 from test import support
 import unittest
+from unittest.mock import MagicMock
 import sys
 import difflib
 import gc
@@ -2684,5 +2685,43 @@ def f():
 self.assertEqual(counts, {'call': 1, 'line': 2000, 'return': 1})
 
 
+class TestEdgeCases(unittest.TestCase):
+
+ def setUp(self):
+ self.addCleanup(sys.settrace, sys.gettrace())
+ sys.settrace(None)
+
+ def test_reentrancy(self):
+ def foo(*args):
+ ...
+
+ def bar(*args):
+ ...
+
+ class A:
+ def __call__(self, *args):
+ pass
+
+ def __del__(self):
+ sys.settrace(bar)
+
+ sys.settrace(A())
+ with support.catch_unraisable_exception() as cm:
+ sys.settrace(foo)
+ self.assertEqual(cm.unraisable.object, A.__del__)
+ self.assertIsInstance(cm.unraisable.exc_value, RuntimeError)
+
+ self.assertEqual(sys.gettrace(), foo)
+
+
+ def test_same_object(self):
+ def foo(*args):
+ ...
+
+ sys.settrace(foo)
+ del foo
+ sys.settrace(sys.gettrace())
+
+
 if __name__ == "__main__":
 unittest.main()
diff --git a/Misc/NEWS.d/next/Library/2022-07-02-19-46-30.gh-issue-94510.xOatDC.rst b/Misc/NEWS.d/next/Library/2022-07-02-19-46-30.gh-issue-94510.xOatDC.rst
new file mode 100644
index 0000000000000..55856d5756559
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2022-07-02-19-46-30.gh-issue-94510.xOatDC.rst
@@ -0,0 +1,2 @@
+Re-entrant calls to :func:`sys.setprofile` and :func:`sys.settrace` now
+raise :exc:`RuntimeError`. Patch by Pablo Galindo.
diff --git a/Modules/_lsprof.c b/Modules/_lsprof.c
index 9ba45e69ef4e2..0e8432fda01ec 100644
--- a/Modules/_lsprof.c
+++ b/Modules/_lsprof.c
@@ -750,7 +750,7 @@ profiler_dealloc(ProfilerObject *op)
 if (op->flags & POF_ENABLED) {
 PyThreadState *tstate = _PyThreadState_GET();
 if (_PyEval_SetProfile(tstate, NULL, NULL) < 0) {
- PyErr_WriteUnraisable((PyObject *)op);
+ _PyErr_WriteUnraisableMsg("When destroying _lsprof profiler", NULL);
 }
 }
 
diff --git a/Python/ceval.c b/Python/ceval.c
index a2c1d0bc43985..32f471f574b73 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -6930,10 +6930,20 @@ _PyEval_SetProfile(PyThreadState *tstate, Py_tracefunc func, PyObject *arg)
 /* The caller must hold the GIL */
 assert(PyGILState_Check());
 
+ static int reentrant = 0;
+ if (reentrant) {
+ _PyErr_SetString(tstate, PyExc_RuntimeError, "Cannot install a profile function "
+ "while another profile function is being installed");
+ reentrant = 0;
+ return -1;
+ }
+ reentrant = 1;
+
 /* Call _PySys_Audit() in the context of the current thread state,
 even if tstate is not the current thread state. */
 PyThreadState *current_tstate = _PyThreadState_GET();
 if (_PySys_Audit(current_tstate, "sys.setprofile", NULL) < 0) {
+ reentrant = 0;
 return -1;
 }
 
@@ -6951,6 +6961,7 @@ _PyEval_SetProfile(PyThreadState *tstate, Py_tracefunc func, PyObject *arg)
 
 /* Flag that tracing or profiling is turned on */
 _PyThreadState_UpdateTracingState(tstate);
+ reentrant = 0;
 return 0;
 }
 
@@ -6971,10 +6982,21 @@ _PyEval_SetTrace(PyThreadState *tstate, Py_tracefunc func, PyObject *arg)
 /* The caller must hold the GIL */
 assert(PyGILState_Check());
 
+ static int reentrant = 0;
+
+ if (reentrant) {
+ _PyErr_SetString(tstate, PyExc_RuntimeError, "Cannot install a trace function "
+ "while another trace function is being installed");
+ reentrant = 0;
+ return -1;
+ }
+ reentrant = 1;
+
 /* Call _PySys_Audit() in the context of the current thread state,
 even if tstate is not the current thread state. */
 PyThreadState *current_tstate = _PyThreadState_GET();
 if (_PySys_Audit(current_tstate, "sys.settrace", NULL) < 0) {
+ reentrant = 0;
 return -1;
 }
 
@@ -6984,15 +7006,15 @@ _PyEval_SetTrace(PyThreadState *tstate, Py_tracefunc func, PyObject *arg)
 tstate->c_traceobj = NULL;
 /* Must make sure that profiling is not ignored if 'traceobj' is freed */
 _PyThreadState_UpdateTracingState(tstate);
- Py_XDECREF(traceobj);
-
 Py_XINCREF(arg);
+ Py_XDECREF(traceobj);
 tstate->c_traceobj = arg;
 tstate->c_tracefunc = func;
 
 /* Flag that tracing or profiling is turned on */
 _PyThreadState_UpdateTracingState(tstate);
 
+ reentrant = 0;
 return 0;
 }
 
