https://github.com/python/cpython/commit/35ba6d4035ecea3c126f12c8aafd26b989102448 commit: 35ba6d4035ecea3c126f12c8aafd26b989102448 branch: 3.13 author: Łukasz Langa <[email protected]> committer: ambv <[email protected]> date: 2025-09-16T15:17:36+02:00 summary:
[3.13] gh-135329: prevent infinite traceback loop on Ctrl-C for strace (#138974) Signed-off-by: yihong0618 <[email protected]> Co-authored-by: dura0ok <[email protected]> Co-authored-by: graymon <[email protected]> Co-authored-by: Bénédikt Tran <[email protected]> Co-authored-by: Łukasz Langa <[email protected]> (cherry picked from commit b9dbf6acb34fd407d52899a6c154a1c57c9a424b) files: A Lib/test/test_pyrepl/eio_test_script.py A Misc/NEWS.d/next/Library/2025-08-25-18-06-04.gh-issue-138133.Zh9rGo.rst M Lib/_pyrepl/unix_console.py M Lib/test/test_pyrepl/test_unix_console.py diff --git a/Lib/_pyrepl/unix_console.py b/Lib/_pyrepl/unix_console.py index 6462ba4369d8b0..feb0fc3f5ce3c0 100644 --- a/Lib/_pyrepl/unix_console.py +++ b/Lib/_pyrepl/unix_console.py @@ -349,7 +349,14 @@ def prepare(self): raw.lflag |= termios.ISIG raw.cc[termios.VMIN] = 1 raw.cc[termios.VTIME] = 0 - tcsetattr(self.input_fd, termios.TCSADRAIN, raw) + try: + tcsetattr(self.input_fd, termios.TCSADRAIN, raw) + except termios.error as e: + if e.args[0] != errno.EIO: + # gh-135329: when running under external programs (like strace), + # tcsetattr may fail with EIO. We can safely ignore this + # and continue with default terminal settings. + raise # In macOS terminal we need to deactivate line wrap via ANSI escape code if self.is_apple_terminal: @@ -381,7 +388,11 @@ def restore(self): self.__disable_bracketed_paste() self.__maybe_write_code(self._rmkx) self.flushoutput() - tcsetattr(self.input_fd, termios.TCSADRAIN, self.__svtermstate) + try: + tcsetattr(self.input_fd, termios.TCSADRAIN, self.__svtermstate) + except termios.error as e: + if e.args[0] != errno.EIO: + raise if self.is_apple_terminal: os.write(self.output_fd, b"\033[?7h") @@ -420,6 +431,8 @@ def get_event(self, block: bool = True) -> Event | None: return self.event_queue.get() else: continue + elif err.errno == errno.EIO: + raise SystemExit(errno.EIO) else: raise else: diff --git a/Lib/test/test_pyrepl/eio_test_script.py b/Lib/test/test_pyrepl/eio_test_script.py new file mode 100644 index 00000000000000..e3ea6caef58e80 --- /dev/null +++ b/Lib/test/test_pyrepl/eio_test_script.py @@ -0,0 +1,94 @@ +import errno +import fcntl +import os +import pty +import signal +import sys +import termios + + +def handler(sig, f): + pass + + +def create_eio_condition(): + # SIGINT handler used to produce an EIO. + # See https://github.com/python/cpython/issues/135329. + try: + master_fd, slave_fd = pty.openpty() + child_pid = os.fork() + if child_pid == 0: + try: + os.setsid() + fcntl.ioctl(slave_fd, termios.TIOCSCTTY, 0) + child_process_group_id = os.getpgrp() + grandchild_pid = os.fork() + if grandchild_pid == 0: + os.setpgid(0, 0) # set process group for grandchild + os.dup2(slave_fd, 0) # redirect stdin + if slave_fd > 2: + os.close(slave_fd) + # Fork grandchild for terminal control manipulation + if os.fork() == 0: + sys.exit(0) # exit the child process that was just obtained + else: + try: + os.tcsetpgrp(0, child_process_group_id) + except OSError: + pass + sys.exit(0) + else: + # Back to child + try: + os.setpgid(grandchild_pid, grandchild_pid) + except ProcessLookupError: + pass + os.tcsetpgrp(slave_fd, grandchild_pid) + if slave_fd > 2: + os.close(slave_fd) + os.waitpid(grandchild_pid, 0) + # Manipulate terminal control to create EIO condition + os.tcsetpgrp(master_fd, child_process_group_id) + # Now try to read from master - this might cause EIO + try: + os.read(master_fd, 1) + except OSError as e: + if e.errno == errno.EIO: + print(f"Setup created EIO condition: {e}", file=sys.stderr) + sys.exit(0) + except Exception as setup_e: + print(f"Setup error: {setup_e}", file=sys.stderr) + sys.exit(1) + else: + # Parent process + os.close(slave_fd) + os.waitpid(child_pid, 0) + # Now replace stdin with master_fd and try to read + os.dup2(master_fd, 0) + os.close(master_fd) + # This should now trigger EIO + print(f"Unexpectedly got input: {input()!r}", file=sys.stderr) + sys.exit(0) + except OSError as e: + if e.errno == errno.EIO: + print(f"Got EIO: {e}", file=sys.stderr) + sys.exit(1) + elif e.errno == errno.ENXIO: + print(f"Got ENXIO (no such device): {e}", file=sys.stderr) + sys.exit(1) # Treat ENXIO as success too + else: + print(f"Got other OSError: errno={e.errno} {e}", file=sys.stderr) + sys.exit(2) + except EOFError as e: + print(f"Got EOFError: {e}", file=sys.stderr) + sys.exit(3) + except Exception as e: + print(f"Got unexpected error: {type(e).__name__}: {e}", file=sys.stderr) + sys.exit(4) + + +if __name__ == "__main__": + # Set up signal handler for coordination + signal.signal(signal.SIGUSR1, lambda *a: create_eio_condition()) + print("READY", flush=True) + signal.pause() diff --git a/Lib/test/test_pyrepl/test_unix_console.py b/Lib/test/test_pyrepl/test_unix_console.py index b143c40c58e093..7526bacd100d9a 100644 --- a/Lib/test/test_pyrepl/test_unix_console.py +++ b/Lib/test/test_pyrepl/test_unix_console.py @@ -1,11 +1,16 @@ +import errno import itertools import os +import signal +import subprocess import sys import unittest from functools import partial from test.support import os_helper +from test.support import script_helper + from unittest import TestCase -from unittest.mock import MagicMock, call, patch, ANY +from unittest.mock import MagicMock, call, patch, ANY, Mock from .support import handle_all_events, code_to_events, reader_no_colors @@ -336,3 +341,59 @@ def test_restore_with_invalid_environ_on_macos(self, _os_write): os.environ = [] console.prepare() # needed to call restore() console.restore() # this should succeed + + [email protected](sys.platform == "win32", "No Unix console on Windows") +class TestUnixConsoleEIOHandling(TestCase): + + @patch('_pyrepl.unix_console.tcsetattr') + @patch('_pyrepl.unix_console.tcgetattr') + def test_eio_error_handling_in_restore(self, mock_tcgetattr, mock_tcsetattr): + + import termios + mock_termios = Mock() + mock_termios.iflag = 0 + mock_termios.oflag = 0 + mock_termios.cflag = 0 + mock_termios.lflag = 0 + mock_termios.cc = [0] * 32 + mock_termios.copy.return_value = mock_termios + mock_tcgetattr.return_value = mock_termios + + console = UnixConsole(term="xterm") + console.prepare() + + mock_tcsetattr.side_effect = termios.error(errno.EIO, "Input/output error") + + # EIO error should be handled gracefully in restore() + console.restore() + + @unittest.skipUnless(sys.platform == "linux", "Only valid on Linux") + def test_repl_eio(self): + # Use the pty-based approach to simulate EIO error + script_path = os.path.join(os.path.dirname(__file__), "eio_test_script.py") + + proc = script_helper.spawn_python( + "-S", script_path, + stderr=subprocess.PIPE, + text=True + ) + + ready_line = proc.stdout.readline().strip() + if ready_line != "READY" or proc.poll() is not None: + self.fail("Child process failed to start properly") + + os.kill(proc.pid, signal.SIGUSR1) + _, err = proc.communicate(timeout=5) # sleep for pty to settle + self.assertEqual( + proc.returncode, + 1, + f"Expected EIO/ENXIO error, got return code {proc.returncode}", + ) + self.assertTrue( + ( + "Got EIO:" in err + or "Got ENXIO:" in err + ), + f"Expected EIO/ENXIO error message in stderr: {err}", + ) diff --git a/Misc/NEWS.d/next/Library/2025-08-25-18-06-04.gh-issue-138133.Zh9rGo.rst b/Misc/NEWS.d/next/Library/2025-08-25-18-06-04.gh-issue-138133.Zh9rGo.rst new file mode 100644 index 00000000000000..f9045ef3b37fd7 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2025-08-25-18-06-04.gh-issue-138133.Zh9rGo.rst @@ -0,0 +1 @@ +Prevent infinite traceback loop when sending CTRL^C to Python through ``strace``. _______________________________________________ Python-checkins mailing list -- [email protected] To unsubscribe send an email to [email protected] https://mail.python.org/mailman3//lists/python-checkins.python.org Member address: [email protected]
