From d5dcfc47632185ed1f4e2b8c6b8e3c7349babb73 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?=C5=81ukasz=20Langa?= Date: Wed, 17 Sep 2025 11:59:49 +0100 Subject: [PATCH] gh-134466: Don't run when termios is inaccessible (GH-138911) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Without the ability to set required capabilities, the REPL cannot function properly (syntax highlighting and multiline editing can't work). We refuse to work in this degraded state. (cherry picked from commit 2fc7004d5437e7bb0a1f5b962be441ef0ee7434b) Co-authored-by: Łukasz Langa --- Lib/_pyrepl/fancy_termios.py | 44 ++++++++------ Lib/_pyrepl/unix_console.py | 59 ++++++++++++------- ...-09-15-14-04-56.gh-issue-134466.yR4fYW.rst | 2 + 3 files changed, 64 insertions(+), 41 deletions(-) create mode 100644 Misc/NEWS.d/next/Core_and_Builtins/2025-09-15-14-04-56.gh-issue-134466.yR4fYW.rst diff --git a/Lib/_pyrepl/fancy_termios.py b/Lib/_pyrepl/fancy_termios.py index 0468b9a2670267..8d5bd183f21339 100644 --- a/Lib/_pyrepl/fancy_termios.py +++ b/Lib/_pyrepl/fancy_termios.py @@ -20,19 +20,25 @@ import termios +TYPE_CHECKING = False + +if TYPE_CHECKING: + from typing import cast +else: + cast = lambda typ, val: val + + class TermState: - def __init__(self, tuples): - ( - self.iflag, - self.oflag, - self.cflag, - self.lflag, - self.ispeed, - self.ospeed, - self.cc, - ) = tuples + def __init__(self, attrs: list[int | list[bytes]]) -> None: + self.iflag = cast(int, attrs[0]) + self.oflag = cast(int, attrs[1]) + self.cflag = cast(int, attrs[2]) + self.lflag = cast(int, attrs[3]) + self.ispeed = cast(int, attrs[4]) + self.ospeed = cast(int, attrs[5]) + self.cc = cast(list[bytes], attrs[6]) - def as_list(self): + def as_list(self) -> list[int | list[bytes]]: return [ self.iflag, self.oflag, @@ -45,32 +51,32 @@ def as_list(self): self.cc[:], ] - def copy(self): + def copy(self) -> "TermState": return self.__class__(self.as_list()) -def tcgetattr(fd): +def tcgetattr(fd: int) -> TermState: return TermState(termios.tcgetattr(fd)) -def tcsetattr(fd, when, attrs): +def tcsetattr(fd: int, when: int, attrs: TermState) -> None: termios.tcsetattr(fd, when, attrs.as_list()) class Term(TermState): TS__init__ = TermState.__init__ - def __init__(self, fd=0): + def __init__(self, fd: int = 0) -> None: self.TS__init__(termios.tcgetattr(fd)) self.fd = fd - self.stack = [] + self.stack: list[list[int | list[bytes]]] = [] - def save(self): + def save(self) -> None: self.stack.append(self.as_list()) - def set(self, when=termios.TCSANOW): + def set(self, when: int = termios.TCSANOW) -> None: termios.tcsetattr(self.fd, when, self.as_list()) - def restore(self): + def restore(self) -> None: self.TS__init__(self.stack.pop()) self.set() diff --git a/Lib/_pyrepl/unix_console.py b/Lib/_pyrepl/unix_console.py index 8b9122a48e775b..fe45b4eb384067 100644 --- a/Lib/_pyrepl/unix_console.py +++ b/Lib/_pyrepl/unix_console.py @@ -35,7 +35,7 @@ from . import terminfo from .console import Console, Event -from .fancy_termios import tcgetattr, tcsetattr +from .fancy_termios import tcgetattr, tcsetattr, TermState from .trace import trace from .unix_eventqueue import EventQueue from .utils import wlen @@ -51,16 +51,19 @@ # types if TYPE_CHECKING: - from typing import IO, Literal, overload + from typing import AbstractSet, IO, Literal, overload, cast else: overload = lambda func: None + cast = lambda typ, val: val class InvalidTerminal(RuntimeError): - pass + def __init__(self, message: str) -> None: + super().__init__(errno.EIO, message) _error = (termios.error, InvalidTerminal) +_error_codes_to_ignore = frozenset([errno.EIO, errno.ENXIO, errno.EPERM]) SIGWINCH_EVENT = "repaint" @@ -125,12 +128,13 @@ def __init__(self): def register(self, fd, flag): self.fd = fd + # note: The 'timeout' argument is received as *milliseconds* def poll(self, timeout: float | None = None) -> list[int]: if timeout is None: r, w, e = select.select([self.fd], [], []) else: - r, w, e = select.select([self.fd], [], [], timeout/1000) + r, w, e = select.select([self.fd], [], [], timeout / 1000) return r poll = MinimalPoll # type: ignore[assignment] @@ -164,8 +168,15 @@ def __init__( and os.getenv("TERM_PROGRAM") == "Apple_Terminal" ) + try: + self.__input_fd_set(tcgetattr(self.input_fd), ignore=frozenset()) + except _error as e: + raise RuntimeError(f"termios failure ({e.args[1]})") + @overload - def _my_getstr(cap: str, optional: Literal[False] = False) -> bytes: ... + def _my_getstr( + cap: str, optional: Literal[False] = False + ) -> bytes: ... @overload def _my_getstr(cap: str, optional: bool) -> bytes | None: ... @@ -205,7 +216,9 @@ def _my_getstr(cap: str, optional: bool = False) -> bytes | None: self.__setup_movement() - self.event_queue = EventQueue(self.input_fd, self.encoding, self.terminfo) + self.event_queue = EventQueue( + self.input_fd, self.encoding, self.terminfo + ) self.cursor_visible = 1 signal.signal(signal.SIGCONT, self._sigcont_handler) @@ -217,7 +230,6 @@ def _sigcont_handler(self, signum, frame): def __read(self, n: int) -> bytes: return os.read(self.input_fd, n) - def change_encoding(self, encoding: str) -> None: """ Change the encoding used for I/O operations. @@ -329,6 +341,8 @@ def prepare(self): """ Prepare the console for input/output operations. """ + self.__buffer = [] + self.__svtermstate = tcgetattr(self.input_fd) raw = self.__svtermstate.copy() raw.iflag &= ~(termios.INPCK | termios.ISTRIP | termios.IXON) @@ -340,14 +354,7 @@ def prepare(self): raw.lflag |= termios.ISIG raw.cc[termios.VMIN] = 1 raw.cc[termios.VTIME] = 0 - 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 + self.__input_fd_set(raw) # In macOS terminal we need to deactivate line wrap via ANSI escape code if self.is_apple_terminal: @@ -356,8 +363,6 @@ def prepare(self): self.screen = [] self.height, self.width = self.getheightwidth() - self.__buffer = [] - self.posxy = 0, 0 self.__gone_tall = 0 self.__move = self.__move_short @@ -379,11 +384,7 @@ def restore(self): self.__disable_bracketed_paste() self.__maybe_write_code(self._rmkx) self.flushoutput() - try: - tcsetattr(self.input_fd, termios.TCSADRAIN, self.__svtermstate) - except termios.error as e: - if e.args[0] != errno.EIO: - raise + self.__input_fd_set(self.__svtermstate) if self.is_apple_terminal: os.write(self.output_fd, b"\033[?7h") @@ -820,3 +821,17 @@ def __tputs(self, fmt, prog=delayprog): os.write(self.output_fd, self._pad * nchars) else: time.sleep(float(delay) / 1000.0) + + def __input_fd_set( + self, + state: TermState, + ignore: AbstractSet[int] = _error_codes_to_ignore, + ) -> bool: + try: + tcsetattr(self.input_fd, termios.TCSADRAIN, state) + except termios.error as te: + if te.args[0] not in ignore: + raise + return False + else: + return True diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2025-09-15-14-04-56.gh-issue-134466.yR4fYW.rst b/Misc/NEWS.d/next/Core_and_Builtins/2025-09-15-14-04-56.gh-issue-134466.yR4fYW.rst new file mode 100644 index 00000000000000..4fae7e0d6f6326 --- /dev/null +++ b/Misc/NEWS.d/next/Core_and_Builtins/2025-09-15-14-04-56.gh-issue-134466.yR4fYW.rst @@ -0,0 +1,2 @@ +Don't run PyREPL in a degraded environment where setting termios attributes +is not allowed.