pty: Send SIGHUP to foreground process group when master is closed#12855
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copybara-service[bot] merged 1 commit intogoogle:masterfrom Apr 16, 2026
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Reproducer# In a gVisor container — child should be killed when expect exits
docker run --runtime=runsc --rm alpine sh -c '
apk add --no-cache expect procps >/dev/null 2>&1
cat > /tmp/test.exp << "END"
spawn sleep 300
expect timeout
END
expect -f /tmp/test.exp &
PID=$!
sleep 2
SLEEP_PID=$(ps -ef | awk "/sleep 300/ && !/awk|sh -c/ {print \$2}" | head -1)
echo "Sleep PID: $SLEEP_PID"
kill $PID 2>/dev/null
sleep 2
if [ -n "$SLEEP_PID" ] && kill -0 "$SLEEP_PID" 2>/dev/null; then
echo "BUG: sleep process still running after expect exit"
else
echo "OK: sleep process terminated"
fi
'Before fix: |
EtiennePerot
approved these changes
Apr 2, 2026
shailend-g
reviewed
Apr 14, 2026
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shailend-g
reviewed
Apr 14, 2026
When the PTY master is closed, send SIGHUPto the foreground process group of the session that has the slave as its controlling terminal. This matches Linux's pty_close() -> tty_vhangup(tty->link) behavior (drivers/tty/pty.c). Without this, child processes spawned via PTY (e.g. by expect/telnet) are never notified of the hangup and remain running indefinitely. Signed-off-by: Tan Yifeng <yiftan@tencent.com>
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1686126
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shailend-g
approved these changes
Apr 15, 2026
copybara-service Bot
pushed a commit
that referenced
this pull request
Apr 15, 2026
When the PTY master is closed, send SIGHUPto the foreground process group of the session that has the slave as its controlling terminal. This matches Linux's pty_close() -> tty_vhangup(tty->link) behavior (drivers/tty/pty.c). Without this, child processes spawned via PTY (e.g. by expect/telnet) are never notified of the hangup and remain running indefinitely. FUTURE_COPYBARA_INTEGRATE_REVIEW=#12855 from tanyifeng:pty-sighup-on-master-close 1686126 PiperOrigin-RevId: 900302848
copybara-service Bot
pushed a commit
that referenced
this pull request
Apr 15, 2026
When the PTY master is closed, send SIGHUPto the foreground process group of the session that has the slave as its controlling terminal. This matches Linux's pty_close() -> tty_vhangup(tty->link) behavior (drivers/tty/pty.c). Without this, child processes spawned via PTY (e.g. by expect/telnet) are never notified of the hangup and remain running indefinitely. FUTURE_COPYBARA_INTEGRATE_REVIEW=#12855 from tanyifeng:pty-sighup-on-master-close 1686126 PiperOrigin-RevId: 900302848
copybara-service Bot
pushed a commit
that referenced
this pull request
Apr 15, 2026
When the PTY master is closed, send SIGHUPto the foreground process group of the session that has the slave as its controlling terminal. This matches Linux's pty_close() -> tty_vhangup(tty->link) behavior (drivers/tty/pty.c). Without this, child processes spawned via PTY (e.g. by expect/telnet) are never notified of the hangup and remain running indefinitely. FUTURE_COPYBARA_INTEGRATE_REVIEW=#12855 from tanyifeng:pty-sighup-on-master-close 1686126 PiperOrigin-RevId: 900302848
copybara-service Bot
pushed a commit
that referenced
this pull request
Apr 16, 2026
When the PTY master is closed, send SIGHUPto the foreground process group of the session that has the slave as its controlling terminal. This matches Linux's pty_close() -> tty_vhangup(tty->link) behavior (drivers/tty/pty.c). Without this, child processes spawned via PTY (e.g. by expect/telnet) are never notified of the hangup and remain running indefinitely. FUTURE_COPYBARA_INTEGRATE_REVIEW=#12855 from tanyifeng:pty-sighup-on-master-close 1686126 PiperOrigin-RevId: 900302848
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pty: Send SIGHUP to foreground process group on master close
When the PTY master is closed, send SIGHUPto the foreground process group of the session that has the slave as its controlling terminal. This matches Linux's pty_close() -> tty_vhangup(tty->link) behavior (drivers/tty/pty.c).
Without this, child processes spawned via PTY (e.g. by expect/telnet) are never notified of the hangup and remain running indefinitely.