[gentoo-portage-dev] [PATCH] pid-sandbox: pid-ns-init TIOCSCTTY after setsid (bug 675868)

[gentoo-portage-dev] [PATCH] pid-sandbox: pid-ns-init TIOCSCTTY after setsid (bug 675868)

[Zac Medico]

Set the controlling terminal to the stdout pty after calling setsid,
in order to avoid "No such device or address" ENXIO errors when
attempting to open /dev/tty.

Bug: https://bugs.gentoo.org/675868
Signed-off-by: Zac Medico <zmedico@gentoo.org>
---
 bin/pid-ns-init | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/bin/pid-ns-init b/bin/pid-ns-init
index f01d69fc2..ac4509bd0 100644
--- a/bin/pid-ns-init
+++ b/bin/pid-ns-init
@@ -3,12 +3,14 @@
 # Distributed under the terms of the GNU General Public License v2
 
 import errno
+import fcntl
 import functools
 import os
 import platform
 import signal
 import subprocess
 import sys
+import termios
 
 
 KILL_SIGNALS = (
@@ -75,6 +77,15 @@ def main(argv):
 		# Isolate parent process from process group SIGSTOP (bug 675870)
 		setsid = True
 		os.setsid()
+		try:
+			fcntl.ioctl(sys.stdout, termios.TIOCSCTTY, 0)
+		except OSError as e:
+			if e.errno == errno.EPERM:
+				# This means that stdout refers to the same tty as the parent
+				# process, and in this case we do not want to steel it.
+				pass
+			else:
+				raise
 		proc = subprocess.Popen(args, executable=binary, **popen_kwargs)
 		main_child_pid = proc.pid
 
-- 
2.18.1