[gentoo-commits] proj/portage:master commit in: pym/portage/util/_async/

["Zac Medico" <zmedico@gentoo.org>]

commit:     b28b01a78e4cc0199111e804af5b56a33319356d
Author:     Zac Medico <zmedico <AT> gentoo <DOT> org>
AuthorDate: Mon May 14 15:33:15 2018 +0000
Commit:     Zac Medico <zmedico <AT> gentoo <DOT> org>
CommitDate: Mon May 14 15:35:53 2018 +0000
URL:        https://gitweb.gentoo.org/proj/portage.git/commit/?id=b28b01a7

ForkProcess: unregister SIGCHLD and wakeup_fd (bug 655656)

In order to prevent forked processes from invoking the parent process's
SIGCHLD handler and writing to wakeup_fd (triggering BlockingIOError),
unregister the SIGCHLD and wakeup_fd.

Bug: https://bugs.gentoo.org/655656
Reported-by: Helmut Jarausch <jarausch <AT> igpm.rwth-aachen.de>

 pym/portage/util/_async/ForkProcess.py | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/pym/portage/util/_async/ForkProcess.py b/pym/portage/util/_async/ForkProcess.py
index 25f72d308..d84e93833 100644
--- a/pym/portage/util/_async/ForkProcess.py
+++ b/pym/portage/util/_async/ForkProcess.py
@@ -37,6 +37,16 @@ class ForkProcess(SpawnProcess):
 				signal.signal(signal.SIGINT, signal.SIG_DFL)
 				signal.signal(signal.SIGTERM, signal.SIG_DFL)
 
+				# Unregister SIGCHLD handler and wakeup_fd for the parent
+				# process's event loop (bug 655656).
+				signal.signal(signal.SIGCHLD, signal.SIG_DFL)
+				try:
+					wakeup_fd = signal.set_wakeup_fd(-1)
+					if wakeup_fd > 0:
+						os.close(wakeup_fd)
+				except (ValueError, OSError):
+					pass
+
 				portage.locks._close_fds()
 				# We don't exec, so use close_fds=False
 				# (see _setup_pipes docstring).