[gentoo-commits] proj/portage:master commit in: pym/portage/dbapi/, pym/portage/

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

commit:     b2a5f03abc0c172b6189226e6f9a7491a002cf51
Author:     Zac Medico <zmedico <AT> gentoo <DOT> org>
AuthorDate: Thu May 17 18:38:27 2018 +0000
Commit:     Zac Medico <zmedico <AT> gentoo <DOT> org>
CommitDate: Thu May 17 18:38:27 2018 +0000
URL:        https://gitweb.gentoo.org/proj/portage.git/commit/?id=b2a5f03a

MergeProcess,spawn: 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/dbapi/_MergeProcess.py | 10 ++++++++++
 pym/portage/process.py             | 10 ++++++++++
 2 files changed, 20 insertions(+)

diff --git a/pym/portage/dbapi/_MergeProcess.py b/pym/portage/dbapi/_MergeProcess.py
index fefdf8635..371550079 100644
--- a/pym/portage/dbapi/_MergeProcess.py
+++ b/pym/portage/dbapi/_MergeProcess.py
@@ -178,6 +178,16 @@ class MergeProcess(ForkProcess):
 			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).

diff --git a/pym/portage/process.py b/pym/portage/process.py
index 2af783e22..fd326731a 100644
--- a/pym/portage/process.py
+++ b/pym/portage/process.py
@@ -472,6 +472,16 @@ def _exec(binary, mycommand, opt_name, fd_pipes, env, gid, groups, uid, umask,
 	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
+
 	# Quiet killing of subprocesses by SIGPIPE (see bug #309001).
 	signal.signal(signal.SIGPIPE, signal.SIG_DFL)