From 09851b8460010a60168e1803388cca3bc218216c Mon Sep 17 00:00:00 2001
From: Michael Marineau <michael.marineau@coreos.com>
Date: Tue, 15 Dec 2015 16:30:27 -0800
Subject: [PATCH] enter_chroot: ensure the chroot's root directory is a mount
 point

---
 sdk_lib/enter_chroot.sh | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/sdk_lib/enter_chroot.sh b/sdk_lib/enter_chroot.sh
index 2434960e05..b344ee7bd5 100755
--- a/sdk_lib/enter_chroot.sh
+++ b/sdk_lib/enter_chroot.sh
@@ -216,6 +216,10 @@ setup_env() {
     # Using 'slave' means we see global changes but cannot change global state.
     mount --make-rslave /
 
+    # Make sure the new root directory itself is a mount point. Tools like
+    # unshare assume that things like `mount --make-rprivate /` work.
+    setup_mount "${MOUNTED_PATH}" "--bind" /
+
     setup_mount none "-t proc" /proc
     setup_mount none "-t sysfs" /sys
     setup_mount /dev "--bind" /dev