diff -ru python3.5-3.5.1-orig/configure.ac python3.5-3.5.1/configure.ac
--- python3.5-3.5.1-orig/configure.ac	2015-12-07 01:39:11.000000000 +0000
+++ python3.5-3.5.1/configure.ac	2016-05-13 09:00:55.356227833 +0100
@@ -1799,7 +1799,7 @@
 sys/stat.h sys/syscall.h sys/sys_domain.h sys/termio.h sys/time.h \
 sys/times.h sys/types.h sys/uio.h sys/un.h sys/utsname.h sys/wait.h pty.h \
 libutil.h sys/resource.h netpacket/packet.h sysexits.h bluetooth.h \
-bluetooth/bluetooth.h linux/tipc.h spawn.h util.h alloca.h endian.h \
+bluetooth/bluetooth.h linux/tipc.h linux/random.h spawn.h util.h alloca.h endian.h \
 sys/endian.h)
 AC_HEADER_DIRENT
 AC_HEADER_MAJOR
diff -ru python3.5-3.5.1-orig/pyconfig.h.in python3.5-3.5.1/pyconfig.h.in
--- python3.5-3.5.1-orig/pyconfig.h.in	2015-12-07 01:39:11.000000000 +0000
+++ python3.5-3.5.1/pyconfig.h.in	2016-05-13 09:00:33.689556635 +0100
@@ -546,6 +546,9 @@
 /* Define to 1 if you have the <linux/tipc.h> header file. */
 #undef HAVE_LINUX_TIPC_H
 
+/* Define to 1 if you have the <linux/random.h> header file. */
+#undef HAVE_LINUX_RANDOM_H
+
 /* Define to 1 if you have the `lockf' function. */
 #undef HAVE_LOCKF
 
diff -ru python3.5-3.5.1-orig/Python/random.c python3.5-3.5.1/Python/random.c
--- python3.5-3.5.1-orig/Python/random.c	2015-12-07 01:39:11.000000000 +0000
+++ python3.5-3.5.1/Python/random.c	2016-05-14 02:49:35.898574571 +0100
@@ -6,6 +6,9 @@
 #  ifdef HAVE_SYS_STAT_H
 #    include <sys/stat.h>
 #  endif
+#  ifdef HAVE_LINUX_RANDOM_H
+#    include <linux/random.h>
+#  endif
 #  ifdef HAVE_GETRANDOM
 #    include <sys/random.h>
 #  elif defined(HAVE_GETRANDOM_SYSCALL)
@@ -122,9 +125,14 @@
     /* Is getrandom() supported by the running kernel?
      * Need Linux kernel 3.17 or newer, or Solaris 11.3 or newer */
     static int getrandom_works = 1;
-    /* Use non-blocking /dev/urandom device. On Linux at boot, the getrandom()
-     * syscall blocks until /dev/urandom is initialized with enough entropy. */
-    const int flags = 0;
+
+    /* getrandom() on Linux will block if called before the kernel has
+     * initialized the urandom entropy pool. This will cause Python
+     * to hang on startup if called very early in the boot process -
+     * see https://bugs.python.org/issue26839. To avoid this, use the
+     * GRND_NONBLOCK flag. */
+
+    const int flags = GRND_NONBLOCK;
     int n;
 
     if (!getrandom_works)
@@ -161,6 +169,17 @@
                 getrandom_works = 0;
                 return 0;
             }
+	    if (errno == EAGAIN) {
+		/* If we failed with EAGAIN, the entropy pool was
+		 * uninitialized. In this case, we return failure to fall
+		 * back to reading from /dev/urandom.
+		 * Note: in this case the data read will not be random so
+		 * should not be used for cryptographic purposes. Retaining
+		 * the existing semantics for practical purposes. */
+		/* Alternative might be to return all-zeroes as a strong
+		 * signal that these are not random data. */
+		return 0;
+	    }
 
             if (errno == EINTR) {
                 if (PyErr_CheckSignals()) {