checkkconfigsymbols.py: avoid shell injection

"""Find Kconfig symbols that are referenced but not defined."""

# (c) 2014-2015 Valentin Rothberg <valentinrothberg@gmail.com>

# (c) 2014-2016 Valentin Rothberg <valentinrothberg@gmail.com>

# (c) 2014 Stefan Hengelein <stefan.hengelein@fau.de>

#

# Licensed under the terms of the GNU GPL License version 2

import os

import re

import signal

import subprocess

import sys

from multiprocessing import Pool, cpu_count

from optparse import OptionParser

def execute(cmd):

    """Execute %cmd and return stdout.  Exit in case of error."""

    pop = Popen(cmd, stdout=PIPE, stderr=STDOUT, shell=True)

    (stdout, _) = pop.communicate()  # wait until finished

    if pop.returncode != 0:

        sys.exit(stdout)

    try:

        cmdlist = cmd.split(" ")

        stdout = subprocess.check_output(cmdlist, stderr=STDOUT, shell=False)

    except subprocess.CalledProcessError as fail:

        exit("Failed to execute %s\n%s" % (cmd, fail))

    return stdout