# SPDX-License-Identifier: GPL-2.0## Runs UML kernel, collects output, and handles errors.## Copyright (C) 2019, Google LLC.# Author: Felix Guo <felixguoxiuping@gmail.com># Author: Brendan Higgins <brendanhiggins@google.com>  import loggingimport subprocessimport os import kunit_config KCONFIG_PATH = '.config'kunitconfig_path = '.kunitconfig' class ConfigError(Exception):	"""Represents an error trying to configure the Linux kernel."""  class BuildError(Exception):	"""Represents an error trying to build the Linux kernel."""  class LinuxSourceTreeOperations(object):	"""An abstraction over command line operations performed on a source tree.""" 	def make_mrproper(self):		try:			subprocess.check_output(['make', 'mrproper'])		except OSError as e:			raise ConfigError('Could not call make command: ' + e)		except subprocess.CalledProcessError as e:			raise ConfigError(e.output) 	def make_olddefconfig(self, build_dir):		command = ['make', 'ARCH=um', 'olddefconfig']		if build_dir:			command += ['O=' + build_dir]		try:			subprocess.check_output(command)		except OSError as e:			raise ConfigError('Could not call make command: ' + e)		except subprocess.CalledProcessError as e:			raise ConfigError(e.output) 	def make(self, jobs, build_dir):		command = ['make', 'ARCH=um', '--jobs=' + str(jobs)]		if build_dir:			command += ['O=' + build_dir]		try:			subprocess.check_output(command)		except OSError as e:			raise BuildError('Could not call execute make: ' + e)		except subprocess.CalledProcessError as e:			raise BuildError(e.output) 	def linux_bin(self, params, timeout, build_dir):		"""Runs the Linux UML binary. Must be named 'linux'."""		linux_bin = './linux'		if build_dir:			linux_bin = os.path.join(build_dir, 'linux')		process = subprocess.Popen(			[linux_bin] + params,			stdin=subprocess.PIPE,			stdout=subprocess.PIPE,			stderr=subprocess.PIPE)		process.wait(timeout=timeout)		return process  def get_kconfig_path(build_dir):	kconfig_path = KCONFIG_PATH	if build_dir:		kconfig_path = os.path.join(build_dir, KCONFIG_PATH)	return kconfig_path class LinuxSourceTree(object):	"""Represents a Linux kernel source tree with KUnit tests.""" 	def __init__(self):		self._kconfig = kunit_config.Kconfig()		self._kconfig.read_from_file(kunitconfig_path)		self._ops = LinuxSourceTreeOperations() 	def clean(self):		try:			self._ops.make_mrproper()		except ConfigError as e:			logging.error(e)			return False		return True 	def validate_config(self, build_dir):		kconfig_path = get_kconfig_path(build_dir)		validated_kconfig = kunit_config.Kconfig()		validated_kconfig.read_from_file(kconfig_path)		if not self._kconfig.is_subset_of(validated_kconfig):			invalid = self._kconfig.entries() - validated_kconfig.entries()			message = 'Provided Kconfig is not contained in validated .config. Following fields found in kunitconfig, ' \					  'but not in .config: %s' % (					', '.join([str(e) for e in invalid])			)			logging.error(message)			return False		return True 	def build_config(self, build_dir):		kconfig_path = get_kconfig_path(build_dir)		if build_dir and not os.path.exists(build_dir):			os.mkdir(build_dir)		self._kconfig.write_to_file(kconfig_path)		try:			self._ops.make_olddefconfig(build_dir)		except ConfigError as e:			logging.error(e)			return False		return self.validate_config(build_dir) 	def build_reconfig(self, build_dir):		"""Creates a new .config if it is not a subset of the .kunitconfig."""		kconfig_path = get_kconfig_path(build_dir)		if os.path.exists(kconfig_path):			existing_kconfig = kunit_config.Kconfig()			existing_kconfig.read_from_file(kconfig_path)			if not self._kconfig.is_subset_of(existing_kconfig):				print('Regenerating .config ...')				os.remove(kconfig_path)				return self.build_config(build_dir)			else:				return True		else:			print('Generating .config ...')			return self.build_config(build_dir) 	def build_um_kernel(self, jobs, build_dir):		try:			self._ops.make_olddefconfig(build_dir)			self._ops.make(jobs, build_dir)		except (ConfigError, BuildError) as e:			logging.error(e)			return False		return self.validate_config(build_dir) 	def run_kernel(self, args=[], timeout=None, build_dir=''):		args.extend(['mem=256M'])		process = self._ops.linux_bin(args, timeout, build_dir)		with open(os.path.join(build_dir, 'test.log'), 'w') as f:			for line in process.stdout:				f.write(line.rstrip().decode('ascii') + '\n')				yield line.rstrip().decode('ascii')