tools/testing/kunit/kunit_kernel.py - linux/kernel/git/herbert/crypto-2.6 - Git at Google

 # 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 importlib.abc
 import importlib.util
 import logging
 import subprocess
 import os
 import shlex
 import shutil
 import signal
 import threading
 from typing import Iterator, List, Optional, Tuple

 import kunit_config
 from kunit_printer import stdout
 import qemu_config

 KCONFIG_PATH = '.config'
 KUNITCONFIG_PATH = '.kunitconfig'
 OLD_KUNITCONFIG_PATH = 'last_used_kunitconfig'
 DEFAULT_KUNITCONFIG_PATH = 'tools/testing/kunit/configs/default.config'
 BROKEN_ALLCONFIG_PATH = 'tools/testing/kunit/configs/broken_on_uml.config'
 UML_KCONFIG_PATH = 'tools/testing/kunit/configs/arch_uml.config'
 OUTFILE_PATH = 'test.log'
 ABS_TOOL_PATH = os.path.abspath(os.path.dirname(__file__))
 QEMU_CONFIGS_DIR = os.path.join(ABS_TOOL_PATH, 'qemu_configs')

 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:
 	"""An abstraction over command line operations performed on a source tree."""

 	def __init__(self, linux_arch: str, cross_compile: Optional[str]):
 		self._linux_arch = linux_arch
 		self._cross_compile = cross_compile

 	def make_mrproper(self) -> None:
 		try:
 			subprocess.check_output(['make', 'mrproper'], stderr=subprocess.STDOUT)
 		except OSError as e:
 			raise ConfigError('Could not call make command: ' + str(e))
 		except subprocess.CalledProcessError as e:
 			raise ConfigError(e.output.decode())

 	def make_arch_config(self, base_kunitconfig: kunit_config.Kconfig) -> kunit_config.Kconfig:
 		return base_kunitconfig

 	def make_allyesconfig(self, build_dir: str, make_options) -> None:
 		raise ConfigError('Only the "um" arch is supported for alltests')

 	def make_olddefconfig(self, build_dir: str, make_options) -> None:
 		command = ['make', 'ARCH=' + self._linux_arch, 'O=' + build_dir, 'olddefconfig']
 		if self._cross_compile:
 			command += ['CROSS_COMPILE=' + self._cross_compile]
 		if make_options:
 			command.extend(make_options)
 		print('Populating config with:\n$', ' '.join(command))
 		try:
 			subprocess.check_output(command, stderr=subprocess.STDOUT)
 		except OSError as e:
 			raise ConfigError('Could not call make command: ' + str(e))
 		except subprocess.CalledProcessError as e:
 			raise ConfigError(e.output.decode())

 	def make(self, jobs, build_dir: str, make_options) -> None:
 		command = ['make', 'ARCH=' + self._linux_arch, 'O=' + build_dir, '--jobs=' + str(jobs)]
 		if make_options:
 			command.extend(make_options)
 		if self._cross_compile:
 			command += ['CROSS_COMPILE=' + self._cross_compile]
 		print('Building with:\n$', ' '.join(command))
 		try:
 			proc = subprocess.Popen(command,
 						stderr=subprocess.PIPE,
 						stdout=subprocess.DEVNULL)
 		except OSError as e:
 			raise BuildError('Could not call execute make: ' + str(e))
 		except subprocess.CalledProcessError as e:
 			raise BuildError(e.output)
 		_, stderr = proc.communicate()
 		if proc.returncode != 0:
 			raise BuildError(stderr.decode())
 		if stderr:  # likely only due to build warnings
 			print(stderr.decode())

 	def start(self, params: List[str], build_dir: str) -> subprocess.Popen:
 		raise RuntimeError('not implemented!')


 class LinuxSourceTreeOperationsQemu(LinuxSourceTreeOperations):

 	def __init__(self, qemu_arch_params: qemu_config.QemuArchParams, cross_compile: Optional[str]):
 		super().__init__(linux_arch=qemu_arch_params.linux_arch,
 				 cross_compile=cross_compile)
 		self._kconfig = qemu_arch_params.kconfig
 		self._qemu_arch = qemu_arch_params.qemu_arch
 		self._kernel_path = qemu_arch_params.kernel_path
 		self._kernel_command_line = qemu_arch_params.kernel_command_line + ' kunit_shutdown=reboot'
 		self._extra_qemu_params = qemu_arch_params.extra_qemu_params

 	def make_arch_config(self, base_kunitconfig: kunit_config.Kconfig) -> kunit_config.Kconfig:
 		kconfig = kunit_config.parse_from_string(self._kconfig)
 		kconfig.merge_in_entries(base_kunitconfig)
 		return kconfig

 	def start(self, params: List[str], build_dir: str) -> subprocess.Popen:
 		kernel_path = os.path.join(build_dir, self._kernel_path)
 		qemu_command = ['qemu-system-' + self._qemu_arch,
 				'-nodefaults',
 				'-m', '1024',
 				'-kernel', kernel_path,
 				'-append', ' '.join(params + [self._kernel_command_line]),
 				'-no-reboot',
 				'-nographic',
 				'-serial', 'stdio'] + self._extra_qemu_params
 		# Note: shlex.join() does what we want, but requires python 3.8+.
 		print('Running tests with:\n$', ' '.join(shlex.quote(arg) for arg in qemu_command))
 		return subprocess.Popen(qemu_command,
 					stdin=subprocess.PIPE,
 					stdout=subprocess.PIPE,
 					stderr=subprocess.STDOUT,
 					text=True, errors='backslashreplace')

 class LinuxSourceTreeOperationsUml(LinuxSourceTreeOperations):
 	"""An abstraction over command line operations performed on a source tree."""

 	def __init__(self, cross_compile=None):
 		super().__init__(linux_arch='um', cross_compile=cross_compile)

 	def make_arch_config(self, base_kunitconfig: kunit_config.Kconfig) -> kunit_config.Kconfig:
 		kconfig = kunit_config.parse_file(UML_KCONFIG_PATH)
 		kconfig.merge_in_entries(base_kunitconfig)
 		return kconfig

 	def make_allyesconfig(self, build_dir: str, make_options) -> None:
 		stdout.print_with_timestamp(
 			'Enabling all CONFIGs for UML...')
 		command = ['make', 'ARCH=um', 'O=' + build_dir, 'allyesconfig']
 		if make_options:
 			command.extend(make_options)
 		process = subprocess.Popen(
 			command,
 			stdout=subprocess.DEVNULL,
 			stderr=subprocess.STDOUT)
 		process.wait()
 		stdout.print_with_timestamp(
 			'Disabling broken configs to run KUnit tests...')

 		with open(get_kconfig_path(build_dir), 'a') as config:
 			with open(BROKEN_ALLCONFIG_PATH, 'r') as disable:
 				config.write(disable.read())
 		stdout.print_with_timestamp(
 			'Starting Kernel with all configs takes a few minutes...')

 	def start(self, params: List[str], build_dir: str) -> subprocess.Popen:
 		"""Runs the Linux UML binary. Must be named 'linux'."""
 		linux_bin = os.path.join(build_dir, 'linux')
 		params.extend(['mem=1G', 'console=tty', 'kunit_shutdown=halt'])
 		return subprocess.Popen([linux_bin] + params,
 					   stdin=subprocess.PIPE,
 					   stdout=subprocess.PIPE,
 					   stderr=subprocess.STDOUT,
 					   text=True, errors='backslashreplace')

 def get_kconfig_path(build_dir: str) -> str:
 	return os.path.join(build_dir, KCONFIG_PATH)

 def get_kunitconfig_path(build_dir: str) -> str:
 	return os.path.join(build_dir, KUNITCONFIG_PATH)

 def get_old_kunitconfig_path(build_dir: str) -> str:
 	return os.path.join(build_dir, OLD_KUNITCONFIG_PATH)

 def get_parsed_kunitconfig(build_dir: str,
 			   kunitconfig_paths: Optional[List[str]]=None) -> kunit_config.Kconfig:
 	if not kunitconfig_paths:
 		path = get_kunitconfig_path(build_dir)
 		if not os.path.exists(path):
 			shutil.copyfile(DEFAULT_KUNITCONFIG_PATH, path)
 		return kunit_config.parse_file(path)

 	merged = kunit_config.Kconfig()

 	for path in kunitconfig_paths:
 		if os.path.isdir(path):
 			path = os.path.join(path, KUNITCONFIG_PATH)
 		if not os.path.exists(path):
 			raise ConfigError(f'Specified kunitconfig ({path}) does not exist')

 		partial = kunit_config.parse_file(path)
 		diff = merged.conflicting_options(partial)
 		if diff:
 			diff_str = '\n\n'.join(f'{a}\n  vs from {path}\n{b}' for a, b in diff)
 			raise ConfigError(f'Multiple values specified for {len(diff)} options in kunitconfig:\n{diff_str}')
 		merged.merge_in_entries(partial)
 	return merged

 def get_outfile_path(build_dir: str) -> str:
 	return os.path.join(build_dir, OUTFILE_PATH)

 def _default_qemu_config_path(arch: str) -> str:
 	config_path = os.path.join(QEMU_CONFIGS_DIR, arch + '.py')
 	if os.path.isfile(config_path):
 		return config_path

 	options = [f[:-3] for f in os.listdir(QEMU_CONFIGS_DIR) if f.endswith('.py')]
 	raise ConfigError(arch + ' is not a valid arch, options are ' + str(sorted(options)))

 def _get_qemu_ops(config_path: str,
 		  extra_qemu_args: Optional[List[str]],
 		  cross_compile: Optional[str]) -> Tuple[str, LinuxSourceTreeOperations]:
 	# The module name/path has very little to do with where the actual file
 	# exists (I learned this through experimentation and could not find it
 	# anywhere in the Python documentation).
 	#
 	# Bascially, we completely ignore the actual file location of the config
 	# we are loading and just tell Python that the module lives in the
 	# QEMU_CONFIGS_DIR for import purposes regardless of where it actually
 	# exists as a file.
 	module_path = '.' + os.path.join(os.path.basename(QEMU_CONFIGS_DIR), os.path.basename(config_path))
 	spec = importlib.util.spec_from_file_location(module_path, config_path)
 	assert spec is not None
 	config = importlib.util.module_from_spec(spec)
 	# See https://github.com/python/typeshed/pull/2626 for context.
 	assert isinstance(spec.loader, importlib.abc.Loader)
 	spec.loader.exec_module(config)

 	if not hasattr(config, 'QEMU_ARCH'):
 		raise ValueError('qemu_config module missing "QEMU_ARCH": ' + config_path)
 	params: qemu_config.QemuArchParams = config.QEMU_ARCH  # type: ignore
 	if extra_qemu_args:
 		params.extra_qemu_params.extend(extra_qemu_args)
 	return params.linux_arch, LinuxSourceTreeOperationsQemu(
 			params, cross_compile=cross_compile)

 class LinuxSourceTree:
 	"""Represents a Linux kernel source tree with KUnit tests."""

 	def __init__(
 	      self,
 	      build_dir: str,
 	      kunitconfig_paths: Optional[List[str]]=None,
 	      kconfig_add: Optional[List[str]]=None,
 	      arch=None,
 	      cross_compile=None,
 	      qemu_config_path=None,
 	      extra_qemu_args=None) -> None:
 		signal.signal(signal.SIGINT, self.signal_handler)
 		if qemu_config_path:
 			self._arch, self._ops = _get_qemu_ops(qemu_config_path, extra_qemu_args, cross_compile)
 		else:
 			self._arch = 'um' if arch is None else arch
 			if self._arch == 'um':
 				self._ops = LinuxSourceTreeOperationsUml(cross_compile=cross_compile)
 			else:
 				qemu_config_path = _default_qemu_config_path(self._arch)
 				_, self._ops = _get_qemu_ops(qemu_config_path, extra_qemu_args, cross_compile)

 		self._kconfig = get_parsed_kunitconfig(build_dir, kunitconfig_paths)
 		if kconfig_add:
 			kconfig = kunit_config.parse_from_string('\n'.join(kconfig_add))
 			self._kconfig.merge_in_entries(kconfig)

 	def arch(self) -> str:
 		return self._arch

 	def clean(self) -> bool:
 		try:
 			self._ops.make_mrproper()
 		except ConfigError as e:
 			logging.error(e)
 			return False
 		return True

 	def validate_config(self, build_dir: str) -> bool:
 		kconfig_path = get_kconfig_path(build_dir)
 		validated_kconfig = kunit_config.parse_file(kconfig_path)
 		if self._kconfig.is_subset_of(validated_kconfig):
 			return True
 		missing = set(self._kconfig.as_entries()) - set(validated_kconfig.as_entries())
 		message = 'Not all Kconfig options selected in kunitconfig were in the generated .config.\n' \
 			  'This is probably due to unsatisfied dependencies.\n' \
 			  'Missing: ' + ', '.join(str(e) for e in missing)
 		if self._arch == 'um':
 			message += '\nNote: many Kconfig options aren\'t available on UML. You can try running ' \
 				   'on a different architecture with something like "--arch=x86_64".'
 		logging.error(message)
 		return False

 	def build_config(self, build_dir: str, make_options) -> bool:
 		kconfig_path = get_kconfig_path(build_dir)
 		if build_dir and not os.path.exists(build_dir):
 			os.mkdir(build_dir)
 		try:
 			self._kconfig = self._ops.make_arch_config(self._kconfig)
 			self._kconfig.write_to_file(kconfig_path)
 			self._ops.make_olddefconfig(build_dir, make_options)
 		except ConfigError as e:
 			logging.error(e)
 			return False
 		if not self.validate_config(build_dir):
 			return False

 		old_path = get_old_kunitconfig_path(build_dir)
 		if os.path.exists(old_path):
 			os.remove(old_path)  # write_to_file appends to the file
 		self._kconfig.write_to_file(old_path)
 		return True

 	def _kunitconfig_changed(self, build_dir: str) -> bool:
 		old_path = get_old_kunitconfig_path(build_dir)
 		if not os.path.exists(old_path):
 			return True

 		old_kconfig = kunit_config.parse_file(old_path)
 		return old_kconfig != self._kconfig

 	def build_reconfig(self, build_dir: str, make_options) -> bool:
 		"""Creates a new .config if it is not a subset of the .kunitconfig."""
 		kconfig_path = get_kconfig_path(build_dir)
 		if not os.path.exists(kconfig_path):
 			print('Generating .config ...')
 			return self.build_config(build_dir, make_options)

 		existing_kconfig = kunit_config.parse_file(kconfig_path)
 		self._kconfig = self._ops.make_arch_config(self._kconfig)

 		if self._kconfig.is_subset_of(existing_kconfig) and not self._kunitconfig_changed(build_dir):
 			return True
 		print('Regenerating .config ...')
 		os.remove(kconfig_path)
 		return self.build_config(build_dir, make_options)

 	def build_kernel(self, alltests, jobs, build_dir: str, make_options) -> bool:
 		try:
 			if alltests:
 				self._ops.make_allyesconfig(build_dir, make_options)
 			self._ops.make_olddefconfig(build_dir, make_options)
 			self._ops.make(jobs, build_dir, make_options)
 		except (ConfigError, BuildError) as e:
 			logging.error(e)
 			return False
 		return self.validate_config(build_dir)

 	def run_kernel(self, args=None, build_dir='', filter_glob='', timeout=None) -> Iterator[str]:
 		if not args:
 			args = []
 		if filter_glob:
 			args.append('kunit.filter_glob='+filter_glob)

 		process = self._ops.start(args, build_dir)
 		assert process.stdout is not None  # tell mypy it's set

 		# Enforce the timeout in a background thread.
 		def _wait_proc():
 			try:
 				process.wait(timeout=timeout)
 			except Exception as e:
 				print(e)
 				process.terminate()
 				process.wait()
 		waiter = threading.Thread(target=_wait_proc)
 		waiter.start()

 		output = open(get_outfile_path(build_dir), 'w')
 		try:
 			# Tee the output to the file and to our caller in real time.
 			for line in process.stdout:
 				output.write(line)
 				yield line
 		# This runs even if our caller doesn't consume every line.
 		finally:
 			# Flush any leftover output to the file
 			output.write(process.stdout.read())
 			output.close()
 			process.stdout.close()

 			waiter.join()
 			subprocess.call(['stty', 'sane'])

 	def signal_handler(self, unused_sig, unused_frame) -> None:
 		logging.error('Build interruption occurred. Cleaning console.')
 		subprocess.call(['stty', 'sane'])
	# 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 importlib.abc
	import importlib.util
	import logging
	import subprocess
	import os
	import shlex
	import shutil
	import signal
	import threading
	from typing import Iterator, List, Optional, Tuple

	import kunit_config
	from kunit_printer import stdout
	import qemu_config

	KCONFIG_PATH = '.config'
	KUNITCONFIG_PATH = '.kunitconfig'
	OLD_KUNITCONFIG_PATH = 'last_used_kunitconfig'
	DEFAULT_KUNITCONFIG_PATH = 'tools/testing/kunit/configs/default.config'
	BROKEN_ALLCONFIG_PATH = 'tools/testing/kunit/configs/broken_on_uml.config'
	UML_KCONFIG_PATH = 'tools/testing/kunit/configs/arch_uml.config'
	OUTFILE_PATH = 'test.log'
	ABS_TOOL_PATH = os.path.abspath(os.path.dirname(__file__))
	QEMU_CONFIGS_DIR = os.path.join(ABS_TOOL_PATH, 'qemu_configs')

	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:
	"""An abstraction over command line operations performed on a source tree."""

	def __init__(self, linux_arch: str, cross_compile: Optional[str]):
	self._linux_arch = linux_arch
	self._cross_compile = cross_compile

	def make_mrproper(self) -> None:
	try:
	subprocess.check_output(['make', 'mrproper'], stderr=subprocess.STDOUT)
	except OSError as e:
	raise ConfigError('Could not call make command: ' + str(e))
	except subprocess.CalledProcessError as e:
	raise ConfigError(e.output.decode())

	def make_arch_config(self, base_kunitconfig: kunit_config.Kconfig) -> kunit_config.Kconfig:
	return base_kunitconfig

	def make_allyesconfig(self, build_dir: str, make_options) -> None:
	raise ConfigError('Only the "um" arch is supported for alltests')

	def make_olddefconfig(self, build_dir: str, make_options) -> None:
	command = ['make', 'ARCH=' + self._linux_arch, 'O=' + build_dir, 'olddefconfig']
	if self._cross_compile:
	command += ['CROSS_COMPILE=' + self._cross_compile]
	if make_options:
	command.extend(make_options)
	print('Populating config with:\n$', ' '.join(command))
	try:
	subprocess.check_output(command, stderr=subprocess.STDOUT)
	except OSError as e:
	raise ConfigError('Could not call make command: ' + str(e))
	except subprocess.CalledProcessError as e:
	raise ConfigError(e.output.decode())

	def make(self, jobs, build_dir: str, make_options) -> None:
	command = ['make', 'ARCH=' + self._linux_arch, 'O=' + build_dir, '--jobs=' + str(jobs)]
	if make_options:
	command.extend(make_options)
	if self._cross_compile:
	command += ['CROSS_COMPILE=' + self._cross_compile]
	print('Building with:\n$', ' '.join(command))
	try:
	proc = subprocess.Popen(command,
	stderr=subprocess.PIPE,
	stdout=subprocess.DEVNULL)
	except OSError as e:
	raise BuildError('Could not call execute make: ' + str(e))
	except subprocess.CalledProcessError as e:
	raise BuildError(e.output)
	_, stderr = proc.communicate()
	if proc.returncode != 0:
	raise BuildError(stderr.decode())
	if stderr: # likely only due to build warnings
	print(stderr.decode())

	def start(self, params: List[str], build_dir: str) -> subprocess.Popen:
	raise RuntimeError('not implemented!')


	class LinuxSourceTreeOperationsQemu(LinuxSourceTreeOperations):

	def __init__(self, qemu_arch_params: qemu_config.QemuArchParams, cross_compile: Optional[str]):
	super().__init__(linux_arch=qemu_arch_params.linux_arch,
	cross_compile=cross_compile)
	self._kconfig = qemu_arch_params.kconfig
	self._qemu_arch = qemu_arch_params.qemu_arch
	self._kernel_path = qemu_arch_params.kernel_path
	self._kernel_command_line = qemu_arch_params.kernel_command_line + ' kunit_shutdown=reboot'
	self._extra_qemu_params = qemu_arch_params.extra_qemu_params

	def make_arch_config(self, base_kunitconfig: kunit_config.Kconfig) -> kunit_config.Kconfig:
	kconfig = kunit_config.parse_from_string(self._kconfig)
	kconfig.merge_in_entries(base_kunitconfig)
	return kconfig

	def start(self, params: List[str], build_dir: str) -> subprocess.Popen:
	kernel_path = os.path.join(build_dir, self._kernel_path)
	qemu_command = ['qemu-system-' + self._qemu_arch,
	'-nodefaults',
	'-m', '1024',
	'-kernel', kernel_path,
	'-append', ' '.join(params + [self._kernel_command_line]),
	'-no-reboot',
	'-nographic',
	'-serial', 'stdio'] + self._extra_qemu_params
	# Note: shlex.join() does what we want, but requires python 3.8+.
	print('Running tests with:\n$', ' '.join(shlex.quote(arg) for arg in qemu_command))
	return subprocess.Popen(qemu_command,
	stdin=subprocess.PIPE,
	stdout=subprocess.PIPE,
	stderr=subprocess.STDOUT,
	text=True, errors='backslashreplace')

	class LinuxSourceTreeOperationsUml(LinuxSourceTreeOperations):
	"""An abstraction over command line operations performed on a source tree."""

	def __init__(self, cross_compile=None):
	super().__init__(linux_arch='um', cross_compile=cross_compile)

	def make_arch_config(self, base_kunitconfig: kunit_config.Kconfig) -> kunit_config.Kconfig:
	kconfig = kunit_config.parse_file(UML_KCONFIG_PATH)
	kconfig.merge_in_entries(base_kunitconfig)
	return kconfig

	def make_allyesconfig(self, build_dir: str, make_options) -> None:
	stdout.print_with_timestamp(
	'Enabling all CONFIGs for UML...')
	command = ['make', 'ARCH=um', 'O=' + build_dir, 'allyesconfig']
	if make_options:
	command.extend(make_options)
	process = subprocess.Popen(
	command,
	stdout=subprocess.DEVNULL,
	stderr=subprocess.STDOUT)
	process.wait()
	stdout.print_with_timestamp(
	'Disabling broken configs to run KUnit tests...')

	with open(get_kconfig_path(build_dir), 'a') as config:
	with open(BROKEN_ALLCONFIG_PATH, 'r') as disable:
	config.write(disable.read())
	stdout.print_with_timestamp(
	'Starting Kernel with all configs takes a few minutes...')

	def start(self, params: List[str], build_dir: str) -> subprocess.Popen:
	"""Runs the Linux UML binary. Must be named 'linux'."""
	linux_bin = os.path.join(build_dir, 'linux')
	params.extend(['mem=1G', 'console=tty', 'kunit_shutdown=halt'])
	return subprocess.Popen([linux_bin] + params,
	stdin=subprocess.PIPE,
	stdout=subprocess.PIPE,
	stderr=subprocess.STDOUT,
	text=True, errors='backslashreplace')

	def get_kconfig_path(build_dir: str) -> str:
	return os.path.join(build_dir, KCONFIG_PATH)

	def get_kunitconfig_path(build_dir: str) -> str:
	return os.path.join(build_dir, KUNITCONFIG_PATH)

	def get_old_kunitconfig_path(build_dir: str) -> str:
	return os.path.join(build_dir, OLD_KUNITCONFIG_PATH)

	def get_parsed_kunitconfig(build_dir: str,
	kunitconfig_paths: Optional[List[str]]=None) -> kunit_config.Kconfig:
	if not kunitconfig_paths:
	path = get_kunitconfig_path(build_dir)
	if not os.path.exists(path):
	shutil.copyfile(DEFAULT_KUNITCONFIG_PATH, path)
	return kunit_config.parse_file(path)

	merged = kunit_config.Kconfig()

	for path in kunitconfig_paths:
	if os.path.isdir(path):
	path = os.path.join(path, KUNITCONFIG_PATH)
	if not os.path.exists(path):
	raise ConfigError(f'Specified kunitconfig ({path}) does not exist')

	partial = kunit_config.parse_file(path)
	diff = merged.conflicting_options(partial)
	if diff:
	diff_str = '\n\n'.join(f'{a}\n vs from {path}\n{b}' for a, b in diff)
	raise ConfigError(f'Multiple values specified for {len(diff)} options in kunitconfig:\n{diff_str}')
	merged.merge_in_entries(partial)
	return merged

	def get_outfile_path(build_dir: str) -> str:
	return os.path.join(build_dir, OUTFILE_PATH)

	def _default_qemu_config_path(arch: str) -> str:
	config_path = os.path.join(QEMU_CONFIGS_DIR, arch + '.py')
	if os.path.isfile(config_path):
	return config_path

	options = [f[:-3] for f in os.listdir(QEMU_CONFIGS_DIR) if f.endswith('.py')]
	raise ConfigError(arch + ' is not a valid arch, options are ' + str(sorted(options)))

	def _get_qemu_ops(config_path: str,
	extra_qemu_args: Optional[List[str]],
	cross_compile: Optional[str]) -> Tuple[str, LinuxSourceTreeOperations]:
	# The module name/path has very little to do with where the actual file
	# exists (I learned this through experimentation and could not find it
	# anywhere in the Python documentation).
	#
	# Bascially, we completely ignore the actual file location of the config
	# we are loading and just tell Python that the module lives in the
	# QEMU_CONFIGS_DIR for import purposes regardless of where it actually
	# exists as a file.
	module_path = '.' + os.path.join(os.path.basename(QEMU_CONFIGS_DIR), os.path.basename(config_path))
	spec = importlib.util.spec_from_file_location(module_path, config_path)
	assert spec is not None
	config = importlib.util.module_from_spec(spec)
	# See https://github.com/python/typeshed/pull/2626 for context.
	assert isinstance(spec.loader, importlib.abc.Loader)
	spec.loader.exec_module(config)

	if not hasattr(config, 'QEMU_ARCH'):
	raise ValueError('qemu_config module missing "QEMU_ARCH": ' + config_path)
	params: qemu_config.QemuArchParams = config.QEMU_ARCH # type: ignore
	if extra_qemu_args:
	params.extra_qemu_params.extend(extra_qemu_args)
	return params.linux_arch, LinuxSourceTreeOperationsQemu(
	params, cross_compile=cross_compile)

	class LinuxSourceTree:
	"""Represents a Linux kernel source tree with KUnit tests."""

	def __init__(
	self,
	build_dir: str,
	kunitconfig_paths: Optional[List[str]]=None,
	kconfig_add: Optional[List[str]]=None,
	arch=None,
	cross_compile=None,
	qemu_config_path=None,
	extra_qemu_args=None) -> None:
	signal.signal(signal.SIGINT, self.signal_handler)
	if qemu_config_path:
	self._arch, self._ops = _get_qemu_ops(qemu_config_path, extra_qemu_args, cross_compile)
	else:
	self._arch = 'um' if arch is None else arch
	if self._arch == 'um':
	self._ops = LinuxSourceTreeOperationsUml(cross_compile=cross_compile)
	else:
	qemu_config_path = _default_qemu_config_path(self._arch)
	_, self._ops = _get_qemu_ops(qemu_config_path, extra_qemu_args, cross_compile)

	self._kconfig = get_parsed_kunitconfig(build_dir, kunitconfig_paths)
	if kconfig_add:
	kconfig = kunit_config.parse_from_string('\n'.join(kconfig_add))
	self._kconfig.merge_in_entries(kconfig)

	def arch(self) -> str:
	return self._arch

	def clean(self) -> bool:
	try:
	self._ops.make_mrproper()
	except ConfigError as e:
	logging.error(e)
	return False
	return True

	def validate_config(self, build_dir: str) -> bool:
	kconfig_path = get_kconfig_path(build_dir)
	validated_kconfig = kunit_config.parse_file(kconfig_path)
	if self._kconfig.is_subset_of(validated_kconfig):
	return True
	missing = set(self._kconfig.as_entries()) - set(validated_kconfig.as_entries())
	message = 'Not all Kconfig options selected in kunitconfig were in the generated .config.\n' \
	'This is probably due to unsatisfied dependencies.\n' \
	'Missing: ' + ', '.join(str(e) for e in missing)
	if self._arch == 'um':
	message += '\nNote: many Kconfig options aren\'t available on UML. You can try running ' \
	'on a different architecture with something like "--arch=x86_64".'
	logging.error(message)
	return False

	def build_config(self, build_dir: str, make_options) -> bool:
	kconfig_path = get_kconfig_path(build_dir)
	if build_dir and not os.path.exists(build_dir):
	os.mkdir(build_dir)
	try:
	self._kconfig = self._ops.make_arch_config(self._kconfig)
	self._kconfig.write_to_file(kconfig_path)
	self._ops.make_olddefconfig(build_dir, make_options)
	except ConfigError as e:
	logging.error(e)
	return False
	if not self.validate_config(build_dir):
	return False

	old_path = get_old_kunitconfig_path(build_dir)
	if os.path.exists(old_path):
	os.remove(old_path) # write_to_file appends to the file
	self._kconfig.write_to_file(old_path)
	return True

	def _kunitconfig_changed(self, build_dir: str) -> bool:
	old_path = get_old_kunitconfig_path(build_dir)
	if not os.path.exists(old_path):
	return True

	old_kconfig = kunit_config.parse_file(old_path)
	return old_kconfig != self._kconfig

	def build_reconfig(self, build_dir: str, make_options) -> bool:
	"""Creates a new .config if it is not a subset of the .kunitconfig."""
	kconfig_path = get_kconfig_path(build_dir)
	if not os.path.exists(kconfig_path):
	print('Generating .config ...')
	return self.build_config(build_dir, make_options)

	existing_kconfig = kunit_config.parse_file(kconfig_path)
	self._kconfig = self._ops.make_arch_config(self._kconfig)

	if self._kconfig.is_subset_of(existing_kconfig) and not self._kunitconfig_changed(build_dir):
	return True
	print('Regenerating .config ...')
	os.remove(kconfig_path)
	return self.build_config(build_dir, make_options)

	def build_kernel(self, alltests, jobs, build_dir: str, make_options) -> bool:
	try:
	if alltests:
	self._ops.make_allyesconfig(build_dir, make_options)
	self._ops.make_olddefconfig(build_dir, make_options)
	self._ops.make(jobs, build_dir, make_options)
	except (ConfigError, BuildError) as e:
	logging.error(e)
	return False
	return self.validate_config(build_dir)

	def run_kernel(self, args=None, build_dir='', filter_glob='', timeout=None) -> Iterator[str]:
	if not args:
	args = []
	if filter_glob:
	args.append('kunit.filter_glob='+filter_glob)

	process = self._ops.start(args, build_dir)
	assert process.stdout is not None # tell mypy it's set

	# Enforce the timeout in a background thread.
	def _wait_proc():
	try:
	process.wait(timeout=timeout)
	except Exception as e:
	print(e)
	process.terminate()
	process.wait()
	waiter = threading.Thread(target=_wait_proc)
	waiter.start()

	output = open(get_outfile_path(build_dir), 'w')
	try:
	# Tee the output to the file and to our caller in real time.
	for line in process.stdout:
	output.write(line)
	yield line
	# This runs even if our caller doesn't consume every line.
	finally:
	# Flush any leftover output to the file
	output.write(process.stdout.read())
	output.close()
	process.stdout.close()

	waiter.join()
	subprocess.call(['stty', 'sane'])

	def signal_handler(self, unused_sig, unused_frame) -> None:
	logging.error('Build interruption occurred. Cleaning console.')
	subprocess.call(['stty', 'sane'])