Merge tag 'linux-kselftest-kunit-fixes-5.8-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull kunit fixes from Shuah Khan
 "Fixes for build and run-times failures.

  Also includes troubleshooting tips updates to kunit user
  documentation"

* tag 'linux-kselftest-kunit-fixes-5.8-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  Documentation: kunit: Add some troubleshooting tips to the FAQ
  kunit: kunit_tool: Fix invalid result when build fails
  kunit: show error if kunit results are not present
  kunit: kunit_config: Fix parsing of CONFIG options with space

Documentation/dev-tools/kunit/faq.rst

@@ -61,3 +61,43 @@ test, or an end-to-end test.
   kernel by installing a production configuration of the kernel on production
   hardware with a production userspace and then trying to exercise some behavior
   that depends on interactions between the hardware, the kernel, and userspace.
+
+KUnit isn't working, what should I do?
+======================================
+
+Unfortunately, there are a number of things which can break, but here are some
+things to try.
+
+1. Try running ``./tools/testing/kunit/kunit.py run`` with the ``--raw_output``
+   parameter. This might show details or error messages hidden by the kunit_tool
+   parser.
+2. Instead of running ``kunit.py run``, try running ``kunit.py config``,
+   ``kunit.py build``, and ``kunit.py exec`` independently. This can help track
+   down where an issue is occurring. (If you think the parser is at fault, you
+   can run it manually against stdin or a file with ``kunit.py parse``.)
+3. Running the UML kernel directly can often reveal issues or error messages
+   kunit_tool ignores. This should be as simple as running ``./vmlinux`` after
+   building the UML kernel (e.g., by using ``kunit.py build``). Note that UML
+   has some unusual requirements (such as the host having a tmpfs filesystem
+   mounted), and has had issues in the past when built statically and the host
+   has KASLR enabled. (On older host kernels, you may need to run ``setarch
+   `uname -m` -R ./vmlinux`` to disable KASLR.)
+4. Make sure the kernel .config has ``CONFIG_KUNIT=y`` and at least one test
+   (e.g. ``CONFIG_KUNIT_EXAMPLE_TEST=y``). kunit_tool will keep its .config
+   around, so you can see what config was used after running ``kunit.py run``.
+   It also preserves any config changes you might make, so you can
+   enable/disable things with ``make ARCH=um menuconfig`` or similar, and then
+   re-run kunit_tool.
+5. Try to run ``make ARCH=um defconfig`` before running ``kunit.py run``. This
+   may help clean up any residual config items which could be causing problems.
+6. Finally, try running KUnit outside UML. KUnit and KUnit tests can run be
+   built into any kernel, or can be built as a module and loaded at runtime.
+   Doing so should allow you to determine if UML is causing the issue you're
+   seeing. When tests are built-in, they will execute when the kernel boots, and
+   modules will automatically execute associated tests when loaded. Test results
+   can be collected from ``/sys/kernel/debug/kunit/<test suite>/results``, and
+   can be parsed with ``kunit.py parse``. For more details, see "KUnit on
+   non-UML architectures" in :doc:`usage`.
+
+If none of the above tricks help, you are always welcome to email any issues to
+kunit-dev@googlegroups.com.

tools/testing/kunit/kunit.py

@@ -82,7 +82,9 @@ def build_tests(linux: kunit_kernel.LinuxSourceTree,
 					request.make_options)
 	build_end = time.time()
 	if not success:
-		return KunitResult(KunitStatus.BUILD_FAILURE, 'could not build kernel')
+		return KunitResult(KunitStatus.BUILD_FAILURE,
+				   'could not build kernel',
+				   build_end - build_start)
 	if not success:
 		return KunitResult(KunitStatus.BUILD_FAILURE,
 				   'could not build kernel',

tools/testing/kunit/kunit_config.py

@@ -10,7 +10,7 @@ import collections
 import re
 
 CONFIG_IS_NOT_SET_PATTERN = r'^# CONFIG_(\w+) is not set$'
-CONFIG_PATTERN = r'^CONFIG_(\w+)=(\S+)$'
+CONFIG_PATTERN = r'^CONFIG_(\w+)=(\S+|".*")$'
 
 KconfigEntryBase = collections.namedtuple('KconfigEntry', ['name', 'value'])
 

tools/testing/kunit/kunit_parser.py

@@ -265,11 +265,9 @@ def bubble_up_suite_errors(test_suite_list: List[TestSuite]) -> TestStatus:
 	return bubble_up_errors(lambda x: x.status, test_suite_list)
 
 def parse_test_result(lines: List[str]) -> TestResult:
-	if not lines:
-		return TestResult(TestStatus.NO_TESTS, [], lines)
 	consume_non_diagnositic(lines)
-	if not parse_tap_header(lines):
-		return None
+	if not lines or not parse_tap_header(lines):
+		return TestResult(TestStatus.NO_TESTS, [], lines)
 	test_suites = []
 	test_suite = parse_test_suite(lines)
 	while test_suite:
@@ -282,6 +280,8 @@ def parse_run_tests(kernel_output) -> TestResult:
 	failed_tests = 0
 	crashed_tests = 0
 	test_result = parse_test_result(list(isolate_kunit_output(kernel_output)))
+	if test_result.status == TestStatus.NO_TESTS:
+		print_with_timestamp(red('[ERROR] ') + 'no kunit output detected')
 	for test_suite in test_result.suites:
 		if test_suite.status == TestStatus.SUCCESS:
 			print_suite_divider(green('[PASSED] ') + test_suite.name)

tools/testing/kunit/kunit_tool_test.py

@@ -170,6 +170,17 @@ class KUnitParserTest(unittest.TestCase):
 			result.status)
 		file.close()
 
+	def test_no_kunit_output(self):
+		crash_log = get_absolute_path(
+			'test_data/test_insufficient_memory.log')
+		file = open(crash_log)
+		print_mock = mock.patch('builtins.print').start()
+		result = kunit_parser.parse_run_tests(
+			kunit_parser.isolate_kunit_output(file.readlines()))
+		print_mock.assert_any_call(StrContains("no kunit output detected"))
+		print_mock.stop()
+		file.close()
+
 	def test_crashed_test(self):
 		crashed_log = get_absolute_path(
 			'test_data/test_is_test_passed-crash.log')