linux_kselftest-kunit-fixes-7.0-rc3

kunit:
 - Fixes rust warnings when CONFIG_PRINTK is disabled.
 - Reduces stack usage in kunit_run_tests() to fix warnings when
   CONFIG_FRAME_WARN is set to a relatively low value.
 - Updates email address for David Gow.
 
 kunit tool:
 - Copies caller args in run_kernel to prevent mutation.
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEPZKym/RZuOCGeA/kCwJExA0NQxwFAmmrNf4ACgkQCwJExA0N
 QxyVNxAAtemv6AH1pP/cR23teXd5uuBThTM8EASEAC9/VJmCuPjg9mb6df816EXx
 2ZrTKGR5k/5basYDhNKIAJTGGjT3pcau7OKmD7Piy3bbhJEq5kb31rVbbmCV1STl
 vzJcBbSNP5Z+otz/flmewoeiL+xYarQvCrfFll5Y+gMer3HFevG0y0rCpEe0+7tH
 avgq01m7rHFg0DLYxJhjE3NFgFlgYaKdHyQPrGYOtZUXJDSNUO1cULJ8ZrMG3skc
 JWngB/5eS6hP/3QSaBm9coHKbrAYatpPWLfg9wtgfuj3be2oEAnWeynb/vWrdEV3
 uid96CEs1UPG8Z/jTtRK86q1md+5I2QX6s7B74EXnzCo0bg150h1qtT2J/za1Kxu
 7CP6Rq59VHCL6SMpQ4cks00zpWffCCtAphto2yk9ZphbisyVUGN8zEiCdd0FrLob
 putdMLeJVLXbnWFCnLA/8gFfx6Inp+PXNoVr+6LNZo/qB4W/EJOLDUvjaVJ7abpY
 yUxvJVj0+dwOlYUYnpldGCz9pfywgIyLI7ERtu4KIwJ5EMsVo8yJgykEd2MkQbZ+
 2Db3omyalnAn/vXP5p48vawI9oj6scMNxukBRTdqZsQGRma/jj6FnZCi77llQY+g
 V6pTQPjJRhRGLIwow+dCkJ4CucafNacp1RVuf61MM/I03XOQEwU=
 =j8w0
 -----END PGP SIGNATURE-----

Merge tag 'linux_kselftest-kunit-fixes-7.0-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull kunit fixes from Shuah Khan:

 - Fix rust warnings when CONFIG_PRINTK is disabled

 - Reduce stack usage in kunit_run_tests() to fix warnings when
   CONFIG_FRAME_WARN is set to a relatively low value

 - Update email address for David Gow

 - Copy caller args in kunit tool in run_kernel to prevent mutation

* tag 'linux_kselftest-kunit-fixes-7.0-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  kunit: reduce stack usage in kunit_run_tests()
  kunit: tool: copy caller args in run_kernel to prevent mutation
  rust: kunit: fix warning when !CONFIG_PRINTK
  MAINTAINERS: Update email address for David Gow

.mailmap

@@ -219,6 +219,7 @@ Daniele Alessandrelli <daniele.alessandrelli@gmail.com> <daniele.alessandrelli@i
 Danilo Krummrich <dakr@kernel.org> <dakr@redhat.com>
 David Brownell <david-b@pacbell.net>
 David Collins <quic_collinsd@quicinc.com> <collinsd@codeaurora.org>
+David Gow <david@davidgow.net> <davidgow@google.com>
 David Heidelberg <david@ixit.cz> <d.okias@gmail.com>
 David Hildenbrand <david@kernel.org> <david@redhat.com>
 David Rheinsberg <david@readahead.eu> <dh.herrmann@gmail.com>

MAINTAINERS

@@ -13938,7 +13938,7 @@ F:	fs/smb/server/
 
 KERNEL UNIT TESTING FRAMEWORK (KUnit)
 M:	Brendan Higgins <brendan.higgins@linux.dev>
-M:	David Gow <davidgow@google.com>
+M:	David Gow <david@davidgow.net>
 R:	Rae Moar <raemoar63@gmail.com>
 L:	linux-kselftest@vger.kernel.org
 L:	kunit-dev@googlegroups.com
@@ -14758,7 +14758,7 @@ F:	drivers/misc/lis3lv02d/
 F:	drivers/platform/x86/hp/hp_accel.c
 
 LIST KUNIT TEST
-M:	David Gow <davidgow@google.com>
+M:	David Gow <david@davidgow.net>
 L:	linux-kselftest@vger.kernel.org
 L:	kunit-dev@googlegroups.com
 S:	Maintained

lib/kunit/test.c

@@ -94,7 +94,7 @@ struct kunit_result_stats {
 	unsigned long total;
 };
 
-static bool kunit_should_print_stats(struct kunit_result_stats stats)
+static bool kunit_should_print_stats(struct kunit_result_stats *stats)
 {
 	if (kunit_stats_enabled == 0)
 		return false;
@@ -102,11 +102,11 @@ static bool kunit_should_print_stats(struct kunit_result_stats stats)
 	if (kunit_stats_enabled == 2)
 		return true;
 
-	return (stats.total > 1);
+	return (stats->total > 1);
 }
 
 static void kunit_print_test_stats(struct kunit *test,
-				   struct kunit_result_stats stats)
+				   struct kunit_result_stats *stats)
 {
 	if (!kunit_should_print_stats(stats))
 		return;
@@ -115,10 +115,10 @@ static void kunit_print_test_stats(struct kunit *test,
 		  KUNIT_SUBTEST_INDENT
 		  "# %s: pass:%lu fail:%lu skip:%lu total:%lu",
 		  test->name,
-		  stats.passed,
+		  stats->passed,
-		  stats.failed,
+		  stats->failed,
-		  stats.skipped,
+		  stats->skipped,
-		  stats.total);
+		  stats->total);
 }
 
 /* Append formatted message to log. */
@@ -600,26 +600,26 @@ static void kunit_run_case_catch_errors(struct kunit_suite *suite,
 }
 
 static void kunit_print_suite_stats(struct kunit_suite *suite,
-				    struct kunit_result_stats suite_stats,
+				    struct kunit_result_stats *suite_stats,
-				    struct kunit_result_stats param_stats)
+				    struct kunit_result_stats *param_stats)
 {
 	if (kunit_should_print_stats(suite_stats)) {
 		kunit_log(KERN_INFO, suite,
 			  "# %s: pass:%lu fail:%lu skip:%lu total:%lu",
 			  suite->name,
-			  suite_stats.passed,
+			  suite_stats->passed,
-			  suite_stats.failed,
+			  suite_stats->failed,
-			  suite_stats.skipped,
+			  suite_stats->skipped,
-			  suite_stats.total);
+			  suite_stats->total);
 	}
 
 	if (kunit_should_print_stats(param_stats)) {
 		kunit_log(KERN_INFO, suite,
 			  "# Totals: pass:%lu fail:%lu skip:%lu total:%lu",
-			  param_stats.passed,
+			  param_stats->passed,
-			  param_stats.failed,
+			  param_stats->failed,
-			  param_stats.skipped,
+			  param_stats->skipped,
-			  param_stats.total);
+			  param_stats->total);
 	}
 }
 
@@ -681,13 +681,116 @@ static void kunit_init_parent_param_test(struct kunit_case *test_case, struct ku
 	}
 }
 
-int kunit_run_tests(struct kunit_suite *suite)
+static noinline_for_stack void
+kunit_run_param_test(struct kunit_suite *suite, struct kunit_case *test_case,
+		     struct kunit *test,
+		     struct kunit_result_stats *suite_stats,
+		     struct kunit_result_stats *total_stats,
+		     struct kunit_result_stats *param_stats)
 {
 	char param_desc[KUNIT_PARAM_DESC_SIZE];
+	const void *curr_param;
+
+	kunit_init_parent_param_test(test_case, test);
+	if (test_case->status == KUNIT_FAILURE) {
+		kunit_update_stats(param_stats, test->status);
+		return;
+	}
+	/* Get initial param. */
+	param_desc[0] = '\0';
+	/* TODO: Make generate_params try-catch */
+	curr_param = test_case->generate_params(test, NULL, param_desc);
+	test_case->status = KUNIT_SKIPPED;
+	kunit_log(KERN_INFO, test, KUNIT_SUBTEST_INDENT KUNIT_SUBTEST_INDENT
+		  "KTAP version 1\n");
+	kunit_log(KERN_INFO, test, KUNIT_SUBTEST_INDENT KUNIT_SUBTEST_INDENT
+		  "# Subtest: %s", test_case->name);
+	if (test->params_array.params &&
+	    test_case->generate_params == kunit_array_gen_params) {
+		kunit_log(KERN_INFO, test, KUNIT_SUBTEST_INDENT
+			  KUNIT_SUBTEST_INDENT "1..%zd\n",
+			  test->params_array.num_params);
+	}
+
+	while (curr_param) {
+		struct kunit param_test = {
+			.param_value = curr_param,
+			.param_index = ++test->param_index,
+			.parent = test,
+		};
+		kunit_init_test(&param_test, test_case->name, NULL);
+		param_test.log = test_case->log;
+		kunit_run_case_catch_errors(suite, test_case, &param_test);
+
+		if (param_desc[0] == '\0') {
+			snprintf(param_desc, sizeof(param_desc),
+				 "param-%d", param_test.param_index);
+		}
+
+		kunit_print_ok_not_ok(&param_test, KUNIT_LEVEL_CASE_PARAM,
+				      param_test.status,
+				      param_test.param_index,
+				      param_desc,
+				      param_test.status_comment);
+
+		kunit_update_stats(param_stats, param_test.status);
+
+		/* Get next param. */
+		param_desc[0] = '\0';
+		curr_param = test_case->generate_params(test, curr_param,
+							param_desc);
+	}
+	/*
+	 * TODO: Put into a try catch. Since we don't need suite->exit
+	 * for it we can't reuse kunit_try_run_cleanup for this yet.
+	 */
+	if (test_case->param_exit)
+		test_case->param_exit(test);
+	/* TODO: Put this kunit_cleanup into a try-catch. */
+	kunit_cleanup(test);
+}
+
+static noinline_for_stack void
+kunit_run_one_test(struct kunit_suite *suite, struct kunit_case *test_case,
+		   struct kunit_result_stats *suite_stats,
+		   struct kunit_result_stats *total_stats)
+{
+	struct kunit test = { .param_value = NULL, .param_index = 0 };
+	struct kunit_result_stats param_stats = { 0 };
+
+	kunit_init_test(&test, test_case->name, test_case->log);
+	if (test_case->status == KUNIT_SKIPPED) {
+		/* Test marked as skip */
+		test.status = KUNIT_SKIPPED;
+		kunit_update_stats(&param_stats, test.status);
+	} else if (!test_case->generate_params) {
+		/* Non-parameterised test. */
+		test_case->status = KUNIT_SKIPPED;
+		kunit_run_case_catch_errors(suite, test_case, &test);
+		kunit_update_stats(&param_stats, test.status);
+	} else {
+		kunit_run_param_test(suite, test_case, &test, suite_stats,
+				     total_stats, &param_stats);
+	}
+	kunit_print_attr((void *)test_case, true, KUNIT_LEVEL_CASE);
+
+	kunit_print_test_stats(&test, &param_stats);
+
+	kunit_print_ok_not_ok(&test, KUNIT_LEVEL_CASE, test_case->status,
+			      kunit_test_case_num(suite, test_case),
+			      test_case->name,
+			      test.status_comment);
+
+	kunit_update_stats(suite_stats, test_case->status);
+	kunit_accumulate_stats(total_stats, param_stats);
+}
+
+
+int kunit_run_tests(struct kunit_suite *suite)
+{
 	struct kunit_case *test_case;
 	struct kunit_result_stats suite_stats = { 0 };
 	struct kunit_result_stats total_stats = { 0 };
-	const void *curr_param;
 
 	/* Taint the kernel so we know we've run tests. */
 	add_taint(TAINT_TEST, LOCKDEP_STILL_OK);
@@ -703,97 +806,13 @@ int kunit_run_tests(struct kunit_suite *suite)
 
 	kunit_print_suite_start(suite);
 
-	kunit_suite_for_each_test_case(suite, test_case) {
+	kunit_suite_for_each_test_case(suite, test_case)
-		struct kunit test = { .param_value = NULL, .param_index = 0 };
+		kunit_run_one_test(suite, test_case, &suite_stats, &total_stats);
-		struct kunit_result_stats param_stats = { 0 };
-
-		kunit_init_test(&test, test_case->name, test_case->log);
-		if (test_case->status == KUNIT_SKIPPED) {
-			/* Test marked as skip */
-			test.status = KUNIT_SKIPPED;
-			kunit_update_stats(&param_stats, test.status);
-		} else if (!test_case->generate_params) {
-			/* Non-parameterised test. */
-			test_case->status = KUNIT_SKIPPED;
-			kunit_run_case_catch_errors(suite, test_case, &test);
-			kunit_update_stats(&param_stats, test.status);
-		} else {
-			kunit_init_parent_param_test(test_case, &test);
-			if (test_case->status == KUNIT_FAILURE) {
-				kunit_update_stats(&param_stats, test.status);
-				goto test_case_end;
-			}
-			/* Get initial param. */
-			param_desc[0] = '\0';
-			/* TODO: Make generate_params try-catch */
-			curr_param = test_case->generate_params(&test, NULL, param_desc);
-			test_case->status = KUNIT_SKIPPED;
-			kunit_log(KERN_INFO, &test, KUNIT_SUBTEST_INDENT KUNIT_SUBTEST_INDENT
-				  "KTAP version 1\n");
-			kunit_log(KERN_INFO, &test, KUNIT_SUBTEST_INDENT KUNIT_SUBTEST_INDENT
-				  "# Subtest: %s", test_case->name);
-			if (test.params_array.params &&
-			    test_case->generate_params == kunit_array_gen_params) {
-				kunit_log(KERN_INFO, &test, KUNIT_SUBTEST_INDENT
-					  KUNIT_SUBTEST_INDENT "1..%zd\n",
-					  test.params_array.num_params);
-			}
-
-			while (curr_param) {
-				struct kunit param_test = {
-					.param_value = curr_param,
-					.param_index = ++test.param_index,
-					.parent = &test,
-				};
-				kunit_init_test(&param_test, test_case->name, NULL);
-				param_test.log = test_case->log;
-				kunit_run_case_catch_errors(suite, test_case, &param_test);
-
-				if (param_desc[0] == '\0') {
-					snprintf(param_desc, sizeof(param_desc),
-						 "param-%d", param_test.param_index);
-				}
-
-				kunit_print_ok_not_ok(&param_test, KUNIT_LEVEL_CASE_PARAM,
-						      param_test.status,
-						      param_test.param_index,
-						      param_desc,
-						      param_test.status_comment);
-
-				kunit_update_stats(&param_stats, param_test.status);
-
-				/* Get next param. */
-				param_desc[0] = '\0';
-				curr_param = test_case->generate_params(&test, curr_param,
-									param_desc);
-			}
-			/*
-			 * TODO: Put into a try catch. Since we don't need suite->exit
-			 * for it we can't reuse kunit_try_run_cleanup for this yet.
-			 */
-			if (test_case->param_exit)
-				test_case->param_exit(&test);
-			/* TODO: Put this kunit_cleanup into a try-catch. */
-			kunit_cleanup(&test);
-		}
-test_case_end:
-		kunit_print_attr((void *)test_case, true, KUNIT_LEVEL_CASE);
-
-		kunit_print_test_stats(&test, param_stats);
-
-		kunit_print_ok_not_ok(&test, KUNIT_LEVEL_CASE, test_case->status,
-				      kunit_test_case_num(suite, test_case),
-				      test_case->name,
-				      test.status_comment);
-
-		kunit_update_stats(&suite_stats, test_case->status);
-		kunit_accumulate_stats(&total_stats, param_stats);
-	}
 
 	if (suite->suite_exit)
 		suite->suite_exit(suite);
 
-	kunit_print_suite_stats(suite, suite_stats, total_stats);
+	kunit_print_suite_stats(suite, &suite_stats, &total_stats);
 suite_end:
 	kunit_print_suite_end(suite);
 

rust/kernel/kunit.rs

@@ -14,6 +14,10 @@ use crate::prelude::*;
 /// Public but hidden since it should only be used from KUnit generated code.
 #[doc(hidden)]
 pub fn err(args: fmt::Arguments<'_>) {
+    // `args` is unused if `CONFIG_PRINTK` is not set - this avoids a build-time warning.
+    #[cfg(not(CONFIG_PRINTK))]
+    let _ = args;
+
     // SAFETY: The format string is null-terminated and the `%pA` specifier matches the argument we
     // are passing.
     #[cfg(CONFIG_PRINTK)]
@@ -30,6 +34,10 @@ pub fn err(args: fmt::Arguments<'_>) {
 /// Public but hidden since it should only be used from KUnit generated code.
 #[doc(hidden)]
 pub fn info(args: fmt::Arguments<'_>) {
+    // `args` is unused if `CONFIG_PRINTK` is not set - this avoids a build-time warning.
+    #[cfg(not(CONFIG_PRINTK))]
+    let _ = args;
+
     // SAFETY: The format string is null-terminated and the `%pA` specifier matches the argument we
     // are passing.
     #[cfg(CONFIG_PRINTK)]

tools/testing/kunit/kunit_kernel.py

@@ -346,8 +346,10 @@ class LinuxSourceTree:
 		return self.validate_config(build_dir)
 
 	def run_kernel(self, args: Optional[List[str]]=None, build_dir: str='', filter_glob: str='', filter: str='', filter_action: Optional[str]=None, timeout: Optional[int]=None) -> Iterator[str]:
-		if not args:
+		# Copy to avoid mutating the caller-supplied list. exec_tests() reuses
-			args = []
+		# the same args across repeated run_kernel() calls (e.g. --run_isolated),
+		# so appending to the original would accumulate stale flags on each call.
+		args = list(args) if args else []
 		if filter_glob:
 			args.append('kunit.filter_glob=' + filter_glob)
 		if filter:

tools/testing/kunit/kunit_tool_test.py

@@ -503,6 +503,32 @@ class LinuxSourceTreeTest(unittest.TestCase):
 			with open(kunit_kernel.get_outfile_path(build_dir), 'rt') as outfile:
 				self.assertEqual(outfile.read(), 'hi\nbye\n', msg='Missing some output')
 
+	def test_run_kernel_args_not_mutated(self):
+		"""Verify run_kernel() copies args so callers can reuse them."""
+		start_calls = []
+
+		def fake_start(start_args, unused_build_dir):
+			start_calls.append(list(start_args))
+			return subprocess.Popen(['printf', 'KTAP version 1\n'],
+						text=True, stdout=subprocess.PIPE)
+
+		with tempfile.TemporaryDirectory('') as build_dir:
+			tree = kunit_kernel.LinuxSourceTree(build_dir,
+					kunitconfig_paths=[os.devnull])
+			with mock.patch.object(tree._ops, 'start', side_effect=fake_start), \
+			     mock.patch.object(kunit_kernel.subprocess, 'call'):
+				kernel_args = ['mem=1G']
+				for _ in tree.run_kernel(args=kernel_args, build_dir=build_dir,
+							 filter_glob='suite.test1'):
+					pass
+				for _ in tree.run_kernel(args=kernel_args, build_dir=build_dir,
+							 filter_glob='suite.test2'):
+					pass
+				self.assertEqual(kernel_args, ['mem=1G'],
+					'run_kernel() should not modify caller args')
+				self.assertIn('kunit.filter_glob=suite.test1', start_calls[0])
+				self.assertIn('kunit.filter_glob=suite.test2', start_calls[1])
+
 	def test_build_reconfig_no_config(self):
 		with tempfile.TemporaryDirectory('') as build_dir:
 			with open(kunit_kernel.get_kunitconfig_path(build_dir), 'w') as f: