[PATCH v7 linux-kselftest-test 0/6] kunit: support building core/tests as modules

[PATCH v7 linux-kselftest-test 0/6] kunit: support building core/tests as modules

[Alan Maguire]

The current kunit execution model is to provide base kunit functionality
and tests built-in to the kernel.  The aim of this series is to allow
building kunit itself and tests as modules.  This in turn allows a
simple form of selective execution; load the module you wish to test.
In doing so, kunit itself (if also built as a module) will be loaded as
an implicit dependency.

Because this requires a core API modification - if a module delivers
multiple suites, they must be declared with the kunit_test_suites()
macro - we're proposing this patch set as a candidate to be applied to the
test tree before too many kunit consumers appear.  We attempt to deal
with existing consumers in patch 3.

Changes since v6:
 - reintroduce kunit_test_suite() definition to handle users in other trees
   not yet converted to using kunit_test_suites() (kbuild error when
   applying patches to ext4/dev tree)
 - modify drivers/base/power/qos-test.c to use kunit_test_suites()
   to register suite.  We do not convert it to support module build now as
   the suite uses a few unexported function; see patch 3 for details.
   
Changes since v5:
 - fixed fs/ext4/Makefile to remove unneeded conditional compilation
   (Iurii, patch 3)
 - added Reviewed-by, Acked-by to patches 3, 4, 5 and 6

Changes since v4:
 - fixed signoff chain to use Co-developed-by: prior to Knut's signoff
   (Stephen, all patches)
 - added Reviewed-by, Tested-by for patches 1, 2, 4 and 6
 - updated comment describing try-catch-impl.h (Stephen, patch 2)
 - fixed MODULE_LICENSEs to be GPL v2 (Stephen, patches 3, 5)
 - added __init to kunit_init() (Stephen, patch 5)

Changes since v3:
 - removed symbol lookup patch for separate submission later
 - removed use of sysctl_hung_task_timeout_seconds (patch 4, as discussed
   with Brendan and Stephen)
 - disabled build of string-stream-test when CONFIG_KUNIT_TEST=m; this
   is to avoid having to deal with symbol lookup issues
 - changed string-stream-impl.h back to string-stream.h (Brendan)
 - added module build support to new list, ext4 tests

Changes since v2:
 - moved string-stream.h header to lib/kunit/string-stream-impl.h (Brendan)
   (patch 1)
 - split out non-exported interfaces in try-catch-impl.h (Brendan)
   (patch 2)
 - added kunit_find_symbol() and KUNIT_INIT_SYMBOL to lookup non-exported
   symbols (patches 3, 4)
 - removed #ifdef MODULE around module licenses (Randy, Brendan, Andy)
   (patch 4)
 - replaced kunit_test_suite() with kunit_test_suites() rather than
   supporting both (Brendan) (patch 4)
 - lookup sysctl_hung_task_timeout_secs as kunit may be built as a module
   and the symbol may not be available (patch 5)

Alan Maguire (6):
  kunit: move string-stream.h to lib/kunit
  kunit: hide unexported try-catch interface in try-catch-impl.h
  kunit: allow kunit tests to be loaded as a module
  kunit: remove timeout dependence on sysctl_hung_task_timeout_seconds
  kunit: allow kunit to be loaded as a module
  kunit: update documentation to describe module-based build

 Documentation/dev-tools/kunit/faq.rst              |  3 +-
 Documentation/dev-tools/kunit/index.rst            |  3 ++
 Documentation/dev-tools/kunit/usage.rst            | 16 ++++++++++
 drivers/base/power/qos-test.c                      |  2 +-
 fs/ext4/Kconfig                                    |  2 +-
 fs/ext4/Makefile                                   |  3 +-
 fs/ext4/inode-test.c                               |  4 ++-
 include/kunit/assert.h                             |  3 +-
 include/kunit/test.h                               | 37 ++++++++++++++++------
 include/kunit/try-catch.h                          | 10 ------
 kernel/sysctl-test.c                               |  4 ++-
 lib/Kconfig.debug                                  |  4 +--
 lib/kunit/Kconfig                                  |  6 ++--
 lib/kunit/Makefile                                 | 14 +++++---
 lib/kunit/assert.c                                 | 10 ++++++
 lib/kunit/{example-test.c => kunit-example-test.c} |  4 ++-
 lib/kunit/{test-test.c => kunit-test.c}            |  7 ++--
 lib/kunit/string-stream-test.c                     |  5 +--
 lib/kunit/string-stream.c                          |  3 +-
 {include => lib}/kunit/string-stream.h             |  0
 lib/kunit/test.c                                   | 25 ++++++++++++++-
 lib/kunit/try-catch-impl.h                         | 27 ++++++++++++++++
 lib/kunit/try-catch.c                              | 37 +++++-----------------
 lib/list-test.c                                    |  4 ++-
 24 files changed, 160 insertions(+), 73 deletions(-)
 rename lib/kunit/{example-test.c => kunit-example-test.c} (97%)
 rename lib/kunit/{test-test.c => kunit-test.c} (98%)
 rename {include => lib}/kunit/string-stream.h (100%)
 create mode 100644 lib/kunit/try-catch-impl.h

-- 
1.8.3.1

[PATCH v7 linux-kselftest-test 1/6] kunit: move string-stream.h to lib/kunit

[Alan Maguire]

string-stream interfaces are not intended for external use;
move them from include/kunit to lib/kunit accordingly.

Co-developed-by: Knut Omang <knut.omang@oracle.com>
Signed-off-by: Knut Omang <knut.omang@oracle.com>
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Tested-by: Brendan Higgins <brendanhiggins@google.com>
---
 include/kunit/assert.h                 | 3 ++-
 lib/kunit/assert.c                     | 2 ++
 lib/kunit/string-stream-test.c         | 3 ++-
 lib/kunit/string-stream.c              | 3 ++-
 {include => lib}/kunit/string-stream.h | 0
 lib/kunit/test.c                       | 2 ++
 6 files changed, 10 insertions(+), 3 deletions(-)
 rename {include => lib}/kunit/string-stream.h (100%)

diff --git a/include/kunit/assert.h b/include/kunit/assert.h
index db6a0fc..ad889b5 100644
--- a/include/kunit/assert.h
+++ b/include/kunit/assert.h
@@ -9,10 +9,11 @@
 #ifndef _KUNIT_ASSERT_H
 #define _KUNIT_ASSERT_H
 
-#include <kunit/string-stream.h>
 #include <linux/err.h>
+#include <linux/kernel.h>
 
 struct kunit;
+struct string_stream;
 
 /**
  * enum kunit_assert_type - Type of expectation/assertion.
diff --git a/lib/kunit/assert.c b/lib/kunit/assert.c
index 86013d4..9aca71c 100644
--- a/lib/kunit/assert.c
+++ b/lib/kunit/assert.c
@@ -7,6 +7,8 @@
  */
 #include <kunit/assert.h>
 
+#include "string-stream.h"
+
 void kunit_base_assert_format(const struct kunit_assert *assert,
 			      struct string_stream *stream)
 {
diff --git a/lib/kunit/string-stream-test.c b/lib/kunit/string-stream-test.c
index 76cc05e..6c70dc8 100644
--- a/lib/kunit/string-stream-test.c
+++ b/lib/kunit/string-stream-test.c
@@ -6,10 +6,11 @@
  * Author: Brendan Higgins <brendanhiggins@google.com>
  */
 
-#include <kunit/string-stream.h>
 #include <kunit/test.h>
 #include <linux/slab.h>
 
+#include "string-stream.h"
+
 static void string_stream_test_empty_on_creation(struct kunit *test)
 {
 	struct string_stream *stream = alloc_string_stream(test, GFP_KERNEL);
diff --git a/lib/kunit/string-stream.c b/lib/kunit/string-stream.c
index e6d17aa..3503920 100644
--- a/lib/kunit/string-stream.c
+++ b/lib/kunit/string-stream.c
@@ -6,11 +6,12 @@
  * Author: Brendan Higgins <brendanhiggins@google.com>
  */
 
-#include <kunit/string-stream.h>
 #include <kunit/test.h>
 #include <linux/list.h>
 #include <linux/slab.h>
 
+#include "string-stream.h"
+
 struct string_stream_fragment_alloc_context {
 	struct kunit *test;
 	int len;
diff --git a/include/kunit/string-stream.h b/lib/kunit/string-stream.h
similarity index 100%
rename from include/kunit/string-stream.h
rename to lib/kunit/string-stream.h
diff --git a/lib/kunit/test.c b/lib/kunit/test.c
index c83c0fa..36ebf47 100644
--- a/lib/kunit/test.c
+++ b/lib/kunit/test.c
@@ -11,6 +11,8 @@
 #include <linux/kernel.h>
 #include <linux/sched/debug.h>
 
+#include "string-stream.h"
+
 static void kunit_set_failure(struct kunit *test)
 {
 	WRITE_ONCE(test->success, false);
-- 
1.8.3.1

[PATCH v7 linux-kselftest-test 2/6] kunit: hide unexported try-catch interface in try-catch-impl.h

[Alan Maguire]

Define function as static inline in try-catch-impl.h to allow it to
be used in kunit itself and tests.  Also remove unused
kunit_generic_try_catch

Co-developed-by: Knut Omang <knut.omang@oracle.com>
Signed-off-by: Knut Omang <knut.omang@oracle.com>
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Tested-by: Brendan Higgins <brendanhiggins@google.com>
---
 include/kunit/try-catch.h  | 10 ----------
 lib/kunit/test-test.c      |  2 ++
 lib/kunit/test.c           |  2 +-
 lib/kunit/try-catch-impl.h | 27 +++++++++++++++++++++++++++
 lib/kunit/try-catch.c      | 13 ++-----------
 5 files changed, 32 insertions(+), 22 deletions(-)
 create mode 100644 lib/kunit/try-catch-impl.h

diff --git a/include/kunit/try-catch.h b/include/kunit/try-catch.h
index 404f336..c507dd4 100644
--- a/include/kunit/try-catch.h
+++ b/include/kunit/try-catch.h
@@ -53,11 +53,6 @@ struct kunit_try_catch {
 	void *context;
 };
 
-void kunit_try_catch_init(struct kunit_try_catch *try_catch,
-			  struct kunit *test,
-			  kunit_try_catch_func_t try,
-			  kunit_try_catch_func_t catch);
-
 void kunit_try_catch_run(struct kunit_try_catch *try_catch, void *context);
 
 void __noreturn kunit_try_catch_throw(struct kunit_try_catch *try_catch);
@@ -67,9 +62,4 @@ static inline int kunit_try_catch_get_result(struct kunit_try_catch *try_catch)
 	return try_catch->try_result;
 }
 
-/*
- * Exposed for testing only.
- */
-void kunit_generic_try_catch_init(struct kunit_try_catch *try_catch);
-
 #endif /* _KUNIT_TRY_CATCH_H */
diff --git a/lib/kunit/test-test.c b/lib/kunit/test-test.c
index 5ebe059..5a6cc04 100644
--- a/lib/kunit/test-test.c
+++ b/lib/kunit/test-test.c
@@ -7,6 +7,8 @@
  */
 #include <kunit/test.h>
 
+#include "try-catch-impl.h"
+
 struct kunit_try_catch_test_context {
 	struct kunit_try_catch *try_catch;
 	bool function_called;
diff --git a/lib/kunit/test.c b/lib/kunit/test.c
index 36ebf47..58a6227 100644
--- a/lib/kunit/test.c
+++ b/lib/kunit/test.c
@@ -7,11 +7,11 @@
  */
 
 #include <kunit/test.h>
-#include <kunit/try-catch.h>
 #include <linux/kernel.h>
 #include <linux/sched/debug.h>
 
 #include "string-stream.h"
+#include "try-catch-impl.h"
 
 static void kunit_set_failure(struct kunit *test)
 {
diff --git a/lib/kunit/try-catch-impl.h b/lib/kunit/try-catch-impl.h
new file mode 100644
index 0000000..203ba6a
--- /dev/null
+++ b/lib/kunit/try-catch-impl.h
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Internal kunit try catch implementation to be shared with tests.
+ *
+ * Copyright (C) 2019, Google LLC.
+ * Author: Brendan Higgins <brendanhiggins@google.com>
+ */
+
+#ifndef _KUNIT_TRY_CATCH_IMPL_H
+#define _KUNIT_TRY_CATCH_IMPL_H
+
+#include <kunit/try-catch.h>
+#include <linux/types.h>
+
+struct kunit;
+
+static inline void kunit_try_catch_init(struct kunit_try_catch *try_catch,
+					struct kunit *test,
+					kunit_try_catch_func_t try,
+					kunit_try_catch_func_t catch)
+{
+	try_catch->test = test;
+	try_catch->try = try;
+	try_catch->catch = catch;
+}
+
+#endif /* _KUNIT_TRY_CATCH_IMPL_H */
diff --git a/lib/kunit/try-catch.c b/lib/kunit/try-catch.c
index 55686839..4a66d16 100644
--- a/lib/kunit/try-catch.c
+++ b/lib/kunit/try-catch.c
@@ -8,12 +8,13 @@
  */
 
 #include <kunit/test.h>
-#include <kunit/try-catch.h>
 #include <linux/completion.h>
 #include <linux/kernel.h>
 #include <linux/kthread.h>
 #include <linux/sched/sysctl.h>
 
+#include "try-catch-impl.h"
+
 void __noreturn kunit_try_catch_throw(struct kunit_try_catch *try_catch)
 {
 	try_catch->try_result = -EFAULT;
@@ -106,13 +107,3 @@ void kunit_try_catch_run(struct kunit_try_catch *try_catch, void *context)
 
 	try_catch->catch(try_catch->context);
 }
-
-void kunit_try_catch_init(struct kunit_try_catch *try_catch,
-			  struct kunit *test,
-			  kunit_try_catch_func_t try,
-			  kunit_try_catch_func_t catch)
-{
-	try_catch->test = test;
-	try_catch->try = try;
-	try_catch->catch = catch;
-}
-- 
1.8.3.1

[PATCH v7 linux-kselftest-test 3/6] kunit: allow kunit tests to be loaded as a module

[Alan Maguire]

As tests are added to kunit, it will become less feasible to execute
all built tests together.  By supporting modular tests we provide
a simple way to do selective execution on a running system; specifying

CONFIG_KUNIT=y
CONFIG_KUNIT_EXAMPLE_TEST=m

...means we can simply "insmod example-test.ko" to run the tests.

To achieve this we need to do the following:

o export the required symbols in kunit
o string-stream tests utilize non-exported symbols so for now we skip
  building them when CONFIG_KUNIT_TEST=m.
o drivers/base/power/qos-test.c contains a few unexported interface
  references, namely freq_qos_read_value() and freq_constraints_init().
  Both of these could be potentially defined as static inline functions
  in include/linux/pm_qos.h, but for now we simply avoid supporting
  module build for that test suite.
o support a new way of declaring test suites.  Because a module cannot
  do multiple late_initcall()s, we provide a kunit_test_suites() macro
  to declare multiple suites within the same module at once.
o some test module names would have been too general ("test-test"
  and "example-test" for kunit tests, "inode-test" for ext4 tests);
  rename these as appropriate ("kunit-test", "kunit-example-test"
  and "ext4-inode-test" respectively).

Also define kunit_test_suite() via kunit_test_suites()
as callers in other trees may need the old definition.

Co-developed-by: Knut Omang <knut.omang@oracle.com>
Signed-off-by: Knut Omang <knut.omang@oracle.com>
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Acked-by: Theodore Ts'o <tytso@mit.edu> # for ext4 bits
Acked-by: David Gow <davidgow@google.com> # For list-test
Reported-by: kbuild test robot <lkp@intel.com>
---
 drivers/base/power/qos-test.c                      |  2 +-
 fs/ext4/Kconfig                                    |  2 +-
 fs/ext4/Makefile                                   |  3 +-
 fs/ext4/inode-test.c                               |  4 ++-
 include/kunit/test.h                               | 37 ++++++++++++++++------
 kernel/sysctl-test.c                               |  4 ++-
 lib/Kconfig.debug                                  |  4 +--
 lib/kunit/Kconfig                                  |  4 +--
 lib/kunit/Makefile                                 | 10 ++++--
 lib/kunit/assert.c                                 |  8 +++++
 lib/kunit/{example-test.c => kunit-example-test.c} |  4 ++-
 lib/kunit/{test-test.c => kunit-test.c}            |  5 +--
 lib/kunit/string-stream-test.c                     |  2 +-
 lib/kunit/test.c                                   |  8 +++++
 lib/kunit/try-catch.c                              |  2 ++
 lib/list-test.c                                    |  4 ++-
 16 files changed, 76 insertions(+), 27 deletions(-)
 rename lib/kunit/{example-test.c => kunit-example-test.c} (97%)
 rename lib/kunit/{test-test.c => kunit-test.c} (98%)

diff --git a/drivers/base/power/qos-test.c b/drivers/base/power/qos-test.c
index 3115db0..79fc6c4 100644
--- a/drivers/base/power/qos-test.c
+++ b/drivers/base/power/qos-test.c
@@ -114,4 +114,4 @@ static void freq_qos_test_readd(struct kunit *test)
 	.name = "qos-kunit-test",
 	.test_cases = pm_qos_test_cases,
 };
-kunit_test_suite(pm_qos_test_module);
+kunit_test_suites(&pm_qos_test_module);
diff --git a/fs/ext4/Kconfig b/fs/ext4/Kconfig
index ef42ab0..435510f 100644
--- a/fs/ext4/Kconfig
+++ b/fs/ext4/Kconfig
@@ -108,7 +108,7 @@ config EXT4_DEBUG
 		echo 1 > /sys/module/ext4/parameters/mballoc_debug
 
 config EXT4_KUNIT_TESTS
-	bool "KUnit tests for ext4"
+	tristate "KUnit tests for ext4"
 	select EXT4_FS
 	depends on KUNIT
 	help
diff --git a/fs/ext4/Makefile b/fs/ext4/Makefile
index 840b91d..4ccb3c9 100644
--- a/fs/ext4/Makefile
+++ b/fs/ext4/Makefile
@@ -13,5 +13,6 @@ ext4-y	:= balloc.o bitmap.o block_validity.o dir.o ext4_jbd2.o extents.o \
 
 ext4-$(CONFIG_EXT4_FS_POSIX_ACL)	+= acl.o
 ext4-$(CONFIG_EXT4_FS_SECURITY)		+= xattr_security.o
-ext4-$(CONFIG_EXT4_KUNIT_TESTS)		+= inode-test.o
+ext4-inode-test-objs			+= inode-test.o
+obj-$(CONFIG_EXT4_KUNIT_TESTS)		+= ext4-inode-test.o
 ext4-$(CONFIG_FS_VERITY)		+= verity.o
diff --git a/fs/ext4/inode-test.c b/fs/ext4/inode-test.c
index 92a9da1..95620bf 100644
--- a/fs/ext4/inode-test.c
+++ b/fs/ext4/inode-test.c
@@ -269,4 +269,6 @@ static void inode_test_xtimestamp_decoding(struct kunit *test)
 	.test_cases = ext4_inode_test_cases,
 };
 
-kunit_test_suite(ext4_inode_test_suite);
+kunit_test_suites(&ext4_inode_test_suite);
+
+MODULE_LICENSE("GPL v2");
diff --git a/include/kunit/test.h b/include/kunit/test.h
index dba4830..2dfb550 100644
--- a/include/kunit/test.h
+++ b/include/kunit/test.h
@@ -12,6 +12,7 @@
 #include <kunit/assert.h>
 #include <kunit/try-catch.h>
 #include <linux/kernel.h>
+#include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/types.h>
 
@@ -197,31 +198,47 @@ struct kunit {
 int kunit_run_tests(struct kunit_suite *suite);
 
 /**
- * kunit_test_suite() - used to register a &struct kunit_suite with KUnit.
+ * kunit_test_suites() - used to register one or more &struct kunit_suite
+ *			 with KUnit.
  *
- * @suite: a statically allocated &struct kunit_suite.
+ * @suites: a statically allocated list of &struct kunit_suite.
  *
- * Registers @suite with the test framework. See &struct kunit_suite for
+ * Registers @suites with the test framework. See &struct kunit_suite for
  * more information.
  *
- * NOTE: Currently KUnit tests are all run as late_initcalls; this means
+ * When builtin,  KUnit tests are all run as late_initcalls; this means
  * that they cannot test anything where tests must run at a different init
  * phase. One significant restriction resulting from this is that KUnit
  * cannot reliably test anything that is initialize in the late_init phase;
  * another is that KUnit is useless to test things that need to be run in
  * an earlier init phase.
  *
+ * An alternative is to build the tests as a module.  Because modules
+ * do not support multiple late_initcall()s, we need to initialize an
+ * array of suites for a module.
+ *
  * TODO(brendanhiggins@google.com): Don't run all KUnit tests as
  * late_initcalls.  I have some future work planned to dispatch all KUnit
  * tests from the same place, and at the very least to do so after
  * everything else is definitely initialized.
  */
-#define kunit_test_suite(suite)						       \
-	static int kunit_suite_init##suite(void)			       \
-	{								       \
-		return kunit_run_tests(&suite);				       \
-	}								       \
-	late_initcall(kunit_suite_init##suite)
+#define kunit_test_suites(...)						\
+	static struct kunit_suite *suites[] = { __VA_ARGS__, NULL};	\
+	static int kunit_test_suites_init(void)				\
+	{								\
+		unsigned int i;						\
+		for (i = 0; suites[i] != NULL; i++)			\
+			kunit_run_tests(suites[i]);			\
+		return 0;						\
+	}								\
+	late_initcall(kunit_test_suites_init);				\
+	static void __exit kunit_test_suites_exit(void)			\
+	{								\
+		return;							\
+	}								\
+	module_exit(kunit_test_suites_exit)
+
+#define kunit_test_suite(suite)	kunit_test_suites(&suite)
 
 /*
  * Like kunit_alloc_resource() below, but returns the struct kunit_resource
diff --git a/kernel/sysctl-test.c b/kernel/sysctl-test.c
index 2a63241..ccb7850 100644
--- a/kernel/sysctl-test.c
+++ b/kernel/sysctl-test.c
@@ -389,4 +389,6 @@ static void sysctl_test_api_dointvec_write_single_greater_int_max(
 	.test_cases = sysctl_test_cases,
 };
 
-kunit_test_suite(sysctl_test_suite);
+kunit_test_suites(&sysctl_test_suite);
+
+MODULE_LICENSE("GPL v2");
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index d1842fe..e23c923 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1980,7 +1980,7 @@ config TEST_SYSCTL
 	  If unsure, say N.
 
 config SYSCTL_KUNIT_TEST
-	bool "KUnit test for sysctl"
+	tristate "KUnit test for sysctl"
 	depends on KUNIT
 	help
 	  This builds the proc sysctl unit test, which runs on boot.
@@ -1991,7 +1991,7 @@ config SYSCTL_KUNIT_TEST
 	  If unsure, say N.
 
 config LIST_KUNIT_TEST
-	bool "KUnit Test for Kernel Linked-list structures"
+	tristate "KUnit Test for Kernel Linked-list structures"
 	depends on KUNIT
 	help
 	  This builds the linked list KUnit test suite.
diff --git a/lib/kunit/Kconfig b/lib/kunit/Kconfig
index af37016..9ebd5e6 100644
--- a/lib/kunit/Kconfig
+++ b/lib/kunit/Kconfig
@@ -15,7 +15,7 @@ menuconfig KUNIT
 if KUNIT
 
 config KUNIT_TEST
-	bool "KUnit test for KUnit"
+	tristate "KUnit test for KUnit"
 	help
 	  Enables the unit tests for the KUnit test framework. These tests test
 	  the KUnit test framework itself; the tests are both written using
@@ -24,7 +24,7 @@ config KUNIT_TEST
 	  expected.
 
 config KUNIT_EXAMPLE_TEST
-	bool "Example test for KUnit"
+	tristate "Example test for KUnit"
 	help
 	  Enables an example unit test that illustrates some of the basic
 	  features of KUnit. This test only exists to help new users understand
diff --git a/lib/kunit/Makefile b/lib/kunit/Makefile
index 769d940..bc6e5e54 100644
--- a/lib/kunit/Makefile
+++ b/lib/kunit/Makefile
@@ -3,7 +3,11 @@ obj-$(CONFIG_KUNIT) +=			test.o \
 					assert.o \
 					try-catch.o
 
-obj-$(CONFIG_KUNIT_TEST) +=		test-test.o \
-					string-stream-test.o
+obj-$(CONFIG_KUNIT_TEST) +=		kunit-test.o
 
-obj-$(CONFIG_KUNIT_EXAMPLE_TEST) +=	example-test.o
+# string-stream-test compiles built-in only.
+ifeq ($(CONFIG_KUNIT_TEST),y)
+obj-$(CONFIG_KUNIT_TEST) +=		string-stream-test.o
+endif
+
+obj-$(CONFIG_KUNIT_EXAMPLE_TEST) +=	kunit-example-test.o
diff --git a/lib/kunit/assert.c b/lib/kunit/assert.c
index 9aca71c..b24bebc 100644
--- a/lib/kunit/assert.c
+++ b/lib/kunit/assert.c
@@ -26,6 +26,7 @@ void kunit_base_assert_format(const struct kunit_assert *assert,
 	string_stream_add(stream, "%s FAILED at %s:%d\n",
 			 expect_or_assert, assert->file, assert->line);
 }
+EXPORT_SYMBOL_GPL(kunit_base_assert_format);
 
 void kunit_assert_print_msg(const struct kunit_assert *assert,
 			    struct string_stream *stream)
@@ -33,6 +34,7 @@ void kunit_assert_print_msg(const struct kunit_assert *assert,
 	if (assert->message.fmt)
 		string_stream_add(stream, "\n%pV", &assert->message);
 }
+EXPORT_SYMBOL_GPL(kunit_assert_print_msg);
 
 void kunit_fail_assert_format(const struct kunit_assert *assert,
 			      struct string_stream *stream)
@@ -40,6 +42,7 @@ void kunit_fail_assert_format(const struct kunit_assert *assert,
 	kunit_base_assert_format(assert, stream);
 	string_stream_add(stream, "%pV", &assert->message);
 }
+EXPORT_SYMBOL_GPL(kunit_fail_assert_format);
 
 void kunit_unary_assert_format(const struct kunit_assert *assert,
 			       struct string_stream *stream)
@@ -58,6 +61,7 @@ void kunit_unary_assert_format(const struct kunit_assert *assert,
 				 unary_assert->condition);
 	kunit_assert_print_msg(assert, stream);
 }
+EXPORT_SYMBOL_GPL(kunit_unary_assert_format);
 
 void kunit_ptr_not_err_assert_format(const struct kunit_assert *assert,
 				     struct string_stream *stream)
@@ -78,6 +82,7 @@ void kunit_ptr_not_err_assert_format(const struct kunit_assert *assert,
 	}
 	kunit_assert_print_msg(assert, stream);
 }
+EXPORT_SYMBOL_GPL(kunit_ptr_not_err_assert_format);
 
 void kunit_binary_assert_format(const struct kunit_assert *assert,
 				struct string_stream *stream)
@@ -99,6 +104,7 @@ void kunit_binary_assert_format(const struct kunit_assert *assert,
 			 binary_assert->right_value);
 	kunit_assert_print_msg(assert, stream);
 }
+EXPORT_SYMBOL_GPL(kunit_binary_assert_format);
 
 void kunit_binary_ptr_assert_format(const struct kunit_assert *assert,
 				    struct string_stream *stream)
@@ -120,6 +126,7 @@ void kunit_binary_ptr_assert_format(const struct kunit_assert *assert,
 			 binary_assert->right_value);
 	kunit_assert_print_msg(assert, stream);
 }
+EXPORT_SYMBOL_GPL(kunit_binary_ptr_assert_format);
 
 void kunit_binary_str_assert_format(const struct kunit_assert *assert,
 				    struct string_stream *stream)
@@ -141,3 +148,4 @@ void kunit_binary_str_assert_format(const struct kunit_assert *assert,
 			 binary_assert->right_value);
 	kunit_assert_print_msg(assert, stream);
 }
+EXPORT_SYMBOL_GPL(kunit_binary_str_assert_format);
diff --git a/lib/kunit/example-test.c b/lib/kunit/kunit-example-test.c
similarity index 97%
rename from lib/kunit/example-test.c
rename to lib/kunit/kunit-example-test.c
index f64a829..be1164e 100644
--- a/lib/kunit/example-test.c
+++ b/lib/kunit/kunit-example-test.c
@@ -85,4 +85,6 @@ static int example_test_init(struct kunit *test)
  * This registers the above test suite telling KUnit that this is a suite of
  * tests that need to be run.
  */
-kunit_test_suite(example_test_suite);
+kunit_test_suites(&example_test_suite);
+
+MODULE_LICENSE("GPL v2");
diff --git a/lib/kunit/test-test.c b/lib/kunit/kunit-test.c
similarity index 98%
rename from lib/kunit/test-test.c
rename to lib/kunit/kunit-test.c
index 5a6cc04..ccb8d2e 100644
--- a/lib/kunit/test-test.c
+++ b/lib/kunit/kunit-test.c
@@ -102,7 +102,6 @@ static int kunit_try_catch_test_init(struct kunit *test)
 	.init = kunit_try_catch_test_init,
 	.test_cases = kunit_try_catch_test_cases,
 };
-kunit_test_suite(kunit_try_catch_test_suite);
 
 /*
  * Context for testing test managed resources
@@ -330,4 +329,6 @@ static void kunit_resource_test_exit(struct kunit *test)
 	.exit = kunit_resource_test_exit,
 	.test_cases = kunit_resource_test_cases,
 };
-kunit_test_suite(kunit_resource_test_suite);
+kunit_test_suites(&kunit_try_catch_test_suite, &kunit_resource_test_suite);
+
+MODULE_LICENSE("GPL v2");
diff --git a/lib/kunit/string-stream-test.c b/lib/kunit/string-stream-test.c
index 6c70dc8..110f3a9 100644
--- a/lib/kunit/string-stream-test.c
+++ b/lib/kunit/string-stream-test.c
@@ -50,4 +50,4 @@ static void string_stream_test_get_string(struct kunit *test)
 	.name = "string-stream-test",
 	.test_cases = string_stream_test_cases
 };
-kunit_test_suite(string_stream_test_suite);
+kunit_test_suites(&string_stream_test_suite);
diff --git a/lib/kunit/test.c b/lib/kunit/test.c
index 58a6227..87b5cf1 100644
--- a/lib/kunit/test.c
+++ b/lib/kunit/test.c
@@ -173,6 +173,7 @@ void kunit_do_assertion(struct kunit *test,
 	if (assert->type == KUNIT_ASSERTION)
 		kunit_abort(test);
 }
+EXPORT_SYMBOL_GPL(kunit_do_assertion);
 
 void kunit_init_test(struct kunit *test, const char *name)
 {
@@ -181,6 +182,7 @@ void kunit_init_test(struct kunit *test, const char *name)
 	test->name = name;
 	test->success = true;
 }
+EXPORT_SYMBOL_GPL(kunit_init_test);
 
 /*
  * Initializes and runs test case. Does not clean up or do post validations.
@@ -319,6 +321,7 @@ int kunit_run_tests(struct kunit_suite *suite)
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(kunit_run_tests);
 
 struct kunit_resource *kunit_alloc_and_get_resource(struct kunit *test,
 						    kunit_resource_init_t init,
@@ -344,6 +347,7 @@ struct kunit_resource *kunit_alloc_and_get_resource(struct kunit *test,
 
 	return res;
 }
+EXPORT_SYMBOL_GPL(kunit_alloc_and_get_resource);
 
 static void kunit_resource_free(struct kunit *test, struct kunit_resource *res)
 {
@@ -402,6 +406,7 @@ int kunit_resource_destroy(struct kunit *test,
 	kunit_resource_free(test, resource);
 	return 0;
 }
+EXPORT_SYMBOL_GPL(kunit_resource_destroy);
 
 struct kunit_kmalloc_params {
 	size_t size;
@@ -437,6 +442,7 @@ void *kunit_kmalloc(struct kunit *test, size_t size, gfp_t gfp)
 				    gfp,
 				    &params);
 }
+EXPORT_SYMBOL_GPL(kunit_kmalloc);
 
 void kunit_kfree(struct kunit *test, const void *ptr)
 {
@@ -449,6 +455,7 @@ void kunit_kfree(struct kunit *test, const void *ptr)
 
 	WARN_ON(rc);
 }
+EXPORT_SYMBOL_GPL(kunit_kfree);
 
 void kunit_cleanup(struct kunit *test)
 {
@@ -478,3 +485,4 @@ void kunit_cleanup(struct kunit *test)
 		kunit_resource_free(test, resource);
 	}
 }
+EXPORT_SYMBOL_GPL(kunit_cleanup);
diff --git a/lib/kunit/try-catch.c b/lib/kunit/try-catch.c
index 4a66d16..0247a28 100644
--- a/lib/kunit/try-catch.c
+++ b/lib/kunit/try-catch.c
@@ -20,6 +20,7 @@ void __noreturn kunit_try_catch_throw(struct kunit_try_catch *try_catch)
 	try_catch->try_result = -EFAULT;
 	complete_and_exit(try_catch->try_completion, -EFAULT);
 }
+EXPORT_SYMBOL_GPL(kunit_try_catch_throw);
 
 static int kunit_generic_run_threadfn_adapter(void *data)
 {
@@ -107,3 +108,4 @@ void kunit_try_catch_run(struct kunit_try_catch *try_catch, void *context)
 
 	try_catch->catch(try_catch->context);
 }
+EXPORT_SYMBOL_GPL(kunit_try_catch_run);
diff --git a/lib/list-test.c b/lib/list-test.c
index 363c600..76babb1 100644
--- a/lib/list-test.c
+++ b/lib/list-test.c
@@ -743,4 +743,6 @@ static void list_test_list_for_each_entry_reverse(struct kunit *test)
 	.test_cases = list_test_cases,
 };
 
-kunit_test_suite(list_test_module);
+kunit_test_suites(&list_test_module);
+
+MODULE_LICENSE("GPL v2");
-- 
1.8.3.1

[PATCH v7 linux-kselftest-test 4/6] kunit: remove timeout dependence on sysctl_hung_task_timeout_seconds

[Alan Maguire]

In discussion of how to handle timeouts, it was noted that if
sysctl_hung_task_timeout_seconds is exceeded for a kunit test,
the test task will be killed and an oops generated.  This should
suffice as a means of debugging such timeout issues for now.

Hence remove use of sysctl_hung_task_timeout_secs, which has the
added benefit of avoiding the need to export that symbol from
the core kernel.

Co-developed-by: Knut Omang <knut.omang@oracle.com>
Signed-off-by: Knut Omang <knut.omang@oracle.com>
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Acked-by: Brendan Higgins <brendanhiggins@google.com>
---
 lib/kunit/try-catch.c | 22 ++++------------------
 1 file changed, 4 insertions(+), 18 deletions(-)

diff --git a/lib/kunit/try-catch.c b/lib/kunit/try-catch.c
index 0247a28..0dd434e 100644
--- a/lib/kunit/try-catch.c
+++ b/lib/kunit/try-catch.c
@@ -11,7 +11,6 @@
 #include <linux/completion.h>
 #include <linux/kernel.h>
 #include <linux/kthread.h>
-#include <linux/sched/sysctl.h>
 
 #include "try-catch-impl.h"
 
@@ -33,8 +32,6 @@ static int kunit_generic_run_threadfn_adapter(void *data)
 
 static unsigned long kunit_test_timeout(void)
 {
-	unsigned long timeout_msecs;
-
 	/*
 	 * TODO(brendanhiggins@google.com): We should probably have some type of
 	 * variable timeout here. The only question is what that timeout value
@@ -51,22 +48,11 @@ static unsigned long kunit_test_timeout(void)
 	 *
 	 * For more background on this topic, see:
 	 * https://mike-bland.com/2011/11/01/small-medium-large.html
+	 *
+	 * If tests timeout due to exceeding sysctl_hung_task_timeout_secs,
+	 * the task will be killed and an oops generated.
 	 */
-	if (sysctl_hung_task_timeout_secs) {
-		/*
-		 * If sysctl_hung_task is active, just set the timeout to some
-		 * value less than that.
-		 *
-		 * In regards to the above TODO, if we decide on variable
-		 * timeouts, this logic will likely need to change.
-		 */
-		timeout_msecs = (sysctl_hung_task_timeout_secs - 1) *
-				MSEC_PER_SEC;
-	} else {
-		timeout_msecs = 300 * MSEC_PER_SEC; /* 5 min */
-	}
-
-	return timeout_msecs;
+	return 300 * MSEC_PER_SEC; /* 5 min */
 }
 
 void kunit_try_catch_run(struct kunit_try_catch *try_catch, void *context)
-- 
1.8.3.1

[PATCH v7 linux-kselftest-test 5/6] kunit: allow kunit to be loaded as a module

[Alan Maguire]

Making kunit itself buildable as a module allows for "always-on"
kunit configuration; specifying CONFIG_KUNIT=m means the module
is built but only used when loaded.  Kunit test modules will load
kunit.ko as an implicit dependency, so simply running
"modprobe my-kunit-tests" will load the tests along with the kunit
module and run them.

Co-developed-by: Knut Omang <knut.omang@oracle.com>
Signed-off-by: Knut Omang <knut.omang@oracle.com>
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
---
 lib/kunit/Kconfig  |  2 +-
 lib/kunit/Makefile |  4 +++-
 lib/kunit/test.c   | 13 +++++++++++++
 3 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/lib/kunit/Kconfig b/lib/kunit/Kconfig
index 9ebd5e6..065aa16 100644
--- a/lib/kunit/Kconfig
+++ b/lib/kunit/Kconfig
@@ -3,7 +3,7 @@
 #
 
 menuconfig KUNIT
-	bool "KUnit - Enable support for unit tests"
+	tristate "KUnit - Enable support for unit tests"
 	help
 	  Enables support for kernel unit tests (KUnit), a lightweight unit
 	  testing and mocking framework for the Linux kernel. These tests are
diff --git a/lib/kunit/Makefile b/lib/kunit/Makefile
index bc6e5e54..fab5564 100644
--- a/lib/kunit/Makefile
+++ b/lib/kunit/Makefile
@@ -1,4 +1,6 @@
-obj-$(CONFIG_KUNIT) +=			test.o \
+obj-$(CONFIG_KUNIT) +=			kunit.o
+
+kunit-objs +=				test.o \
 					string-stream.o \
 					assert.o \
 					try-catch.o
diff --git a/lib/kunit/test.c b/lib/kunit/test.c
index 87b5cf1..9242f93 100644
--- a/lib/kunit/test.c
+++ b/lib/kunit/test.c
@@ -486,3 +486,16 @@ void kunit_cleanup(struct kunit *test)
 	}
 }
 EXPORT_SYMBOL_GPL(kunit_cleanup);
+
+static int __init kunit_init(void)
+{
+	return 0;
+}
+late_initcall(kunit_init);
+
+static void __exit kunit_exit(void)
+{
+}
+module_exit(kunit_exit);
+
+MODULE_LICENSE("GPL v2");
-- 
1.8.3.1

[PATCH v7 linux-kselftest-test 6/6] kunit: update documentation to describe module-based build

[Alan Maguire]

Documentation should describe how to build kunit and tests as
modules.

Co-developed-by: Knut Omang <knut.omang@oracle.com>
Signed-off-by: Knut Omang <knut.omang@oracle.com>
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
---
 Documentation/dev-tools/kunit/faq.rst   |  3 ++-
 Documentation/dev-tools/kunit/index.rst |  3 +++
 Documentation/dev-tools/kunit/usage.rst | 16 ++++++++++++++++
 3 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/Documentation/dev-tools/kunit/faq.rst b/Documentation/dev-tools/kunit/faq.rst
index bf20951..ea55b24 100644
--- a/Documentation/dev-tools/kunit/faq.rst
+++ b/Documentation/dev-tools/kunit/faq.rst
@@ -29,7 +29,8 @@ Yes, well, mostly.
 
 For the most part, the KUnit core framework (what you use to write the tests)
 can compile to any architecture; it compiles like just another part of the
-kernel and runs when the kernel boots. However, there is some infrastructure,
+kernel and runs when the kernel boots, or when built as a module, when the
+module is loaded.  However, there is some infrastructure,
 like the KUnit Wrapper (``tools/testing/kunit/kunit.py``) that does not support
 other architectures.
 
diff --git a/Documentation/dev-tools/kunit/index.rst b/Documentation/dev-tools/kunit/index.rst
index 26ffb46..7ddc385 100644
--- a/Documentation/dev-tools/kunit/index.rst
+++ b/Documentation/dev-tools/kunit/index.rst
@@ -48,6 +48,9 @@ to a standalone program that can be run like any other program directly inside
 of a host operating system; to be clear, it does not require any virtualization
 support; it is just a regular program.
 
+Alternatively, kunit and kunit tests can be built as modules and tests will
+run when the test module is loaded.
+
 KUnit is fast. Excluding build time, from invocation to completion KUnit can run
 several dozen tests in only 10 to 20 seconds; this might not sound like a big
 deal to some people, but having such fast and easy to run tests fundamentally
diff --git a/Documentation/dev-tools/kunit/usage.rst b/Documentation/dev-tools/kunit/usage.rst
index c6e6963..82f9213 100644
--- a/Documentation/dev-tools/kunit/usage.rst
+++ b/Documentation/dev-tools/kunit/usage.rst
@@ -539,6 +539,22 @@ Interspersed in the kernel logs you might see the following:
 
 Congratulations, you just ran a KUnit test on the x86 architecture!
 
+In a similar manner, kunit and kunit tests can also be built as modules,
+so if you wanted to run tests in this way you might add the following config
+options to your ``.config``:
+
+.. code-block:: none
+
+	CONFIG_KUNIT=m
+	CONFIG_KUNIT_EXAMPLE_TEST=m
+
+Once the kernel is built and installed, a simple
+
+.. code-block:: bash
+	modprobe example-test
+
+...will run the tests.
+
 Writing new tests for other architectures
 -----------------------------------------
 
-- 
1.8.3.1