Merge tag 'linux-kselftest-kunit-next-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull KUnit updates from Shuah Khan:
 "Several enhancements, fixes, clean-ups, documentation updates,
  improvements to logging and KTAP compliance of KUnit test output:

   - log numbers in decimal and hex

   - parse KTAP compliant test output

   - allow conditionally exposing static symbols to tests when KUNIT is
     enabled

   - make static symbols visible during kunit testing

   - clean-ups to remove unused structure definition"

* tag 'linux-kselftest-kunit-next-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: (29 commits)
  Documentation: dev-tools: Clarify requirements for result description
  apparmor: test: make static symbols visible during kunit testing
  kunit: add macro to allow conditionally exposing static symbols to tests
  kunit: tool: make parser preserve whitespace when printing test log
  Documentation: kunit: Fix "How Do I Use This" / "Next Steps" sections
  kunit: tool: don't include KTAP headers and the like in the test log
  kunit: improve KTAP compliance of KUnit test output
  kunit: tool: parse KTAP compliant test output
  mm: slub: test: Use the kunit_get_current_test() function
  kunit: Use the static key when retrieving the current test
  kunit: Provide a static key to check if KUnit is actively running tests
  kunit: tool: make --json do nothing if --raw_ouput is set
  kunit: tool: tweak error message when no KTAP found
  kunit: remove KUNIT_INIT_MEM_ASSERTION macro
  Documentation: kunit: Remove redundant 'tips.rst' page
  Documentation: KUnit: reword description of assertions
  Documentation: KUnit: make usage.rst a superset of tips.rst, remove duplication
  kunit: eliminate KUNIT_INIT_*_ASSERT_STRUCT macros
  kunit: tool: remove redundant file.close() call in unit test
  kunit: tool: unit tests all check parser errors, standardize formatting a bit
  ...

Documentation/dev-tools/ktap.rst

@@ -80,8 +80,8 @@ have the number 1 and the number then must increase by 1 for each additional
 subtest within the same test at the same nesting level.
 
 The description is a description of the test, generally the name of
-the test, and can be any string of words (can't include #). The
-description is optional, but recommended.
+the test, and can be any string of characters other than # or a
+newline.  The description is optional, but recommended.
 
 The directive and any diagnostic data is optional. If either are present, they
 must follow a hash sign, "#".

Documentation/dev-tools/kunit/architecture.rst

@@ -4,16 +4,17 @@
 KUnit Architecture
 ==================
 
-The KUnit architecture can be divided into two parts:
+The KUnit architecture is divided into two parts:
 
 - `In-Kernel Testing Framework`_
-- `kunit_tool (Command Line Test Harness)`_
+- `kunit_tool (Command-line Test Harness)`_
 
 In-Kernel Testing Framework
 ===========================
 
 The kernel testing library supports KUnit tests written in C using
-KUnit. KUnit tests are kernel code. KUnit does several things:
+KUnit. These KUnit tests are kernel code. KUnit performs the following
+tasks:
 
 - Organizes tests
 - Reports test results
@@ -22,19 +23,17 @@ KUnit. KUnit tests are kernel code. KUnit does several things:
 Test Cases
 ----------
 
-The fundamental unit in KUnit is the test case. The KUnit test cases are
-grouped into KUnit suites. A KUnit test case is a function with type
-signature ``void (*)(struct kunit *test)``.
-These test case functions are wrapped in a struct called
-struct kunit_case.
+The test case is the fundamental unit in KUnit. KUnit test cases are organised
+into suites. A KUnit test case is a function with type signature
+``void (*)(struct kunit *test)``. These test case functions are wrapped in a
+struct called struct kunit_case.
 
 .. note:
 	``generate_params`` is optional for non-parameterized tests.
 
-Each KUnit test case gets a ``struct kunit`` context
-object passed to it that tracks a running test. The KUnit assertion
-macros and other KUnit utilities use the ``struct kunit`` context
-object. As an exception, there are two fields:
+Each KUnit test case receives a ``struct kunit`` context object that tracks a
+running test. The KUnit assertion macros and other KUnit utilities use the
+``struct kunit`` context object. As an exception, there are two fields:
 
 - ``->priv``: The setup functions can use it to store arbitrary test
   user data.
@@ -77,12 +76,13 @@ Executor
 
 The KUnit executor can list and run built-in KUnit tests on boot.
 The Test suites are stored in a linker section
-called ``.kunit_test_suites``. For code, see:
-https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/asm-generic/vmlinux.lds.h?h=v5.15#n945.
+called ``.kunit_test_suites``. For the code, see ``KUNIT_TABLE()`` macro
+definition in
+`include/asm-generic/vmlinux.lds.h <https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/asm-generic/vmlinux.lds.h?h=v6.0#n950>`_.
 The linker section consists of an array of pointers to
 ``struct kunit_suite``, and is populated by the ``kunit_test_suites()``
-macro. To run all tests compiled into the kernel, the KUnit executor
-iterates over the linker section array.
+macro. The KUnit executor iterates over the linker section array in order to
+run all the tests that are compiled into the kernel.
 
 .. kernel-figure:: kunit_suitememorydiagram.svg
 	:alt:	KUnit Suite Memory
@@ -90,17 +90,17 @@ iterates over the linker section array.
 	KUnit Suite Memory Diagram
 
 On the kernel boot, the KUnit executor uses the start and end addresses
-of this section to iterate over and run all tests. For code, see:
-https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/lib/kunit/executor.c
-
+of this section to iterate over and run all tests. For the implementation of the
+executor, see
+`lib/kunit/executor.c <https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/lib/kunit/executor.c>`_.
 When built as a module, the ``kunit_test_suites()`` macro defines a
 ``module_init()`` function, which runs all the tests in the compilation
 unit instead of utilizing the executor.
 
 In KUnit tests, some error classes do not affect other tests
 or parts of the kernel, each KUnit case executes in a separate thread
-context. For code, see:
-https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/lib/kunit/try-catch.c?h=v5.15#n58
+context. See the ``kunit_try_catch_run()`` function in
+`lib/kunit/try-catch.c <https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/lib/kunit/try-catch.c?h=v5.15#n58>`_.
 
 Assertion Macros
 ----------------
@@ -111,37 +111,36 @@ All expectations/assertions are formatted as:
 
 - ``{EXPECT|ASSERT}`` determines whether the check is an assertion or an
   expectation.
+  In the event of a failure, the testing flow differs as follows:
 
-	- For an expectation, if the check fails, marks the test as failed
-	  and logs the failure.
+	- For expectations, the test is marked as failed and the failure is logged.
 
-	- An assertion, on failure, causes the test case to terminate
-	  immediately.
+	- Failing assertions, on the other hand, result in the test case being
+	  terminated immediately.
 
-		- Assertions call function:
+		- Assertions call the function:
 		  ``void __noreturn kunit_abort(struct kunit *)``.
 
-		- ``kunit_abort`` calls function:
+		- ``kunit_abort`` calls the function:
 		  ``void __noreturn kunit_try_catch_throw(struct kunit_try_catch *try_catch)``.
 
-		- ``kunit_try_catch_throw`` calls function:
+		- ``kunit_try_catch_throw`` calls the function:
 		  ``void kthread_complete_and_exit(struct completion *, long) __noreturn;``
 		  and terminates the special thread context.
 
 - ``<op>`` denotes a check with options: ``TRUE`` (supplied property
-  has the boolean value “true”), ``EQ`` (two supplied properties are
+  has the boolean value "true"), ``EQ`` (two supplied properties are
   equal), ``NOT_ERR_OR_NULL`` (supplied pointer is not null and does not
-  contain an “err” value).
+  contain an "err" value).
 
 - ``[_MSG]`` prints a custom message on failure.
 
 Test Result Reporting
 ---------------------
-KUnit prints test results in KTAP format. KTAP is based on TAP14, see:
-https://github.com/isaacs/testanything.github.io/blob/tap14/tap-version-14-specification.md.
-KTAP (yet to be standardized format) works with KUnit and Kselftest.
-The KUnit executor prints KTAP results to dmesg, and debugfs
-(if configured).
+KUnit prints the test results in KTAP format. KTAP is based on TAP14, see
+Documentation/dev-tools/ktap.rst.
+KTAP works with KUnit and Kselftest. The KUnit executor prints KTAP results to
+dmesg, and debugfs (if configured).
 
 Parameterized Tests
 -------------------
@@ -150,33 +149,35 @@ Each KUnit parameterized test is associated with a collection of
 parameters. The test is invoked multiple times, once for each parameter
 value and the parameter is stored in the ``param_value`` field.
 The test case includes a KUNIT_CASE_PARAM() macro that accepts a
-generator function.
-The generator function is passed the previous parameter and returns the next
-parameter. It also provides a macro to generate common-case generators based on
-arrays.
+generator function. The generator function is passed the previous parameter
+and returns the next parameter. It also includes a macro for generating
+array-based common-case generators.
 
-kunit_tool (Command Line Test Harness)
+kunit_tool (Command-line Test Harness)
 ======================================
 
-kunit_tool is a Python script ``(tools/testing/kunit/kunit.py)``
-that can be used to configure, build, exec, parse and run (runs other
-commands in order) test results. You can either run KUnit tests using
-kunit_tool or can include KUnit in kernel and parse manually.
+``kunit_tool`` is a Python script, found in ``tools/testing/kunit/kunit.py``. It
+is used to configure, build, execute, parse test results and run all of the
+previous commands in correct order (i.e., configure, build, execute and parse).
+You have two options for running KUnit tests: either build the kernel with KUnit
+enabled and manually parse the results (see
+Documentation/dev-tools/kunit/run_manual.rst) or use ``kunit_tool``
+(see Documentation/dev-tools/kunit/run_wrapper.rst).
 
 - ``configure`` command generates the kernel ``.config`` from a
   ``.kunitconfig`` file (and any architecture-specific options).
-  For some architectures, additional config options are specified in the
-  ``qemu_config`` Python script
-  (For example: ``tools/testing/kunit/qemu_configs/powerpc.py``).
+  The Python scripts available in ``qemu_configs`` folder
+  (for example, ``tools/testing/kunit/qemu configs/powerpc.py``) contains
+  additional configuration options for specific architectures.
   It parses both the existing ``.config`` and the ``.kunitconfig`` files
-  and ensures that ``.config`` is a superset of ``.kunitconfig``.
-  If this is not the case, it will combine the two and run
-  ``make olddefconfig`` to regenerate the ``.config`` file. It then
-  verifies that ``.config`` is now a superset. This checks if all
-  Kconfig dependencies are correctly specified in ``.kunitconfig``.
-  ``kunit_config.py`` includes the parsing Kconfigs code. The code which
-  runs ``make olddefconfig`` is a part of ``kunit_kernel.py``. You can
-  invoke this command via: ``./tools/testing/kunit/kunit.py config`` and
+  to ensure that ``.config`` is a superset of ``.kunitconfig``.
+  If not, it will combine the two and run ``make olddefconfig`` to regenerate
+  the ``.config`` file. It then checks to see if ``.config`` has become a superset.
+  This verifies that all the Kconfig dependencies are correctly specified in the
+  file ``.kunitconfig``. The ``kunit_config.py`` script contains the code for parsing
+  Kconfigs. The code which runs ``make olddefconfig`` is part of the
+  ``kunit_kernel.py`` script. You can invoke this command through:
+  ``./tools/testing/kunit/kunit.py config`` and
   generate a ``.config`` file.
 - ``build`` runs ``make`` on the kernel tree with required options
   (depends on the architecture and some options, for example: build_dir)
@@ -184,8 +185,8 @@ kunit_tool or can include KUnit in kernel and parse manually.
   To build a KUnit kernel from the current ``.config``, you can use the
   ``build`` argument: ``./tools/testing/kunit/kunit.py build``.
 - ``exec`` command executes kernel results either directly (using
-  User-mode Linux configuration), or via an emulator such
-  as QEMU. It reads results from the log via standard
+  User-mode Linux configuration), or through an emulator such
+  as QEMU. It reads results from the log using standard
   output (stdout), and passes them to ``parse`` to be parsed.
   If you already have built a kernel with built-in KUnit tests,
   you can run the kernel and display the test results with the ``exec``

Documentation/dev-tools/kunit/index.rst

@@ -16,7 +16,6 @@ KUnit - Linux Kernel Unit Testing
 	api/index
 	style
 	faq
-	tips
 	running_tips
 
 This section details the kernel unit testing framework.
@@ -100,14 +99,11 @@ Read also :ref:`kinds-of-tests`.
 How do I use it?
 ================
 
-*   Documentation/dev-tools/kunit/start.rst - for KUnit new users.
-*   Documentation/dev-tools/kunit/architecture.rst - KUnit architecture.
-*   Documentation/dev-tools/kunit/run_wrapper.rst - run kunit_tool.
-*   Documentation/dev-tools/kunit/run_manual.rst - run tests without kunit_tool.
-*   Documentation/dev-tools/kunit/usage.rst - write tests.
-*   Documentation/dev-tools/kunit/tips.rst - best practices with
-    examples.
-*   Documentation/dev-tools/kunit/api/index.rst - KUnit APIs
-    used for testing.
-*   Documentation/dev-tools/kunit/faq.rst - KUnit common questions and
-    answers.
+You can find a step-by-step guide to writing and running KUnit tests in
+Documentation/dev-tools/kunit/start.rst
+
+Alternatively, feel free to look through the rest of the KUnit documentation,
+or to experiment with tools/testing/kunit/kunit.py and the example test under
+lib/kunit/kunit-example-test.c
+
+Happy testing!

Documentation/dev-tools/kunit/start.rst

@@ -294,13 +294,11 @@ Congrats! You just wrote your first KUnit test.
 Next Steps
 ==========
 
-*   Documentation/dev-tools/kunit/architecture.rst - KUnit architecture.
-*   Documentation/dev-tools/kunit/run_wrapper.rst - run kunit_tool.
-*   Documentation/dev-tools/kunit/run_manual.rst - run tests without kunit_tool.
-*   Documentation/dev-tools/kunit/usage.rst - write tests.
-*   Documentation/dev-tools/kunit/tips.rst - best practices with
-    examples.
-*   Documentation/dev-tools/kunit/api/index.rst - KUnit APIs
-    used for testing.
-*   Documentation/dev-tools/kunit/faq.rst - KUnit common questions and
-    answers.
+If you're interested in using some of the more advanced features of kunit.py,
+take a look at Documentation/dev-tools/kunit/run_wrapper.rst
+
+If you'd like to run tests without using kunit.py, check out
+Documentation/dev-tools/kunit/run_manual.rst
+
+For more information on writing KUnit tests (including some common techniques
+for testing different things), see Documentation/dev-tools/kunit/usage.rst

Documentation/dev-tools/kunit/tips.rst

@@ -1,190 +0,0 @@
-.. SPDX-License-Identifier: GPL-2.0
-
-============================
-Tips For Writing KUnit Tests
-============================
-
-Exiting early on failed expectations
-------------------------------------
-
-``KUNIT_EXPECT_EQ`` and friends will mark the test as failed and continue
-execution.  In some cases, it's unsafe to continue and you can use the
-``KUNIT_ASSERT`` variant to exit on failure.
-
-.. code-block:: c
-
-	void example_test_user_alloc_function(struct kunit *test)
-	{
-		void *object = alloc_some_object_for_me();
-
-		/* Make sure we got a valid pointer back. */
-		KUNIT_ASSERT_NOT_ERR_OR_NULL(test, object);
-		do_something_with_object(object);
-	}
-
-Allocating memory
------------------
-
-Where you would use ``kzalloc``, you should prefer ``kunit_kzalloc`` instead.
-KUnit will ensure the memory is freed once the test completes.
-
-This is particularly useful since it lets you use the ``KUNIT_ASSERT_EQ``
-macros to exit early from a test without having to worry about remembering to
-call ``kfree``.
-
-Example:
-
-.. code-block:: c
-
-	void example_test_allocation(struct kunit *test)
-	{
-		char *buffer = kunit_kzalloc(test, 16, GFP_KERNEL);
-		/* Ensure allocation succeeded. */
-		KUNIT_ASSERT_NOT_ERR_OR_NULL(test, buffer);
-
-		KUNIT_ASSERT_STREQ(test, buffer, "");
-	}
-
-
-Testing static functions
-------------------------
-
-If you don't want to expose functions or variables just for testing, one option
-is to conditionally ``#include`` the test file at the end of your .c file, e.g.
-
-.. code-block:: c
-
-	/* In my_file.c */
-
-	static int do_interesting_thing();
-
-	#ifdef CONFIG_MY_KUNIT_TEST
-	#include "my_kunit_test.c"
-	#endif
-
-Injecting test-only code
-------------------------
-
-Similarly to the above, it can be useful to add test-specific logic.
-
-.. code-block:: c
-
-	/* In my_file.h */
-
-	#ifdef CONFIG_MY_KUNIT_TEST
-	/* Defined in my_kunit_test.c */
-	void test_only_hook(void);
-	#else
-	void test_only_hook(void) { }
-	#endif
-
-This test-only code can be made more useful by accessing the current kunit
-test, see below.
-
-Accessing the current test
---------------------------
-
-In some cases, you need to call test-only code from outside the test file, e.g.
-like in the example above or if you're providing a fake implementation of an
-ops struct.
-There is a ``kunit_test`` field in ``task_struct``, so you can access it via
-``current->kunit_test``.
-
-Here's a slightly in-depth example of how one could implement "mocking":
-
-.. code-block:: c
-
-	#include <linux/sched.h> /* for current */
-
-	struct test_data {
-		int foo_result;
-		int want_foo_called_with;
-	};
-
-	static int fake_foo(int arg)
-	{
-		struct kunit *test = current->kunit_test;
-		struct test_data *test_data = test->priv;
-
-		KUNIT_EXPECT_EQ(test, test_data->want_foo_called_with, arg);
-		return test_data->foo_result;
-	}
-
-	static void example_simple_test(struct kunit *test)
-	{
-		/* Assume priv is allocated in the suite's .init */
-		struct test_data *test_data = test->priv;
-
-		test_data->foo_result = 42;
-		test_data->want_foo_called_with = 1;
-
-		/* In a real test, we'd probably pass a pointer to fake_foo somewhere
-		 * like an ops struct, etc. instead of calling it directly. */
-		KUNIT_EXPECT_EQ(test, fake_foo(1), 42);
-	}
-
-
-Note: here we're able to get away with using ``test->priv``, but if you wanted
-something more flexible you could use a named ``kunit_resource``, see
-Documentation/dev-tools/kunit/api/test.rst.
-
-Failing the current test
-------------------------
-
-But sometimes, you might just want to fail the current test. In that case, we
-have ``kunit_fail_current_test(fmt, args...)`` which is defined in ``<kunit/test-bug.h>`` and
-doesn't require pulling in ``<kunit/test.h>``.
-
-E.g. say we had an option to enable some extra debug checks on some data structure:
-
-.. code-block:: c
-
-	#include <kunit/test-bug.h>
-
-	#ifdef CONFIG_EXTRA_DEBUG_CHECKS
-	static void validate_my_data(struct data *data)
-	{
-		if (is_valid(data))
-			return;
-
-		kunit_fail_current_test("data %p is invalid", data);
-
-		/* Normal, non-KUnit, error reporting code here. */
-	}
-	#else
-	static void my_debug_function(void) { }
-	#endif
-
-
-Customizing error messages
---------------------------
-
-Each of the ``KUNIT_EXPECT`` and ``KUNIT_ASSERT`` macros have a ``_MSG`` variant.
-These take a format string and arguments to provide additional context to the automatically generated error messages.
-
-.. code-block:: c
-
-	char some_str[41];
-	generate_sha1_hex_string(some_str);
-
-	/* Before. Not easy to tell why the test failed. */
-	KUNIT_EXPECT_EQ(test, strlen(some_str), 40);
-
-	/* After. Now we see the offending string. */
-	KUNIT_EXPECT_EQ_MSG(test, strlen(some_str), 40, "some_str='%s'", some_str);
-
-Alternatively, one can take full control over the error message by using ``KUNIT_FAIL()``, e.g.
-
-.. code-block:: c
-
-	/* Before */
-	KUNIT_EXPECT_EQ(test, some_setup_function(), 0);
-
-	/* After: full control over the failure message. */
-	if (some_setup_function())
-		KUNIT_FAIL(test, "Failed to setup thing for testing");
-
-Next Steps
-==========
-*   Optional: see the Documentation/dev-tools/kunit/usage.rst page for a more
-    in-depth explanation of KUnit.

Documentation/dev-tools/kunit/usage.rst

@@ -112,11 +112,45 @@ terminates the test case if the condition is not satisfied. For example:
 			KUNIT_EXPECT_LE(test, a[i], a[i + 1]);
 	}
 
-In this example, the method under test should return pointer to a value. If the
-pointer returns null or an errno, we want to stop the test since the following
-expectation could crash the test case. `ASSERT_NOT_ERR_OR_NULL(...)` allows us
-to bail out of the test case if the appropriate conditions are not satisfied to
-complete the test.
+In this example, we need to be able to allocate an array to test the ``sort()``
+function. So we use ``KUNIT_ASSERT_NOT_ERR_OR_NULL()`` to abort the test if
+there's an allocation error.
+
+.. note::
+   In other test frameworks, ``ASSERT`` macros are often implemented by calling
+   ``return`` so they only work from the test function. In KUnit, we stop the
+   current kthread on failure, so you can call them from anywhere.
+
+Customizing error messages
+--------------------------
+
+Each of the ``KUNIT_EXPECT`` and ``KUNIT_ASSERT`` macros have a ``_MSG``
+variant.  These take a format string and arguments to provide additional
+context to the automatically generated error messages.
+
+.. code-block:: c
+
+	char some_str[41];
+	generate_sha1_hex_string(some_str);
+
+	/* Before. Not easy to tell why the test failed. */
+	KUNIT_EXPECT_EQ(test, strlen(some_str), 40);
+
+	/* After. Now we see the offending string. */
+	KUNIT_EXPECT_EQ_MSG(test, strlen(some_str), 40, "some_str='%s'", some_str);
+
+Alternatively, one can take full control over the error message by using
+``KUNIT_FAIL()``, e.g.
+
+.. code-block:: c
+
+	/* Before */
+	KUNIT_EXPECT_EQ(test, some_setup_function(), 0);
+
+	/* After: full control over the failure message. */
+	if (some_setup_function())
+		KUNIT_FAIL(test, "Failed to setup thing for testing");
+
 
 Test Suites
 ~~~~~~~~~~~
@@ -546,24 +580,6 @@ By reusing the same ``cases`` array from above, we can write the test as a
 		{}
 	};
 
-Exiting Early on Failed Expectations
-------------------------------------
-
-We can use ``KUNIT_EXPECT_EQ`` to mark the test as failed and continue
-execution.  In some cases, it is unsafe to continue. We can use the
-``KUNIT_ASSERT`` variant to exit on failure.
-
-.. code-block:: c
-
-	void example_test_user_alloc_function(struct kunit *test)
-	{
-		void *object = alloc_some_object_for_me();
-
-		/* Make sure we got a valid pointer back. */
-		KUNIT_ASSERT_NOT_ERR_OR_NULL(test, object);
-		do_something_with_object(object);
-	}
-
 Allocating Memory
 -----------------
 
@@ -625,17 +641,23 @@ as shown in next section: *Accessing The Current Test*.
 Accessing The Current Test
 --------------------------
 
-In some cases, we need to call test-only code from outside the test file.
-For example, see example in section *Injecting Test-Only Code* or if
-we are providing a fake implementation of an ops struct. Using
-``kunit_test`` field in ``task_struct``, we can access it via
-``current->kunit_test``.
+In some cases, we need to call test-only code from outside the test file.  This
+is helpful, for example, when providing a fake implementation of a function, or
+to fail any current test from within an error handler.
+We can do this via the ``kunit_test`` field in ``task_struct``, which we can
+access using the ``kunit_get_current_test()`` function in ``kunit/test-bug.h``.
 
-The example below includes how to implement "mocking":
+``kunit_get_current_test()`` is safe to call even if KUnit is not enabled. If
+KUnit is not enabled, was built as a module (``CONFIG_KUNIT=m``), or no test is
+running in the current task, it will return ``NULL``. This compiles down to
+either a no-op or a static key check, so will have a negligible performance
+impact when no test is running.
+
+The example below uses this to implement a "mock" implementation of a function, ``foo``:
 
 .. code-block:: c
 
-	#include <linux/sched.h> /* for current */
+	#include <kunit/test-bug.h> /* for kunit_get_current_test */
 
 	struct test_data {
 		int foo_result;
@@ -644,7 +666,7 @@ The example below includes how to implement "mocking":
 
 	static int fake_foo(int arg)
 	{
-		struct kunit *test = current->kunit_test;
+		struct kunit *test = kunit_get_current_test();
 		struct test_data *test_data = test->priv;
 
 		KUNIT_EXPECT_EQ(test, test_data->want_foo_called_with, arg);
@@ -675,7 +697,7 @@ Each test can have multiple resources which have string names providing the same
 flexibility as a ``priv`` member, but also, for example, allowing helper
 functions to create resources without conflicting with each other. It is also
 possible to define a clean up function for each resource, making it easy to
-avoid resource leaks. For more information, see Documentation/dev-tools/kunit/api/test.rst.
+avoid resource leaks. For more information, see Documentation/dev-tools/kunit/api/resource.rst.
 
 Failing The Current Test
 ------------------------
@@ -703,3 +725,9 @@ structures as shown below:
 	static void my_debug_function(void) { }
 	#endif
 
+``kunit_fail_current_test()`` is safe to call even if KUnit is not enabled. If
+KUnit is not enabled, was built as a module (``CONFIG_KUNIT=m``), or no test is
+running in the current task, it will do nothing. This compiles down to either a
+no-op or a static key check, so will have a negligible performance impact when
+no test is running.
+

drivers/gpu/drm/tests/drm_format_helper_test.c

@@ -315,7 +315,7 @@ static void drm_test_fb_xrgb8888_to_gray8(struct kunit *test)
 	iosys_map_set_vaddr(&src, xrgb8888);
 
 	drm_fb_xrgb8888_to_gray8(&dst, &result->dst_pitch, &src, &fb, &params->clip);
-	KUNIT_EXPECT_EQ(test, memcmp(buf, result->expected, dst_size), 0);
+	KUNIT_EXPECT_MEMEQ(test, buf, result->expected, dst_size);
 }
 
 static void drm_test_fb_xrgb8888_to_rgb332(struct kunit *test)
@@ -345,7 +345,7 @@ static void drm_test_fb_xrgb8888_to_rgb332(struct kunit *test)
 	iosys_map_set_vaddr(&src, xrgb8888);
 
 	drm_fb_xrgb8888_to_rgb332(&dst, &result->dst_pitch, &src, &fb, &params->clip);
-	KUNIT_EXPECT_EQ(test, memcmp(buf, result->expected, dst_size), 0);
+	KUNIT_EXPECT_MEMEQ(test, buf, result->expected, dst_size);
 }
 
 static void drm_test_fb_xrgb8888_to_rgb565(struct kunit *test)
@@ -375,10 +375,10 @@ static void drm_test_fb_xrgb8888_to_rgb565(struct kunit *test)
 	iosys_map_set_vaddr(&src, xrgb8888);
 
 	drm_fb_xrgb8888_to_rgb565(&dst, &result->dst_pitch, &src, &fb, &params->clip, false);
-	KUNIT_EXPECT_EQ(test, memcmp(buf, result->expected, dst_size), 0);
+	KUNIT_EXPECT_MEMEQ(test, buf, result->expected, dst_size);
 
 	drm_fb_xrgb8888_to_rgb565(&dst, &result->dst_pitch, &src, &fb, &params->clip, true);
-	KUNIT_EXPECT_EQ(test, memcmp(buf, result->expected_swab, dst_size), 0);
+	KUNIT_EXPECT_MEMEQ(test, buf, result->expected_swab, dst_size);
 }
 
 static void drm_test_fb_xrgb8888_to_rgb888(struct kunit *test)
@@ -408,7 +408,7 @@ static void drm_test_fb_xrgb8888_to_rgb888(struct kunit *test)
 	iosys_map_set_vaddr(&src, xrgb8888);
 
 	drm_fb_xrgb8888_to_rgb888(&dst, &result->dst_pitch, &src, &fb, &params->clip);
-	KUNIT_EXPECT_EQ(test, memcmp(buf, result->expected, dst_size), 0);
+	KUNIT_EXPECT_MEMEQ(test, buf, result->expected, dst_size);
 }
 
 static void drm_test_fb_xrgb8888_to_xrgb2101010(struct kunit *test)
@@ -439,7 +439,7 @@ static void drm_test_fb_xrgb8888_to_xrgb2101010(struct kunit *test)
 
 	drm_fb_xrgb8888_to_xrgb2101010(&dst, &result->dst_pitch, &src, &fb, &params->clip);
 	buf = le32buf_to_cpu(test, buf, dst_size / sizeof(u32));
-	KUNIT_EXPECT_EQ(test, memcmp(buf, result->expected, dst_size), 0);
+	KUNIT_EXPECT_MEMEQ(test, buf, result->expected, dst_size);
 }
 
 static struct kunit_case drm_format_helper_test_cases[] = {

include/kunit/assert.h

@@ -90,19 +90,6 @@ void kunit_unary_assert_format(const struct kunit_assert *assert,
 			       const struct va_format *message,
 			       struct string_stream *stream);
 
-/**
- * KUNIT_INIT_UNARY_ASSERT_STRUCT() - Initializes &struct kunit_unary_assert.
- * @cond: A string representation of the expression asserted true or false.
- * @expect_true: True if of type KUNIT_{EXPECT|ASSERT}_TRUE, false otherwise.
- *
- * Initializes a &struct kunit_unary_assert. Intended to be used in
- * KUNIT_EXPECT_* and KUNIT_ASSERT_* macros.
- */
-#define KUNIT_INIT_UNARY_ASSERT_STRUCT(cond, expect_true) {		       \
-	.condition = cond,						       \
-	.expected_true = expect_true					       \
-}
-
 /**
  * struct kunit_ptr_not_err_assert - An expectation/assertion that a pointer is
  *	not NULL and not a -errno.
@@ -123,20 +110,6 @@ void kunit_ptr_not_err_assert_format(const struct kunit_assert *assert,
 				     const struct va_format *message,
 				     struct string_stream *stream);
 
-/**
- * KUNIT_INIT_PTR_NOT_ERR_ASSERT_STRUCT() - Initializes a
- *	&struct kunit_ptr_not_err_assert.
- * @txt: A string representation of the expression passed to the expectation.
- * @val: The actual evaluated pointer value of the expression.
- *
- * Initializes a &struct kunit_ptr_not_err_assert. Intended to be used in
- * KUNIT_EXPECT_* and KUNIT_ASSERT_* macros.
- */
-#define KUNIT_INIT_PTR_NOT_ERR_STRUCT(txt, val) {			       \
-	.text = txt,							       \
-	.value = val							       \
-}
-
 /**
  * struct kunit_binary_assert_text - holds strings for &struct
  *	kunit_binary_assert and friends to try and make the structs smaller.
@@ -173,27 +146,6 @@ void kunit_binary_assert_format(const struct kunit_assert *assert,
 				const struct va_format *message,
 				struct string_stream *stream);
 
-/**
- * KUNIT_INIT_BINARY_ASSERT_STRUCT() - Initializes a binary assert like
- *	kunit_binary_assert, kunit_binary_ptr_assert, etc.
- *
- * @text_: Pointer to a kunit_binary_assert_text.
- * @left_val: The actual evaluated value of the expression in the left slot.
- * @right_val: The actual evaluated value of the expression in the right slot.
- *
- * Initializes a binary assert like kunit_binary_assert,
- * kunit_binary_ptr_assert, etc. This relies on these structs having the same
- * fields but with different types for left_val/right_val.
- * This is ultimately used by binary assertion macros like KUNIT_EXPECT_EQ, etc.
- */
-#define KUNIT_INIT_BINARY_ASSERT_STRUCT(text_,				       \
-					left_val,			       \
-					right_val) {			       \
-	.text = text_,							       \
-	.left_value = left_val,						       \
-	.right_value = right_val					       \
-}
-
 /**
  * struct kunit_binary_ptr_assert - An expectation/assertion that compares two
  *	pointer values (for example, KUNIT_EXPECT_PTR_EQ(test, foo, bar)).
@@ -240,4 +192,30 @@ void kunit_binary_str_assert_format(const struct kunit_assert *assert,
 				    const struct va_format *message,
 				    struct string_stream *stream);
 
+/**
+ * struct kunit_mem_assert - An expectation/assertion that compares two
+ *	memory blocks.
+ * @assert: The parent of this type.
+ * @text: Holds the textual representations of the operands and comparator.
+ * @left_value: The actual evaluated value of the expression in the left slot.
+ * @right_value: The actual evaluated value of the expression in the right slot.
+ * @size: Size of the memory block analysed in bytes.
+ *
+ * Represents an expectation/assertion that compares two memory blocks. For
+ * example, to expect that the first three bytes of foo is equal to the
+ * first three bytes of bar, you can use the expectation
+ * KUNIT_EXPECT_MEMEQ(test, foo, bar, 3);
+ */
+struct kunit_mem_assert {
+	struct kunit_assert assert;
+	const struct kunit_binary_assert_text *text;
+	const void *left_value;
+	const void *right_value;
+	const size_t size;
+};
+
+void kunit_mem_assert_format(const struct kunit_assert *assert,
+			     const struct va_format *message,
+			     struct string_stream *stream);
+
 #endif /*  _KUNIT_ASSERT_H */

include/kunit/test-bug.h

@@ -9,16 +9,63 @@
 #ifndef _KUNIT_TEST_BUG_H
 #define _KUNIT_TEST_BUG_H
 
-#define kunit_fail_current_test(fmt, ...) \
-	__kunit_fail_current_test(__FILE__, __LINE__, fmt, ##__VA_ARGS__)
-
 #if IS_BUILTIN(CONFIG_KUNIT)
 
+#include <linux/jump_label.h> /* For static branch */
+#include <linux/sched.h>
+
+/* Static key if KUnit is running any tests. */
+DECLARE_STATIC_KEY_FALSE(kunit_running);
+
+/**
+ * kunit_get_current_test() - Return a pointer to the currently running
+ *			      KUnit test.
+ *
+ * If a KUnit test is running in the current task, returns a pointer to its
+ * associated struct kunit. This pointer can then be passed to any KUnit
+ * function or assertion. If no test is running (or a test is running in a
+ * different task), returns NULL.
+ *
+ * This function is safe to call even when KUnit is disabled. If CONFIG_KUNIT
+ * is not enabled, it will compile down to nothing and will return quickly no
+ * test is running.
+ */
+static inline struct kunit *kunit_get_current_test(void)
+{
+	if (!static_branch_unlikely(&kunit_running))
+		return NULL;
+
+	return current->kunit_test;
+}
+
+
+/**
+ * kunit_fail_current_test() - If a KUnit test is running, fail it.
+ *
+ * If a KUnit test is running in the current task, mark that test as failed.
+ *
+ * This macro will only work if KUnit is built-in (though the tests
+ * themselves can be modules). Otherwise, it compiles down to nothing.
+ */
+#define kunit_fail_current_test(fmt, ...) do {					\
+		if (static_branch_unlikely(&kunit_running)) {			\
+			__kunit_fail_current_test(__FILE__, __LINE__,		\
+						  fmt, ##__VA_ARGS__);		\
+		}								\
+	} while (0)
+
+
 extern __printf(3, 4) void __kunit_fail_current_test(const char *file, int line,
 						    const char *fmt, ...);
 
 #else
 
+static inline struct kunit *kunit_get_current_test(void) { return NULL; }
+
+/* We define this with an empty helper function so format string warnings work */
+#define kunit_fail_current_test(fmt, ...) \
+		__kunit_fail_current_test(__FILE__, __LINE__, fmt, ##__VA_ARGS__)
+
 static inline __printf(3, 4) void __kunit_fail_current_test(const char *file, int line,
 							    const char *fmt, ...)
 {

include/kunit/test.h

@@ -16,6 +16,7 @@
 #include <linux/container_of.h>
 #include <linux/err.h>
 #include <linux/init.h>
+#include <linux/jump_label.h>
 #include <linux/kconfig.h>
 #include <linux/kref.h>
 #include <linux/list.h>
@@ -27,6 +28,9 @@
 
 #include <asm/rwonce.h>
 
+/* Static key: true if any KUnit tests are currently running */
+DECLARE_STATIC_KEY_FALSE(kunit_running);
+
 struct kunit;
 
 /* Size of log associated with test. */
@@ -515,22 +519,25 @@ void kunit_do_failed_assertion(struct kunit *test,
 			     fmt,					       \
 			     ##__VA_ARGS__)
 
+/* Helper to safely pass around an initializer list to other macros. */
+#define KUNIT_INIT_ASSERT(initializers...) { initializers }
+
 #define KUNIT_UNARY_ASSERTION(test,					       \
 			      assert_type,				       \
-			      condition,				       \
-			      expected_true,				       \
+			      condition_,				       \
+			      expected_true_,				       \
 			      fmt,					       \
 			      ...)					       \
 do {									       \
-	if (likely(!!(condition) == !!expected_true))			       \
+	if (likely(!!(condition_) == !!expected_true_))			       \
 		break;							       \
 									       \
 	_KUNIT_FAILED(test,						       \
 		      assert_type,					       \
 		      kunit_unary_assert,				       \
 		      kunit_unary_assert_format,			       \
-		      KUNIT_INIT_UNARY_ASSERT_STRUCT(#condition,	       \
-						     expected_true),	       \
+		      KUNIT_INIT_ASSERT(.condition = #condition_,	       \
+					.expected_true = expected_true_),      \
 		      fmt,						       \
 		      ##__VA_ARGS__);					       \
 } while (0)
@@ -590,9 +597,9 @@ do {									       \
 		      assert_type,					       \
 		      assert_class,					       \
 		      format_func,					       \
-		      KUNIT_INIT_BINARY_ASSERT_STRUCT(&__text,		       \
-						      __left,		       \
-						      __right),		       \
+		      KUNIT_INIT_ASSERT(.text = &__text,		       \
+					.left_value = __left,		       \
+					.right_value = __right),	       \
 		      fmt,						       \
 		      ##__VA_ARGS__);					       \
 } while (0)
@@ -651,9 +658,42 @@ do {									       \
 		      assert_type,					       \
 		      kunit_binary_str_assert,				       \
 		      kunit_binary_str_assert_format,			       \
-		      KUNIT_INIT_BINARY_ASSERT_STRUCT(&__text,		       \
-						      __left,		       \
-						      __right),		       \
+		      KUNIT_INIT_ASSERT(.text = &__text,		       \
+					.left_value = __left,		       \
+					.right_value = __right),	       \
+		      fmt,						       \
+		      ##__VA_ARGS__);					       \
+} while (0)
+
+#define KUNIT_MEM_ASSERTION(test,					       \
+			    assert_type,				       \
+			    left,					       \
+			    op,						       \
+			    right,					       \
+			    size_,					       \
+			    fmt,					       \
+			    ...)					       \
+do {									       \
+	const void *__left = (left);					       \
+	const void *__right = (right);					       \
+	const size_t __size = (size_);					       \
+	static const struct kunit_binary_assert_text __text = {		       \
+		.operation = #op,					       \
+		.left_text = #left,					       \
+		.right_text = #right,					       \
+	};								       \
+									       \
+	if (likely(memcmp(__left, __right, __size) op 0))		       \
+		break;							       \
+									       \
+	_KUNIT_FAILED(test,						       \
+		      assert_type,					       \
+		      kunit_mem_assert,					       \
+		      kunit_mem_assert_format,				       \
+		      KUNIT_INIT_ASSERT(.text = &__text,		       \
+					.left_value = __left,		       \
+					.right_value = __right,		       \
+					.size = __size),		       \
 		      fmt,						       \
 		      ##__VA_ARGS__);					       \
 } while (0)
@@ -673,7 +713,7 @@ do {									       \
 		      assert_type,					       \
 		      kunit_ptr_not_err_assert,				       \
 		      kunit_ptr_not_err_assert_format,			       \
-		      KUNIT_INIT_PTR_NOT_ERR_STRUCT(#ptr, __ptr),	       \
+		      KUNIT_INIT_ASSERT(.text = #ptr, .value = __ptr),	       \
 		      fmt,						       \
 		      ##__VA_ARGS__);					       \
 } while (0)
@@ -928,6 +968,60 @@ do {									       \
 				   fmt,					       \
 				   ##__VA_ARGS__)
 
+/**
+ * KUNIT_EXPECT_MEMEQ() - Expects that the first @size bytes of @left and @right are equal.
+ * @test: The test context object.
+ * @left: An arbitrary expression that evaluates to the specified size.
+ * @right: An arbitrary expression that evaluates to the specified size.
+ * @size: Number of bytes compared.
+ *
+ * Sets an expectation that the values that @left and @right evaluate to are
+ * equal. This is semantically equivalent to
+ * KUNIT_EXPECT_TRUE(@test, !memcmp((@left), (@right), (@size))). See
+ * KUNIT_EXPECT_TRUE() for more information.
+ *
+ * Although this expectation works for any memory block, it is not recommended
+ * for comparing more structured data, such as structs. This expectation is
+ * recommended for comparing, for example, data arrays.
+ */
+#define KUNIT_EXPECT_MEMEQ(test, left, right, size) \
+	KUNIT_EXPECT_MEMEQ_MSG(test, left, right, size, NULL)
+
+#define KUNIT_EXPECT_MEMEQ_MSG(test, left, right, size, fmt, ...)	       \
+	KUNIT_MEM_ASSERTION(test,					       \
+			    KUNIT_EXPECTATION,				       \
+			    left, ==, right,				       \
+			    size,					       \
+			    fmt,					       \
+			    ##__VA_ARGS__)
+
+/**
+ * KUNIT_EXPECT_MEMNEQ() - Expects that the first @size bytes of @left and @right are not equal.
+ * @test: The test context object.
+ * @left: An arbitrary expression that evaluates to the specified size.
+ * @right: An arbitrary expression that evaluates to the specified size.
+ * @size: Number of bytes compared.
+ *
+ * Sets an expectation that the values that @left and @right evaluate to are
+ * not equal. This is semantically equivalent to
+ * KUNIT_EXPECT_TRUE(@test, memcmp((@left), (@right), (@size))). See
+ * KUNIT_EXPECT_TRUE() for more information.
+ *
+ * Although this expectation works for any memory block, it is not recommended
+ * for comparing more structured data, such as structs. This expectation is
+ * recommended for comparing, for example, data arrays.
+ */
+#define KUNIT_EXPECT_MEMNEQ(test, left, right, size) \
+	KUNIT_EXPECT_MEMNEQ_MSG(test, left, right, size, NULL)
+
+#define KUNIT_EXPECT_MEMNEQ_MSG(test, left, right, size, fmt, ...)	       \
+	KUNIT_MEM_ASSERTION(test,					       \
+			    KUNIT_EXPECTATION,				       \
+			    left, !=, right,				       \
+			    size,					       \
+			    fmt,					       \
+			    ##__VA_ARGS__)
+
 /**
  * KUNIT_EXPECT_NULL() - Expects that @ptr is null.
  * @test: The test context object.

include/kunit/visibility.h

@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * KUnit API to allow symbols to be conditionally visible during KUnit
+ * testing
+ *
+ * Copyright (C) 2022, Google LLC.
+ * Author: Rae Moar <rmoar@google.com>
+ */
+
+#ifndef _KUNIT_VISIBILITY_H
+#define _KUNIT_VISIBILITY_H
+
+#if IS_ENABLED(CONFIG_KUNIT)
+    /**
+     * VISIBLE_IF_KUNIT - A macro that sets symbols to be static if
+     * CONFIG_KUNIT is not enabled. Otherwise if CONFIG_KUNIT is enabled
+     * there is no change to the symbol definition.
+     */
+    #define VISIBLE_IF_KUNIT
+    /**
+     * EXPORT_SYMBOL_IF_KUNIT(symbol) - Exports symbol into
+     * EXPORTED_FOR_KUNIT_TESTING namespace only if CONFIG_KUNIT is
+     * enabled. Must use MODULE_IMPORT_NS(EXPORTED_FOR_KUNIT_TESTING)
+     * in test file in order to use symbols.
+     */
+    #define EXPORT_SYMBOL_IF_KUNIT(symbol) EXPORT_SYMBOL_NS(symbol, \
+	    EXPORTED_FOR_KUNIT_TESTING)
+#else
+    #define VISIBLE_IF_KUNIT static
+    #define EXPORT_SYMBOL_IF_KUNIT(symbol)
+#endif
+
+#endif /* _KUNIT_VISIBILITY_H */

lib/kunit/assert.c

@@ -127,13 +127,15 @@ void kunit_binary_assert_format(const struct kunit_assert *assert,
 			  binary_assert->text->right_text);
 	if (!is_literal(stream->test, binary_assert->text->left_text,
 			binary_assert->left_value, stream->gfp))
-		string_stream_add(stream, KUNIT_SUBSUBTEST_INDENT "%s == %lld\n",
+		string_stream_add(stream, KUNIT_SUBSUBTEST_INDENT "%s == %lld (0x%llx)\n",
 				  binary_assert->text->left_text,
+				  binary_assert->left_value,
 				  binary_assert->left_value);
 	if (!is_literal(stream->test, binary_assert->text->right_text,
 			binary_assert->right_value, stream->gfp))
-		string_stream_add(stream, KUNIT_SUBSUBTEST_INDENT "%s == %lld",
+		string_stream_add(stream, KUNIT_SUBSUBTEST_INDENT "%s == %lld (0x%llx)",
 				  binary_assert->text->right_text,
+				  binary_assert->right_value,
 				  binary_assert->right_value);
 	kunit_assert_print_msg(message, stream);
 }
@@ -204,3 +206,59 @@ void kunit_binary_str_assert_format(const struct kunit_assert *assert,
 	kunit_assert_print_msg(message, stream);
 }
 EXPORT_SYMBOL_GPL(kunit_binary_str_assert_format);
+
+/* Adds a hexdump of a buffer to a string_stream comparing it with
+ * a second buffer. The different bytes are marked with <>.
+ */
+static void kunit_assert_hexdump(struct string_stream *stream,
+				 const void *buf,
+				 const void *compared_buf,
+				 const size_t len)
+{
+	size_t i;
+	const u8 *buf1 = buf;
+	const u8 *buf2 = compared_buf;
+
+	string_stream_add(stream, KUNIT_SUBSUBTEST_INDENT);
+
+	for (i = 0; i < len; ++i) {
+		if (!(i % 16) && i)
+			string_stream_add(stream, "\n" KUNIT_SUBSUBTEST_INDENT);
+
+		if (buf1[i] != buf2[i])
+			string_stream_add(stream, "<%02x>", buf1[i]);
+		else
+			string_stream_add(stream, " %02x ", buf1[i]);
+	}
+}
+
+void kunit_mem_assert_format(const struct kunit_assert *assert,
+			     const struct va_format *message,
+			     struct string_stream *stream)
+{
+	struct kunit_mem_assert *mem_assert;
+
+	mem_assert = container_of(assert, struct kunit_mem_assert,
+				  assert);
+
+	string_stream_add(stream,
+			  KUNIT_SUBTEST_INDENT "Expected %s %s %s, but\n",
+			  mem_assert->text->left_text,
+			  mem_assert->text->operation,
+			  mem_assert->text->right_text);
+
+	string_stream_add(stream, KUNIT_SUBSUBTEST_INDENT "%s ==\n",
+			  mem_assert->text->left_text);
+	kunit_assert_hexdump(stream, mem_assert->left_value,
+			     mem_assert->right_value, mem_assert->size);
+
+	string_stream_add(stream, "\n");
+
+	string_stream_add(stream, KUNIT_SUBSUBTEST_INDENT "%s ==\n",
+			  mem_assert->text->right_text);
+	kunit_assert_hexdump(stream, mem_assert->right_value,
+			     mem_assert->left_value, mem_assert->size);
+
+	kunit_assert_print_msg(message, stream);
+}
+EXPORT_SYMBOL_GPL(kunit_mem_assert_format);

lib/kunit/debugfs.c

@@ -63,7 +63,7 @@ static int debugfs_print_results(struct seq_file *seq, void *v)
 	kunit_suite_for_each_test_case(suite, test_case)
 		debugfs_print_result(seq, suite, test_case);
 
-	seq_printf(seq, "%s %d - %s\n",
+	seq_printf(seq, "%s %d %s\n",
 		   kunit_status_to_ok_not_ok(success), 1, suite->name);
 	return 0;
 }

lib/kunit/executor.c

@@ -166,7 +166,7 @@ static void kunit_exec_run_tests(struct suite_set *suite_set)
 {
 	size_t num_suites = suite_set->end - suite_set->start;
 
-	pr_info("TAP version 14\n");
+	pr_info("KTAP version 1\n");
 	pr_info("1..%zu\n", num_suites);
 
 	__kunit_test_suites_init(suite_set->start, num_suites);
@@ -177,8 +177,8 @@ static void kunit_exec_list_tests(struct suite_set *suite_set)
 	struct kunit_suite * const *suites;
 	struct kunit_case *test_case;
 
-	/* Hack: print a tap header so kunit.py can find the start of KUnit output. */
-	pr_info("TAP version 14\n");
+	/* Hack: print a ktap header so kunit.py can find the start of KUnit output. */
+	pr_info("KTAP version 1\n");
 
 	for (suites = suite_set->start; suites < suite_set->end; suites++)
 		kunit_suite_for_each_test_case((*suites), test_case) {

lib/kunit/kunit-example-test.c

@@ -86,6 +86,9 @@ static void example_mark_skipped_test(struct kunit *test)
  */
 static void example_all_expect_macros_test(struct kunit *test)
 {
+	const u32 array1[] = { 0x0F, 0xFF };
+	const u32 array2[] = { 0x1F, 0xFF };
+
 	/* Boolean assertions */
 	KUNIT_EXPECT_TRUE(test, true);
 	KUNIT_EXPECT_FALSE(test, false);
@@ -109,6 +112,10 @@ static void example_all_expect_macros_test(struct kunit *test)
 	KUNIT_EXPECT_STREQ(test, "hi", "hi");
 	KUNIT_EXPECT_STRNEQ(test, "hi", "bye");
 
+	/* Memory block assertions */
+	KUNIT_EXPECT_MEMEQ(test, array1, array1, sizeof(array1));
+	KUNIT_EXPECT_MEMNEQ(test, array1, array2, sizeof(array1));
+
 	/*
 	 * There are also ASSERT variants of all of the above that abort test
 	 * execution if they fail. Useful for memory allocations, etc.

lib/kunit/string-stream.c

@@ -131,11 +131,6 @@ bool string_stream_is_empty(struct string_stream *stream)
 	return list_empty(&stream->fragments);
 }
 
-struct string_stream_alloc_context {
-	struct kunit *test;
-	gfp_t gfp;
-};
-
 struct string_stream *alloc_string_stream(struct kunit *test, gfp_t gfp)
 {
 	struct string_stream *stream;

lib/kunit/test.c

@@ -20,6 +20,8 @@
 #include "string-stream.h"
 #include "try-catch-impl.h"
 
+DEFINE_STATIC_KEY_FALSE(kunit_running);
+
 #if IS_BUILTIN(CONFIG_KUNIT)
 /*
  * Fail the current test and print an error message to the log.
@@ -149,6 +151,7 @@ EXPORT_SYMBOL_GPL(kunit_suite_num_test_cases);
 
 static void kunit_print_suite_start(struct kunit_suite *suite)
 {
+	kunit_log(KERN_INFO, suite, KUNIT_SUBTEST_INDENT "KTAP version 1\n");
 	kunit_log(KERN_INFO, suite, KUNIT_SUBTEST_INDENT "# Subtest: %s",
 		  suite->name);
 	kunit_log(KERN_INFO, suite, KUNIT_SUBTEST_INDENT "1..%zd",
@@ -175,13 +178,13 @@ static void kunit_print_ok_not_ok(void *test_or_suite,
 	 * representation.
 	 */
 	if (suite)
-		pr_info("%s %zd - %s%s%s\n",
+		pr_info("%s %zd %s%s%s\n",
 			kunit_status_to_ok_not_ok(status),
 			test_number, description, directive_header,
 			(status == KUNIT_SKIPPED) ? directive : "");
 	else
 		kunit_log(KERN_INFO, test,
-			  KUNIT_SUBTEST_INDENT "%s %zd - %s%s%s",
+			  KUNIT_SUBTEST_INDENT "%s %zd %s%s%s",
 			  kunit_status_to_ok_not_ok(status),
 			  test_number, description, directive_header,
 			  (status == KUNIT_SKIPPED) ? directive : "");
@@ -542,6 +545,8 @@ int kunit_run_tests(struct kunit_suite *suite)
 			/* Get initial param. */
 			param_desc[0] = '\0';
 			test.param_value = test_case->generate_params(NULL, param_desc);
+			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);
 
@@ -555,7 +560,7 @@ int kunit_run_tests(struct kunit_suite *suite)
 
 				kunit_log(KERN_INFO, &test,
 					  KUNIT_SUBTEST_INDENT KUNIT_SUBTEST_INDENT
-					  "%s %d - %s",
+					  "%s %d %s",
 					  kunit_status_to_ok_not_ok(test.status),
 					  test.param_index + 1, param_desc);
 
@@ -612,10 +617,14 @@ int __kunit_test_suites_init(struct kunit_suite * const * const suites, int num_
 		return 0;
 	}
 
+	static_branch_inc(&kunit_running);
+
 	for (i = 0; i < num_suites; i++) {
 		kunit_init_suite(suites[i]);
 		kunit_run_tests(suites[i]);
 	}
+
+	static_branch_dec(&kunit_running);
 	return 0;
 }
 EXPORT_SYMBOL_GPL(__kunit_test_suites_init);

lib/slub_kunit.c

@@ -1,5 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0
 #include <kunit/test.h>
+#include <kunit/test-bug.h>
 #include <linux/mm.h>
 #include <linux/slab.h>
 #include <linux/module.h>

mm/slub.c

@@ -39,6 +39,7 @@
 #include <linux/memcontrol.h>
 #include <linux/random.h>
 #include <kunit/test.h>
+#include <kunit/test-bug.h>
 #include <linux/sort.h>
 
 #include <linux/debugfs.h>
@@ -618,7 +619,7 @@ static bool slab_add_kunit_errors(void)
 {
 	struct kunit_resource *resource;
 
-	if (likely(!current->kunit_test))
+	if (!kunit_get_current_test())
 		return false;
 
 	resource = kunit_find_named_resource(current->kunit_test, "slab_errors");

net/core/dev_addr_lists_test.c

@@ -71,11 +71,11 @@ static void dev_addr_test_basic(struct kunit *test)
 
 	memset(addr, 2, sizeof(addr));
 	eth_hw_addr_set(netdev, addr);
-	KUNIT_EXPECT_EQ(test, 0, memcmp(netdev->dev_addr, addr, sizeof(addr)));
+	KUNIT_EXPECT_MEMEQ(test, netdev->dev_addr, addr, sizeof(addr));
 
 	memset(addr, 3, sizeof(addr));
 	dev_addr_set(netdev, addr);
-	KUNIT_EXPECT_EQ(test, 0, memcmp(netdev->dev_addr, addr, sizeof(addr)));
+	KUNIT_EXPECT_MEMEQ(test, netdev->dev_addr, addr, sizeof(addr));
 }
 
 static void dev_addr_test_sync_one(struct kunit *test)