diff --git a/include/test/string-stream.h b/include/test/string-stream.h
new file mode 100644
index 0000000..8e8b531
--- /dev/null
+++ b/include/test/string-stream.h
@@ -0,0 +1,27 @@
+#ifndef _TEST_STRING_STREAM_H
+#define _TEST_STRING_STREAM_H
+
+#include <linux/types.h>
+#include <stdarg.h>
+
+struct string_stream_fragment {
+	struct list_head node;
+	char *fragment;
+};
+
+struct string_stream {
+	size_t length;
+	struct list_head fragments;
+
+	int (*add)(struct string_stream *this, const char *fmt, ...);
+	int (*vadd)(struct string_stream *this, const char *fmt, va_list args);
+	char *(*get_string)(struct string_stream *this);
+	void (*clear)(struct string_stream *this);
+	bool (*is_empty)(struct string_stream *this);
+};
+
+struct string_stream *new_string_stream(void);
+
+void destroy_string_stream(struct string_stream *stream);
+
+#endif /* _TEST_STRING_STREAM_H */
diff --git a/include/test/test-stream.h b/include/test/test-stream.h
new file mode 100644
index 0000000..540d341
--- /dev/null
+++ b/include/test/test-stream.h
@@ -0,0 +1,39 @@
+#ifndef _TEST_TEST_STREAM_H
+#define _TEST_TEST_STREAM_H
+
+#include <linux/types.h>
+#include <test/string-stream.h>
+
+struct test;
+
+/**
+ * struct test_stream - a std::stream style string builder.
+ * @set_level: sets the level that this string should be printed at.
+ * @add: adds the formatted input to the internal buffer.
+ * @commit: prints out the internal buffer to the user.
+ * @clear: clears the internal buffer.
+ *
+ * A std::stream style string builder. Allows messages to be built up and
+ * printed all at once.
+ */
+struct test_stream {
+	void (*set_level)(struct test_stream *this, const char *level);
+	void (*add)(struct test_stream *this, const char *fmt, ...);
+	void (*append)(struct test_stream *this, struct test_stream *other);
+	void (*commit)(struct test_stream *this);
+	void (*clear)(struct test_stream *this);
+	/* private: internal use only. */
+	struct test *test;
+	const char *level;
+	struct string_stream *internal_stream;
+};
+
+/**
+ * test_new_stream() - constructs a new &struct test_stream.
+ * @test: The test context object.
+ *
+ * Constructs a new test managed &struct test_stream.
+ */
+struct test_stream *test_new_stream(struct test *test);
+
+#endif /* _TEST_TEST_STREAM_H */
diff --git a/include/test/test.h b/include/test/test.h
new file mode 100644
index 0000000..a2419ec
--- /dev/null
+++ b/include/test/test.h
@@ -0,0 +1,512 @@
+#ifndef _TEST_TEST_H
+#define _TEST_TEST_H
+
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <test/test-stream.h>
+
+/**
+ * struct test_resource - represents a *test managed resource*
+ * @allocation: for the user to store arbitrary data.
+ * @free: a user supplied function to free the resource. Populated by
+ * test_alloc_resource().
+ *
+ * Represents a *test managed resource*, a resource which will automatically be
+ * cleaned up at the end of a test case.
+ *
+ * Example:
+ *
+ * .. code-block:: c
+ *
+ *	struct test_kmalloc_params {
+ *		size_t size;
+ *		gfp_t gfp;
+ *	};
+ *
+ *	static int test_kmalloc_init(struct test_resource *res, void *context)
+ *	{
+ *		struct test_kmalloc_params *params = context;
+ *		res->allocation = kmalloc(params->size, params->gfp);
+ *
+ *		if (!res->allocation)
+ *			return -ENOMEM;
+ *
+ *		return 0;
+ *	}
+ *
+ *	static void test_kmalloc_free(struct test_resource *res)
+ *	{
+ *		kfree(res->allocation);
+ *	}
+ *
+ *	void *test_kmalloc(struct test *test, size_t size, gfp_t gfp)
+ *	{
+ *		struct test_kmalloc_params params;
+ *		struct test_resource *res;
+ *
+ *		params.size = size;
+ *		params.gfp = gfp;
+ *
+ *		// TODO(felixguo@google.com): The & gets interpreted via
+ *		// Kerneldoc but we don't want that.
+ *		res = test_alloc_resource(test, test_kmalloc_init,
+ *			test_kmalloc_free, & params);
+ *		if (res)
+ *			return res->allocation;
+ *		else
+ *			return NULL;
+ *	}
+ */
+struct test_resource {
+	void *allocation;
+	void (*free)(struct test_resource *res);
+	/* private: internal use only. */
+	struct list_head node;
+};
+
+struct test;
+
+/**
+ * struct test_case - represents an individual test case.
+ * @run_case: the function representing the actual test case.
+ * @name: the name of the test case.
+ *
+ * A test case is a function with the signature, ``void (*)(struct test *)``
+ * that makes expectations (see EXPECT_TRUE()) about code under test. Each test
+ * case is associated with a &struct test_module and will be run after the
+ * module's init function and followed by the module's exit function.
+ *
+ * A test case should be static and should only be created with the TEST_CASE()
+ * macro; additionally, every array of test cases should be terminated with an
+ * empty test case.
+ *
+ * Example:
+ *
+ * .. code-block:: c
+ *
+ *	void add_test_basic(struct test *test)
+ *	{
+ *		EXPECT_EQ(test, 1, add(1, 0));
+ *		EXPECT_EQ(test, 2, add(1, 1));
+ *		EXPECT_EQ(test, 0, add(-1, 1));
+ *		EXPECT_EQ(test, INT_MAX, add(0, INT_MAX));
+ *		EXPECT_EQ(test, -1, add(INT_MAX, INT_MIN));
+ *	}
+ *
+ *	static struct test_case example_test_cases[] = {
+ *		TEST_CASE(add_test_basic),
+ *		{},
+ *	};
+ *
+ */
+struct test_case {
+	void (*run_case)(struct test *test);
+	const char name[256];
+	/* private: internal use only. */
+	bool success;
+};
+
+/**
+ * TEST_CASE - A helper for creating a &struct test_case
+ * @test_name: a reference to a test case function.
+ *
+ * Takes a symbol for a function representing a test case and creates a &struct
+ * test_case object from it. See the documentation for &struct test_case for an
+ * example on how to use it.
+ */
+#define TEST_CASE(test_name) { .run_case = test_name, .name = #test_name }
+
+/**
+ * struct test_module - describes a related collection of &struct test_case s.
+ * @name: the name of the test. Purely informational.
+ * @init: called before every test case.
+ * @exit: called after every test case.
+ * @test_cases: a null terminated array of test cases.
+ *
+ * A test_module is a collection of related &struct test_case s, such that
+ * @init is called before every test case and @exit is called after every test
+ * case, similar to the notion of a *test fixture* or a *test class* in other
+ * unit testing frameworks like JUnit or Googletest.
+ *
+ * Every &struct test_case must be associated with a test_module for KUnit to
+ * run it.
+ */
+struct test_module {
+	const char name[256];
+	int (*init)(struct test *test);
+	void (*exit)(struct test *test);
+	struct test_case *test_cases;
+};
+
+/**
+ * struct test - represents a running instance of a test.
+ * @priv: for user to store arbitrary data. Commonly used to pass data created
+ * in the init function (see &struct test_module).
+ *
+ * Used to store information about the current context under which the test is
+ * running. Most of this data is private and should only be accessed indirectly
+ * via public functions; the one exception is @priv which can be used by the
+ * test writer to store arbitrary data.
+ */
+struct test {
+	void *priv;
+	/* private: internal use only. */
+	struct list_head resources;
+	const char *name;
+	bool success;
+	void (*vprintk)(const struct test *test,
+			const char *level,
+			struct va_format *vaf);
+	void (*fail)(struct test *test, struct test_stream *stream);
+};
+
+int test_init_test(struct test *test, const char *name);
+
+int test_run_tests(struct test_module *module);
+
+/**
+ * module_test() - used to register a &struct test_module with KUnit.
+ * @module: a statically allocated &struct test_module.
+ *
+ * Registers @module with the test framework. See &struct test_module for more
+ * information.
+ */
+#define module_test(module) \
+		static int module_test_init##module(void) \
+		{ \
+			return test_run_tests(&module); \
+		} \
+		late_initcall(module_test_init##module)
+
+/**
+ * test_alloc_resource() - Allocates a *test managed resource*.
+ * @test: The test context object.
+ * @init: a user supplied function to initialize the resource.
+ * @free: a user supplied function to free the resource.
+ * @context: for the user to pass in arbitrary data.
+ *
+ * Allocates a *test managed resource*, a resource which will automatically be
+ * cleaned up at the end of a test case. See &struct test_resource for an
+ * example.
+ */
+struct test_resource *test_alloc_resource(struct test *test,
+					  int (*init)(struct test_resource *,
+						      void *),
+					  void (*free)(struct test_resource *),
+					  void *context);
+
+void test_free_resource(struct test *test, struct test_resource *res);
+
+/**
+ * test_kmalloc() - Just like kmalloc() except the allocation is *test managed*.
+ * @test: The test context object.
+ * @size: The size in bytes of the desired memory.
+ * @gfp: flags passed to underlying kmalloc().
+ *
+ * Just like `kmalloc(...)`, except the allocation is managed by the test case
+ * and is automatically cleaned up after the test case concludes. See &struct
+ * test_resource for more information.
+ */
+void *test_kmalloc(struct test *test, size_t size, gfp_t gfp);
+
+/**
+ * test_kzalloc() - Just like test_kmalloc(), but zeroes the allocation.
+ * @test: The test context object.
+ * @size: The size in bytes of the desired memory.
+ * @gfp: flags passed to underlying kmalloc().
+ *
+ * See kzalloc() and test_kmalloc() for more information.
+ */
+static inline void *test_kzalloc(struct test *test, size_t size, gfp_t gfp)
+{
+	return test_kmalloc(test, size, gfp | __GFP_ZERO);
+}
+
+void test_cleanup(struct test *test);
+
+void test_printk(const char *level,
+		 const struct test *test,
+		 const char *fmt, ...);
+
+/**
+ * test_info() - Prints an INFO level message associated with the current test.
+ * @test: The test context object.
+ * @fmt: A printk() style format string.
+ *
+ * Prints an info level message associated with the test module being run. Takes
+ * a variable number of format parameters just like printk().
+ */
+#define test_info(test, fmt, ...) \
+		test_printk(KERN_INFO, test, fmt, ##__VA_ARGS__)
+
+/**
+ * test_warn() - Prints a WARN level message associated with the current test.
+ * @test: The test context object.
+ * @fmt: A printk() style format string.
+ *
+ * See test_info().
+ */
+#define test_warn(test, fmt, ...) \
+		test_printk(KERN_WARNING, test, fmt, ##__VA_ARGS__)
+
+/**
+ * test_err() - Prints an ERROR level message associated with the current test.
+ * @test: The test context object.
+ * @fmt: A printk() style format string.
+ *
+ * See test_info().
+ */
+#define test_err(test, fmt, ...) \
+		test_printk(KERN_ERR, test, fmt, ##__VA_ARGS__)
+
+static inline struct test_stream *test_expect_start(struct test *test,
+						    const char *file,
+						    const char *line)
+{
+	struct test_stream *stream = test_new_stream(test);
+
+	stream->add(stream, "EXPECTATION FAILED at %s:%s\n\t", file, line);
+
+	return stream;
+}
+
+static inline void test_expect_end(struct test *test,
+				   bool success,
+				   struct test_stream *stream)
+{
+	if (!success)
+		test->fail(test, stream);
+	else
+		stream->clear(stream);
+}
+
+#define EXPECT_START(test) \
+		test_expect_start(test, __FILE__, __stringify(__LINE__))
+
+#define EXPECT_END(test, success, stream) test_expect_end(test, success, stream)
+
+#define EXPECT(test, success, message) do {\
+	struct test_stream *__stream = EXPECT_START(test); \
+	\
+	__stream->add(__stream, message); \
+	EXPECT_END(test, success, __stream); \
+} while (0)
+
+/**
+ * SUCCEED() - A no-op expectation. Only exists for code clarity.
+ * @test: The test context object.
+ *
+ * The opposite of FAIL(), it is an expectation that cannot fail. In other
+ * words, it does nothing and only exists for code clarity. See EXPECT_TRUE()
+ * for more information.
+ */
+#define SUCCEED(test) do {} while (0)
+
+/**
+ * FAIL() - Always causes a test to fail when evaluated.
+ * @test: The test context object.
+ * @message: an informational message to be printed when the assertion is made.
+ *
+ * The opposite of SUCCEED(), it is an expectation that always fails. In other
+ * words, it always results in a failed expectation, and consequently always
+ * causes the test case to fail when evaluated. See EXPECT_TRUE() for more
+ * information.
+ */
+#define FAIL(test, message) EXPECT(test, false, message)
+
+/**
+ * EXPECT_TRUE() - Causes a test failure when the given expression is not true.
+ * @test: The test context object.
+ * @condition: an arbitrary boolean expression. The test fails when this does
+ * not evaluate to true.
+ *
+ * This and expectations of the form `EXPECT_*` will cause the test case to fail
+ * when the specified condition is not met; however, it will not prevent the
+ * test case from continuing to run; this is otherwise known as an *expectation
+ * failure*.
+ */
+#define EXPECT_TRUE(test, condition)					       \
+		EXPECT(test, (condition),				       \
+		       "Expected " #condition " is true, but is false.")
+
+/**
+ * EXPECT_FALSE() - Causes a test failure when the expression is not false.
+ * @test: The test context object.
+ * @condition: an arbitrary boolean expression. The test fails when this does
+ * not evaluate to false.
+ *
+ * Sets an expectation that @condition evaluates to false. See EXPECT_TRUE() for
+ * more information.
+ */
+#define EXPECT_FALSE(test, condition)					       \
+		EXPECT(test, !(condition),				       \
+		       "Expected " #condition " is false, but is true.")
+
+static inline void test_expect_binary(struct test *test,
+				      long long left, const char *left_name,
+				      long long right, const char *right_name,
+				      bool compare_result,
+				      const char *compare_name,
+				      const char *file,
+				      const char *line)
+{
+	struct test_stream *stream = test_expect_start(test, file, line);
+
+	stream->add(stream,
+		    "Expected %s %s %s, but\n",
+		    left_name, compare_name, right_name);
+	stream->add(stream, "\t\t%s == %lld\n", left_name, left);
+	stream->add(stream, "\t\t%s == %lld", right_name, right);
+
+	test_expect_end(test, compare_result, stream);
+}
+
+/*
+ * A factory macro for defining the expectations for the basic comparisons
+ * defined for the built in types.
+ *
+ * Unfortunately, there is no common type that all types can be promoted to for
+ * which all the binary operators behave the same way as for the actual types
+ * (for example, there is no type that long long and unsigned long long can
+ * both be cast to where the comparison result is preserved for all values). So
+ * the best we can do is do the comparison in the original types and then coerce
+ * everything to long long for printing; this way, the comparison behaves
+ * correctly and the printed out value usually makes sense without
+ * interpretation, but can always be interpretted to figure out the actual
+ * value.
+ */
+#define EXPECT_BINARY(test, left, condition, right) do {		       \
+	typeof(left) __left = (left);					       \
+	typeof(right) __right = (right);				       \
+	test_expect_binary(test,					       \
+			   (long long) __left, #left,			       \
+			   (long long) __right, #right,			       \
+			   __left condition __right, #condition,	       \
+			   __FILE__, __stringify(__LINE__));		       \
+} while (0)
+
+/**
+ * EXPECT_EQ() - Sets an expectation that @left and @right are equal.
+ * @test: The test context object.
+ * @left: an arbitrary expression that evaluates to a primitive C type.
+ * @right: an arbitrary expression that evaluates to a primitive C type.
+ *
+ * Sets an expectation that the values that @left and @right evaluate to are
+ * equal. This is semantically equivalent to EXPECT_TRUE(@test, (@left) ==
+ * (@right)).  See EXPECT_TRUE() for more information.
+ */
+#define EXPECT_EQ(test, left, right) EXPECT_BINARY(test, left, ==, right)
+
+/**
+ * EXPECT_NE() - An expectation that @left and @right are not equal.
+ * @test: The test context object.
+ * @left: an arbitrary expression that evaluates to a primitive C type.
+ * @right: an arbitrary expression that evaluates to a primitive C type.
+ *
+ * Sets an expectation that the values that @left and @right evaluate to are not
+ * equal. This is semantically equivalent to EXPECT_TRUE(@test, (@left) !=
+ * (@right)).  See EXPECT_TRUE() for more information.
+ */
+#define EXPECT_NE(test, left, right) EXPECT_BINARY(test, left, !=, right)
+
+/**
+ * EXPECT_LT() - An expectation that @left is less than @right.
+ * @test: The test context object.
+ * @left: an arbitrary expression that evaluates to a primitive C type.
+ * @right: an arbitrary expression that evaluates to a primitive C type.
+ *
+ * Sets an expectation that the value that @left evaluates to is less than the
+ * value that @right evaluates to. This is semantically equivalent to
+ * EXPECT_TRUE(@test, (@left) < (@right)). See EXPECT_TRUE() for more
+ * information.
+ */
+#define EXPECT_LT(test, left, right) EXPECT_BINARY(test, left, <, right)
+
+/**
+ * EXPECT_LE() - An expectation that @left is less than or equal to @right.
+ * @test: The test context object.
+ * @left: an arbitrary expression that evaluates to a primitive C type.
+ * @right: an arbitrary expression that evaluates to a primitive C type.
+ *
+ * Sets an expectation that the value that @left evaluates to is less than or
+ * equal to the value that @right evaluates to. Semantically this is equivalent
+ * to EXPECT_TRUE(@test, (@left) <= (@right)). See EXPECT_TRUE() for more
+ * information.
+ */
+#define EXPECT_LE(test, left, right) EXPECT_BINARY(test, left, <=, right)
+
+/**
+ * EXPECT_GT() - An expectation that @left is greater than @right.
+ * @test: The test context object.
+ * @left: an arbitrary expression that evaluates to a primitive C type.
+ * @right: an arbitrary expression that evaluates to a primitive C type.
+ *
+ * Sets an expectation that the value that @left evaluates to is greater than
+ * the value that @right evaluates to. This is semantically equivalent to
+ * EXPECT_TRUE(@test, (@left) > (@right)). See EXPECT_TRUE() for more
+ * information.
+ */
+#define EXPECT_GT(test, left, right) EXPECT_BINARY(test, left, >, right)
+
+/**
+ * EXPECT_GE() - An expectation that @left is greater than or equal to @right.
+ * @test: The test context object.
+ * @left: an arbitrary expression that evaluates to a primitive C type.
+ * @right: an arbitrary expression that evaluates to a primitive C type.
+ *
+ * Sets an expectation that the value that @left evaluates to is greater than
+ * the value that @right evaluates to. This is semantically equivalent to
+ * EXPECT_TRUE(@test, (@left) >= (@right)). See EXPECT_TRUE() for more
+ * information.
+ */
+#define EXPECT_GE(test, left, right) EXPECT_BINARY(test, left, >=, right)
+
+/**
+ * EXPECT_STREQ() - An expectation that strings @left and @right are equal.
+ * @test: The test context object.
+ * @left: an arbitrary expression that evaluates to a null terminated string.
+ * @right: an arbitrary expression that evaluates to a null terminated string.
+ *
+ * Sets an expectation that the values that @left and @right evaluate to are
+ * equal. This is semantically equivalent to
+ * EXPECT_TRUE(@test, !strcmp((@left), (@right))). See EXPECT_TRUE() for more
+ * information.
+ */
+#define EXPECT_STREQ(test, left, right) do {				       \
+	struct test_stream *__stream = EXPECT_START(test);		       \
+	typeof(left) __left = (left);					       \
+	typeof(right) __right = (right);				       \
+									       \
+	__stream->add(__stream, "Expected " #left " == " #right ", but\n");    \
+	__stream->add(__stream, "\t\t%s == %s\n", #left, __left);	       \
+	__stream->add(__stream, "\t\t%s == %s\n", #right, __right);	       \
+									       \
+	EXPECT_END(test, !strcmp(left, right), __stream);		       \
+} while (0)
+
+/**
+ * EXPECT_NOT_ERR_OR_NULL() - An expectation that @ptr is not null and not err.
+ * @test: The test context object.
+ * @ptr: an arbitrary pointer.
+ *
+ * Sets an expectation that the value that @ptr evaluates to is not null and not
+ * an errno stored in a pointer. This is semantically equivalent to
+ * EXPECT_TRUE(@test, !IS_ERR_OR_NULL(@ptr)). See EXPECT_TRUE() for more
+ * information.
+ */
+#define EXPECT_NOT_ERR_OR_NULL(test, ptr) do {				       \
+	struct test_stream *__stream = EXPECT_START(test);		       \
+	typeof(ptr) __ptr = (ptr);					       \
+									       \
+	if (!__ptr)							       \
+		__stream->add(__stream,					       \
+			      "Expected " #ptr " is not null, but is.");       \
+	if (IS_ERR(__ptr))						       \
+		__stream->add(__stream,					       \
+			      "Expected " #ptr " is not error, but is: %ld",   \
+			      PTR_ERR(__ptr));				       \
+									       \
+	EXPECT_END(test, !IS_ERR_OR_NULL(__ptr), __stream);		       \
+} while (0)
+
+#endif /* _TEST_TEST_H */
diff --git a/test/Kconfig b/test/Kconfig
new file mode 100644
index 0000000..2b6f57c
--- /dev/null
+++ b/test/Kconfig
@@ -0,0 +1,14 @@
+config TEST
+	bool
+	default y
+
+config TEST_TEST
+	bool
+	depends on TEST
+	default y
+
+config EXAMPLE_TEST
+	bool
+	depends on TEST
+	default y
+
diff --git a/test/Makefile b/test/Makefile
new file mode 100644
index 0000000..911c9ff
--- /dev/null
+++ b/test/Makefile
@@ -0,0 +1,3 @@
+obj-$(CONFIG_TEST)		+= test.o string-stream.o test-stream.o
+obj-$(CONFIG_TEST_TEST)		+= string-stream-test.o
+obj-$(CONFIG_EXAMPLE_TEST)	+= example-test.o
diff --git a/test/example-test.c b/test/example-test.c
new file mode 100644
index 0000000..53ec488
--- /dev/null
+++ b/test/example-test.c
@@ -0,0 +1,25 @@
+#include <test/test.h>
+
+static void example_simple_test(struct test *test)
+{
+	EXPECT_EQ(test, 1, 1);
+}
+
+static int example_test_init(struct test *test)
+{
+	test_info(test, "initializing");
+
+	return 0;
+}
+
+static struct test_case example_test_cases[] = {
+	TEST_CASE(example_simple_test),
+	{},
+};
+
+static struct test_module example_test_module = {
+	.name = "example",
+	.init = example_test_init,
+	.test_cases = example_test_cases,
+};
+module_test(example_test_module);
diff --git a/test/string-stream-test.c b/test/string-stream-test.c
new file mode 100644
index 0000000..442e748
--- /dev/null
+++ b/test/string-stream-test.c
@@ -0,0 +1,53 @@
+#include <linux/slab.h>
+#include <test/test.h>
+#include <test/string-stream.h>
+
+static void string_stream_test_get_string(struct test *test)
+{
+	struct string_stream *stream = new_string_stream();
+	char *output;
+
+	stream->add(stream, "Foo");
+	stream->add(stream, " %s", "bar");
+
+	output = stream->get_string(stream);
+	EXPECT_STREQ(test, output, "Foo bar");
+	kfree(output);
+	destroy_string_stream(stream);
+}
+
+static void string_stream_test_add_and_clear(struct test *test)
+{
+	struct string_stream *stream = new_string_stream();
+	char *output;
+	int i;
+
+	for (i = 0; i < 10; i++)
+		stream->add(stream, "A");
+
+	output = stream->get_string(stream);
+	EXPECT_STREQ(test, output, "AAAAAAAAAA");
+	EXPECT_EQ(test, stream->length, 10);
+	EXPECT_FALSE(test, stream->is_empty(stream));
+	kfree(output);
+
+	stream->clear(stream);
+
+	output = stream->get_string(stream);
+	EXPECT_STREQ(test, output, "");
+	EXPECT_TRUE(test, stream->is_empty(stream));
+	destroy_string_stream(stream);
+}
+
+static struct test_case string_stream_test_cases[] = {
+	TEST_CASE(string_stream_test_get_string),
+	TEST_CASE(string_stream_test_add_and_clear),
+	{}
+};
+
+static struct test_module string_stream_test_module = {
+	.name = "string-stream-test",
+	.test_cases = string_stream_test_cases
+};
+module_test(string_stream_test_module);
+
diff --git a/test/string-stream.c b/test/string-stream.c
new file mode 100644
index 0000000..f6049d6
--- /dev/null
+++ b/test/string-stream.c
@@ -0,0 +1,105 @@
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <test/string-stream.h>
+
+static int string_stream_vadd(struct string_stream *this,
+			       const char *fmt,
+			       va_list args)
+{
+	struct string_stream_fragment *fragment;
+	int len;
+	va_list args_for_counting;
+
+	/* Make a copy because `vsnprintf` could change it */
+	va_copy(args_for_counting, args);
+
+	/* Need space for null byte. */
+	len = vsnprintf(NULL, 0, fmt, args_for_counting) + 1;
+
+	va_end(args_for_counting);
+
+	fragment = kmalloc(sizeof(*fragment), GFP_KERNEL);
+	if (!fragment)
+		return -ENOMEM;
+
+	fragment->fragment = kmalloc(len + 1, GFP_KERNEL);
+	if (!fragment->fragment) {
+		kfree(fragment);
+		return -ENOMEM;
+	}
+
+	len = vsnprintf(fragment->fragment, len, fmt, args);
+	this->length += len;
+	list_add_tail(&fragment->node, &this->fragments);
+	return 0;
+}
+
+static int string_stream_add(struct string_stream *this, const char *fmt, ...)
+{
+	va_list args;
+	int result;
+
+	va_start(args, fmt);
+	result = string_stream_vadd(this, fmt, args);
+	va_end(args);
+	return result;
+}
+
+static void string_stream_clear(struct string_stream *this)
+{
+	struct string_stream_fragment *fragment, *fragment_safe;
+
+	list_for_each_entry_safe(fragment,
+				 fragment_safe,
+				 &this->fragments,
+				 node) {
+		list_del(&fragment->node);
+		kfree(fragment->fragment);
+		kfree(fragment);
+	}
+
+	this->length = 0;
+}
+
+static char *string_stream_get_string(struct string_stream *this)
+{
+	struct string_stream_fragment *fragment;
+	char *buf;
+
+	buf = kzalloc(this->length + 1, GFP_KERNEL);
+	if (!buf)
+		return NULL;
+
+	list_for_each_entry(fragment, &this->fragments, node) {
+		strcat(buf, fragment->fragment);
+	}
+	return buf;
+}
+
+static bool string_stream_is_empty(struct string_stream *this)
+{
+	return list_empty(&this->fragments);
+}
+
+void destroy_string_stream(struct string_stream *stream)
+{
+	stream->clear(stream);
+	kfree(stream);
+}
+
+struct string_stream *new_string_stream(void)
+{
+	struct string_stream *stream = kzalloc(sizeof(*stream), GFP_KERNEL);
+
+	if (!stream)
+		return NULL;
+
+	INIT_LIST_HEAD(&stream->fragments);
+	stream->length = 0;
+	stream->add = string_stream_add;
+	stream->vadd = string_stream_vadd;
+	stream->get_string = string_stream_get_string;
+	stream->clear = string_stream_clear;
+	stream->is_empty = string_stream_is_empty;
+	return stream;
+}
diff --git a/test/test-stream.c b/test/test-stream.c
new file mode 100644
index 0000000..89f0a08
--- /dev/null
+++ b/test/test-stream.c
@@ -0,0 +1,125 @@
+#include <test/test.h>
+#include <test/test-stream.h>
+#include <test/string-stream.h>
+
+static void test_stream_set_level(struct test_stream *this,
+				  const char *level)
+{
+	this->level = level;
+}
+
+static void test_stream_add(struct test_stream *this, const char *fmt, ...)
+{
+	va_list args;
+	struct string_stream *stream = this->internal_stream;
+
+	va_start(args, fmt);
+	if (stream->vadd(stream, fmt, args) < 0)
+		test_err(this->test, "Failed to allocate fragment: %s", fmt);
+
+	va_end(args);
+}
+
+static void test_stream_append(struct test_stream *this,
+			       struct test_stream *other)
+{
+	struct string_stream *other_stream = other->internal_stream;
+	const char *other_content;
+
+	other_content = other_stream->get_string(other_stream);
+
+	if (!other_content) {
+		test_err(this->test,
+			 "Failed to get string from second argument for appending.");
+		return;
+	}
+
+	this->add(this, other_content);
+}
+
+static void test_stream_clear(struct test_stream *this)
+{
+	this->internal_stream->clear(this->internal_stream);
+}
+
+static void test_stream_commit(struct test_stream *this)
+{
+	char *buf;
+	struct string_stream_fragment *fragment;
+	struct string_stream *stream = this->internal_stream;
+
+	if (!this->level) {
+		test_err(this->test,
+			 "Stream was committed without a specified log level.");
+		this->set_level(this, KERN_ERR);
+	}
+
+	buf = stream->get_string(stream);
+	if (!buf) {
+		test_err(this->test,
+			 "Could not allocate buffer, dumping stream:");
+		list_for_each_entry(fragment, &stream->fragments, node) {
+			test_err(this->test, fragment->fragment);
+		}
+		goto cleanup;
+	}
+
+	test_printk(this->level, this->test, buf);
+	kfree(buf);
+
+cleanup:
+	this->clear(this);
+}
+
+static int test_stream_init(struct test_resource *res, void *context)
+{
+	struct test_stream *stream;
+	struct test *test = context;
+
+	stream = kzalloc(sizeof(*stream), GFP_KERNEL);
+	if (!stream)
+		return -ENOMEM;
+	res->allocation = stream;
+	stream->test = test;
+	stream->level = NULL;
+	stream->internal_stream = new_string_stream();
+
+	if (!stream->internal_stream)
+		return -ENOMEM;
+
+	stream->set_level = test_stream_set_level;
+	stream->add = test_stream_add;
+	stream->append = test_stream_append;
+	stream->commit = test_stream_commit;
+	stream->clear = test_stream_clear;
+	return 0;
+}
+
+static void test_stream_free(struct test_resource *res)
+{
+	struct test_stream *stream = res->allocation;
+
+	if (!stream->internal_stream->is_empty(stream->internal_stream)) {
+		test_err(stream->test,
+			 "End of test case reached with uncommitted stream entries.");
+		stream->commit(stream);
+	}
+
+	destroy_string_stream(stream->internal_stream);
+	kfree(stream);
+}
+
+struct test_stream *test_new_stream(struct test *test)
+{
+	struct test_resource *res;
+
+	res = test_alloc_resource(test,
+				  test_stream_init,
+				  test_stream_free,
+				  test);
+
+	if (res)
+		return res->allocation;
+	else
+		return NULL;
+}
diff --git a/test/test.c b/test/test.c
new file mode 100644
index 0000000..ba8deef
--- /dev/null
+++ b/test/test.c
@@ -0,0 +1,236 @@
+#include <linux/sched.h>
+#include <linux/sched/debug.h>
+#include <os.h>
+#include <test/test.h>
+
+static int test_vprintk_emit(const struct test *test,
+			     int level,
+			     const char *fmt,
+			     va_list args)
+{
+	return vprintk_emit(0, level, NULL, 0, fmt, args);
+}
+
+static int test_printk_emit(const struct test *test,
+			    int level,
+			    const char *fmt, ...)
+{
+	va_list args;
+	int ret;
+
+	va_start(args, fmt);
+	ret = test_vprintk_emit(test, level, fmt, args);
+	va_end(args);
+
+	return ret;
+}
+
+static void test_vprintk(const struct test *test,
+			 const char *level,
+			 struct va_format *vaf)
+{
+	test_printk_emit(test,
+			 level[1] - '0',
+			 "kunit %s: %pV", test->name, vaf);
+}
+
+static void test_fail(struct test *test, struct test_stream *stream)
+{
+	test->success = false;
+	stream->set_level(stream, KERN_ERR);
+	stream->commit(stream);
+}
+
+int test_init_test(struct test *test, const char *name)
+{
+	INIT_LIST_HEAD(&test->resources);
+	test->name = name;
+	test->vprintk = test_vprintk;
+	test->fail = test_fail;
+
+	return 0;
+}
+
+/*
+ * Initializes and runs test case. Does not clean up or do post validations.
+ */
+static void test_run_case_internal(struct test *test,
+				   struct test_module *module,
+				   struct test_case *test_case)
+{
+	int ret;
+
+	if (module->init) {
+		ret = module->init(test);
+		if (ret) {
+			test_err(test, "failed to initialize: %d", ret);
+			test->success = false;
+			return;
+		}
+	}
+
+	test_case->run_case(test);
+}
+
+static void test_case_internal_cleanup(struct test *test)
+{
+	test_cleanup(test);
+}
+
+/*
+ * Performs post validations and cleanup after a test case was run.
+ * XXX: Should ONLY BE CALLED AFTER test_run_case_internal!
+ */
+static void test_run_case_cleanup(struct test *test,
+				  struct test_module *module,
+				  struct test_case *test_case)
+{
+	if (module->exit)
+		module->exit(test);
+
+	test_case_internal_cleanup(test);
+}
+
+/*
+ * Performs all logic to run a test case.
+ */
+static bool test_run_case(struct test *test,
+			  struct test_module *module,
+			  struct test_case *test_case)
+{
+	test->success = true;
+
+	test_run_case_internal(test, module, test_case);
+	test_run_case_cleanup(test, module, test_case);
+
+	return test->success;
+}
+
+int test_run_tests(struct test_module *module)
+{
+	bool all_passed = true, success;
+	struct test_case *test_case;
+	struct test test;
+	int ret;
+
+	ret = test_init_test(&test, module->name);
+	if (ret)
+		return ret;
+
+	for (test_case = module->test_cases; test_case->run_case; test_case++) {
+		success = test_run_case(&test, module, test_case);
+		if (!success)
+			all_passed = false;
+
+		test_info(&test,
+			  "%s %s",
+			  test_case->name,
+			  success ? "passed" : "failed");
+	}
+
+	if (all_passed)
+		test_info(&test, "all tests passed");
+	else
+		test_info(&test, "one or more tests failed");
+
+	return 0;
+}
+
+struct test_resource *test_alloc_resource(struct test *test,
+					  int (*init)(struct test_resource *,
+						      void *),
+					  void (*free)(struct test_resource *),
+					  void *context)
+{
+	struct test_resource *res;
+	int ret;
+
+	res = kzalloc(sizeof(*res), GFP_KERNEL);
+	if (!res)
+		return NULL;
+
+	ret = init(res, context);
+	if (ret)
+		return NULL;
+
+	res->free = free;
+	list_add_tail(&res->node, &test->resources);
+
+	return res;
+}
+
+void test_free_resource(struct test *test, struct test_resource *res)
+{
+	res->free(res);
+	list_del(&res->node);
+	kfree(res);
+}
+
+struct test_kmalloc_params {
+	size_t size;
+	gfp_t gfp;
+};
+
+static int test_kmalloc_init(struct test_resource *res, void *context)
+{
+	struct test_kmalloc_params *params = context;
+
+	res->allocation = kmalloc(params->size, params->gfp);
+	if (!res->allocation)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static void test_kmalloc_free(struct test_resource *res)
+{
+	kfree(res->allocation);
+}
+
+void *test_kmalloc(struct test *test, size_t size, gfp_t gfp)
+{
+	struct test_kmalloc_params params;
+	struct test_resource *res;
+
+	params.size = size;
+	params.gfp = gfp;
+
+	res = test_alloc_resource(test,
+				  test_kmalloc_init,
+				  test_kmalloc_free,
+				  &params);
+
+	if (res)
+		return res->allocation;
+	else
+		return NULL;
+}
+
+void test_cleanup(struct test *test)
+{
+	struct test_resource *resource, *resource_safe;
+
+	list_for_each_entry_safe(resource,
+				 resource_safe,
+				 &test->resources,
+				 node) {
+		test_free_resource(test, resource);
+	}
+}
+
+void test_printk(const char *level,
+		 const struct test *test,
+		 const char *fmt, ...)
+{
+	struct va_format vaf;
+	va_list args;
+
+	va_start(args, fmt);
+
+	vaf.fmt = fmt;
+	vaf.va = &args;
+
+	test->vprintk(test, level, &vaf);
+
+	va_end(args);
+}