Commit 1e9599df authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'linux-kselftest-kunit-5.13-rc1' of... 

Merge tag 'linux-kselftest-kunit-5.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull KUnit updates from Shuah Khan:
 "Several fixes and a new feature to support failure from dynamic
  analysis tools such as UBSAN and fake ops for testing.

   - a fake ops struct for testing a "free" function to complain if it
     was called with an invalid argument, or caught a double-free. Most
     return void and have no normal means of signalling failure (e.g.
     super_operations, iommu_ops, etc.)"

* tag 'linux-kselftest-kunit-5.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  Documentation: kunit: add tips for using current->kunit_test
  kunit: fix -Wunused-function warning for __kunit_fail_current_test
  kunit: support failure from dynamic analysis tools
  kunit: tool: make --kunitconfig accept dirs, add lib/kunit fragment
  kunit: make KUNIT_EXPECT_STREQ() quote values, don't print literals
  kunit: Match parenthesis alignment to improve code readability
parents 2a68c268 de2fcb3e

Documentation/dev-tools/kunit/tips.rst

+76 −2
Original line number Diff line number Diff line
@@ -78,8 +78,82 @@ Similarly to the above, it can be useful to add test-specific logic. 
	void test_only_hook(void) { }

	#endif



TODO(dlatypov@google.com): add an example of using ``current->kunit_test`` in

such a hook when it's not only updated for ``CONFIG_KASAN=y``.

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 :doc:`api/test`.



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

--------------------------

include/kunit/test-bug.h

0 → 100644
+29 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0 */

/*

 * KUnit API allowing dynamic analysis tools to interact with KUnit tests

 *

 * Copyright (C) 2020, Google LLC.

 * Author: Uriel Guajardo <urielguajardo@google.com>

 */



#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)



extern __printf(3, 4) void __kunit_fail_current_test(const char *file, int line,

						    const char *fmt, ...);



#else



static inline __printf(3, 4) void __kunit_fail_current_test(const char *file, int line,

							    const char *fmt, ...)

{

}



#endif



#endif /* _KUNIT_TEST_BUG_H */

lib/kunit/.kunitconfig

0 → 100644
+3 −0
Original line number Diff line number Diff line 
CONFIG_KUNIT=y

CONFIG_KUNIT_TEST=y

CONFIG_KUNIT_EXAMPLE_TEST=y

lib/kunit/assert.c

+44 −17
Original line number Diff line number Diff line
@@ -48,8 +48,9 @@ EXPORT_SYMBOL_GPL(kunit_fail_assert_format); 
void kunit_unary_assert_format(const struct kunit_assert *assert,

			       struct string_stream *stream)

{

	struct kunit_unary_assert *unary_assert = container_of(

			assert, struct kunit_unary_assert, assert);

	struct kunit_unary_assert *unary_assert;



	unary_assert = container_of(assert, struct kunit_unary_assert, assert);



	kunit_base_assert_format(assert, stream);

	if (unary_assert->expected_true)
@@ -67,8 +68,10 @@ EXPORT_SYMBOL_GPL(kunit_unary_assert_format); 
void kunit_ptr_not_err_assert_format(const struct kunit_assert *assert,

				     struct string_stream *stream)

{

	struct kunit_ptr_not_err_assert *ptr_assert = container_of(

			assert, struct kunit_ptr_not_err_assert, assert);

	struct kunit_ptr_not_err_assert *ptr_assert;



	ptr_assert = container_of(assert, struct kunit_ptr_not_err_assert,

				  assert);



	kunit_base_assert_format(assert, stream);

	if (!ptr_assert->value) {
@@ -111,8 +114,10 @@ static bool is_literal(struct kunit *test, const char *text, long long value, 
void kunit_binary_assert_format(const struct kunit_assert *assert,

				struct string_stream *stream)

{

	struct kunit_binary_assert *binary_assert = container_of(

			assert, struct kunit_binary_assert, assert);

	struct kunit_binary_assert *binary_assert;



	binary_assert = container_of(assert, struct kunit_binary_assert,

				     assert);



	kunit_base_assert_format(assert, stream);

	string_stream_add(stream,
@@ -137,8 +142,10 @@ EXPORT_SYMBOL_GPL(kunit_binary_assert_format); 
void kunit_binary_ptr_assert_format(const struct kunit_assert *assert,

				    struct string_stream *stream)

{

	struct kunit_binary_ptr_assert *binary_assert = container_of(

			assert, struct kunit_binary_ptr_assert, assert);

	struct kunit_binary_ptr_assert *binary_assert;



	binary_assert = container_of(assert, struct kunit_binary_ptr_assert,

				     assert);



	kunit_base_assert_format(assert, stream);

	string_stream_add(stream,
@@ -156,11 +163,29 @@ void kunit_binary_ptr_assert_format(const struct kunit_assert *assert, 
}

EXPORT_SYMBOL_GPL(kunit_binary_ptr_assert_format);



/* Checks if KUNIT_EXPECT_STREQ() args were string literals.

 * Note: `text` will have ""s where as `value` will not.

 */

static bool is_str_literal(const char *text, const char *value)

{

	int len;



	len = strlen(text);

	if (len < 2)

		return false;

	if (text[0] != '\"' || text[len - 1] != '\"')

		return false;



	return strncmp(text + 1, value, len - 2) == 0;

}



void kunit_binary_str_assert_format(const struct kunit_assert *assert,

				    struct string_stream *stream)

{

	struct kunit_binary_str_assert *binary_assert = container_of(

			assert, struct kunit_binary_str_assert, assert);

	struct kunit_binary_str_assert *binary_assert;



	binary_assert = container_of(assert, struct kunit_binary_str_assert,

				     assert);



	kunit_base_assert_format(assert, stream);

	string_stream_add(stream,
@@ -168,10 +193,12 @@ void kunit_binary_str_assert_format(const struct kunit_assert *assert, 
			  binary_assert->left_text,

			  binary_assert->operation,

			  binary_assert->right_text);

	string_stream_add(stream, KUNIT_SUBSUBTEST_INDENT "%s == %s\n",

	if (!is_str_literal(binary_assert->left_text, binary_assert->left_value))

		string_stream_add(stream, KUNIT_SUBSUBTEST_INDENT "%s == \"%s\"\n",

				  binary_assert->left_text,

				  binary_assert->left_value);

	string_stream_add(stream, KUNIT_SUBSUBTEST_INDENT "%s == %s",

	if (!is_str_literal(binary_assert->right_text, binary_assert->right_value))

		string_stream_add(stream, KUNIT_SUBSUBTEST_INDENT "%s == \"%s\"",

				  binary_assert->right_text,

				  binary_assert->right_value);

	kunit_assert_print_msg(assert, stream);

lib/kunit/test.c

+35 −4
Original line number Diff line number Diff line
@@ -7,6 +7,7 @@ 
 */



#include <kunit/test.h>

#include <kunit/test-bug.h>

#include <linux/kernel.h>

#include <linux/kref.h>

#include <linux/sched/debug.h>
@@ -16,6 +17,40 @@ 
#include "string-stream.h"

#include "try-catch-impl.h"



#if IS_BUILTIN(CONFIG_KUNIT)

/*

 * Fail the current test and print an error message to the log.

 */

void __kunit_fail_current_test(const char *file, int line, const char *fmt, ...)

{

	va_list args;

	int len;

	char *buffer;



	if (!current->kunit_test)

		return;



	kunit_set_failure(current->kunit_test);



	/* kunit_err() only accepts literals, so evaluate the args first. */

	va_start(args, fmt);

	len = vsnprintf(NULL, 0, fmt, args) + 1;

	va_end(args);



	buffer = kunit_kmalloc(current->kunit_test, len, GFP_KERNEL);

	if (!buffer)

		return;



	va_start(args, fmt);

	vsnprintf(buffer, len, fmt, args);

	va_end(args);



	kunit_err(current->kunit_test, "%s:%d: %s", file, line, buffer);

	kunit_kfree(current->kunit_test, buffer);

}

EXPORT_SYMBOL_GPL(__kunit_fail_current_test);

#endif



/*

 * Append formatted message to log, size of which is limited to

 * KUNIT_LOG_SIZE bytes (including null terminating byte).
@@ -273,9 +308,7 @@ static void kunit_try_run_case(void *data) 
	struct kunit_suite *suite = ctx->suite;

	struct kunit_case *test_case = ctx->test_case;



#if (IS_ENABLED(CONFIG_KASAN) && IS_ENABLED(CONFIG_KUNIT))

	current->kunit_test = test;

#endif /* IS_ENABLED(CONFIG_KASAN) && IS_ENABLED(CONFIG_KUNIT) */



	/*

	 * kunit_run_case_internal may encounter a fatal error; if it does,
@@ -624,9 +657,7 @@ void kunit_cleanup(struct kunit *test) 
		spin_unlock(&test->lock);

		kunit_remove_resource(test, res);

	}

#if (IS_ENABLED(CONFIG_KASAN) && IS_ENABLED(CONFIG_KUNIT))

	current->kunit_test = NULL;

#endif /* IS_ENABLED(CONFIG_KASAN) && IS_ENABLED(CONFIG_KUNIT)*/

}

EXPORT_SYMBOL_GPL(kunit_cleanup);