Commit 359a3760 authored by Uriel Guajardo's avatar Uriel Guajardo Committed by Shuah Khan
Browse files

kunit: support failure from dynamic analysis tools 



Add a kunit_fail_current_test() function to fail the currently running
test, if any, with an error message.

This is largely intended for dynamic analysis tools like UBSAN and for
fakes.
E.g. say I had a fake ops struct for testing and I wanted my `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.).

Key points:
* Always update current->kunit_test so anyone can use it.
  * commit 83c4e7a0 ("KUnit: KASAN Integration") only updated it for
  CONFIG_KASAN=y

* Create a new header <kunit/test-bug.h> so non-test code doesn't have
to include all of <kunit/test.h> (e.g. lib/ubsan.c)

* Forward the file and line number to make it easier to track down
failures

* Declare the helper function for nice __printf() warnings about mismatched
format strings even when KUnit is not enabled.

Example output from kunit_fail_current_test("message"):
[15:19:34] [FAILED] example_simple_test
[15:19:34]     # example_simple_test: initializing
[15:19:34]     # example_simple_test: lib/kunit/kunit-example-test.c:24: message
[15:19:34]     not ok 1 - example_simple_test

Fixed minor check patch with checkpatch --fix option:
Shuah Khan <skhan@linuxfoundation.org>

Signed-off-by: default avatarDaniel Latypov <dlatypov@google.com>
Signed-off-by: default avatarUriel Guajardo <urielguajardo@google.com>
Reviewed-by: default avatarAlan Maguire <alan.maguire@oracle.com>
Reviewed-by: default avatarBrendan Higgins <brendanhiggins@google.com>
Signed-off-by: default avatarShuah Khan <skhan@linuxfoundation.org>
parent 9854781d

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

						    const char *fmt, ...)

{

}



#endif



#endif /* _KUNIT_TEST_BUG_H */

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);