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 83c4e7a036 ("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: Daniel Latypov <dlatypov@google.com>
Signed-off-by: Uriel Guajardo <urielguajardo@google.com>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
This commit is contained in:
Uriel Guajardo 2021-03-11 07:23:13 -08:00 committed by Shuah Khan
parent 9854781dba
commit 359a376081
2 changed files with 64 additions and 4 deletions

29
include/kunit/test-bug.h Normal file
View file

@ -0,0 +1,29 @@
/* 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 */

View file

@ -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);