From: Uriel Guajardo urielguajardo@google.com

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 83c4e7a0363b ("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

Co-developed-by: Daniel Latypov dlatypov@google.com Signed-off-by: Daniel Latypov dlatypov@google.com Signed-off-by: Uriel Guajardo urielguajardo@google.com Reviewed-by: Alan Maguire alan.maguire@oracle.com --- include/kunit/test-bug.h | 30 ++++++++++++++++++++++++++++++ lib/kunit/test.c | 39 +++++++++++++++++++++++++++++++++++---- 2 files changed, 65 insertions(+), 4 deletions(-) create mode 100644 include/kunit/test-bug.h

diff --git a/include/kunit/test-bug.h b/include/kunit/test-bug.h new file mode 100644 index 000000000000..e88b74a4fd85 --- /dev/null +++ b/include/kunit/test-bug.h @@ -0,0 +1,30 @@ +/* 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 */ diff --git a/lib/kunit/test.c b/lib/kunit/test.c index ec9494e914ef..2f6cc0123232 100644 --- a/lib/kunit/test.c +++ b/lib/kunit/test.c @@ -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);

From: Uriel Guajardo urielguajardo@google.com

Integrates UBSAN into the KUnit testing framework. It fails KUnit tests whenever it reports undefined behavior.

When CONFIG_KUNIT=n, nothing is printed or even formatted, so this has no behavioral impact outside of tests.

kunit_fail_current_test() effectively does a pr_err() as well, so there's some slight duplication, but it also ensures an error is recorded in the debugfs entry for the running KUnit test.

Print a shorter version of the message to make it less spammy.

Co-developed-by: Daniel Latypov dlatypov@google.com Signed-off-by: Daniel Latypov dlatypov@google.com Signed-off-by: Uriel Guajardo urielguajardo@google.com Reviewed-by: Alan Maguire alan.maguire@oracle.com --- lib/ubsan.c | 3 +++ 1 file changed, 3 insertions(+)

diff --git a/lib/ubsan.c b/lib/ubsan.c index 26229973049d..bdc380ff5d5c 100644 --- a/lib/ubsan.c +++ b/lib/ubsan.c @@ -14,6 +14,7 @@ #include <linux/types.h> #include <linux/sched.h> #include <linux/uaccess.h> +#include <kunit/test-bug.h>

#include "ubsan.h"

@@ -141,6 +142,8 @@ static void ubsan_prologue(struct source_location *loc, const char *reason) "========================================\n"); pr_err("UBSAN: %s in %s:%d:%d\n", reason, loc->file_name, loc->line & LINE_MASK, loc->column & COLUMN_MASK); + + kunit_fail_current_test("%s in %s", reason, loc->file_name); }

static void ubsan_epilogue(void)