On Thu, Aug 6, 2020 at 10:43 AM Uriel Guajardo urielguajardojr@gmail.com wrote:

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

Signed-off-by: Uriel Guajardo urielguajardo@google.com

You should resend this to the UBSAN maintainers as well; they will need to sign off on this.

In the future, make sure to run get_maintainers.pl

Reviewed-by: Brendan Higgins brendanhiggins@google.com

---

lib/ubsan.c | 2 ++ 1 file changed, 2 insertions(+)

diff --git a/lib/ubsan.c b/lib/ubsan.c index cb9af3f6b77e..1460e2c828c8 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.h>

#include "ubsan.h"

@@ -137,6 +138,7 @@ static void ubsan_prologue(struct source_location *loc, const char *reason) { current->in_ubsan++;

•   kunit_fail_current_test();
    pr_err("========================================"
            "========================================\n");
    pr_err("UBSAN: %s in %s:%d:%d\n", reason, loc->file_name,
  

-- 2.28.0.163.g6104cc2f0b6-goog

On Thu, Aug 06, 2020 at 05:43:26PM +0000, Uriel Guajardo wrote:

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

Signed-off-by: Uriel Guajardo urielguajardo@google.com

It looks like this patch had been merged into linux-next but the "[PATCH 1/2] kunit: support failure from dynamic analysis tools" did not. Hence, it caused a compiling failure.

lib/ubsan.c: In function ‘ubsan_prologue’: lib/ubsan.c:141:2: error: implicit declaration of function ‘kunit_fail_current_test’; did you mean ‘kunit_init_test’? [-Werror=implicit-function-declaration] kunit_fail_current_test(); ^~~~~~~~~~~~~~~~~~~~~~~ kunit_init_test cc1: some warnings being treated as errors

---

lib/ubsan.c | 2 ++ 1 file changed, 2 insertions(+)

diff --git a/lib/ubsan.c b/lib/ubsan.c index cb9af3f6b77e..1460e2c828c8 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.h> #include "ubsan.h" @@ -137,6 +138,7 @@ static void ubsan_prologue(struct source_location *loc, const char *reason) { current->in_ubsan++;

• kunit_fail_current_test(); pr_err("========================================" "========================================\n"); pr_err("UBSAN: %s in %s:%d:%d\n", reason, loc->file_name,

-- 2.28.0.163.g6104cc2f0b6-goog

On Fri, Aug 7, 2020 at 9:16 AM Alan Maguire alan.maguire@oracle.com wrote:

On Thu, 6 Aug 2020, Uriel Guajardo wrote:

...

Adds an API to allow dynamic analysis tools to fail the currently running KUnit test case.

• Always places the kunit test in the task_struct to allow other tools

to access the currently running KUnit test.

• Creates a new header file to avoid circular dependencies that could be

created from the test.h file.

Requires KASAN-KUnit integration patch to access the kunit test from task_struct: https://lore.kernel.org/linux-kselftest/20200606040349.246780-2-davidgow@goo...

Signed-off-by: Uriel Guajardo urielguajardo@google.com

include/kunit/test-bug.h | 24 ++++++++++++++++++++++++ include/kunit/test.h | 1 + lib/kunit/test.c | 10 ++++++---- 3 files changed, 31 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..283c19ec328f --- /dev/null +++ b/include/kunit/test-bug.h @@ -0,0 +1,24 @@ +/* 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

+#if IS_ENABLED(CONFIG_KUNIT)

+extern void kunit_fail_current_test(void);

+#else

+static inline void kunit_fail_current_test(void) +{ +}

+#endif

+#endif /* _KUNIT_TEST_BUG_H */

This is great stuff!

One thing I wonder though; how obvious will it be to someone running a KUnit test that the cause of the test failure is a dynamic analysis tool? Yes we'll see the dmesg logging from that tool but I don't think there's any context _within_ KUnit that could clarify the source of the failure. What about changing the above API to include a string message that KUnit can log, so it can at least identify the source of the failure (ubsan, kasan etc). That would alert anyone looking at KUnit output only that there's an external context to examine.

Good point! You're right: as it stands, there is no context within KUnit indicating the source of the failure, and the tool itself is responsible for logging. This patch is mainly focused on just failing test cases from outside KUnit.

I'm actually working on sending a follow-up patch soon that supports the expectation of failures from specific tools. It will introduce something similar to what you are suggesting, so that KUnit can properly distinguish between different failures and log them appropriately. Thanks for the suggestion!

...

diff --git a/include/kunit/test.h b/include/kunit/test.h index 3391f38389f8..81bf43a1abda 100644 --- a/include/kunit/test.h +++ b/include/kunit/test.h @@ -11,6 +11,7 @@

#include <kunit/assert.h> #include <kunit/try-catch.h> +#include <kunit/test-bug.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/slab.h> diff --git a/lib/kunit/test.c b/lib/kunit/test.c index dcc35fd30d95..d8189d827368 100644 --- a/lib/kunit/test.c +++ b/lib/kunit/test.c @@ -16,6 +16,12 @@ #include "string-stream.h" #include "try-catch-impl.h"

+void kunit_fail_current_test(void) +{

• if (current->kunit_test)
  

•         kunit_set_failure(current->kunit_test);
  

+}

static void kunit_print_tap_version(void) { static bool kunit_has_printed_tap_version; @@ -284,9 +290,7 @@ 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,

@@ -602,9 +606,7 @@ 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);

-- 2.28.0.163.g6104cc2f0b6-goog