Re: [PATCH v3 03/15] kunit: Add test cases for backtrace warning suppression

On Wed, 3 Apr 2024 at 21:19, Guenter Roeck linux@roeck-us.net wrote:

Add unit tests to verify that warning backtrace suppression works.

If backtrace suppression does _not_ work, the unit tests will likely trigger unsuppressed backtraces, which should actually help to get the affected architectures / platforms fixed.

Tested-by: Linux Kernel Functional Testing lkft@linaro.org Acked-by: Dan Carpenter dan.carpenter@linaro.org Reviewed-by: Kees Cook keescook@chromium.org Signed-off-by: Guenter Roeck linux@roeck-us.net

---

There's a typo in the Makefile, which stops this from being built at all. Otherwise, it seems good to me.

-- David

v2:

• Rebased to v6.9-rc1
• Added Tested-by:, Acked-by:, and Reviewed-by: tags
• Introduced KUNIT_SUPPRESS_BACKTRACE configuration option

v3:

• Rebased to v6.9-rc2

lib/kunit/Makefile | 7 +- lib/kunit/backtrace-suppression-test.c | 104 +++++++++++++++++++++++++ 2 files changed, 109 insertions(+), 2 deletions(-) create mode 100644 lib/kunit/backtrace-suppression-test.c

diff --git a/lib/kunit/Makefile b/lib/kunit/Makefile index 545b57c3be48..3eee1bd0ce5e 100644 --- a/lib/kunit/Makefile +++ b/lib/kunit/Makefile @@ -16,10 +16,13 @@ endif

# KUnit 'hooks' and bug handling are built-in even when KUnit is built # as a module. -obj-y += hooks.o \

•                                   bug.o
  

+obj-y += hooks.o +obj-$(CONFIG_KUNIT_SUPPRESS_BACKTRACE) += bug.o

obj-$(CONFIG_KUNIT_TEST) += kunit-test.o +ifeq ($(CCONFIG_KUNIT_SUPPRESS_BACKTRACE),y)

s/CCONFIG_/CONFIG_/ ?

+obj-$(CONFIG_KUNIT_TEST) += backtrace-suppression-test.o +endif

# string-stream-test compiles built-in only. ifeq ($(CONFIG_KUNIT_TEST),y) diff --git a/lib/kunit/backtrace-suppression-test.c b/lib/kunit/backtrace-suppression-test.c new file mode 100644 index 000000000000..47c619283802 --- /dev/null +++ b/lib/kunit/backtrace-suppression-test.c @@ -0,0 +1,104 @@ +// SPDX-License-Identifier: GPL-2.0 +/*

• • KUnit test for suppressing warning tracebacks
• • Copyright (C) 2024, Guenter Roeck
• • Author: Guenter Roeck linux@roeck-us.net
• */

+#include <kunit/test.h> +#include <linux/bug.h>

+static void backtrace_suppression_test_warn_direct(struct kunit *test) +{

•   DEFINE_SUPPRESSED_WARNING(backtrace_suppression_test_warn_direct);
  

•   START_SUPPRESSED_WARNING(backtrace_suppression_test_warn_direct);
  

•   WARN(1, "This backtrace should be suppressed");
  

•   END_SUPPRESSED_WARNING(backtrace_suppression_test_warn_direct);
  

•   KUNIT_EXPECT_EQ(test, SUPPRESSED_WARNING_COUNT(backtrace_suppression_test_warn_direct), 1);
  

+}

+static void trigger_backtrace_warn(void) +{

•   WARN(1, "This backtrace should be suppressed");
  

+}

+static void backtrace_suppression_test_warn_indirect(struct kunit *test) +{

•   DEFINE_SUPPRESSED_WARNING(trigger_backtrace_warn);
  

•   START_SUPPRESSED_WARNING(trigger_backtrace_warn);
  

•   trigger_backtrace_warn();
  

•   END_SUPPRESSED_WARNING(trigger_backtrace_warn);
  

•   KUNIT_EXPECT_EQ(test, SUPPRESSED_WARNING_COUNT(trigger_backtrace_warn), 1);
  

+}

+static void backtrace_suppression_test_warn_multi(struct kunit *test) +{

•   DEFINE_SUPPRESSED_WARNING(trigger_backtrace_warn);
  

•   DEFINE_SUPPRESSED_WARNING(backtrace_suppression_test_warn_multi);
  

•   START_SUPPRESSED_WARNING(backtrace_suppression_test_warn_multi);
  

•   START_SUPPRESSED_WARNING(trigger_backtrace_warn);
  

•   WARN(1, "This backtrace should be suppressed");
  

•   trigger_backtrace_warn();
  

•   END_SUPPRESSED_WARNING(trigger_backtrace_warn);
  

•   END_SUPPRESSED_WARNING(backtrace_suppression_test_warn_multi);
  

•   KUNIT_EXPECT_EQ(test, SUPPRESSED_WARNING_COUNT(backtrace_suppression_test_warn_multi), 1);
  

•   KUNIT_EXPECT_EQ(test, SUPPRESSED_WARNING_COUNT(trigger_backtrace_warn), 1);
  

+}

+static void backtrace_suppression_test_warn_on_direct(struct kunit *test) +{

•   DEFINE_SUPPRESSED_WARNING(backtrace_suppression_test_warn_on_direct);
  

•   if (!IS_ENABLED(CONFIG_DEBUG_BUGVERBOSE) && !IS_ENABLED(CONFIG_KALLSYMS))
  

•           kunit_skip(test, "requires CONFIG_DEBUG_BUGVERBOSE or CONFIG_KALLSYMS");
  

•   START_SUPPRESSED_WARNING(backtrace_suppression_test_warn_on_direct);
  

•   WARN_ON(1);
  

•   END_SUPPRESSED_WARNING(backtrace_suppression_test_warn_on_direct);
  

•   KUNIT_EXPECT_EQ(test,
  

•                   SUPPRESSED_WARNING_COUNT(backtrace_suppression_test_warn_on_direct), 1);
  

+}

+static void trigger_backtrace_warn_on(void) +{

•   WARN_ON(1);
  

+}

+static void backtrace_suppression_test_warn_on_indirect(struct kunit *test) +{

•   DEFINE_SUPPRESSED_WARNING(trigger_backtrace_warn_on);
  

•   if (!IS_ENABLED(CONFIG_DEBUG_BUGVERBOSE))
  

•           kunit_skip(test, "requires CONFIG_DEBUG_BUGVERBOSE");
  

•   START_SUPPRESSED_WARNING(trigger_backtrace_warn_on);
  

•   trigger_backtrace_warn_on();
  

•   END_SUPPRESSED_WARNING(trigger_backtrace_warn_on);
  

•   KUNIT_EXPECT_EQ(test, SUPPRESSED_WARNING_COUNT(trigger_backtrace_warn_on), 1);
  

+}

+static struct kunit_case backtrace_suppression_test_cases[] = {

•   KUNIT_CASE(backtrace_suppression_test_warn_direct),
  

•   KUNIT_CASE(backtrace_suppression_test_warn_indirect),
  

•   KUNIT_CASE(backtrace_suppression_test_warn_multi),
  

•   KUNIT_CASE(backtrace_suppression_test_warn_on_direct),
  

•   KUNIT_CASE(backtrace_suppression_test_warn_on_indirect),
  

•   {}
  

+};

+static struct kunit_suite backtrace_suppression_test_suite = {

•   .name = "backtrace-suppression-test",
  

•   .test_cases = backtrace_suppression_test_cases,
  

+}; +kunit_test_suites(&backtrace_suppression_test_suite);

+MODULE_LICENSE("GPL");

2.39.2