From: Guenter Roeck linux@roeck-us.net
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 Signed-off-by: Alessandro Carminati acarmina@redhat.com --- lib/kunit/Makefile | 3 + lib/kunit/backtrace-suppression-test.c | 105 +++++++++++++++++++++++++ 2 files changed, 108 insertions(+) create mode 100644 lib/kunit/backtrace-suppression-test.c
diff --git a/lib/kunit/Makefile b/lib/kunit/Makefile index 3195e861d63c..05fb19d69709 100644 --- a/lib/kunit/Makefile +++ b/lib/kunit/Makefile @@ -23,6 +23,9 @@ obj-y += hooks.o \
obj-$(CONFIG_KUNIT_TEST) += kunit-test.o obj-$(CONFIG_KUNIT_TEST) += platform-test.o +ifeq ($(CONFIG_KUNIT_SUPPRESS_BACKTRACE),y) +obj-$(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..a3d5991b9b15 --- /dev/null +++ b/lib/kunit/backtrace-suppression-test.c @@ -0,0 +1,105 @@ +// 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) +{ + KUNIT_DEFINE_SUPPRESSED_WARNING(backtrace_suppression_test_warn_direct); + + KUNIT_START_SUPPRESSED_WARNING(backtrace_suppression_test_warn_direct); + WARN(1, "This backtrace should be suppressed"); + KUNIT_END_SUPPRESSED_WARNING(backtrace_suppression_test_warn_direct); + + KUNIT_EXPECT_EQ(test, KUNIT_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) +{ + KUNIT_DEFINE_SUPPRESSED_WARNING(trigger_backtrace_warn); + + KUNIT_START_SUPPRESSED_WARNING(trigger_backtrace_warn); + trigger_backtrace_warn(); + KUNIT_END_SUPPRESSED_WARNING(trigger_backtrace_warn); + + KUNIT_EXPECT_EQ(test, KUNIT_SUPPRESSED_WARNING_COUNT(trigger_backtrace_warn), 1); +} + +static void backtrace_suppression_test_warn_multi(struct kunit *test) +{ + KUNIT_DEFINE_SUPPRESSED_WARNING(trigger_backtrace_warn); + KUNIT_DEFINE_SUPPRESSED_WARNING(backtrace_suppression_test_warn_multi); + + KUNIT_START_SUPPRESSED_WARNING(backtrace_suppression_test_warn_multi); + KUNIT_START_SUPPRESSED_WARNING(trigger_backtrace_warn); + WARN(1, "This backtrace should be suppressed"); + trigger_backtrace_warn(); + KUNIT_END_SUPPRESSED_WARNING(trigger_backtrace_warn); + KUNIT_END_SUPPRESSED_WARNING(backtrace_suppression_test_warn_multi); + + KUNIT_EXPECT_EQ(test, KUNIT_SUPPRESSED_WARNING_COUNT(backtrace_suppression_test_warn_multi), 1); + KUNIT_EXPECT_EQ(test, KUNIT_SUPPRESSED_WARNING_COUNT(trigger_backtrace_warn), 1); +} + +static void backtrace_suppression_test_warn_on_direct(struct kunit *test) +{ + KUNIT_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"); + + KUNIT_START_SUPPRESSED_WARNING(backtrace_suppression_test_warn_on_direct); + WARN_ON(1); + KUNIT_END_SUPPRESSED_WARNING(backtrace_suppression_test_warn_on_direct); + + KUNIT_EXPECT_EQ(test, + KUNIT_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) +{ + KUNIT_DEFINE_SUPPRESSED_WARNING(trigger_backtrace_warn_on); + + if (!IS_ENABLED(CONFIG_DEBUG_BUGVERBOSE)) + kunit_skip(test, "requires CONFIG_DEBUG_BUGVERBOSE"); + + KUNIT_START_SUPPRESSED_WARNING(trigger_backtrace_warn_on); + trigger_backtrace_warn_on(); + KUNIT_END_SUPPRESSED_WARNING(trigger_backtrace_warn_on); + + KUNIT_EXPECT_EQ(test, KUNIT_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"); +MODULE_DESCRIPTION("KUnit test to verify warning backtrace suppression");