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 --- 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 ($(CCONFIG_KUNIT_SUPPRESS_BACKTRACE),y) +obj-$(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");