On Wed, Aug 12, 2020 at 07:33:32PM +0000, Uriel Guajardo wrote:
> KUnit will fail tests upon observing a lockdep failure. Because lockdep
> turns itself off after its first failure, only fail the first test and
> warn users to not expect any future failures from lockdep.
>
> Similar to lib/locking-selftest [1], we check if the status of
> debug_locks has changed after the execution of a test case. However, we
> do not reset lockdep afterwards.
>
> Like the locking selftests, we also fix possible preemption count
> corruption from lock bugs.
> +static void kunit_check_locking_bugs(struct kunit *test,
> + unsigned long saved_preempt_count,
> + bool saved_debug_locks)
> +{
> + preempt_count_set(saved_preempt_count);
> +#ifdef CONFIG_TRACE_IRQFLAGS
> + if (softirq_count())
> + current->softirqs_enabled = 0;
> + else
> + current->softirqs_enabled = 1;
> +#endif
Urgh, don't silently change these... if they're off that's a hard fail.
if (DEBUG_LOCKS_WARN_ON(preempt_count() != saved_preempt_count))
preempt_count_set(saved_preempt_count);
And by using DEBUG_LOCKS_WARN_ON() it will kill IRQ tracing and trigger
the below fail.
> + if (saved_debug_locks && !debug_locks) {
> + kunit_set_failure(test);
> + kunit_warn(test, "Dynamic analysis tool failure from LOCKDEP.");
> + kunit_warn(test, "Further tests will have LOCKDEP disabled.");
> + }
> +}
