[PATCH v2 14/14] rv: Add KUnit tests for some LTL monitors

[Gabriele Monaco <gmonaco@redhat.com>]

Validate the functionality of LTL monitors by injecting events in a
controlled environment (KUnit) and expecting reactions, just like it is
done in DA monitors.

Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
---
 include/rv/ltl_monitor.h                      | 37 +++++++++++++
 .../trace/rv/monitors/pagefault/pagefault.c   | 25 +++++++++
 kernel/trace/rv/monitors/sleep/sleep.c        | 52 +++++++++++++++++++
 kernel/trace/rv/rv_monitors_test.c            |  4 ++
 4 files changed, 118 insertions(+)

diff --git a/include/rv/ltl_monitor.h b/include/rv/ltl_monitor.h
index 35bc870d808a..75c9c6230dae 100644
--- a/include/rv/ltl_monitor.h
+++ b/include/rv/ltl_monitor.h
@@ -172,3 +172,40 @@ static void __maybe_unused ltl_atom_pulse(struct task_struct *task, enum ltl_ato
 	ltl_atom_set(mon, atom, !value);
 	ltl_validate(task, mon);
 }
+
+#ifdef CONFIG_RV_MONITORS_KUNIT_TEST
+
+/*
+ * ltl_teardown_test - Disable the monitor for a kunit test
+ */
+static inline void ltl_teardown_test(void *arg)
+{
+	struct rv_monitor *rv_this = arg;
+	struct kunit *test = kunit_get_current_test();
+
+	if (test) {
+		struct rv_kunit_ctx *ctx = test->priv;
+
+		RV_KUNIT_EXPECT_NO_REACTION(test, ctx);
+	}
+
+	rv_this->enabled = 0;
+	ltl_monitor_destroy();
+}
+
+/*
+ * ltl_prepare_test - Enable the monitor for a kunit test
+ *
+ * Do the bare minimum to set up the monitor, make sure it is not active and
+ * real tracepoint handlers are NOT attached.
+ */
+static inline void ltl_prepare_test(struct kunit *test, struct rv_monitor *rv_this)
+{
+	KUNIT_ASSERT_FALSE(test, rv_this->enabled);
+	ltl_monitor_init();
+	rv_this->enabled = 1;
+
+	KUNIT_ASSERT_EQ(test, 0,
+			kunit_add_action_or_reset(test, ltl_teardown_test, rv_this));
+}
+#endif /* CONFIG_RV_MONITORS_KUNIT_TEST */
diff --git a/kernel/trace/rv/monitors/pagefault/pagefault.c b/kernel/trace/rv/monitors/pagefault/pagefault.c
index 56abe5079676..28c3382eabb0 100644
--- a/kernel/trace/rv/monitors/pagefault/pagefault.c
+++ b/kernel/trace/rv/monitors/pagefault/pagefault.c
@@ -86,3 +86,28 @@ module_exit(unregister_pagefault);
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Nam Cao <namcao@linutronix.de>");
 MODULE_DESCRIPTION("pagefault: Monitor that RT tasks do not raise page faults");
+
+#ifdef CONFIG_RV_MONITORS_KUNIT_TEST
+void rv_test_pagefault(struct kunit *test);
+
+void rv_test_pagefault(struct kunit *test)
+{
+	struct task_struct *target;
+	struct rv_kunit_ctx *ctx = test->priv;
+
+	ltl_prepare_test(test, &rv_pagefault);
+	target = kunit_kzalloc(test, sizeof(struct task_struct), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, target);
+	target->policy = SCHED_FIFO;
+	target->prio = MAX_RT_PRIO - 1;
+	handle_task_newtask(NULL, target, 0);
+
+	ltl_attempt_start(target, ltl_get_monitor(target));
+
+	/* RT task has a page fault */
+	rv_mock_current(ctx, target);
+	RV_KUNIT_EXPECT_REACTION_HERE(test, ctx)
+		handle_page_fault(NULL, 0, NULL, 0);
+}
+EXPORT_SYMBOL_GPL(rv_test_pagefault);
+#endif
diff --git a/kernel/trace/rv/monitors/sleep/sleep.c b/kernel/trace/rv/monitors/sleep/sleep.c
index 8b44161d47d3..76e70e2db992 100644
--- a/kernel/trace/rv/monitors/sleep/sleep.c
+++ b/kernel/trace/rv/monitors/sleep/sleep.c
@@ -247,3 +247,55 @@ module_exit(unregister_sleep);
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Nam Cao <namcao@linutronix.de>");
 MODULE_DESCRIPTION("sleep: Monitor that RT tasks do not undesirably sleep");
+
+#ifdef CONFIG_RV_MONITORS_KUNIT_TEST
+void rv_test_sleep(struct kunit *test);
+
+void rv_test_sleep(struct kunit *test)
+{
+	struct task_struct *target, *other;
+	struct rv_kunit_ctx *ctx = test->priv;
+	unsigned long args[6] = {0};
+	struct pt_regs regs;
+
+	ltl_prepare_test(test, &rv_sleep);
+	target = kunit_kzalloc(test, sizeof(struct task_struct), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, target);
+	target->policy = SCHED_FIFO;
+	target->prio = MAX_RT_PRIO - 2;
+	other = kunit_kzalloc(test, sizeof(struct task_struct), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, other);
+	other->policy = SCHED_FIFO;
+	other->prio = MAX_RT_PRIO - 1;
+	handle_task_newtask(NULL, target, 0);
+
+	/* RT task sleeps on a non RT-friendly nanosleep */
+	rv_mock_current(ctx, target);
+	args[0] = CLOCK_REALTIME;
+	syscall_set_arguments(target, &regs, args);
+#ifdef __NR_clock_nanosleep
+	handle_sys_enter(NULL, &regs, __NR_clock_nanosleep);
+#elif defined(__NR_clock_nanosleep_time64)
+	handle_sys_enter(NULL, &regs, __NR_clock_nanosleep_time64);
+#endif
+	RV_KUNIT_EXPECT_REACTION_HERE(test, ctx)
+		handle_sched_set_state(NULL, target, TASK_INTERRUPTIBLE);
+	handle_sys_exit(NULL, NULL, 0);
+
+	/* RT task woken up by lower priority task */
+	args[1] = FUTEX_WAIT;
+	syscall_set_arguments(target, &regs, args);
+	rv_mock_current(ctx, target);
+#ifdef __NR_futex
+	handle_sys_enter(NULL, &regs, __NR_futex);
+#elif defined(__NR_futex_time64)
+	handle_sys_enter(NULL, &regs, __NR_futex_time64);
+#endif
+	handle_sched_set_state(NULL, target, TASK_INTERRUPTIBLE);
+	rv_mock_current(ctx, other);
+	handle_sched_waking(NULL, target);
+	RV_KUNIT_EXPECT_REACTION_HERE(test, ctx)
+		handle_sched_wakeup(NULL, target);
+}
+EXPORT_SYMBOL_GPL(rv_test_sleep);
+#endif
diff --git a/kernel/trace/rv/rv_monitors_test.c b/kernel/trace/rv/rv_monitors_test.c
index 01cbee9ac6c0..d3e3aa1ac4ec 100644
--- a/kernel/trace/rv/rv_monitors_test.c
+++ b/kernel/trace/rv/rv_monitors_test.c
@@ -137,6 +137,8 @@ DECLARE_RV_TEST(rv_test_sssw);
 DECLARE_RV_TEST(rv_test_sts);
 DECLARE_RV_TEST(rv_test_opid);
 DECLARE_RV_TEST(rv_test_nomiss);
+DECLARE_RV_TEST(rv_test_pagefault);
+DECLARE_RV_TEST(rv_test_sleep);
 
 static struct kunit_case rv_mon_test_cases[] = {
 	KUNIT_CASE(rv_test_sco),
@@ -144,6 +146,8 @@ static struct kunit_case rv_mon_test_cases[] = {
 	KUNIT_CASE(rv_test_sts),
 	KUNIT_CASE(rv_test_opid),
 	KUNIT_CASE(rv_test_nomiss),
+	KUNIT_CASE(rv_test_pagefault),
+	KUNIT_CASE(rv_test_sleep),
 	{}
 };
 
-- 
2.54.0