[RFC PATCH 12/12] 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                      | 31 ++++++++++++++
 .../trace/rv/monitors/pagefault/pagefault.c   | 24 +++++++++++
 kernel/trace/rv/monitors/sleep/sleep.c        | 42 +++++++++++++++++++
 kernel/trace/rv/rv_monitors_test.c            |  2 +
 kernel/trace/rv/rv_monitors_test.h            | 18 ++++++++
 5 files changed, 117 insertions(+)

diff --git a/include/rv/ltl_monitor.h b/include/rv/ltl_monitor.h
index 0f2c3820b9b8..49e680b769f6 100644
--- a/include/rv/ltl_monitor.h
+++ b/include/rv/ltl_monitor.h
@@ -172,3 +172,34 @@ 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
+#include <kunit/test.h>
+
+/*
+ * rv_prepare_test - Disable the monitor for a kunit test
+ */
+static inline void ltl_teardown_test(void *arg)
+{
+	struct rv_monitor *rv_this = arg;
+
+	rv_this->enabled = 0;
+	ltl_monitor_destroy();
+}
+
+/*
+ * rv_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..1849d7b81545 100644
--- a/kernel/trace/rv/monitors/pagefault/pagefault.c
+++ b/kernel/trace/rv/monitors/pagefault/pagefault.c
@@ -86,3 +86,27 @@ 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
+#include "rv_monitors_test.h"
+
+void rv_test_pagefault(struct kunit *test)
+{
+	static 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);
+	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);
+	handle_page_fault(NULL, 0, NULL, 0);
+	RV_KUNIT_EXPECT_REACTION(test, ctx);
+}
+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 7c16967add70..9388ffb55aa9 100644
--- a/kernel/trace/rv/monitors/sleep/sleep.c
+++ b/kernel/trace/rv/monitors/sleep/sleep.c
@@ -247,3 +247,45 @@ 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
+#include "rv_monitors_test.h"
+
+void rv_test_sleep(struct kunit *test)
+{
+	static struct task_struct *target, *other;
+	struct rv_kunit_ctx *ctx = test->priv;
+	unsigned long args[6];
+	struct pt_regs regs;
+
+	ltl_prepare_test(test, &rv_sleep);
+	target = kunit_kzalloc(test, sizeof(struct task_struct), GFP_KERNEL);
+	target->policy = SCHED_FIFO;
+	target->prio = MAX_RT_PRIO - 2;
+	other = kunit_kzalloc(test, sizeof(struct task_struct), GFP_KERNEL);
+	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);
+	handle_sys_enter(NULL, &regs, __NR_clock_nanosleep);
+	handle_sys_exit(NULL, NULL, 0);
+	handle_sched_set_state(NULL, target, TASK_INTERRUPTIBLE);
+	RV_KUNIT_EXPECT_REACTION(test, ctx);
+
+	/* RT task woken up by lower priority task */
+	args[1] = FUTEX_WAIT;
+	syscall_set_arguments(target, &regs, args);
+	rv_mock_current(ctx, target);
+	handle_sys_enter(NULL, &regs, __NR_futex);
+	handle_sched_set_state(NULL, target, TASK_INTERRUPTIBLE);
+	rv_mock_current(ctx, other);
+	handle_sched_waking(NULL, target);
+	handle_sched_wakeup(NULL, target);
+	RV_KUNIT_EXPECT_REACTION(test, ctx);
+}
+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 a57a40932d34..78af77310d56 100644
--- a/kernel/trace/rv/rv_monitors_test.c
+++ b/kernel/trace/rv/rv_monitors_test.c
@@ -81,6 +81,8 @@ static struct kunit_case rv_trigger_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),
 	{}
 };
 
diff --git a/kernel/trace/rv/rv_monitors_test.h b/kernel/trace/rv/rv_monitors_test.h
index 3015943c5dda..c745edc85991 100644
--- a/kernel/trace/rv/rv_monitors_test.h
+++ b/kernel/trace/rv/rv_monitors_test.h
@@ -70,3 +70,21 @@ static inline void rv_test_nomiss(struct kunit *test)
 	kunit_skip(test, "Monitor not enabled\n");
 }
 #endif
+
+#ifdef CONFIG_RV_MON_PAGEFAULT
+extern void rv_test_pagefault(struct kunit *test);
+#else
+static inline void rv_test_pagefault(struct kunit *test)
+{
+	kunit_skip(test, "Monitor not enabled\n");
+}
+#endif
+
+#ifdef CONFIG_RV_MON_SLEEP
+extern void rv_test_sleep(struct kunit *test);
+#else
+static inline void rv_test_sleep(struct kunit *test)
+{
+	kunit_skip(test, "Monitor not enabled\n");
+}
+#endif
-- 
2.53.0