[PATCH v4 14/17] rv: Add KUnit tests for some LTL monitors

From: Gabriele Monaco

Date: Fri Jul 17 2026 - 11:52:50 EST


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.

Reviewed-by: Nam Cao <namcao@xxxxxxxxxxxxx>
Signed-off-by: Gabriele Monaco <gmonaco@xxxxxxxxxx>
---
include/rv/ltl_monitor.h | 8 +++
.../trace/rv/monitors/pagefault/pagefault.c | 12 ++++
.../rv/monitors/pagefault/pagefault_kunit.c | 34 +++++++++++
.../rv/monitors/pagefault/pagefault_kunit.h | 24 ++++++++
kernel/trace/rv/monitors/sleep/sleep.c | 19 ++++++
kernel/trace/rv/monitors/sleep/sleep_kunit.c | 58 +++++++++++++++++++
kernel/trace/rv/monitors/sleep/sleep_kunit.h | 30 ++++++++++
kernel/trace/rv/rv_monitors_test.c | 4 ++
8 files changed, 189 insertions(+)
create mode 100644 kernel/trace/rv/monitors/pagefault/pagefault_kunit.c
create mode 100644 kernel/trace/rv/monitors/pagefault/pagefault_kunit.h
create mode 100644 kernel/trace/rv/monitors/sleep/sleep_kunit.c
create mode 100644 kernel/trace/rv/monitors/sleep/sleep_kunit.h

diff --git a/include/rv/ltl_monitor.h b/include/rv/ltl_monitor.h
index d7dc01db4dd9..e9fd8265a3da 100644
--- a/include/rv/ltl_monitor.h
+++ b/include/rv/ltl_monitor.h
@@ -172,3 +172,11 @@ static void __maybe_unused ltl_atom_pulse(struct task_struct *task, enum ltl_ato
ltl_atom_set(mon, atom, !value);
ltl_validate(task, mon);
}
+
+#if IS_ENABLED(CONFIG_RV_MONITORS_KUNIT_TEST)
+#define RV_MON_OPS_INIT() { \
+ .rv_this = &rv_this, \
+ .is_per_task = true, \
+ .task_slot = &ltl_monitor_slot, \
+}
+#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 e52500fd2de0..c599fc19fc88 100644
--- a/kernel/trace/rv/monitors/pagefault/pagefault.c
+++ b/kernel/trace/rv/monitors/pagefault/pagefault.c
@@ -86,3 +86,15 @@ module_exit(unregister_pagefault);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Nam Cao <namcao@xxxxxxxxxxxxx>");
MODULE_DESCRIPTION("pagefault: Monitor that RT tasks do not raise page faults");
+
+#if IS_ENABLED(CONFIG_RV_MONITORS_KUNIT_TEST)
+#include <kunit/visibility.h>
+#include "pagefault_kunit.h"
+
+const struct rv_pagefault_ops rv_pagefault_ops = {
+ .mon = RV_MON_OPS_INIT(),
+ .handle_page_fault = handle_page_fault,
+ .handle_task_newtask = handle_task_newtask,
+};
+EXPORT_SYMBOL_IF_KUNIT(rv_pagefault_ops);
+#endif
diff --git a/kernel/trace/rv/monitors/pagefault/pagefault_kunit.c b/kernel/trace/rv/monitors/pagefault/pagefault_kunit.c
new file mode 100644
index 000000000000..98ac7d4ec014
--- /dev/null
+++ b/kernel/trace/rv/monitors/pagefault/pagefault_kunit.c
@@ -0,0 +1,34 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/kernel.h>
+#include <linux/rv.h>
+#include <rv/kunit.h>
+#include <linux/sched/deadline.h>
+#include <linux/sched/rt.h>
+#include "pagefault_kunit.h"
+
+#if IS_REACHABLE(CONFIG_RV_MON_PAGEFAULT)
+
+static void rv_test_pagefault(struct kunit *test)
+{
+ struct task_struct *target = rv_kunit_alloc_mock_task(test);
+ struct rv_kunit_ctx *ctx = test->priv;
+
+ prepare_test(test, &rv_pagefault_ops.mon);
+
+ /* Initial pagefault when non-RT to start the model without failure */
+ target->policy = SCHED_NORMAL;
+ target->prio = MAX_RT_PRIO + 20;
+ rv_pagefault_ops.handle_task_newtask(NULL, target, 0);
+ rv_mock_current(ctx, target);
+ rv_pagefault_ops.handle_page_fault(NULL, 0, NULL, 0);
+
+ /* RT task has a page fault */
+ target->policy = SCHED_FIFO;
+ target->prio = MAX_RT_PRIO - 1;
+ RV_KUNIT_EXPECT_REACTION_HERE(test, ctx)
+ rv_pagefault_ops.handle_page_fault(NULL, 0, NULL, 0);
+}
+
+#else
+#define rv_test_pagefault rv_test_stub
+#endif
diff --git a/kernel/trace/rv/monitors/pagefault/pagefault_kunit.h b/kernel/trace/rv/monitors/pagefault/pagefault_kunit.h
new file mode 100644
index 000000000000..2f9652f08b3f
--- /dev/null
+++ b/kernel/trace/rv/monitors/pagefault/pagefault_kunit.h
@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Automatically generated by rvgen kunit.
+ * May need manual intervention for function prototypes that couldn't be
+ * found (e.g. are in another file) or variables to be exported.
+ */
+
+#ifndef __PAGEFAULT_KUNIT_H
+#define __PAGEFAULT_KUNIT_H
+
+#if IS_ENABLED(CONFIG_RV_MONITORS_KUNIT_TEST)
+
+#include <linux/rv.h>
+#include <rv/kunit.h>
+
+extern const struct rv_pagefault_ops {
+ struct rv_kunit_mon mon;
+ void (*handle_page_fault)(void *data, unsigned long address, struct pt_regs *regs,
+ unsigned long error_code);
+ void (*handle_task_newtask)(void *data, struct task_struct *task, u64 flags);
+} rv_pagefault_ops;
+#endif
+
+#endif /* __PAGEFAULT_KUNIT_H */
diff --git a/kernel/trace/rv/monitors/sleep/sleep.c b/kernel/trace/rv/monitors/sleep/sleep.c
index 71d2005ce520..f84a61a21825 100644
--- a/kernel/trace/rv/monitors/sleep/sleep.c
+++ b/kernel/trace/rv/monitors/sleep/sleep.c
@@ -247,3 +247,22 @@ module_exit(unregister_sleep);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Nam Cao <namcao@xxxxxxxxxxxxx>");
MODULE_DESCRIPTION("sleep: Monitor that RT tasks do not undesirably sleep");
+
+#if IS_ENABLED(CONFIG_RV_MONITORS_KUNIT_TEST)
+#include <kunit/visibility.h>
+#include "sleep_kunit.h"
+
+const struct rv_sleep_ops rv_sleep_ops = {
+ .mon = RV_MON_OPS_INIT(),
+ .handle_sched_waking = handle_sched_waking,
+ .handle_sched_wakeup = handle_sched_wakeup,
+ .handle_sched_set_state = handle_sched_set_state,
+ .handle_contention_begin = handle_contention_begin,
+ .handle_contention_end = handle_contention_end,
+ .handle_kthread_stop = handle_kthread_stop,
+ .handle_sys_enter = handle_sys_enter,
+ .handle_sys_exit = handle_sys_exit,
+ .handle_task_newtask = handle_task_newtask,
+};
+EXPORT_SYMBOL_IF_KUNIT(rv_sleep_ops);
+#endif
diff --git a/kernel/trace/rv/monitors/sleep/sleep_kunit.c b/kernel/trace/rv/monitors/sleep/sleep_kunit.c
new file mode 100644
index 000000000000..9bbe3822a76d
--- /dev/null
+++ b/kernel/trace/rv/monitors/sleep/sleep_kunit.c
@@ -0,0 +1,58 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/kernel.h>
+#include <linux/rv.h>
+#include <rv/kunit.h>
+#include <trace/events/syscalls.h>
+#include <trace/events/sched.h>
+#include <uapi/linux/futex.h>
+#include "sleep_kunit.h"
+
+#if IS_REACHABLE(CONFIG_RV_MON_SLEEP)
+
+static void rv_test_sleep(struct kunit *test)
+{
+ struct task_struct *target = rv_kunit_alloc_mock_task(test);
+ struct task_struct *other = rv_kunit_alloc_mock_task(test);
+ struct rv_kunit_ctx *ctx = test->priv;
+ unsigned long args[6] = {0};
+ struct pt_regs regs = {0};
+
+ prepare_test(test, &rv_sleep_ops.mon);
+ target->policy = SCHED_FIFO;
+ target->prio = MAX_RT_PRIO - 2;
+ other->policy = SCHED_FIFO;
+ other->prio = MAX_RT_PRIO - 1;
+ rv_sleep_ops.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
+ rv_sleep_ops.handle_sys_enter(NULL, &regs, __NR_clock_nanosleep);
+#elif defined(__NR_clock_nanosleep_time64)
+ rv_sleep_ops.handle_sys_enter(NULL, &regs, __NR_clock_nanosleep_time64);
+#endif
+ RV_KUNIT_EXPECT_REACTION_HERE(test, ctx)
+ rv_sleep_ops.handle_sched_set_state(NULL, target, TASK_INTERRUPTIBLE);
+ rv_sleep_ops.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
+ rv_sleep_ops.handle_sys_enter(NULL, &regs, __NR_futex);
+#elif defined(__NR_futex_time64)
+ rv_sleep_ops.handle_sys_enter(NULL, &regs, __NR_futex_time64);
+#endif
+ rv_sleep_ops.handle_sched_set_state(NULL, target, TASK_INTERRUPTIBLE);
+ rv_mock_current(ctx, other);
+ rv_sleep_ops.handle_sched_waking(NULL, target);
+ RV_KUNIT_EXPECT_REACTION_HERE(test, ctx)
+ rv_sleep_ops.handle_sched_wakeup(NULL, target);
+}
+
+#else
+#define rv_test_sleep rv_test_stub
+#endif
diff --git a/kernel/trace/rv/monitors/sleep/sleep_kunit.h b/kernel/trace/rv/monitors/sleep/sleep_kunit.h
new file mode 100644
index 000000000000..2cd61e31a6af
--- /dev/null
+++ b/kernel/trace/rv/monitors/sleep/sleep_kunit.h
@@ -0,0 +1,30 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Automatically generated by rvgen kunit.
+ * May need manual intervention for function prototypes that couldn't be
+ * found (e.g. are in another file) or variables to be exported.
+ */
+
+#ifndef __SLEEP_KUNIT_H
+#define __SLEEP_KUNIT_H
+
+#if IS_ENABLED(CONFIG_RV_MONITORS_KUNIT_TEST)
+
+#include <linux/rv.h>
+#include <rv/kunit.h>
+
+extern const struct rv_sleep_ops {
+ struct rv_kunit_mon mon;
+ void (*handle_sched_waking)(void *data, struct task_struct *task);
+ void (*handle_sched_wakeup)(void *data, struct task_struct *task);
+ void (*handle_sched_set_state)(void *data, struct task_struct *task, int state);
+ void (*handle_contention_begin)(void *data, void *lock, unsigned int flags);
+ void (*handle_contention_end)(void *data, void *lock, int ret);
+ void (*handle_kthread_stop)(void *data, struct task_struct *task);
+ void (*handle_sys_enter)(void *data, struct pt_regs *regs, long id);
+ void (*handle_sys_exit)(void *data, struct pt_regs *regs, long ret);
+ void (*handle_task_newtask)(void *data, struct task_struct *task, u64 flags);
+} rv_sleep_ops;
+#endif
+
+#endif /* __SLEEP_KUNIT_H */
diff --git a/kernel/trace/rv/rv_monitors_test.c b/kernel/trace/rv/rv_monitors_test.c
index 2108973383b2..c565bca2b4ae 100644
--- a/kernel/trace/rv/rv_monitors_test.c
+++ b/kernel/trace/rv/rv_monitors_test.c
@@ -157,6 +157,8 @@ static void rv_test_dummy(struct kunit *test)
#include "monitors/sts/sts_kunit.c"
#include "monitors/opid/opid_kunit.c"
#include "monitors/nomiss/nomiss_kunit.c"
+#include "monitors/pagefault/pagefault_kunit.c"
+#include "monitors/sleep/sleep_kunit.c"

static struct kunit_case rv_mon_test_cases[] = {
KUNIT_CASE(rv_test_dummy),
@@ -165,6 +167,8 @@ 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),
{}
};

--
2.55.0