[PATCH v5 6/6] kasan: Forbid kunit tests when async mode is enabled

[Vincenzo Frascino]

Architectures supported by KASAN_HW_TAGS can provide a sync or async
mode of execution. KASAN KUNIT tests can be executed only when sync
mode is enabled.

Forbid the execution of the KASAN KUNIT tests when async mode is
enabled.

Cc: Dmitry Vyukov <dvyukov at google.com>
Cc: Andrey Ryabinin <aryabinin at virtuozzo.com>
Cc: Alexander Potapenko <glider at google.com>
Cc: Andrey Konovalov <andreyknvl at google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino at arm.com>
---
 lib/test_kasan.c | 5 +++++
 mm/kasan/kasan.h | 2 ++
 2 files changed, 7 insertions(+)

diff --git a/lib/test_kasan.c b/lib/test_kasan.c
index 7285dcf9fcc1..1306f707b4fe 100644
--- a/lib/test_kasan.c
+++ b/lib/test_kasan.c
@@ -52,6 +52,11 @@ static int kasan_test_init(struct kunit *test)
 		return -1;
 	}
 
+	if (!hw_is_mode_sync()) {
+		kunit_err(test, "can't run KASAN tests in async mode");
+		return -1;
+	}
+
 	multishot = kasan_save_enable_multi_shot();
 	hw_set_tagging_report_once(false);
 	return 0;
diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index 3923d9744105..3464113042ab 100644
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -296,6 +296,7 @@ static inline const void *arch_kasan_set_tag(const void *addr, u8 tag)
 
 #define hw_enable_tagging_sync()		arch_enable_tagging_sync()
 #define hw_enable_tagging_async()		arch_enable_tagging_async()
+#define hw_is_mode_sync()			arch_is_mode_sync()
 #define hw_init_tags(max_tag)			arch_init_tags(max_tag)
 #define hw_set_tagging_report_once(state)	arch_set_tagging_report_once(state)
 #define hw_get_random_tag()			arch_get_random_tag()
@@ -306,6 +307,7 @@ static inline const void *arch_kasan_set_tag(const void *addr, u8 tag)
 
 #define hw_enable_tagging_sync()
 #define hw_enable_tagging_async()
+#define hw_is_mode_sync()
 #define hw_set_tagging_report_once(state)
 
 #endif /* CONFIG_KASAN_HW_TAGS */
-- 
2.30.0