[PATCH v2 4/5] kasan, arm64: add arch_suppress_tag_checks_start/stop

[andrey.konovalov at linux.dev]

From: Andrey Konovalov <andreyknvl at google.com>

Add two new tagging-related routines arch_suppress_tag_checks_start/stop
that suppress MTE tag checking via the TCO register.

These rouines are used in the next patch.

Signed-off-by: Andrey Konovalov <andreyknvl at google.com>
---
 arch/arm64/include/asm/memory.h | 2 ++
 mm/kasan/kasan.h                | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
index faf42bff9a60..05e42bd3555f 100644
--- a/arch/arm64/include/asm/memory.h
+++ b/arch/arm64/include/asm/memory.h
@@ -264,6 +264,8 @@ static inline const void *__tag_set(const void *addr, u8 tag)
 #define arch_enable_tag_checks_sync()		mte_enable_kernel_sync()
 #define arch_enable_tag_checks_async()		mte_enable_kernel_async()
 #define arch_enable_tag_checks_asymm()		mte_enable_kernel_asymm()
+#define arch_suppress_tag_checks_start()	mte_enable_tco()
+#define arch_suppress_tag_checks_stop()		mte_disable_tco()
 #define arch_force_async_tag_fault()		mte_check_tfsr_exit()
 #define arch_get_random_tag()			mte_get_random_tag()
 #define arch_get_mem_tag(addr)			mte_get_mem_tag(addr)
diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index a1613f5d7608..f5e4f5f2ba20 100644
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -398,6 +398,8 @@ static inline const void *arch_kasan_set_tag(const void *addr, u8 tag)
 #define hw_enable_tag_checks_sync()		arch_enable_tag_checks_sync()
 #define hw_enable_tag_checks_async()		arch_enable_tag_checks_async()
 #define hw_enable_tag_checks_asymm()		arch_enable_tag_checks_asymm()
+#define hw_suppress_tag_checks_start()		arch_suppress_tag_checks_start()
+#define hw_suppress_tag_checks_stop()		arch_suppress_tag_checks_stop()
 #define hw_force_async_tag_fault()		arch_force_async_tag_fault()
 #define hw_get_random_tag()			arch_get_random_tag()
 #define hw_get_mem_tag(addr)			arch_get_mem_tag(addr)
-- 
2.25.1