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From:   andrey.konovalov@linux.dev
To:     Marco Elver <elver@google.com>,
        Catalin Marinas <catalin.marinas@arm.com>
Cc:     Andrey Konovalov <andreyknvl@gmail.com>,
        Alexander Potapenko <glider@google.com>,
        Dmitry Vyukov <dvyukov@google.com>,
        Andrey Ryabinin <ryabinin.a.a@gmail.com>,
        kasan-dev@googlegroups.com,
        Vincenzo Frascino <vincenzo.frascino@arm.com>,
        Will Deacon <will@kernel.org>,
        linux-arm-kernel@lists.infradead.org,
        Peter Collingbourne <pcc@google.com>,
        Evgenii Stepanov <eugenis@google.com>,
        Andrew Morton <akpm@linux-foundation.org>, linux-mm@kvack.org,
        Weizhao Ouyang <ouyangweizhao@zeku.com>,
        linux-kernel@vger.kernel.org,
        Andrey Konovalov <andreyknvl@google.com>
Subject: [PATCH v2 4/5] kasan, arm64: add arch_suppress_tag_checks_start/stop
Date:   Wed, 29 Mar 2023 20:37:47 +0200
Message-Id: <7ad5e5a9db79e3aba08d8f43aca24350b04080f6.1680114854.git.andreyknvl@google.com>
In-Reply-To: <dc432429a6d87f197eefb179f26012c6c1ec6cd9.1680114854.git.andreyknvl@google.com>
References: <dc432429a6d87f197eefb179f26012c6c1ec6cd9.1680114854.git.andreyknvl@google.com>
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From: Andrey Konovalov <andreyknvl@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@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