Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Sender: "andreyknvl via sendgmr" <andreyknvl@andreyknvl3.muc.corp.google.com>
Date:   Fri, 13 Nov 2020 23:16:01 +0100
In-Reply-To: <cover.1605305705.git.andreyknvl@google.com>
Message-Id: <69ccb75b7fc7ec766e05ac62335e14e5bf0c50e2.1605305705.git.andreyknvl@google.com>
Mime-Version: 1.0
References: <cover.1605305705.git.andreyknvl@google.com>
Subject: [PATCH mm v10 33/42] arm64: kasan: Add arch layer for memory tagging helpers
From:   Andrey Konovalov <andreyknvl@google.com>
To:     Andrew Morton <akpm@linux-foundation.org>
Cc:     Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will.deacon@arm.com>,
        Vincenzo Frascino <vincenzo.frascino@arm.com>,
        Dmitry Vyukov <dvyukov@google.com>,
        Andrey Ryabinin <aryabinin@virtuozzo.com>,
        Alexander Potapenko <glider@google.com>,
        Marco Elver <elver@google.com>,
        Evgenii Stepanov <eugenis@google.com>,
        Branislav Rankov <Branislav.Rankov@arm.com>,
        Kevin Brodsky <kevin.brodsky@arm.com>,
        kasan-dev@googlegroups.com, linux-arm-kernel@lists.infradead.org,
        linux-mm@kvack.org, linux-kernel@vger.kernel.org,
        Andrey Konovalov <andreyknvl@google.com>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

This patch add a set of arch_*() memory tagging helpers currently only
defined for arm64 when hardware tag-based KASAN is enabled. These helpers
will be used by KASAN runtime to implement the hardware tag-based mode.

The arch-level indirection level is introduced to simplify adding hardware
tag-based KASAN support for other architectures in the future by defining
the appropriate arch_*() macros.

Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Co-developed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
---
Change-Id: I42b0795a28067872f8308e00c6f0195bca435c2a
---
 arch/arm64/include/asm/memory.h |  9 +++++++++
 mm/kasan/kasan.h                | 26 ++++++++++++++++++++++++++
 2 files changed, 35 insertions(+)

diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
index 556cb2d62b5b..3bc08e6cf82e 100644
--- a/arch/arm64/include/asm/memory.h
+++ b/arch/arm64/include/asm/memory.h
@@ -230,6 +230,15 @@ static inline const void *__tag_set(const void *addr, u8 tag)
 	return (const void *)(__addr | __tag_shifted(tag));
 }
 
+#ifdef CONFIG_KASAN_HW_TAGS
+#define arch_enable_tagging()			mte_enable_kernel()
+#define arch_init_tags(max_tag)			mte_init_tags(max_tag)
+#define arch_get_random_tag()			mte_get_random_tag()
+#define arch_get_mem_tag(addr)			mte_get_mem_tag(addr)
+#define arch_set_mem_tag_range(addr, size, tag)	\
+			mte_set_mem_tag_range((addr), (size), (tag))
+#endif /* CONFIG_KASAN_HW_TAGS */
+
 /*
  * Physical vs virtual RAM address space conversion.  These are
  * private definitions which should NOT be used outside memory.h
diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index 3b349a6e799d..bc4f28156157 100644
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -243,6 +243,32 @@ static inline const void *arch_kasan_set_tag(const void *addr, u8 tag)
 #define reset_tag(addr)		((void *)arch_kasan_reset_tag(addr))
 #define get_tag(addr)		arch_kasan_get_tag(addr)
 
+#ifdef CONFIG_KASAN_HW_TAGS
+
+#ifndef arch_enable_tagging
+#define arch_enable_tagging()
+#endif
+#ifndef arch_init_tags
+#define arch_init_tags(max_tag)
+#endif
+#ifndef arch_get_random_tag
+#define arch_get_random_tag()	(0xFF)
+#endif
+#ifndef arch_get_mem_tag
+#define arch_get_mem_tag(addr)	(0xFF)
+#endif
+#ifndef arch_set_mem_tag_range
+#define arch_set_mem_tag_range(addr, size, tag) ((void *)(addr))
+#endif
+
+#define hw_enable_tagging()			arch_enable_tagging()
+#define hw_init_tags(max_tag)			arch_init_tags(max_tag)
+#define hw_get_random_tag()			arch_get_random_tag()
+#define hw_get_mem_tag(addr)			arch_get_mem_tag(addr)
+#define hw_set_mem_tag_range(addr, size, tag)	arch_set_mem_tag_range((addr), (size), (tag))
+
+#endif /* CONFIG_KASAN_HW_TAGS */
+
 /*
  * Exported functions for interfaces called from assembly or from generated
  * code. Declarations here to avoid warning about missing declarations.
-- 
2.29.2.299.gdc1121823c-goog