From 2e903b91479782b7dedd869603423d77e079d3de Mon Sep 17 00:00:00 2001
From: Andrey Konovalov <andreyknvl@google.com>
Date: Tue, 22 Dec 2020 12:02:10 -0800
Subject: kasan, arm64: implement HW_TAGS runtime

Provide implementation of KASAN functions required for the hardware
tag-based mode.  Those include core functions for memory and pointer
tagging (tags_hw.c) and bug reporting (report_tags_hw.c).  Also adapt
common KASAN code to support the new mode.

Link: https://lkml.kernel.org/r/cfd0fbede579a6b66755c98c88c108e54f9c56bf.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 arch/arm64/include/asm/memory.h | 4 ++--
 arch/arm64/kernel/cpufeature.c  | 3 +++
 arch/arm64/kernel/smp.c         | 2 ++
 3 files changed, 7 insertions(+), 2 deletions(-)

(limited to 'arch')

diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
index cd671fb6707c..18fce223b67b 100644
--- a/arch/arm64/include/asm/memory.h
+++ b/arch/arm64/include/asm/memory.h
@@ -214,7 +214,7 @@ static inline unsigned long kaslr_offset(void)
 	(__force __typeof__(addr))__addr;				\
 })
 
-#ifdef CONFIG_KASAN_SW_TAGS
+#if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS)
 #define __tag_shifted(tag)	((u64)(tag) << 56)
 #define __tag_reset(addr)	__untagged_addr(addr)
 #define __tag_get(addr)		(__u8)((u64)(addr) >> 56)
@@ -222,7 +222,7 @@ static inline unsigned long kaslr_offset(void)
 #define __tag_shifted(tag)	0UL
 #define __tag_reset(addr)	(addr)
 #define __tag_get(addr)		0
-#endif /* CONFIG_KASAN_SW_TAGS */
+#endif /* CONFIG_KASAN_SW_TAGS || CONFIG_KASAN_HW_TAGS */
 
 static inline const void *__tag_set(const void *addr, u8 tag)
 {
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index d87cfc6246e0..7ffb5f1d8b68 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -70,6 +70,7 @@
 #include <linux/types.h>
 #include <linux/mm.h>
 #include <linux/cpu.h>
+#include <linux/kasan.h>
 #include <asm/cpu.h>
 #include <asm/cpufeature.h>
 #include <asm/cpu_ops.h>
@@ -1710,6 +1711,8 @@ static void cpu_enable_mte(struct arm64_cpu_capabilities const *cap)
 		cleared_zero_page = true;
 		mte_clear_page_tags(lm_alias(empty_zero_page));
 	}
+
+	kasan_init_hw_tags_cpu();
 }
 #endif /* CONFIG_ARM64_MTE */
 
diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index 2499b895efea..19b1705ae5cb 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -462,6 +462,8 @@ void __init smp_prepare_boot_cpu(void)
 	/* Conditionally switch to GIC PMR for interrupt masking */
 	if (system_uses_irq_prio_masking())
 		init_gic_priority_masking();
+
+	kasan_init_hw_tags();
 }
 
 static u64 __init of_get_cpu_mpidr(struct device_node *dn)
-- 
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