3 files changed, 20 insertions, 2 deletions
diff --git a/arch/arm64/include/asm/kasan.h b/arch/arm64/include/asm/kasan.h
index 8758bb008436..b52aacd2c526 100644
--- a/arch/arm64/include/asm/kasan.h
+++ b/arch/arm64/include/asm/kasan.h
@@ -4,12 +4,16 @@
 
 #ifndef __ASSEMBLY__
 
-#ifdef CONFIG_KASAN
-
 #include <linux/linkage.h>
 #include <asm/memory.h>
 #include <asm/pgtable-types.h>
 
+#define arch_kasan_set_tag(addr, tag)	__tag_set(addr, tag)
+#define arch_kasan_reset_tag(addr)	__tag_reset(addr)
+#define arch_kasan_get_tag(addr)	__tag_get(addr)
+
+#ifdef CONFIG_KASAN
+
 /*
  * KASAN_SHADOW_START: beginning of the kernel virtual addresses.
  * KASAN_SHADOW_END: KASAN_SHADOW_START + 1/N of kernel virtual addresses,
diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
index e73bb89d6141..25b46f88726c 100644
--- a/arch/arm64/include/asm/memory.h
+++ b/arch/arm64/include/asm/memory.h
@@ -226,6 +226,18 @@ extern u64			vabits_user;
 #define untagged_addr(addr)	\
 	((__typeof__(addr))sign_extend64((u64)(addr), 55))
 
+#ifdef CONFIG_KASAN_SW_TAGS
+#define __tag_shifted(tag)	((u64)(tag) << 56)
+#define __tag_set(addr, tag)	(__typeof__(addr))( \
+		((u64)(addr) & ~__tag_shifted(0xff)) | __tag_shifted(tag))
+#define __tag_reset(addr)	untagged_addr(addr)
+#define __tag_get(addr)		(__u8)((u64)(addr) >> 56)
+#else
+#define __tag_set(addr, tag)	(addr)
+#define __tag_reset(addr)	(addr)
+#define __tag_get(addr)		0
+#endif
+
 /*
  * Physical vs virtual RAM address space conversion.  These are
  * private definitions which should NOT be used outside memory.h
diff --git a/arch/arm64/mm/kasan_init.c b/arch/arm64/mm/kasan_init.c
index 38fa4bba9279..3e142add890b 100644
--- a/arch/arm64/mm/kasan_init.c
+++ b/arch/arm64/mm/kasan_init.c
@@ -252,6 +252,8 @@ void __init kasan_init(void)
 	memset(kasan_early_shadow_page, KASAN_SHADOW_INIT, PAGE_SIZE);
 	cpu_replace_ttbr1(lm_alias(swapper_pg_dir));
 
+	kasan_init_tags();
+
 	/* At this point kasan is fully initialized. Enable error messages */
 	init_task.kasan_depth = 0;
 	pr_info("KernelAddressSanitizer initialized\n");