# \[PATCH 27/35\] kasan, arm64: align allocations for HW\_TAGS

- From: Andrey Konovalov \<hidden\>
- Date: 2020-08-14 17:28:39 
- List: linux-arm-kernel
- Page: https://ratatoskr.run/linux-arm-kernel/2020/08/6068776
- Thread: https://ratatoskr.run/linux-arm-kernel/2020/08/6068760/t.md

```text
Hardware tag-based KASAN uses the memory tagging approach, which requires
all allocations to be aligned to the memory granule size. Align the
allocations to MTE_GRANULE_SIZE via ARCH_SLAB_MINALIGN when
CONFIG_KASAN_HW_TAGS is enabled.

Signed-off-by: Andrey Konovalov <redacted>
---
 arch/arm64/include/asm/cache.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/arm64/include/asm/cache.h b/arch/arm64/include/asm/cache.h
index a4d1b5f771f6..b8a0cae38470 100644
--- a/arch/arm64/include/asm/cache.h
+++ b/arch/arm64/include/asm/cache.h
@@ -6,6 +6,7 @@
 #define __ASM_CACHE_H
 
 #include <asm/cputype.h>
+#include <asm/mte_asm.h>
 
 #define CTR_L1IP_SHIFT		14
 #define CTR_L1IP_MASK		3
@@ -50,6 +51,8 @@
 
 #ifdef CONFIG_KASAN_SW_TAGS
 #define ARCH_SLAB_MINALIGN	(1ULL << KASAN_SHADOW_SCALE_SHIFT)
+#elif defined(CONFIG_KASAN_HW_TAGS)
+#define ARCH_SLAB_MINALIGN	MTE_GRANULE_SIZE
 #endif
 
 #ifndef __ASSEMBLY__
-- 
2.28.0.220.ged08abb693-goog


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```