Re: [PATCH v9 34/44] arm64: kasan: Align allocations for HW_TAGS

[Alexander Potapenko]

On Tue, Nov 10, 2020 at 11:12 PM Andrey Konovalov <andreyknvl@xxxxxxxxxx> wrote:
>
> 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 <andreyknvl@xxxxxxxxxx>
> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@xxxxxxx>
> Reviewed-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Reviewed-by: Alexander Potapenko <glider@xxxxxxxxxx>

> ---
> Change-Id: I51ebd3f9645e6330e5a92973bf7c86b62d632c2b
> ---
>  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 63d43b5f82f6..77cbbe3625f2 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-kasan.h>
>
>  #define CTR_L1IP_SHIFT         14
>  #define CTR_L1IP_MASK          3
> @@ -51,6 +52,8 @@
>
>  #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__
> --
> 2.29.2.222.g5d2a92d10f8-goog
>


-- 
Alexander Potapenko
Software Engineer

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