Re: [PATCH 28/35] kasan: define KASAN_GRANULE_SIZE for HW_TAGS

From: Vincenzo Frascino
Date: Thu Aug 27 2020 - 11:23:20 EST




On 8/27/20 11:41 AM, Catalin Marinas wrote:
> On Fri, Aug 14, 2020 at 07:27:10PM +0200, Andrey Konovalov wrote:
>> Hardware tag-based KASAN has granules of MTE_GRANULE_SIZE. Define
>> KASAN_GRANULE_SIZE to MTE_GRANULE_SIZE for CONFIG_KASAN_HW_TAGS.
>>
>> Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
>> ---
>> mm/kasan/kasan.h | 6 ++++++
>> 1 file changed, 6 insertions(+)
>>
>> diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
>> index 1d3c7c6ce771..4d8e229f8e01 100644
>> --- a/mm/kasan/kasan.h
>> +++ b/mm/kasan/kasan.h
>> @@ -5,7 +5,13 @@
>> #include <linux/kasan.h>
>> #include <linux/stackdepot.h>
>>
>> +#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
>> #define KASAN_GRANULE_SIZE (1UL << KASAN_SHADOW_SCALE_SHIFT)
>> +#else
>> +#include <asm/mte.h>
>
> You could only include the new asm/mte-def.h file (currently mte_asm.h).
>

Agreed, we should only include asm/mte-def.h here since after the suggested
modification will be sufficient for the purpose.

>> +#define KASAN_GRANULE_SIZE (MTE_GRANULE_SIZE)
>> +#endif
>> +
>> #define KASAN_GRANULE_MASK (KASAN_GRANULE_SIZE - 1)
>>
>> #define KASAN_TAG_KERNEL 0xFF /* native kernel pointers tag */
>> --
>> 2.28.0.220.ged08abb693-goog
>>
>

--
Regards,
Vincenzo