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From:   Andrey Konovalov <andreyknvl@google.com>
Date:   Thu, 27 Aug 2020 14:05:29 +0200
Message-ID: <CAAeHK+wLVK_YG2gWVLk0YsoKozfZhht6zVzz=7N_yz0S=JgHEg@mail.gmail.com>
Subject: Re: [PATCH 28/35] kasan: define KASAN_GRANULE_SIZE for HW_TAGS
To:     Vincenzo Frascino <vincenzo.frascino@arm.com>,
        Catalin Marinas <catalin.marinas@arm.com>
Cc:     Dmitry Vyukov <dvyukov@google.com>,
        kasan-dev <kasan-dev@googlegroups.com>,
        Andrey Ryabinin <aryabinin@virtuozzo.com>,
        Alexander Potapenko <glider@google.com>,
        Marco Elver <elver@google.com>,
        Evgenii Stepanov <eugenis@google.com>,
        Elena Petrova <lenaptr@google.com>,
        Branislav Rankov <Branislav.Rankov@arm.com>,
        Kevin Brodsky <kevin.brodsky@arm.com>,
        Will Deacon <will.deacon@arm.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        Linux Memory Management List <linux-mm@kvack.org>,
        LKML <linux-kernel@vger.kernel.org>
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On Thu, Aug 27, 2020 at 1:05 PM Vincenzo Frascino
<vincenzo.frascino@arm.com> wrote:
>
>
>
> 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@google.com>
> >> ---
> >>  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.

Will do in v2.

>
> >> +#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