[PATCH v2 23/37] arm64: kasan: Add arch layer for memory tagging helpers

[Andrey Konovalov]

On Fri, Sep 18, 2020 at 3:00 PM Marco Elver <elver at google.com> wrote:
>
> On Tue, Sep 15, 2020 at 11:16PM +0200, 'Andrey Konovalov' via kasan-dev wrote:
> > This patch add a set of arch_*() memory tagging helpers currently only
> > defined for arm64 when hardware tag-based KASAN is enabled. These helpers
> > will be used by KASAN runtime to implement the hardware tag-based mode.
> >
> > The arch-level indirection level is introduced to simplify adding hardware
> > tag-based KASAN support for other architectures in the future by defining
> > the appropriate arch_*() macros.
> >
> > Signed-off-by: Andrey Konovalov <andreyknvl at google.com>
> > Co-developed-by: Vincenzo Frascino <vincenzo.frascino at arm.com>
> > Signed-off-by: Vincenzo Frascino <vincenzo.frascino at arm.com>
> > ---
> > Change-Id: I42b0795a28067872f8308e00c6f0195bca435c2a
> > ---
> >  arch/arm64/include/asm/memory.h |  8 ++++++++
> >  mm/kasan/kasan.h                | 19 +++++++++++++++++++
> >  2 files changed, 27 insertions(+)
> >
> > diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
> > index e424fc3a68cb..268a3b6cebd2 100644
> > --- a/arch/arm64/include/asm/memory.h
> > +++ b/arch/arm64/include/asm/memory.h
> > @@ -231,6 +231,14 @@ static inline const void *__tag_set(const void *addr, u8 tag)
> >       return (const void *)(__addr | __tag_shifted(tag));
> >  }
> >
> > +#ifdef CONFIG_KASAN_HW_TAGS
> > +#define arch_init_tags(max_tag)                      mte_init_tags(max_tag)
> > +#define arch_get_random_tag()                        mte_get_random_tag()
> > +#define arch_get_mem_tag(addr)                       mte_get_mem_tag(addr)
> > +#define arch_set_mem_tag_range(addr, size, tag)      \
> > +                     mte_set_mem_tag_range((addr), (size), (tag))
>
> Suggested edit below, assuming you're fine with checkpatch.pl's new
> 100col limit:
>
> -#define set_mem_tag_range(addr, size, tag)     \
> -                               arch_set_mem_tag_range((addr), (size), (tag))
> +#define set_mem_tag_range(addr, size, tag)     arch_set_mem_tag_range((addr), (size), (tag))

Will do in v3, thanks!