[PATCH v4 2/3] kasan: Add explicit preconditions to kasan_report()

[Andrey Konovalov]

On Fri, Jan 22, 2021 at 4:57 PM Vincenzo Frascino
<vincenzo.frascino at arm.com> wrote:
>
> With the introduction of KASAN_HW_TAGS, kasan_report() accesses the
> metadata only when addr_has_metadata() succeeds.
>
> Add a comment to make sure that the preconditions to the function are
> explicitly clarified.
>
> Cc: Andrey Ryabinin <aryabinin at virtuozzo.com>
> Cc: Alexander Potapenko <glider at google.com>
> Cc: Dmitry Vyukov <dvyukov at google.com>
> Cc: Leon Romanovsky <leonro at mellanox.com>
> Cc: Andrey Konovalov <andreyknvl at google.com>
> Signed-off-by: Vincenzo Frascino <vincenzo.frascino at arm.com>
> ---
>  include/linux/kasan.h | 7 +++++++
>  1 file changed, 7 insertions(+)
>
> diff --git a/include/linux/kasan.h b/include/linux/kasan.h
> index fe1ae73ff8b5..0aea9e2a2a01 100644
> --- a/include/linux/kasan.h
> +++ b/include/linux/kasan.h
> @@ -333,6 +333,13 @@ static inline void *kasan_reset_tag(const void *addr)
>         return (void *)arch_kasan_reset_tag(addr);
>  }
>
> +/**
> + * kasan_report - print a report about a bad memory access detected by KASAN
> + * @addr: address of the bad access
> + * @size: size of the bad access
> + * @is_write: whether the bad access is a write or a read
> + * @ip: instruction pointer for the accessibility check or the bad access itself
> + */
>  bool kasan_report(unsigned long addr, size_t size,
>                 bool is_write, unsigned long ip);
>
> --
> 2.30.0

Reviewed-by: Andrey Konovalov <andreyknvl at google.com>