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References: <20210620114756.31304-1-Kuan-Ying.Lee@mediatek.com> <20210620114756.31304-4-Kuan-Ying.Lee@mediatek.com>
In-Reply-To: <20210620114756.31304-4-Kuan-Ying.Lee@mediatek.com>
From:   Andrey Konovalov <andreyknvl@gmail.com>
Date:   Tue, 22 Jun 2021 16:54:49 +0300
Message-ID: <CA+fCnZcSy6LqqhbYfiC8hn16+T640uw_rnUzNPg1zsvg_RwYzw@mail.gmail.com>
Subject: Re: [PATCH v3 3/3] kasan: add memory corruption identification
 support for hardware tag-based mode
To:     Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com>
Cc:     Andrey Ryabinin <ryabinin.a.a@gmail.com>,
        Alexander Potapenko <glider@google.com>,
        Marco Elver <elver@google.com>,
        Dmitry Vyukov <dvyukov@google.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        kasan-dev <kasan-dev@googlegroups.com>,
        LKML <linux-kernel@vger.kernel.org>,
        Linux Memory Management List <linux-mm@kvack.org>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        linux-mediatek@lists.infradead.org, wsd_upstream@mediatek.com,
        chinwen.chang@mediatek.com, nicholas.tang@mediatek.com
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On Sun, Jun 20, 2021 at 2:48 PM Kuan-Ying Lee
<Kuan-Ying.Lee@mediatek.com> wrote:
>
> Add memory corruption identification support for hardware tag-based
> mode. We store one old free pointer tag and free backtrace.

Please explain why only one.

> Signed-off-by: Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com>
> Suggested-by: Marco Elver <elver@google.com>
> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
> Cc: Alexander Potapenko <glider@google.com>
> Cc: Andrey Konovalov <andreyknvl@gmail.com>
> Cc: Dmitry Vyukov <dvyukov@google.com>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> ---
>  lib/Kconfig.kasan | 2 +-
>  mm/kasan/kasan.h  | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/lib/Kconfig.kasan b/lib/Kconfig.kasan
> index 6f5d48832139..2cc25792bc2f 100644
> --- a/lib/Kconfig.kasan
> +++ b/lib/Kconfig.kasan
> @@ -157,7 +157,7 @@ config KASAN_STACK
>
>  config KASAN_TAGS_IDENTIFY
>         bool "Enable memory corruption identification"
> -       depends on KASAN_SW_TAGS
> +       depends on KASAN_SW_TAGS || KASAN_HW_TAGS
>         help
>           This option enables best-effort identification of bug type
>           (use-after-free or out-of-bounds) at the cost of increased
> diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
> index b0fc9a1eb7e3..d6f982b8a84e 100644
> --- a/mm/kasan/kasan.h
> +++ b/mm/kasan/kasan.h
> @@ -153,7 +153,7 @@ struct kasan_track {
>         depot_stack_handle_t stack;
>  };
>
> -#ifdef CONFIG_KASAN_TAGS_IDENTIFY
> +#if defined(CONFIG_KASAN_TAGS_IDENTIFY) && defined(CONFIG_KASAN_SW_TAGS)
>  #define KASAN_NR_FREE_STACKS 5
>  #else
>  #define KASAN_NR_FREE_STACKS 1
> --
> 2.18.0
>

Other than that:

Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>