Subject: Re: [PATCH v2 1/9] kasan: introduce helper functions for determining
 bug type
To: Andrey Konovalov <andreyknvl@google.com>,
        Alexander Potapenko <glider@google.com>,
        Dmitry Vyukov <dvyukov@google.com>, <kasan-dev@googlegroups.com>,
        <linux-mm@kvack.org>, <linux-kernel@vger.kernel.org>
References: <20170302134851.101218-1-andreyknvl@google.com>
 <20170302134851.101218-2-andreyknvl@google.com>
From: Andrey Ryabinin <aryabinin@virtuozzo.com>
Message-ID: <12f7d7bc-23f1-a5b1-5f26-cfe8158e48d5@virtuozzo.com>
Date: Fri, 3 Mar 2017 16:15:10 +0300
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On 03/02/2017 04:48 PM, Andrey Konovalov wrote:
> Introduce get_shadow_bug_type() function, which determines bug type
> based on the shadow value for a particular kernel address.
> Introduce get_wild_bug_type() function, which determines bug type
> for addresses which don't have a corresponding shadow value.
> 
> Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
> ---
>  mm/kasan/report.c | 40 ++++++++++++++++++++++++++++++----------
>  1 file changed, 30 insertions(+), 10 deletions(-)
> 
> diff --git a/mm/kasan/report.c b/mm/kasan/report.c
> index f479365530b6..2790b4cadfa3 100644
> --- a/mm/kasan/report.c
> +++ b/mm/kasan/report.c
> @@ -49,7 +49,13 @@ static const void *find_first_bad_addr(const void *addr, size_t size)
>  	return first_bad_addr;
>  }
>  
> -static void print_error_description(struct kasan_access_info *info)
> +static bool addr_has_shadow(struct kasan_access_info *info)
> +{
> +	return (info->access_addr >=
> +		kasan_shadow_to_mem((void *)KASAN_SHADOW_START));
> +}
> +
> +static const char *get_shadow_bug_type(struct kasan_access_info *info)
>  {
>  	const char *bug_type = "unknown-crash";
>  	u8 *shadow_addr;
> @@ -96,6 +102,27 @@ static void print_error_description(struct kasan_access_info *info)
>  		break;
>  	}
>  
> +	return bug_type;
> +}
> +
> +const char *get_wild_bug_type(struct kasan_access_info *info)

static