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Subject: Re: [PATCH v2 1/2] mm/page_ext: support to record the last stack of
 page
To:     Walter Wu <walter-zh.wu@mediatek.com>,
        Andrey Ryabinin <aryabinin@virtuozzo.com>,
        Alexander Potapenko <glider@google.com>,
        Dmitry Vyukov <dvyukov@google.com>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Martin Schwidefsky <schwidefsky@de.ibm.com>,
        Will Deacon <will@kernel.org>,
        Andrey Konovalov <andreyknvl@google.com>,
        Arnd Bergmann <arnd@arndb.de>,
        Thomas Gleixner <tglx@linutronix.de>,
        Michal Hocko <mhocko@kernel.org>, Qian Cai <cai@lca.pw>
Cc:     linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com,
        linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org,
        linux-mediatek@lists.infradead.org, wsd_upstream@mediatek.com
References: <20190909085339.25350-1-walter-zh.wu@mediatek.com>
From:   Vlastimil Babka <vbabka@suse.cz>
Message-ID: <0fd84c7b-a23b-0b09-519f-a006fade1b4f@suse.cz>
Date:   Mon, 9 Sep 2019 14:59:12 +0200
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On 9/9/19 10:53 AM, Walter Wu wrote:
> KASAN will record last stack of page in order to help programmer
> to see memory corruption caused by page.
> 
> What is difference between page_owner and our patch?
> page_owner records alloc stack of page, but our patch is to record
> last stack(it may be alloc or free stack of page).
> 
> Signed-off-by: Walter Wu <walter-zh.wu@mediatek.com>

There's no point in separating this from patch 2 (and as David pointed 
out, doesn't compile).

> ---
>   mm/page_ext.c | 3 +++
>   1 file changed, 3 insertions(+)
> 
> diff --git a/mm/page_ext.c b/mm/page_ext.c
> index 5f5769c7db3b..7ca33dcd9ffa 100644
> --- a/mm/page_ext.c
> +++ b/mm/page_ext.c
> @@ -65,6 +65,9 @@ static struct page_ext_operations *page_ext_ops[] = {
>   #if defined(CONFIG_IDLE_PAGE_TRACKING) && !defined(CONFIG_64BIT)
>   	&page_idle_ops,
>   #endif
> +#ifdef CONFIG_KASAN
> +	&page_stack_ops,
> +#endif
>   };
>   
>   static unsigned long total_usage;
>