From mboxrd@z Thu Jan  1 00:00:00 1970
From: Walter Wu <walter-zh.wu@mediatek.com>
Subject: Re: [PATCH 1/2] mm/kasan: dump alloc/free stack for page allocator
Date: Wed, 4 Sep 2019 22:16:31 +0800
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To: Andrey Konovalov <andreyknvl@google.com>
Cc: 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>, Arnd Bergmann <arnd@arndb.de>, kasan-dev <kasan-dev@googlegroups.com>, Linux Memory Management List <linux-mm@kvack.org>, LKML <linux-kernel@vger.kernel.org>, Linux ARM <linux-arm-kernel@lists.infradead.org>, linux-mediatek@lists.infradead.org, wsd_upstream@mediatek.com
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On Wed, 2019-09-04 at 15:44 +0200, Andrey Konovalov wrote:
> On Wed, Sep 4, 2019 at 8:51 AM Walter Wu <walter-zh.wu@mediatek.com> wrote:
> > +config KASAN_DUMP_PAGE
> > +       bool "Dump the page last stack information"
> > +       depends on KASAN && PAGE_OWNER
> > +       help
> > +         By default, KASAN doesn't record alloc/free stack for page allocator.
> > +         It is difficult to fix up page use-after-free issue.
> > +         This feature depends on page owner to record the last stack of page.
> > +         It is very helpful for solving the page use-after-free or out-of-bound.
> 
> I'm not sure if we need a separate config for this. Is there any
> reason to not have this enabled by default?

PAGE_OWNER need some memory usage, it is not allowed to enable by
default in low RAM device. so I create new feature option and the person
who wants to use it to enable it.

Thanks.
Walter