From mboxrd@z Thu Jan  1 00:00:00 1970
From: Walter Wu <walter-zh.wu@mediatek.com>
Subject: Re: [PATCH v3] kasan: add memory corruption identification for
 software tag-based mode
Date: Fri, 26 Jul 2019 21:19:24 +0800
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To: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>, Alexander Potapenko <glider@google.com>, Christoph Lameter <cl@linux.com>, Pekka Enberg <penberg@kernel.org>, David Rientjes <rientjes@google.com>, Joonsoo Kim <iamjoonsoo.kim@lge.com>, Matthias Brugger <matthias.bgg@gmail.com>, Martin Schwidefsky <schwidefsky@de.ibm.com>, Arnd Bergmann <arnd@arndb.de>, Vasily Gorbik <gor@linux.ibm.com>, Andrey Konovalov <andreyknvl@google.com>, "Jason A . Donenfeld" <Jason@zx2c4.com>, Miles Chen <miles.chen@mediatek.com>, kasan-dev <kasan-dev@googlegroups.com>, LKML <linux-kernel@vger.kernel.org>, Linux-MM <linux-mm@kvack.org>, Linux ARM <linux-arm-kernel@lists.infradead.org>, linux-mediatek@lists.infradead.org, wsd_upstream <wsd_upstream@mediatek.com>
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On Fri, 2019-07-26 at 15:52 +0300, Andrey Ryabinin wrote:
> 
> On 7/26/19 3:28 PM, Walter Wu wrote:
> > On Fri, 2019-07-26 at 15:00 +0300, Andrey Ryabinin wrote:
> >>
> >
> >>>
> >>>
> >>> I remember that there are already the lists which you concern. Maybe we
> >>> can try to solve those problems one by one.
> >>>
> >>> 1. deadlock issue? cause by kmalloc() after kfree()?
> >>
> >> smp_call_on_cpu()
> > 
> >>> 2. decrease allocation fail, to modify GFP_NOWAIT flag to GFP_KERNEL?
> >>
> >> No, this is not gonna work. Ideally we shouldn't have any allocations there.
> >> It's not reliable and it hurts performance.
> >>
> > I dont know this meaning, we need create a qobject and put into
> > quarantine, so may need to call kmem_cache_alloc(), would you agree this
> > action?
> > 
> 
> How is this any different from what you have now?

I originally thought you already agreed the free-list(tag-based
quarantine) after fix those issue. If no allocation there, i think maybe
only move generic quarantine into tag-based kasan, but its memory
consumption is more bigger our patch. what do you think?