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Date: Thu, 9 Jun 2022 20:02:41 +0900
From: Sergey Senozhatsky <senozhatsky@chromium.org>
To: Minchan Kim <minchan@kernel.org>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>,
	Naresh Kamboju <naresh.kamboju@linaro.org>,
	open list <linux-kernel@vger.kernel.org>,
	linux-fsdevel@vger.kernel.org,
	Linux ARM <linux-arm-kernel@lists.infradead.org>,
	"open list:KERNEL SELFTEST FRAMEWORK" <linux-kselftest@vger.kernel.org>,
	linux-block <linux-block@vger.kernel.org>,
	regressions@lists.linux.dev, Jens Axboe <axboe@kernel.dk>,
	Nitin Gupta <ngupta@vflare.org>
Subject: Re: qemu-arm: zram: mkfs.ext4 : Unable to handle kernel NULL pointer
 dereference at virtual address 00000140
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In-Reply-To: <YqEKapKLBgKEXGBg@google.com>

On (22/06/08 13:45), Minchan Kim wrote:
> 
> I am trying to understand the problem. AFAIK, the mapping_area was
> static allocation per cpu so in zs_cpu_down, we never free the
> mapping_area itself. Then, why do we need to reinitialize the local
> lock again?

Well... Something zero-s out that memory. NULL deref in strcmp() in
lockdep points at NULL ->name. So I'm merely testing my theories here.
If it's not area lock then it's pool->migrate_lock?