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Subject: Re: [PATCH] mm/page_table_check: fix accessing unmapped ptep
To:     Pasha Tatashin <pasha.tatashin@soleen.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        <zhengqi.arch@bytedance.com>, Matthew Wilcox <willy@infradead.org>
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From:   Miaohe Lin <linmiaohe@huawei.com>
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Date:   Fri, 27 May 2022 09:10:53 +0800
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On 2022/5/27 2:31, Pasha Tatashin wrote:
>>> Miaohe, please store the ptep, or maybe drop this patch entirely.
>>
>> I think it's best to fix it.  I rewrote the changelog as
>>
>> : ptep is unmapped too early, so ptep could theoretically be accessed while
>> : it's unmapped.  This might become a problem if/when CONFIG_HIGHPTE becomes
>> : available on riscv.
>> :
>> : Fix it by deferring pte_unmap() until page table checking is done.
>>
>> I'll retain the Fixes:.  This doesn't imply cc:stable in MM, and anyone
>> who backports the original patchset will want to know about this fixup.
> Makes sense.
> 
> 
>> And I queued a fixup for the thing Matthew noticed.
> Thank you Andrew.
> 

Many thanks for all of your comments, review and fixup! :)

> Pasha
> .
>