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Date:   Fri, 11 Aug 2023 12:03:12 +0100
From:   Will Deacon <will@kernel.org>
To:     Qi Zheng <qi.zheng@linux.dev>
Cc:     catalin.marinas@arm.com, akpm@linux-foundation.org,
        wangkefeng.wang@huawei.co, pasha.tatashin@soleen.com,
        muchun.song@linux.dev, linux-arm-kernel@lists.infradead.org,
        linux-kernel@vger.kernel.org, Qi Zheng <zhengqi.arch@bytedance.com>
Subject: Re: [PATCH] arm64: mm: use ptep_clear() instead of pte_clear() in
 clear_flush()
Message-ID: <20230811110311.GB6993@willie-the-truck>
References: <20230810093241.1181142-1-qi.zheng@linux.dev>
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On Thu, Aug 10, 2023 at 09:32:41AM +0000, Qi Zheng wrote:
> From: Qi Zheng <zhengqi.arch@bytedance.com>
> 
> In clear_flush(), the original pte may be a present entry, so we should
> use ptep_clear() to let page_table_check track the pte clearing operation,
> otherwise it may cause false positive in subsequent set_pte_at().

Isn't this true for most users of pte_clear()? There are some in the core
code, so could they trigger the false positive as well?

Will