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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()
Date: Fri, 11 Aug 2023 12:03:12 +0100	[thread overview]
Message-ID: <20230811110311.GB6993@willie-the-truck> (raw)
In-Reply-To: <20230810093241.1181142-1-qi.zheng@linux.dev>

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

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  parent reply	other threads:[~2023-08-11 11:03 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-08-10  9:32 [PATCH] arm64: mm: use ptep_clear() instead of pte_clear() in clear_flush() Qi Zheng
2023-08-11  2:38 ` Qi Zheng
2023-08-11 11:03 ` Will Deacon [this message]
     [not found]   ` <CAOgjDMi6kTZUjEianbO670RQxJ8=JhHxkeci9NspSCRT5rPhYw@mail.gmail.com>
2023-08-11 11:21     ` Will Deacon
     [not found]       ` <CAOgjDMgVZXbEeA6O2yPR9N27JWCMNR3D7cgHJbmbfYYUdKF3eQ@mail.gmail.com>
2023-08-21 20:21         ` Andrew Morton
2023-08-22  2:23           ` Qi Zheng
2023-08-22  9:58           ` Will Deacon

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