Re: [PATCH] mm/autonuma: don't use set_pte_at when updating protnone ptes

From: Rik van Riel
Date: Mon Feb 06 2017 - 13:47:18 EST


On Mon, 2017-02-06 at 22:36 +0530, Aneesh Kumar K.V wrote:
> Architectures like ppc64, use privilege access bit to mark pte non
> accessible.
> This implies that kernel can do a copy_to_user to an address marked
> for numa fault.
> This also implies that there can be a parallel hardware update for
> the pte.
> set_pte_at cannot be used in such scenarios. Hence switch the pte
> update to use ptep_get_and_clear and set_pte_at combination.
>
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx>

Acked-by: Rik van Riel <riel@xxxxxxxxxx>

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