[PATCH 1/3] arch/powerpc/hugetlb: Use pte_access_permitted for hugetlb access check

[Christophe LEROY]

Le 04/12/2017 à 03:19, Aneesh Kumar K.V a écrit :
> No functional change in this patch. This update gup_hugepte to use the
> helper. This will help later when we add memory keys.
> 
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar at linux.vnet.ibm.com>
> ---
>   arch/powerpc/mm/hugetlbpage.c | 4 +---
>   1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
> index a9b9083c5e49..c7e5afe5e118 100644
> --- a/arch/powerpc/mm/hugetlbpage.c
> +++ b/arch/powerpc/mm/hugetlbpage.c
> @@ -855,9 +855,7 @@ int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned long addr,
>   
>   	pte = READ_ONCE(*ptep);
>   
> -	if (!pte_present(pte) || !pte_read(pte))
> -		return 0;
> -	if (write && !pte_write(pte))
> +	if (!pte_access_permitted(pte, write))

Seems like pte_access_permitted() doesn't check _PAGE_RO whereas 
pte_write() does.

Christophe

>   		return 0;
>   
>   	/* hugepages are never "special" */
>