Re: [PATCH, RFC 09/62] x86/mm: Preserve KeyID on pte_modify() and pgprot_modify()

[Peter Zijlstra]

On Wed, May 08, 2019 at 05:43:29PM +0300, Kirill A. Shutemov wrote:
> + * Cast PAGE_MASK to a signed type so that it is sign-extended if
> + * virtual addresses are 32-bits but physical addresses are larger
> + * (ie, 32-bit PAE).

On 32bit, 'long' is still 32bit, did you want to cast to 'long long'
instead? Ideally we'd use pteval_t here, but I see that is unsigned.

>   */
> -#define _PAGE_CHG_MASK	(PTE_PFN_MASK | _PAGE_PCD | _PAGE_PWT |		\
> +#define PTE_PFN_MASK_MAX \
> +	(((signed long)PAGE_MASK) & ((1ULL << __PHYSICAL_MASK_SHIFT) - 1))
> +#define _PAGE_CHG_MASK	(PTE_PFN_MASK_MAX | _PAGE_PCD | _PAGE_PWT |		\
>  			 _PAGE_SPECIAL | _PAGE_ACCESSED | _PAGE_DIRTY |	\
>  			 _PAGE_SOFT_DIRTY | _PAGE_DEVMAP)
>  #define _HPAGE_CHG_MASK (_PAGE_CHG_MASK | _PAGE_PSE)