[PATCH v12 09/11] poweprc: mm: Implement *_user_accessible_page() for ptes

[Pasha Tatashin]

On Tue, Apr 2, 2024 at 1:13 AM Rohan McLure <rmclure at linux.ibm.com> wrote:
>
> Page table checking depends on architectures providing an
> implementation of p{te,md,ud}_user_accessible_page. With
> refactorisations made on powerpc/mm, the pte_access_permitted() and
> similar methods verify whether a userland page is accessible with the
> required permissions.
>
> Since page table checking is the only user of
> p{te,md,ud}_user_accessible_page(), implement these for all platforms,
> using some of the same preliminary checks taken by pte_access_permitted()
> on that platform.
>
> Since Commit 8e9bd41e4ce1 ("powerpc/nohash: Replace pte_user() by pte_read()")
> pte_user() is no longer required to be present on all platforms as it
> may be equivalent to or implied by pte_read(). Hence implementations of
> pte_user_accessible_page() are specialised.
>
> Signed-off-by: Rohan McLure <rmclure at linux.ibm.com>

Reviewed-by: Pasha Tatashin <pasha.tatashin at soleen.com>