Re: [PATCH v16 09/16] fs, arm64: untag user pointers in fs/userfaultfd.c

From: Catalin Marinas
Date: Wed Jun 12 2019 - 06:50:22 EST


On Mon, Jun 03, 2019 at 06:55:11PM +0200, Andrey Konovalov wrote:
> This patch is a part of a series that extends arm64 kernel ABI to allow to
> pass tagged user pointers (with the top byte set to something else other
> than 0x00) as syscall arguments.
>
> userfaultfd code use provided user pointers for vma lookups, which can
> only by done with untagged pointers.
>
> Untag user pointers in validate_range().
>
> Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>

Reviewed-by: Catalin Marinas <catalin.marinas@xxxxxxx>