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

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@google.com

Reviewed-by: Catalin Marinas catalin.marinas@arm.com