[PATCH v15 07/17] mm, arm64: untag user pointers in mm/gup.c
catalin.marinas at arm.com
Wed May 22 11:56:53 UTC 2019
On Mon, May 06, 2019 at 06:30:53PM +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.
> mm/gup.c provides a kernel interface that accepts user addresses and
> manipulates user pages directly (for example get_user_pages, that is used
> by the futex syscall). Since a user can provided tagged addresses, we need
> to handle this case.
> Add untagging to gup.c functions that use user addresses for vma lookups.
> Signed-off-by: Andrey Konovalov <andreyknvl at google.com>
Reviewed-by: Catalin Marinas <catalin.marinas at arm.com>
More information about the amd-gfx