Re: [PATCH 4/6] mm, arm64: untag user addresses in mm/gup.c

[Andrey Konovalov]

On Wed, May 2, 2018 at 5:36 PM, Kirill A. Shutemov
<kirill.shutemov@xxxxxxxxxxxxxxx> wrote:
> On Wed, May 02, 2018 at 02:38:42PM +0000, Andrey Konovalov wrote:
>> > Does having a tagged address here makes any difference? I couldn't hit a
>> > failure with my simple tests (LD_PRELOAD a library that randomly adds
>> > tags to pointers returned by malloc).
>>
>> I think you're right, follow_page_mask is only called from
>> __get_user_pages, which already untagged the address. I'll remove
>> untagging here.
>
> It also called from follow_page(). Have you covered all its callers?

Oh, missed that, will take a look.

Thinking about that, would it make sense to add untagging to find_vma
(and others) instead of trying to cover all find_vma callers?