Re: [PATCH v15 00/17] arm64: untag user pointers passed to the kernel

From: Christoph Hellwig
Date: Wed May 29 2019 - 02:14:58 EST


On Tue, May 28, 2019 at 04:14:45PM +0200, Andrey Konovalov wrote:
> Thanks for a lot of valuable input! I've read through all the replies
> and got somewhat lost. What are the changes I need to do to this
> series?
>
> 1. Should I move untagging for memory syscalls back to the generic
> code so other arches would make use of it as well, or should I keep
> the arm64 specific memory syscalls wrappers and address the comments
> on that patch?

It absolutely needs to move to common code. Having arch code leads
to pointless (often unintentional) semantic difference between
architectures, and lots of boilerplate code.

Btw, can anyone of the arm crowd or Khalid comment on the linux-mm
thread on generic gup where I'm dealing with the pre-existing ADI
case of pointer untagging?