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

Catalin Marinas
2019-05-29T12:12:40Z

On Tue, May 28, 2019 at 11:11:26PM -0700, Christoph Hellwig wrote:
> 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.

That's fine by me as long as we agree on the semantics (which shouldn't
be hard; Khalid already following up). We should probably also move the
proposed ABI document [1] into a common place (or part of since we'll
have arm64-specifics like prctl() calls to explicitly opt in to memory
tagging).

[1] https://lore.kernel.org/lkml/20190318163533.26838-1-vincenzo.frascino@arm.com/T/#u

--
Catalin