[aarch64-port-dev ] [Roland Westrelin] Re: Aarch64 port for ZGC, so far

[Stuart Monteith]

Hello,
  I'm afraid this is the expected behaviour:
    https://www.kernel.org/doc/Documentation/arm64/tagged-pointers.txt

So it is explicit in stating that we don't pass tagged addresses to the kernel.

BR,
   Stuart



BR,
    Stuart

On Sun, 14 Apr 2019 at 12:57, Andrew Haley <aph at redhat.com> wrote:
>
> On 4/13/19 11:33 PM, Stuart Monteith wrote:
> >    At some point earlier on another thread the connection is being
> > closed, hence the XIOError here. This error is being caused because
> > the libx11 library is writing some image data to its socket with
> > "writev(int fd, const struct iovec *iov, int iovcnt);" returning an
> > error. The errno associated with that is EFAULT - which means the
> > kernel was being passed a bad address.
> > The reason running with AWT is exiting is that tagged addresses are
> > regarded as bad by the kernel,
>
> Great catch.
>
> That sounds like a kernel bug to me. The upper bits are supposed to be
> ignored by the system. Can you raise this with a suitable kernel engineer?
>
> --
> Andrew Haley
> Java Platform Lead Engineer
> Red Hat UK Ltd. <https://www.redhat.com>
> EAC8 43EB D3EF DB98 CC77 2FAD A5CD 6035 332F A671