Re: [PATCH 2/2] selftests: vm: pkeys: Fix powerpc access right updates

* Sandipan Das:

Hi Florian,

On 08/05/20 11:31 pm, Florian Weimer wrote:

quoted

* Sandipan Das:

quoted

The Power ISA mandates that all writes to the Authority
Mask Register (AMR) must always be preceded as well as
succeeded by a context-synchronizing instruction. This
applies to both the privileged and unprivileged variants
of the Move To AMR instruction.

Ugh.  Do you have a reference for that?

We need to fix this in glibc.

This is from Table 6 of Chapter 11 in page 1134 of Power
ISA 3.0B. The document can be found here:
https://ibm.ent.box.com/s/1hzcwkwf8rbju5h9iyf44wm94amnlcrv

Thanks a lot!  I filed:

  <https://sourceware.org/bugzilla/show_bug.cgi?id=25954>

Florian