Security: disable nontemporals.

Security: disable nontemporals.

The operations were available on ARM64 and x86-32 but were unused.

It has been conjectured that nontemporals can be used for rowhammer-like bitflips more easily than regular load/store operations. It is therefore desirable to avoid generating these instructions in the future.

R= titzer, jochen, jln, Mark Seaborn, ruiq

Committed: https://crrev.com/a904b569a21ae18f34dd4034b58b283f425a34c6
Cr-Commit-Position: refs/heads/master@{#30139}

[JF, 2015-08-06 23:03:15]

jfb@chromium.org changed reviewers:
+ jln@chromium.org, jochen@chromium.org, mseaborn@chromium.org, ruiq@google.com,
titzer@chromium.org

[JF, 2015-08-06 23:05:45]

PTAL.

[Mark Seaborn, 2015-08-10 16:12:44]

It's not my codebase, but removing the possibility of using these instructions
looks like a good idea to me!

[titzer, 2015-08-12 09:44:05]

On 2015/08/10 16:12:44, Mark Seaborn wrote:
> It's not my codebase, but removing the possibility of using these instructions
> looks like a good idea to me!

Can you update the CL description with the justification (security) and
appropriate links to public information?

[JF, 2015-08-12 15:59:08]

On 2015/08/12 09:44:05, titzer wrote:
> On 2015/08/10 16:12:44, Mark Seaborn wrote:
> > It's not my codebase, but removing the possibility of using these
instructions
> > looks like a good idea to me!
> 
> Can you update the CL description with the justification (security) and
> appropriate links to public information?

Done.

[titzer, 2015-08-12 16:07:38]

On 2015/08/12 15:59:08, JF wrote:
> On 2015/08/12 09:44:05, titzer wrote:
> > On 2015/08/10 16:12:44, Mark Seaborn wrote:
> > > It's not my codebase, but removing the possibility of using these
> instructions
> > > looks like a good idea to me!
> > 
> > Can you update the CL description with the justification (security) and
> > appropriate links to public information?
> 
> Done.

lgtm

[JF, 2015-08-12 16:34:20]

The CQ bit was checked by jfb@chromium.org

[commit-bot: I haz the power, 2015-08-12 16:34:26]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1276113002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1276113002/1

[commit-bot: I haz the power, 2015-08-12 16:57:58]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-08-12 16:58:13]

Patchset 1 (id:??) landed as
https://crrev.com/a904b569a21ae18f34dd4034b58b283f425a34c6
Cr-Commit-Position: refs/heads/master@{#30139}