[stable:PATCH 1/2] arm64: kernel: Save and restore addr_limit on exception entry

On Mon, Aug 15, 2016 at 05:45:43PM +0100, James Morse wrote:

Hi Greg,

On 14/08/16 16:54, Greg KH wrote:

quoted

On Fri, Aug 12, 2016 at 07:11:19PM +0100, James Morse wrote:

quoted

commit e19a6ee2460bdd0d0055a6029383422773f9999a upstream.

If we take an exception while at EL1, the exception handler inherits
the original context's addr_limit value. To be consistent always reset
addr_limit and PSTATE.UAO on (re-)entry to EL1. This prevents accidental
re-use of the original context's addr_limit.

Based on a similar patch for arm from Russell King.

Acked-by: Will Deacon <redacted>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Will Deacon <redacted>
[ backport to stop perf misusing inherited addr_limit.
  Removed code interacting with UAO and the irqstack ]
Link: https://bugs.chromium.org/p/project-zero/issues/detail?id=822
Signed-off-by: James Morse <james.morse@arm.com>
Cc: <redacted> #4.1

Fails to apply to 4.4-stable, can you provide a backport for both of
these to that tree if you want them there?

Sorry - that is what I was trying to do!

v4.4:
http://lists.infradead.org/pipermail/linux-arm-kernel/2016-August/448685.html

v4.1 (this one):
http://lists.infradead.org/pipermail/linux-arm-kernel/2016-August/448684.html


Did I mess something up in the cc/sign-off area?

Ah, that was confusing.  You sent 2 patches, as a series, and didn't
make it obvious what they were to be applied to.

Please make it so I can't miss it, otherwise I will :)

now queued up.

greg k-h