[v2] powerpc/kexec: Fix radix to hash kexec

[Michael Ellerman]

On Thu, 2017-06-29 at 11:57:26 UTC, Balbir Singh wrote:
> This patch fixes a crash seen while doing a kexec from
> radix mode to hash mode. Key 0 is special in hash and
> used in the RPN by default, we set the key values to 0
> today. In radix mode key 0 is used to control
> supervisor<->user access. In hash key 0 is used by default,
> so the first instruction after the switch causes a crash on
> kexec.
> 
> This patch fixes
> (3b10d00 powerpc/mm/radix: Prevent kernel execution of user space)
> The commit above introduced setting of IAMR and AMOR values to
> prevent execution of user mode instructions from supervisor mode.
> We need to clean up these SPR's on kexec.
> 
> Reported-by: Benjamin Herrenschmidt <benh at kernel.crashing.org>
> Signed-off-by: Balbir Singh <bsingharora at gmail.com>

Applied to powerpc fixes, thanks.

https://git.kernel.org/powerpc/c/1e2a516e89fc412a754327522ab271

cheers