tree 259e48a52e0d3725b3f77167b6195066fe26d455
parent 77b67063bb6bce6d475e910d3b886a606d0d91f7
author Catalin Marinas <catalin.marinas@arm.com> 1353000076 +0000
committer Catalin Marinas <catalin.marinas@arm.com> 1353081025 +0000

arm64: Distinguish between user and kernel XN bits

On AArch64, the meaning of the XN bit has changed to UXN (user). The PXN
(privileged) bit must be set to prevent kernel execution. Without the
PXN bit set, the CPU may speculatively access device memory. This patch
ensures that all the mappings that the kernel must not execute from
(including user mappings) have the PXN bit set.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>