Implement support for read-protected memory by wiring it up to the access flag in the page table descriptor. The resulting mapping is implicitly non-writable and non-executable as well, but this is good enough for implementing this attribute, as we never rely on write or execute permissions without read permissions. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Leif Lindholm <quic_llindhol@quicinc.com>