x86/sgx: Create utility to validate user provided offset and length

mainline inclusion
from mainline-6.0-rc1
commit dda03e2c
category: feature
bugzilla: https://gitee.com/openeuler/intel-kernel/issues/I5USAM


CVE: NA

Intel-SIG: commit dda03e2c x86/sgx: Create utility to validate user
provided offset and length.
Backport for SGX EDMM support.

--------------------------------

User provided offset and length is validated when parsing the parameters
of the SGX_IOC_ENCLAVE_ADD_PAGES ioctl(). Extract this validation
(with consistent use of IS_ALIGNED) into a utility that can be used
by the SGX2 ioctl()s that will also provide these values.

Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Link: https://lkml.kernel.org/r/767147bc100047abed47fe27c592901adfbb93a2.1652137848.git.reinette.chatre@intel.com


Signed-off-by: Zhiquan Li <zhiquan1.li@intel.com>