arm64: Do not mask out PTE_RDONLY in pte_same()

commit 6767df245f4736d0cf0c6fb7cf9cf94b27414245 upstream.

Following commit 73e86cb0 ("arm64: Move PTE_RDONLY bit handling out
of set_pte_at()"), the PTE_RDONLY bit is no longer managed by
set_pte_at() but built into the PAGE_* attribute definitions.
Consequently, pte_same() must include this bit when checking two PTEs
for equality.

Remove the arm64-specific pte_same() function, practically reverting
commit 747a70e6 ("arm64: Fix copy-on-write referencing in HugeTLB")

Change-Id: Ide56e18798c2d449a1bc94a0022d8ce011bc88d0
Fixes: 73e86cb0 ("arm64: Move PTE_RDONLY bit handling out of set_pte_at()")
Cc: <stable@vger.kernel.org> # 4.14.x-
Cc: Will Deacon <will@kernel.org>
Cc: Steve Capper <steve.capper@arm.com>
Reported-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Git-commit: 67f5c06a
Git-repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git


Signed-off-by: Blagovest Kolenichev <bkolenichev@codeaurora.org>