Following commit 26ffd0d4 (ARM: mm: introduce present, faulting entries
for PAGE_NONE), if a page has been mapped as PROT_NONE, the L_PTE_VALID
bit is cleared by the set_pte_ext() code. With LPAE the software and
hardware pte share the same location and subsequent modifications of pte
range (change_protection()) will leave the L_PTE_VALID bit cleared.

This patch adds the L_PTE_VALID bit to the newprot mask in pte_modify().
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Reported-by: NSubash Patel <subash.rp@samsung.com>
Tested-by: NSubash Patel <subash.rp@samsung.com>
Acked-by: NWill Deacon <will.deacon@arm.com>
Cc: <stable@vger.kernel.org> # 3.8.x
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>