powerpc/mm: Replace _PAGE_USER with _PAGE_PRIVILEGED
authorAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Fri, 29 Apr 2016 13:25:34 +0000 (23:25 +1000)
committerMichael Ellerman <mpe@ellerman.id.au>
Sun, 1 May 2016 08:32:26 +0000 (18:32 +1000)
commitac29c64089b74d107edb90879e63a2f7a03cd66b
tree3143933d055f49376ec549cc3ffe76a224b23288
parente7bfc462d32fc417d3fea8ad07b62b59f000e925
powerpc/mm: Replace _PAGE_USER with _PAGE_PRIVILEGED

_PAGE_PRIVILEGED means the page can be accessed only by the kernel. This
is done to keep pte bits similar to PowerISA 3.0 Radix PTE format. User
pages are now marked by clearing _PAGE_PRIVILEGED bit.

Previously we allowed the kernel to have a privileged page in the lower
address range (USER_REGION). With this patch such access is denied.

We also prevent a kernel access to a non-privileged page in higher
address range (ie, REGION_ID != 0).

Both the above access scenarios should never happen.

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Jeremy Kerr <jk@ozlabs.org>
Cc: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
12 files changed:
arch/powerpc/include/asm/book3s/64/hash.h
arch/powerpc/include/asm/book3s/64/pgtable.h
arch/powerpc/mm/hash64_4k.c
arch/powerpc/mm/hash64_64k.c
arch/powerpc/mm/hash_utils_64.c
arch/powerpc/mm/hugepage-hash64.c
arch/powerpc/mm/hugetlbpage-hash64.c
arch/powerpc/mm/hugetlbpage.c
arch/powerpc/mm/pgtable.c
arch/powerpc/mm/pgtable_64.c
arch/powerpc/platforms/cell/spufs/fault.c
drivers/misc/cxl/fault.c