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authorAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>2016-04-29 23:25:34 +1000
committerMichael Ellerman <mpe@ellerman.id.au>2016-05-01 18:32:26 +1000
commitac29c64089b74d107edb90879e63a2f7a03cd66b (patch)
tree3143933d055f49376ec549cc3ffe76a224b23288 /drivers
parente7bfc462d32fc417d3fea8ad07b62b59f000e925 (diff)
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>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/misc/cxl/fault.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/misc/cxl/fault.c b/drivers/misc/cxl/fault.c
index 0feeacedcef1..377e650a2a1d 100644
--- a/drivers/misc/cxl/fault.c
+++ b/drivers/misc/cxl/fault.c
@@ -152,8 +152,10 @@ static void cxl_handle_page_fault(struct cxl_context *ctx,
access = _PAGE_PRESENT | _PAGE_READ;
if (dsisr & CXL_PSL_DSISR_An_S)
access |= _PAGE_WRITE;
+
+ access |= _PAGE_PRIVILEGED;
if ((!ctx->kernel) || (REGION_ID(dar) == USER_REGION_ID))
- access |= _PAGE_USER;
+ access &= ~_PAGE_PRIVILEGED;
if (dsisr & DSISR_NOHPTE)
inv_flags |= HPTE_NOHPTE_UPDATE;