[PATCH 4.14 171/193] powerpc/64s/hash: Allow MAP_FIXED allocations to cross 128TB boundary

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

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

From: Nicholas Piggin <npiggin@xxxxxxxxx>

commit 35602f82d0c765f991420e319c8d3a596c921eb8 upstream.

While mapping hints with a length that cross 128TB are disallowed,
MAP_FIXED allocations that cross 128TB are allowed. These are failing
on hash (on radix they succeed). Add an additional case for fixed
mappings to expand the addr_limit when crossing 128TB.

Fixes: f4ea6dcb08ea ("powerpc/mm: Enable mappings above 128TB")
Signed-off-by: Nicholas Piggin <npiggin@xxxxxxxxx>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 arch/powerpc/mm/slice.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/powerpc/mm/slice.c
+++ b/arch/powerpc/mm/slice.c
@@ -418,7 +418,7 @@ unsigned long slice_get_unmapped_area(un
 	unsigned long high_limit;
 
 	high_limit = DEFAULT_MAP_WINDOW;
-	if (addr >= high_limit)
+	if (addr >= high_limit || (fixed && (addr + len > high_limit)))
 		high_limit = TASK_SIZE;
 
 	if (len > high_limit)