For low slice, max addr should be less than 4G. Without limiting this correctly
we will end up with a low slice mask which has 17th bit set. This is not
a problem with the current code because our low slice mask is of type u16. But
in later patch I am switching low slice mask to u64 type and having the 17bit
set result in wrong slice mask which in turn results in mmap failures.
Reviewed-by: Paul Mackerras <pau...@ozlabs.org>
Signed-off-by: Aneesh Kumar K.V <aneesh.ku...@linux.vnet.ibm.com>
---
arch/powerpc/mm/slice.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/mm/slice.c b/arch/powerpc/mm/slice.c
index 2b27458902ee..bf150557dba8 100644
--- a/arch/powerpc/mm/slice.c
+++ b/arch/powerpc/mm/slice.c
@@ -83,11 +83,10 @@ static struct slice_mask slice_range_to_mask(unsigned long
start,
struct slice_mask ret = { 0, 0 };
if (start < SLICE_LOW_TOP) {
- unsigned long mend = min(end, SLICE_LOW_TOP);
- unsigned long mstart = min(start, SLICE_LOW_TOP);
+ unsigned long mend = min(end, (SLICE_LOW_TOP - 1));
ret.low_slices = (1u << (GET_LOW_SLICE_INDEX(mend) + 1))
- - (1u << GET_LOW_SLICE_INDEX(mstart));
+ - (1u << GET_LOW_SLICE_INDEX(start));
}
if ((start + len) > SLICE_LOW_TOP)
--
2.7.4
