diff options
| author | Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> | 2017-03-21 22:59:52 +0530 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2017-03-31 23:09:48 +1100 |
| commit | 98beda74de246520653b42147443292d9814426d (patch) | |
| tree | f6c3d6cc46171c12e3b0a2b353b03dbccb890f38 /arch/powerpc/mm/slice.c | |
| parent | b42279f0165cdfb093718ec368e56dde7e8d80af (diff) | |
| download | linux-98beda74de246520653b42147443292d9814426d.tar.bz2 | |
powerpc/mm/slice: Fix off-by-1 error when computing slice mask
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 <paulus@ozlabs.org>
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 'arch/powerpc/mm/slice.c')
| -rw-r--r-- | arch/powerpc/mm/slice.c | 5 |
1 files 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) |