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authorAnton Blanchard <anton@samba.org>2013-11-18 14:55:28 +1100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-11-29 11:28:08 -0800
commit3aad6072464530c82674f840374c726b467cfcf0 (patch)
treecac9a181b38ca842136a7ae4d8482bf70535d357
parent9a43996524dacb19f9e90484190253873748bd1f (diff)
powerpc: ppc64 address space capped at 32TB, mmap randomisation disabled
commit 5a049f14902982c26538250bdc8d54156d357252 upstream. Commit fba2369e6ceb (mm: use vm_unmapped_area() on powerpc architecture) has a bug in slice_scan_available() where we compare an unsigned long (high_slices) against a shifted int. As a result, comparisons against the top 32 bits of high_slices (representing the top 32TB) always returns 0 and the top of our mmap region is clamped at 32TB This also breaks mmap randomisation since the randomised address is always up near the top of the address space and it gets clamped down to 32TB. Signed-off-by: Anton Blanchard <anton@samba.org> Acked-by: Michel Lespinasse <walken@google.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--arch/powerpc/mm/slice.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/powerpc/mm/slice.c b/arch/powerpc/mm/slice.c
index 3e99c149271a..7ce9cf3b6988 100644
--- a/arch/powerpc/mm/slice.c
+++ b/arch/powerpc/mm/slice.c
@@ -258,7 +258,7 @@ static bool slice_scan_available(unsigned long addr,
slice = GET_HIGH_SLICE_INDEX(addr);
*boundary_addr = (slice + end) ?
((slice + end) << SLICE_HIGH_SHIFT) : SLICE_LOW_TOP;
- return !!(available.high_slices & (1u << slice));
+ return !!(available.high_slices & (1ul << slice));
}
}