[PATCH v2] mm: memblock: fix wrong memmove size in memblock_merge_regions()

[Lin Feng <linfeng@cn.fujitsu.com>]

The memmove span covers from (next+1) to the end of the array, and the index
of next is (i+1), so the index of (next+1) is (i+2). So the size of remaining
array elements is (type->cnt - (i + 2)).

Cc: Tejun Heo <tj@kernel.org>
Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Signed-off-by: Lin Feng <linfeng@cn.fujitsu.com>
---
ChangeLog v1->v2:
- Add a comment pointed out by Tejun.
---
 mm/memblock.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/mm/memblock.c b/mm/memblock.c
index 6259055..88adc8a 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -314,7 +314,8 @@ static void __init_memblock memblock_merge_regions(struct memblock_type *type)
 		}
 
 		this->size += next->size;
-		memmove(next, next + 1, (type->cnt - (i + 1)) * sizeof(*next));
+		/* move forward from next + 1, index of which is i + 2 */
+		memmove(next, next + 1, (type->cnt - (i + 2)) * sizeof(*next));
 		type->cnt--;
 	}
 }
-- 
1.7.11.7

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