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-rw-r--r--lib/radix-tree.c14
1 files changed, 8 insertions, 6 deletions
diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index 53fd44d78716..48c250fe2233 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -1049,12 +1049,14 @@ radix_tree_node_ctor(struct kmem_cache *cachep, void *node)
static __init unsigned long __maxindex(unsigned int height)
{
- unsigned int tmp = height * RADIX_TREE_MAP_SHIFT;
- unsigned long index = (~0UL >> (RADIX_TREE_INDEX_BITS - tmp - 1)) >> 1;
-
- if (tmp >= RADIX_TREE_INDEX_BITS)
- index = ~0UL;
- return index;
+ unsigned int width = height * RADIX_TREE_MAP_SHIFT;
+ int shift = RADIX_TREE_INDEX_BITS - width;
+
+ if (shift < 0)
+ return ~0UL;
+ if (shift >= BITS_PER_LONG)
+ return 0UL;
+ return ~0UL >> shift;
}
static __init void radix_tree_init_maxindex(void)