From 04523354a50761f9eafb38a1e816587b5100de4f Mon Sep 17 00:00:00 2001
From: Peter Lund <firefly@vax64.dk>
Date: Tue, 16 Oct 2007 23:29:35 -0700
Subject: [PATCH] --- yaml --- r: 70664 b: refs/heads/master c:
 430d275a399175c7c0673459738979287ec1fd22 h: refs/heads/master v: v3

---
 [refs]                 |  2 +-
 trunk/lib/radix-tree.c | 14 ++++++++------
 2 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/[refs] b/[refs]
index 83c315d79fb6..7ed8ab7cd48e 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 22e48eaf587d044ba311a73c6fe0d0deaa8fdb63
+refs/heads/master: 430d275a399175c7c0673459738979287ec1fd22
diff --git a/trunk/lib/radix-tree.c b/trunk/lib/radix-tree.c
index 53fd44d78716..48c250fe2233 100644
--- a/trunk/lib/radix-tree.c
+++ b/trunk/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)