[PATCH] 64 bit bug in radix-tree lookup.

The radix tree functions __lookup and __lookup_tag uses (1 << shift) in
their index calculations.  On 64 bit systems the shift can be bigger than
32.  The shift of an integer by more than 32 bits evaluates to zero which
causes the lookup to fail.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

lib/radix-tree.c

@@ -485,8 +485,8 @@ __lookup(struct radix_tree_root *root, void **results, unsigned long index,
 		for ( ; i < RADIX_TREE_MAP_SIZE; i++) {
 			if (slot->slots[i] != NULL)
 				break;
-			index &= ~((1 << shift) - 1);
-			index += 1 << shift;
+			index &= ~((1UL << shift) - 1);
+			index += 1UL << shift;
 			if (index == 0)
 				goto out;	/* 32-bit wraparound */
 		}
@@ -575,8 +575,8 @@ __lookup_tag(struct radix_tree_root *root, void **results, unsigned long index,
 				BUG_ON(slot->slots[i] == NULL);
 				break;
 			}
-			index &= ~((1 << shift) - 1);
-			index += 1 << shift;
+			index &= ~((1UL << shift) - 1);
+			index += 1UL << shift;
 			if (index == 0)
 				goto out;	/* 32-bit wraparound */
 		}