radix-tree: fix sibling entry insertion
The subtraction was the wrong way round, leading to undefined behaviour
(shift by an amount larger than the size of the type).
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Kirill Shutemov <kirill.shutemov@linux.intel.com>
Cc: Jan Kara <jack@suse.com>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index 585965a..c0366d1 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -526,8 +526,8 @@
#ifdef CONFIG_RADIX_TREE_MULTIORDER
/* Insert pointers to the canonical entry */
- if ((shift - order) > 0) {
- int i, n = 1 << (shift - order);
+ if (order > shift) {
+ int i, n = 1 << (order - shift);
offset = offset & ~(n - 1);
slot = ptr_to_indirect(&node->slots[offset]);
for (i = 0; i < n; i++) {