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authorMatthew Wilcox <willy@linux.intel.com>2016-05-20 17:01:59 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-05-20 17:58:30 -0700
commit3b8c00f68405e9c037a6d8ae0d5d9da7f8a34e6a (patch)
tree2669fd1498aa7895abeb85452e82399b91ac78ea
parentdb050f2924fcf39428bdadf28970a32cfaf256ef (diff)
downloadlinux-3b8c00f68405e9c037a6d8ae0d5d9da7f8a34e6a.tar.bz2
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>
-rw-r--r--lib/radix-tree.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index 585965afc808..c0366d1d2613 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -526,8 +526,8 @@ int __radix_tree_create(struct radix_tree_root *root, unsigned long index,
#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++) {