Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754002AbcDFVbE (ORCPT ); Wed, 6 Apr 2016 17:31:04 -0400 Received: from mga14.intel.com ([192.55.52.115]:58435 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753718AbcDFVVx (ORCPT ); Wed, 6 Apr 2016 17:21:53 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.24,448,1455004800"; d="scan'208";a="779550820" From: Matthew Wilcox To: linux-kernel@vger.kernel.org, Andrew Morton Cc: Matthew Wilcox , Ross Zwisler , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Konstantin Khlebnikov , Kirill Shutemov , Jan Kara , Neil Brown Subject: [PATCH 10/30] radix-tree: Fix sibling entry insertion Date: Wed, 6 Apr 2016 17:21:19 -0400 Message-Id: <1459977699-2349-11-git-send-email-willy@linux.intel.com> X-Mailer: git-send-email 2.8.0.rc3 In-Reply-To: <1459977699-2349-1-git-send-email-willy@linux.intel.com> References: <1459977699-2349-1-git-send-email-willy@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 883 Lines: 26 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 Reviewed-by: Ross Zwisler --- lib/radix-tree.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/lib/radix-tree.c b/lib/radix-tree.c index 40343f28a705..42a0492b2ba2 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++) { -- 2.8.0.rc3