From patchwork Tue Nov 5 07:16:01 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Aaron Lu X-Patchwork-Id: 3139671 Return-Path: X-Original-To: patchwork-linux-pm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 3FCE09F407 for ; Tue, 5 Nov 2013 07:15:22 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 4A4C620618 for ; Tue, 5 Nov 2013 07:15:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 363B620615 for ; Tue, 5 Nov 2013 07:15:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750990Ab3KEHPR (ORCPT ); Tue, 5 Nov 2013 02:15:17 -0500 Received: from mga09.intel.com ([134.134.136.24]:36740 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750774Ab3KEHPQ (ORCPT ); Tue, 5 Nov 2013 02:15:16 -0500 Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga102.jf.intel.com with ESMTP; 04 Nov 2013 23:11:48 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.93,535,1378882800"; d="scan'208";a="403741292" Received: from aaronlu.sh.intel.com ([10.239.37.146]) by orsmga001.jf.intel.com with ESMTP; 04 Nov 2013 23:15:14 -0800 Message-ID: <52789B31.70005@intel.com> Date: Tue, 05 Nov 2013 15:16:01 +0800 From: Aaron Lu Organization: Intel, Shanghai, PRC MIME-Version: 1.0 To: "Rafael J. Wysocki" CC: Linux-pm mailing list , Leon Drugi Subject: [PATCH] PM / hibernate: Avoid overflow in hibernate_preallocate_memory Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP When system has a lot of highmem(e.g. 16GiB using a 32 bits kernel), the code to calculate how much memory we need to preallocate in normal zone may cause overflow. As Leon has analysed: " It looks that during computing 'alloc' variable there is overflow: alloc = (3943404 - 1970542) - 1978280 = -5418 (signed) And this function goes to err_out. " Fix this by avoiding that overflow. Reference: https://bugzilla.kernel.org/show_bug.cgi?id=60817 Reported-and-tested-by: Leon Drugi Cc: stable Signed-off-by: Aaron Lu --- kernel/power/snapshot.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index 98c3b34a4cff..91aa616a1f4e 100644 --- a/kernel/power/snapshot.c +++ b/kernel/power/snapshot.c @@ -1402,7 +1402,8 @@ int hibernate_preallocate_memory(void) * highmem and non-highmem zones separately. */ pages_highmem = preallocate_image_highmem(highmem / 2); - alloc = (count - max_size) - pages_highmem; + alloc = (count - max_size) > pages_highmem ? + (count - max_size - pages_highmem) : 0; pages = preallocate_image_memory(alloc, avail_normal); if (pages < alloc) { /* We have exhausted non-highmem pages, try highmem. */