From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 661C0C04A6B for ; Wed, 8 May 2019 05:44:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2BFFD21530 for ; Wed, 8 May 2019 05:44:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727489AbfEHFoO (ORCPT ); Wed, 8 May 2019 01:44:14 -0400 Received: from mx1.redhat.com ([209.132.183.28]:42034 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727478AbfEHFoO (ORCPT ); Wed, 8 May 2019 01:44:14 -0400 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 15F9C3082B4D for ; Wed, 8 May 2019 05:44:14 +0000 (UTC) Received: from xz-x1.nay.redhat.com (dhcp-15-205.nay.redhat.com [10.66.15.205]) by smtp.corp.redhat.com (Postfix) with ESMTP id F291E60139; Wed, 8 May 2019 05:44:11 +0000 (UTC) From: Peter Xu To: kvm@vger.kernel.org Cc: Paolo Bonzini , Juan Quintela , =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= , peterx@redhat.com, "Dr . David Alan Gilbert" Subject: [PATCH 2/2] kvm: Fix loop of clear dirty with off-by-one Date: Wed, 8 May 2019 13:44:03 +0800 Message-Id: <20190508054403.7277-3-peterx@redhat.com> In-Reply-To: <20190508054403.7277-1-peterx@redhat.com> References: <20190508054403.7277-1-peterx@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.45]); Wed, 08 May 2019 05:44:14 +0000 (UTC) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Just imaging the case where num_pages < BITS_PER_LONG, then the loop will be skipped while it shouldn't. Signed-off-by: Peter Xu --- virt/kvm/kvm_main.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index ad39c57de82d..15601a19a87a 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1264,8 +1264,8 @@ int kvm_clear_dirty_log_protect(struct kvm *kvm, return -EFAULT; spin_lock(&kvm->mmu_lock); - for (offset = log->first_page, - i = offset / BITS_PER_LONG, n = log->num_pages / BITS_PER_LONG; n--; + for (offset = log->first_page, i = offset / BITS_PER_LONG, + n = (log->num_pages / BITS_PER_LONG + 1); n--; i++, offset += BITS_PER_LONG) { unsigned long mask = *dirty_bitmap_buffer++; atomic_long_t *p = (atomic_long_t *) &dirty_bitmap[i]; -- 2.17.1