From nobody Thu May 9 13:52:37 2024 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1659109506612220.614358806871; Fri, 29 Jul 2022 08:45:06 -0700 (PDT) Received: from localhost ([::1]:51928 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oHSAj-0004LN-02 for importer@patchew.org; Fri, 29 Jul 2022 11:45:05 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:49954) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oHS9E-0003gw-E5 for qemu-devel@nongnu.org; Fri, 29 Jul 2022 11:43:32 -0400 Received: from prt-mail.chinatelecom.cn ([42.123.76.222]:41793 helo=chinatelecom.cn) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oHS99-0006mk-Vy for qemu-devel@nongnu.org; Fri, 29 Jul 2022 11:43:32 -0400 Received: from clientip-125.69.43.72 (unknown [172.18.0.218]) by chinatelecom.cn (HERMES) with SMTP id CB64F2800B9; Fri, 29 Jul 2022 23:43:11 +0800 (CST) Received: from ([172.18.0.218]) by app0025 with ESMTP id 29b20f0023dd42269242379c37c5552b for qemu-devel@nongnu.org; Fri, 29 Jul 2022 23:43:14 CST HMM_SOURCE_IP: 172.18.0.218:35118.1172650779 HMM_ATTACHE_NUM: 0000 HMM_SOURCE_TYPE: SMTP X-189-SAVE-TO-SEND: +huangy81@chinatelecom.cn X-Transaction-ID: 29b20f0023dd42269242379c37c5552b X-Real-From: huangy81@chinatelecom.cn X-Receive-IP: 172.18.0.218 X-MEDUSA-Status: 0 From: huangy81@chinatelecom.cn To: qemu-devel Cc: "Dr. David Alan Gilbert" , Peter Maydell , leobras@redhat.com, quintela@redhat.com, Richard Henderson , berrange@redhat.com, iii@linux.ibm.com, peterx@redhat.com, =?UTF-8?q?Hyman=20Huang=28=E9=BB=84=E5=8B=87=29?= Subject: [PATCH v1] dirtylimit: Fix overflow when computing MB Date: Fri, 29 Jul 2022 23:42:59 +0800 Message-Id: X-Mailer: git-send-email 1.8.3.1 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=42.123.76.222; envelope-from=huangy81@chinatelecom.cn; helo=chinatelecom.cn X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZM-MESSAGEID: 1659109508835100001 From: Hyman Huang(=E9=BB=84=E5=8B=87) Coverity points out a overflow problem when computing MB, dirty_ring_size and TARGET_PAGE_SIZE are both 32 bits, multiplication will be done as a 32-bit operation, which could overflow. Simplify the formula. Meanwhile, fix spelling mistake of variable name. Reported-by: Peter Maydell Signed-off-by: Peter Maydell Signed-off-by: Richard Henderson Signed-off-by: Hyman Huang(=E9=BB=84=E5=8B=87) --- softmmu/dirtylimit.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/softmmu/dirtylimit.c b/softmmu/dirtylimit.c index 8d98cb7..1423225 100644 --- a/softmmu/dirtylimit.c +++ b/softmmu/dirtylimit.c @@ -236,14 +236,14 @@ static inline int64_t dirtylimit_dirty_ring_full_time= (uint64_t dirtyrate) { static uint64_t max_dirtyrate; uint32_t dirty_ring_size =3D kvm_dirty_ring_size(); - uint64_t dirty_ring_size_meory_MB =3D - dirty_ring_size * TARGET_PAGE_SIZE >> 20; + uint32_t dirty_ring_size_memory_MB =3D + dirty_ring_size >> (20 - TARGET_PAGE_BITS); =20 if (max_dirtyrate < dirtyrate) { max_dirtyrate =3D dirtyrate; } =20 - return dirty_ring_size_meory_MB * 1000000 / max_dirtyrate; + return dirty_ring_size_memory_MB * 1000000ULL / max_dirtyrate; } =20 static inline bool dirtylimit_done(uint64_t quota, --=20 1.8.3.1