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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 77EE7C43381 for ; Tue, 19 Feb 2019 13:57:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4E3552146E for ; Tue, 19 Feb 2019 13:57:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728435AbfBSN5Q (ORCPT ); Tue, 19 Feb 2019 08:57:16 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:54711 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725805AbfBSN5P (ORCPT ); Tue, 19 Feb 2019 08:57:15 -0500 Received: from 1.general.cking.uk.vpn ([10.172.193.212] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.76) (envelope-from ) id 1gw5ta-0002Mh-0U; Tue, 19 Feb 2019 13:57:14 +0000 From: Colin King To: "Michael S . Tsirkin" , Jason Wang , kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH][next] vhost: only return early if ret indicates an error or no iovecs have been processed Date: Tue, 19 Feb 2019 13:57:13 +0000 Message-Id: <20190219135713.10426-1-colin.king@canonical.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Colin Ian King Currently the loop that calls log_write_hva on each iovec is never executed because of an incorrect error check on the return from the call to translate_desc. The check should be checking for a -ve error return and because it makes no sense to iterate over zero items, the checks should also check for zero too. Detected by CoverityScan, CID#1476969 ("Logically dead code") Fixes: cc5e71075947 ("vhost: log dirty page correctly") Signed-off-by: Colin Ian King --- drivers/vhost/vhost.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 24a129fcdd61..a9a1709a859a 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -1788,7 +1788,7 @@ static int log_used(struct vhost_virtqueue *vq, u64 used_offset, u64 len) ret = translate_desc(vq, (uintptr_t)vq->used + used_offset, len, iov, 64, VHOST_ACCESS_WO); - if (ret) + if (ret <= 0) return ret; for (i = 0; i < ret; i++) { -- 2.20.1