From patchwork Sat Mar 25 22:04:50 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arseniy Krasnov X-Patchwork-Id: 13187906 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9DCF3C76196 for ; Sat, 25 Mar 2023 22:08:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231623AbjCYWIK (ORCPT ); Sat, 25 Mar 2023 18:08:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50438 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229488AbjCYWII (ORCPT ); Sat, 25 Mar 2023 18:08:08 -0400 Received: from mx.sberdevices.ru (mx.sberdevices.ru [45.89.227.171]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 670122D41; Sat, 25 Mar 2023 15:08:07 -0700 (PDT) Received: from s-lin-edge02.sberdevices.ru (localhost [127.0.0.1]) by mx.sberdevices.ru (Postfix) with ESMTP id C3AAE5FD02; Sun, 26 Mar 2023 01:08:05 +0300 (MSK) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sberdevices.ru; s=mail; t=1679782085; bh=qj2eKpHg24lBwg8Ceng11FmHD2L6ZT5DPMiSeVXYd5I=; h=Message-ID:Date:MIME-Version:To:From:Subject:Content-Type; b=Ycs9Ovje0B4OKkIJ/clxG6LEDH4VwyLuA93Gz+OTctkXltwnvYo2Q2uVRttVOm+9C HDugKuMhCSpaOUXlwcRksXnHep9dGd5bwA1JmgJUR884hfeiRYSNjTvjjEwtb8zDKE zMNlR5KdIgu0MLluBcpoBcO2jyPCyXxvzJoozSTVQGJ+d3/LBXPoM8eysq/Z59KDnf 4/KqvCV+XcFFnVsWW7GJv2GjgyUAA8o0DAjNdYe7hv9Xazgmy8zzou24aYJSyaI6Tc om1v483NxzYV56k53Fr6ISmAqYsNBXgTUdTL4X7m7JaLg/RRk4k0zViw5AtX7mzOYt Ipz8sBJjAduXg== Received: from S-MS-EXCH01.sberdevices.ru (S-MS-EXCH01.sberdevices.ru [172.16.1.4]) by mx.sberdevices.ru (Postfix) with ESMTP; Sun, 26 Mar 2023 01:08:05 +0300 (MSK) Message-ID: <1ea0c407-814f-38a0-1fb7-4f146e5643ba@sberdevices.ru> Date: Sun, 26 Mar 2023 01:04:50 +0300 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.7.1 Content-Language: en-US In-Reply-To: To: Stefan Hajnoczi , Stefano Garzarella , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Bobby Eshleman CC: , , , , , , From: Arseniy Krasnov Subject: [PATCH net-next v5 2/2] virtio/vsock: check argument to avoid no effect call X-Originating-IP: [172.16.1.6] X-ClientProxiedBy: S-MS-EXCH01.sberdevices.ru (172.16.1.4) To S-MS-EXCH01.sberdevices.ru (172.16.1.4) X-KSMG-Rule-ID: 4 X-KSMG-Message-Action: clean X-KSMG-AntiSpam-Status: not scanned, disabled by settings X-KSMG-AntiSpam-Interceptor-Info: not scanned X-KSMG-AntiPhishing: not scanned, disabled by settings X-KSMG-AntiVirus: Kaspersky Secure Mail Gateway, version 1.1.2.30, bases: 2023/03/25 18:14:00 #21009230 X-KSMG-AntiVirus-Status: Clean, skipped Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Both of these functions have no effect when input argument is 0, so to avoid useless spinlock access, check argument before it. Signed-off-by: Arseniy Krasnov Reviewed-by: Stefano Garzarella --- net/vmw_vsock/virtio_transport_common.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c index 9e87c7d4d7cf..312658c176bd 100644 --- a/net/vmw_vsock/virtio_transport_common.c +++ b/net/vmw_vsock/virtio_transport_common.c @@ -302,6 +302,9 @@ u32 virtio_transport_get_credit(struct virtio_vsock_sock *vvs, u32 credit) { u32 ret; + if (!credit) + return 0; + spin_lock_bh(&vvs->tx_lock); ret = vvs->peer_buf_alloc - (vvs->tx_cnt - vvs->peer_fwd_cnt); if (ret > credit) @@ -315,6 +318,9 @@ EXPORT_SYMBOL_GPL(virtio_transport_get_credit); void virtio_transport_put_credit(struct virtio_vsock_sock *vvs, u32 credit) { + if (!credit) + return; + spin_lock_bh(&vvs->tx_lock); vvs->tx_cnt -= credit; spin_unlock_bh(&vvs->tx_lock);