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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 802D8C433EF for ; Mon, 11 Oct 2021 14:12:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6997560E90 for ; Mon, 11 Oct 2021 14:12:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243304AbhJKOOl (ORCPT ); Mon, 11 Oct 2021 10:14:41 -0400 Received: from mail.kernel.org ([198.145.29.99]:33474 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243035AbhJKOMh (ORCPT ); Mon, 11 Oct 2021 10:12:37 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id D854B611B0; Mon, 11 Oct 2021 14:03:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1633961023; bh=cU5o4ZJSpdsCaG3FQuUCFX6bud+DK3LScMu2fjPx9MU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bvRgIOFO1fVyZp0zHdKU5YJn/aBrCcrRVys0xWLk6ViJ6NDN4CQUCuk+8kh4peSKL UpVlCwMj0T7J+WG+mDD+8LxjwyBxREf2gVVvDwMt2FP5QZTygBYYIztAGuleHCBqxv trK9QRrQDCyZ65oL7znHeg1LenlqmY04eKpbVJyg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Dumazet , Catherine Sullivan , Sagi Shahar , Jon Olson , Willem de Bruijn , Luigi Rizzo , Jeroen de Borst , Tao Liu , "David S. Miller" , Sasha Levin Subject: [PATCH 5.14 112/151] gve: fix gve_get_stats() Date: Mon, 11 Oct 2021 15:46:24 +0200 Message-Id: <20211011134521.435783777@linuxfoundation.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20211011134517.833565002@linuxfoundation.org> References: <20211011134517.833565002@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Eric Dumazet [ Upstream commit 2f57d4975fa027eabd35fdf23a49f8222ef3abf2 ] gve_get_stats() can report wrong numbers if/when u64_stats_fetch_retry() returns true. What is needed here is to sample values in temporary variables, and only use them after each loop is ended. Fixes: f5cedc84a30d ("gve: Add transmit and receive support") Signed-off-by: Eric Dumazet Cc: Catherine Sullivan Cc: Sagi Shahar Cc: Jon Olson Cc: Willem de Bruijn Cc: Luigi Rizzo Cc: Jeroen de Borst Cc: Tao Liu Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/ethernet/google/gve/gve_main.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/drivers/net/ethernet/google/gve/gve_main.c b/drivers/net/ethernet/google/gve/gve_main.c index 29c5f994f92e..1b49e9feacac 100644 --- a/drivers/net/ethernet/google/gve/gve_main.c +++ b/drivers/net/ethernet/google/gve/gve_main.c @@ -41,6 +41,7 @@ static void gve_get_stats(struct net_device *dev, struct rtnl_link_stats64 *s) { struct gve_priv *priv = netdev_priv(dev); unsigned int start; + u64 packets, bytes; int ring; if (priv->rx) { @@ -48,10 +49,12 @@ static void gve_get_stats(struct net_device *dev, struct rtnl_link_stats64 *s) do { start = u64_stats_fetch_begin(&priv->rx[ring].statss); - s->rx_packets += priv->rx[ring].rpackets; - s->rx_bytes += priv->rx[ring].rbytes; + packets = priv->rx[ring].rpackets; + bytes = priv->rx[ring].rbytes; } while (u64_stats_fetch_retry(&priv->rx[ring].statss, start)); + s->rx_packets += packets; + s->rx_bytes += bytes; } } if (priv->tx) { @@ -59,10 +62,12 @@ static void gve_get_stats(struct net_device *dev, struct rtnl_link_stats64 *s) do { start = u64_stats_fetch_begin(&priv->tx[ring].statss); - s->tx_packets += priv->tx[ring].pkt_done; - s->tx_bytes += priv->tx[ring].bytes_done; + packets = priv->tx[ring].pkt_done; + bytes = priv->tx[ring].bytes_done; } while (u64_stats_fetch_retry(&priv->tx[ring].statss, start)); + s->tx_packets += packets; + s->tx_bytes += bytes; } } } -- 2.33.0