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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id F0520C001B0 for ; Wed, 9 Aug 2023 10:59:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232854AbjHIK76 (ORCPT ); Wed, 9 Aug 2023 06:59:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60908 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232846AbjHIK75 (ORCPT ); Wed, 9 Aug 2023 06:59:57 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 099B6210A for ; Wed, 9 Aug 2023 03:59:56 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 83F5C62DC8 for ; Wed, 9 Aug 2023 10:59:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 92532C433C8; Wed, 9 Aug 2023 10:59:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1691578795; bh=ZvQdwN+165wF2gWyzmHSFGBbUJ7XJBFwN3y8jvA0vOk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QUCJVhND1dga0gjePjOMpp7gyRPjWgOHDTwl1ld/EGQJ/wb8/grZ2D30cxFKSymQ/ imJN5DpE5oxqp7Zxlk6rcgWs8+YbOAaGENBjZnB1c29p3RuRysvbEL2Wl1bxELtjbr d/Sdzj9moveSnsNepYpSDOQhLWqDymwuQc3rDOG8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Eric Dumazet , David Ahern , Kuniyuki Iwashima , Jakub Kicinski , Sasha Levin Subject: [PATCH 5.15 52/92] tcp_metrics: annotate data-races around tm->tcpm_net Date: Wed, 9 Aug 2023 12:41:28 +0200 Message-ID: <20230809103635.403231969@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230809103633.485906560@linuxfoundation.org> References: <20230809103633.485906560@linuxfoundation.org> User-Agent: quilt/0.67 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 d5d986ce42c71a7562d32c4e21e026b0f87befec ] tm->tcpm_net can be read or written locklessly. Instead of changing write_pnet() and read_pnet() and potentially hurt performance, add the needed READ_ONCE()/WRITE_ONCE() in tm_net() and tcpm_new(). Fixes: 849e8a0ca8d5 ("tcp_metrics: Add a field tcpm_net and verify it matches on lookup") Signed-off-by: Eric Dumazet Reviewed-by: David Ahern Reviewed-by: Kuniyuki Iwashima Link: https://lore.kernel.org/r/20230802131500.1478140-6-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/ipv4/tcp_metrics.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/net/ipv4/tcp_metrics.c b/net/ipv4/tcp_metrics.c index 0c309fd4e04b2..88b0d952a2888 100644 --- a/net/ipv4/tcp_metrics.c +++ b/net/ipv4/tcp_metrics.c @@ -40,7 +40,7 @@ struct tcp_fastopen_metrics { struct tcp_metrics_block { struct tcp_metrics_block __rcu *tcpm_next; - possible_net_t tcpm_net; + struct net *tcpm_net; struct inetpeer_addr tcpm_saddr; struct inetpeer_addr tcpm_daddr; unsigned long tcpm_stamp; @@ -51,9 +51,10 @@ struct tcp_metrics_block { struct rcu_head rcu_head; }; -static inline struct net *tm_net(struct tcp_metrics_block *tm) +static inline struct net *tm_net(const struct tcp_metrics_block *tm) { - return read_pnet(&tm->tcpm_net); + /* Paired with the WRITE_ONCE() in tcpm_new() */ + return READ_ONCE(tm->tcpm_net); } static bool tcp_metric_locked(struct tcp_metrics_block *tm, @@ -197,7 +198,9 @@ static struct tcp_metrics_block *tcpm_new(struct dst_entry *dst, if (!tm) goto out_unlock; } - write_pnet(&tm->tcpm_net, net); + /* Paired with the READ_ONCE() in tm_net() */ + WRITE_ONCE(tm->tcpm_net, net); + tm->tcpm_saddr = *saddr; tm->tcpm_daddr = *daddr; -- 2.40.1