From patchwork Wed Jul 20 16:50:23 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kuniyuki Iwashima X-Patchwork-Id: 12924331 X-Patchwork-Delegate: kuba@kernel.org 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 41365C433EF for ; Wed, 20 Jul 2022 16:54:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235224AbiGTQyF (ORCPT ); Wed, 20 Jul 2022 12:54:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53372 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234937AbiGTQyE (ORCPT ); Wed, 20 Jul 2022 12:54:04 -0400 Received: from smtp-fw-9103.amazon.com (smtp-fw-9103.amazon.com [207.171.188.200]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C2D68691F2 for ; Wed, 20 Jul 2022 09:54:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1658336043; x=1689872043; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=rEku1SsqZciNE+HKYuQLcEchOPg3p7rwEUMRa9ZjCaQ=; b=OI/cIE0FfuO0zVwrngjH7cZZUlF5xozYKUp1BbaEryIJg7S5TA7Muz9b 3xdXnvMhdQ2WVNyeg4uMLwNW5HtTjS9Qiz4VIudYJDN4ALcsviqfBqvEu lN/UzCvUUtsWcdParic7f7b69343HNIowxg53sgBohuJJI1+x117ufeCC 0=; X-IronPort-AV: E=Sophos;i="5.92,286,1650931200"; d="scan'208";a="1036117430" Received: from pdx4-co-svc-p1-lb2-vlan3.amazon.com (HELO email-inbound-relay-iad-1a-e823fbde.us-east-1.amazon.com) ([10.25.36.214]) by smtp-border-fw-9103.sea19.amazon.com with ESMTP; 20 Jul 2022 16:53:47 +0000 Received: from EX13MTAUWB001.ant.amazon.com (iad12-ws-svc-p26-lb9-vlan3.iad.amazon.com [10.40.163.38]) by email-inbound-relay-iad-1a-e823fbde.us-east-1.amazon.com (Postfix) with ESMTPS id 58EECC0B5D; Wed, 20 Jul 2022 16:53:45 +0000 (UTC) Received: from EX19D004ANA001.ant.amazon.com (10.37.240.138) by EX13MTAUWB001.ant.amazon.com (10.43.161.249) with Microsoft SMTP Server (TLS) id 15.0.1497.36; Wed, 20 Jul 2022 16:53:44 +0000 Received: from 88665a182662.ant.amazon.com (10.43.160.159) by EX19D004ANA001.ant.amazon.com (10.37.240.138) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1118.9; Wed, 20 Jul 2022 16:53:41 +0000 From: Kuniyuki Iwashima To: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , David Ahern CC: Kuniyuki Iwashima , Kuniyuki Iwashima , Subject: [PATCH v1 net 12/15] tcp: Fix a data-race around sysctl_tcp_tso_rtt_log. Date: Wed, 20 Jul 2022 09:50:23 -0700 Message-ID: <20220720165026.59712-13-kuniyu@amazon.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220720165026.59712-1-kuniyu@amazon.com> References: <20220720165026.59712-1-kuniyu@amazon.com> MIME-Version: 1.0 X-Originating-IP: [10.43.160.159] X-ClientProxiedBy: EX13D10UWA004.ant.amazon.com (10.43.160.64) To EX19D004ANA001.ant.amazon.com (10.37.240.138) Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org While reading sysctl_tcp_tso_rtt_log, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: 65466904b015 ("tcp: adjust TSO packet sizes based on min_rtt") Signed-off-by: Kuniyuki Iwashima --- net/ipv4/tcp_output.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 6e29cf391a64..cf6713c9567e 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -1976,7 +1976,7 @@ static u32 tcp_tso_autosize(const struct sock *sk, unsigned int mss_now, bytes = sk->sk_pacing_rate >> READ_ONCE(sk->sk_pacing_shift); - r = tcp_min_rtt(tcp_sk(sk)) >> sock_net(sk)->ipv4.sysctl_tcp_tso_rtt_log; + r = tcp_min_rtt(tcp_sk(sk)) >> READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_tso_rtt_log); if (r < BITS_PER_TYPE(sk->sk_gso_max_size)) bytes += sk->sk_gso_max_size >> r;