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=-10.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 29015C433E8 for ; Mon, 20 Jul 2020 15:56:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 084C420773 for ; Mon, 20 Jul 2020 15:56:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1595260589; bh=Lc8vSDDxqXR0iGuXVyaPfK/4+2pH/3AQLhXm0sg8lk8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=DVJ94Gb8UhMR3IMxuHe69RfIYGBiXQaScEG1xGV5qKROwgRX+FCAvkxs9vydVxRbk 2W94O2HCBr4zVMxj6a70nHX2Ny+JKe3M4cvS3t4AjR/EMesEI12McZtkYQZZgfOMzo 8pDZTqNGeVjEJb50qeEsVR2ih0V61P+8QGJ5vcgc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731242AbgGTP41 (ORCPT ); Mon, 20 Jul 2020 11:56:27 -0400 Received: from mail.kernel.org ([198.145.29.99]:55594 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731764AbgGTP4M (ORCPT ); Mon, 20 Jul 2020 11:56:12 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 28A7D22CAF; Mon, 20 Jul 2020 15:56:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1595260571; bh=Lc8vSDDxqXR0iGuXVyaPfK/4+2pH/3AQLhXm0sg8lk8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1HdRyMDmD2RBbABE7DS0G6sHuvy1nWJi78dsjNaLjm/nIJJKCeztrJenroR6ZBjQ3 7vHVJg4LiYMLP9zBkiIFZMPKYjdwTGGpEINN+yCHvNfHWsCyfd6s2uwy1LsZ/qC+g3 qcHbhFAx1oZaYTENVl/jjE3AfOj8xJyuGhzjwEJk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Dumazet , "David S. Miller" Subject: [PATCH 5.4 017/215] tcp: fix SO_RCVLOWAT possible hangs under high mem pressure Date: Mon, 20 Jul 2020 17:34:59 +0200 Message-Id: <20200720152820.982861036@linuxfoundation.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200720152820.122442056@linuxfoundation.org> References: <20200720152820.122442056@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Eric Dumazet [ Upstream commit ba3bb0e76ccd464bb66665a1941fabe55dadb3ba ] Whenever tcp_try_rmem_schedule() returns an error, we are under trouble and should make sure to wakeup readers so that they can drain socket queues and eventually make room. Fixes: 03f45c883c6f ("tcp: avoid extra wakeups for SO_RCVLOWAT users") Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/tcp_input.c | 2 ++ 1 file changed, 2 insertions(+) --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -4564,6 +4564,7 @@ static void tcp_data_queue_ofo(struct so if (unlikely(tcp_try_rmem_schedule(sk, skb, skb->truesize))) { NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPOFODROP); + sk->sk_data_ready(sk); tcp_drop(sk, skb); return; } @@ -4807,6 +4808,7 @@ queue_and_out: sk_forced_mem_schedule(sk, skb->truesize); else if (tcp_try_rmem_schedule(sk, skb, skb->truesize)) { NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPRCVQDROP); + sk->sk_data_ready(sk); goto drop; }