From patchwork Fri Oct 9 00:35:51 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kosuke Tatsukawa X-Patchwork-Id: 7358031 Return-Path: X-Original-To: patchwork-linux-nfs@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id A329C9F4DC for ; Fri, 9 Oct 2015 00:39:05 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id D0EE2207B9 for ; Fri, 9 Oct 2015 00:39:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DBCE5207B2 for ; Fri, 9 Oct 2015 00:39:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933700AbbJIAiI (ORCPT ); Thu, 8 Oct 2015 20:38:08 -0400 Received: from TYO200.gate.nec.co.jp ([210.143.35.50]:61413 "EHLO tyo200.gate.nec.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933666AbbJIAiG convert rfc822-to-8bit (ORCPT ); Thu, 8 Oct 2015 20:38:06 -0400 Received: from tyo201.gate.nec.co.jp ([10.7.69.201]) by tyo200.gate.nec.co.jp (8.13.8/8.13.4) with ESMTP id t990c4BO022863 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Fri, 9 Oct 2015 09:38:05 +0900 (JST) Received: from mailgate3.nec.co.jp ([10.7.69.192]) by tyo201.gate.nec.co.jp (8.13.8/8.13.4) with ESMTP id t990bp2h018727; Fri, 9 Oct 2015 09:37:51 +0900 (JST) Received: from mailsv3.nec.co.jp (imss62.nec.co.jp [10.7.69.157]) by mailgate3.nec.co.jp (8.11.7/3.7W-MAILGATE-NEC) with ESMTP id t990bo222187; Fri, 9 Oct 2015 09:37:50 +0900 (JST) Received: from mail02.kamome.nec.co.jp (mail02.kamome.nec.co.jp [10.25.43.5]) by mailsv3.nec.co.jp (8.13.8/8.13.4) with ESMTP id t990bovQ007861; Fri, 9 Oct 2015 09:37:50 +0900 (JST) Received: from bpxc99gp.gisp.nec.co.jp ([10.38.151.137] [10.38.151.137]) by mail01b.kamome.nec.co.jp with ESMTP id BT-MMP-2522109; Fri, 9 Oct 2015 09:35:53 +0900 Received: from BPXM09GP.gisp.nec.co.jp ([169.254.1.172]) by BPXC09GP.gisp.nec.co.jp ([10.38.151.137]) with mapi id 14.03.0224.002; Fri, 9 Oct 2015 09:35:52 +0900 From: Kosuke Tatsukawa To: Trond Myklebust , Anna Schumaker , "J. Bruce Fields" , "Jeff Layton" , "David S. Miller" CC: "linux-nfs@vger.kernel.org" , "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: [PATCH] sunrpc: fix waitqueue_active without memory barrier in sunrpc Thread-Topic: [PATCH] sunrpc: fix waitqueue_active without memory barrier in sunrpc Thread-Index: AdECKnNTw192ezMdTFS/5l6/zwP0qg== Date: Fri, 9 Oct 2015 00:35:51 +0000 Message-ID: <17EC94B0A072C34B8DCF0D30AD16044A028747A3@BPXM09GP.gisp.nec.co.jp> Accept-Language: ja-JP, en-US Content-Language: ja-JP X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.34.125.78] MIME-Version: 1.0 Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP There are several places in net/sunrpc/svcsock.c which calls waitqueue_active() without calling a memory barrier. Change the code to call wq_has_sleeper() instead, which other networking code uses in similar places. I found this issue when I was looking through the linux source code for places calling waitqueue_active() before wake_up*(), but without preceding memory barriers, after sending a patch to fix a similar issue in drivers/tty/n_tty.c (Details about the original issue can be found here: https://lkml.org/lkml/2015/9/28/849). Signed-off-by: Kosuke Tatsukawa --- net/sunrpc/svcsock.c | 12 ++++++------ 1 files changed, 6 insertions(+), 6 deletions(-) diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c index 0c81202..cf081b8 100644 --- a/net/sunrpc/svcsock.c +++ b/net/sunrpc/svcsock.c @@ -414,7 +414,7 @@ static void svc_udp_data_ready(struct sock *sk) set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags); svc_xprt_enqueue(&svsk->sk_xprt); } - if (wq && waitqueue_active(wq)) + if (wq_has_sleeper(wq)) wake_up_interruptible(wq); } @@ -432,7 +432,7 @@ static void svc_write_space(struct sock *sk) svc_xprt_enqueue(&svsk->sk_xprt); } - if (wq && waitqueue_active(wq)) { + if (wq_has_sleeper(wq)) { dprintk("RPC svc_write_space: someone sleeping on %p\n", svsk); wake_up_interruptible(wq); @@ -787,7 +787,7 @@ static void svc_tcp_listen_data_ready(struct sock *sk) } wq = sk_sleep(sk); - if (wq && waitqueue_active(wq)) + if (wq_has_sleeper(wq)) wake_up_interruptible_all(wq); } @@ -808,7 +808,7 @@ static void svc_tcp_state_change(struct sock *sk) set_bit(XPT_CLOSE, &svsk->sk_xprt.xpt_flags); svc_xprt_enqueue(&svsk->sk_xprt); } - if (wq && waitqueue_active(wq)) + if (wq_has_sleeper(wq)) wake_up_interruptible_all(wq); } @@ -823,7 +823,7 @@ static void svc_tcp_data_ready(struct sock *sk) set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags); svc_xprt_enqueue(&svsk->sk_xprt); } - if (wq && waitqueue_active(wq)) + if (wq_has_sleeper(wq)) wake_up_interruptible(wq); } @@ -1594,7 +1594,7 @@ static void svc_sock_detach(struct svc_xprt *xprt) sk->sk_write_space = svsk->sk_owspace; wq = sk_sleep(sk); - if (wq && waitqueue_active(wq)) + if (wq_has_sleeper(wq)) wake_up_interruptible(wq); }