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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 4321BC33CAF for ; Thu, 16 Jan 2020 17:12:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 16E0324690 for ; Thu, 16 Jan 2020 17:12:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579194778; bh=1fFE5iS0h/osjV3rPKtgPo6w7c/71rYCJlFdfhgNAiU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=eopZ9CsHZt+v0VEEZStVPed/uw/80JEsw5lH+6rFj5AyhVM8Ad+T+e8hDAgoAXUso qIhJ2QKjyu32SJbPBKbuiq9yxDhmEy8coWO/XBb/08vOJSlp+RpERrWXNCdhKz/62H CU6dq5SgxKa4AonINmuOLyjD2lG/Rk+ABLfp476M= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390615AbgAPRM4 (ORCPT ); Thu, 16 Jan 2020 12:12:56 -0500 Received: from mail.kernel.org ([198.145.29.99]:56466 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390586AbgAPRMw (ORCPT ); Thu, 16 Jan 2020 12:12:52 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D630924696; Thu, 16 Jan 2020 17:12:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579194771; bh=1fFE5iS0h/osjV3rPKtgPo6w7c/71rYCJlFdfhgNAiU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VkGyH10iHJloPIXZkpdzQK2vZtP+Vi3B3kAilrdsy1lliUM4bFNRvtgq9ltXf5q9Q GawzRQfygTo6DHCDbM/JExP4OuXaQC2VMWwVRfov70E5veUSVddTpLlvwWRzbfIWd9 f7sU2yCsHWDTVikMFb/b3qDHIlvPDozoGY6sHN74= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Eric Dumazet , Jakub Kicinski , Sasha Levin , xen-devel@lists.xenproject.org, netdev@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 590/671] net: add {READ|WRITE}_ONCE() annotations on ->rskq_accept_head Date: Thu, 16 Jan 2020 12:03:48 -0500 Message-Id: <20200116170509.12787-327-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200116170509.12787-1-sashal@kernel.org> References: <20200116170509.12787-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore 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 60b173ca3d1cd1782bd0096dc17298ec242f6fb1 ] reqsk_queue_empty() is called from inet_csk_listen_poll() while other cpus might write ->rskq_accept_head value. Use {READ|WRITE}_ONCE() to avoid compiler tricks and potential KCSAN splats. Fixes: fff1f3001cc5 ("tcp: add a spinlock to protect struct request_sock_queue") Signed-off-by: Eric Dumazet Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/xen/pvcalls-back.c | 2 +- include/net/request_sock.h | 4 ++-- net/ipv4/inet_connection_sock.c | 2 +- 3 files changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/xen/pvcalls-back.c b/drivers/xen/pvcalls-back.c index d4ea33581ac2..b3fbfed28682 100644 --- a/drivers/xen/pvcalls-back.c +++ b/drivers/xen/pvcalls-back.c @@ -784,7 +784,7 @@ static int pvcalls_back_poll(struct xenbus_device *dev, mappass->reqcopy = *req; icsk = inet_csk(mappass->sock->sk); queue = &icsk->icsk_accept_queue; - data = queue->rskq_accept_head != NULL; + data = READ_ONCE(queue->rskq_accept_head) != NULL; if (data) { mappass->reqcopy.cmd = 0; ret = 0; diff --git a/include/net/request_sock.h b/include/net/request_sock.h index 347015515a7d..1653435f18f5 100644 --- a/include/net/request_sock.h +++ b/include/net/request_sock.h @@ -183,7 +183,7 @@ void reqsk_fastopen_remove(struct sock *sk, struct request_sock *req, static inline bool reqsk_queue_empty(const struct request_sock_queue *queue) { - return queue->rskq_accept_head == NULL; + return READ_ONCE(queue->rskq_accept_head) == NULL; } static inline struct request_sock *reqsk_queue_remove(struct request_sock_queue *queue, @@ -195,7 +195,7 @@ static inline struct request_sock *reqsk_queue_remove(struct request_sock_queue req = queue->rskq_accept_head; if (req) { sk_acceptq_removed(parent); - queue->rskq_accept_head = req->dl_next; + WRITE_ONCE(queue->rskq_accept_head, req->dl_next); if (queue->rskq_accept_head == NULL) queue->rskq_accept_tail = NULL; } diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c index 636a11c56cf5..79320858e719 100644 --- a/net/ipv4/inet_connection_sock.c +++ b/net/ipv4/inet_connection_sock.c @@ -937,7 +937,7 @@ struct sock *inet_csk_reqsk_queue_add(struct sock *sk, req->sk = child; req->dl_next = NULL; if (queue->rskq_accept_head == NULL) - queue->rskq_accept_head = req; + WRITE_ONCE(queue->rskq_accept_head, req); else queue->rskq_accept_tail->dl_next = req; queue->rskq_accept_tail = req; -- 2.20.1