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=ham 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 5EE13C43331 for ; Wed, 13 Nov 2019 02:21:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3939F222C1 for ; Wed, 13 Nov 2019 02:21:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573611667; bh=seh6PmXvSTkNpVGMUR2DlyeDVyJ5I38GlRYzKWTGXiY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=yoEnp3Zajg1dxz3h2vxCnDmTnu0zn+uK/whFl6P/fRFMbYBL6soSUIeX/TdSQ6IZz tC4cZDEAQKrBFNnKlF6N5+u1At7R0gWMBDlcWlhxQPbiw1SUBLwXW9/SnUVVa5em8N /cW005b0Fdif2TMIVUX65LIaVhaQ7tvwNYayN5h0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729783AbfKMCVG (ORCPT ); Tue, 12 Nov 2019 21:21:06 -0500 Received: from mail.kernel.org ([198.145.29.99]:44516 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727935AbfKMByI (ORCPT ); Tue, 12 Nov 2019 20:54:08 -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 58E85222CD; Wed, 13 Nov 2019 01:54:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573610047; bh=seh6PmXvSTkNpVGMUR2DlyeDVyJ5I38GlRYzKWTGXiY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tNTQnJAdprWe3WgsAAUyrABxhg4t0YvYma9tyjkU66TPWKjrzP2x/NG8SoIHzHC3A R4NFaoKHx6BKqn2S5WJAx5VKDoO0M1LcREyJzO2KfDC0J1dr6+FLBz7/qtkjd0O/on 5Cw6nYwTh6sDYAfeGo2JQJ2xzB7MvXfp2KIE/G8I= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= , Jesper Dangaard Brouer , Song Liu , Daniel Borkmann , Sasha Levin , netdev@vger.kernel.org, bpf@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 135/209] xsk: proper AF_XDP socket teardown ordering Date: Tue, 12 Nov 2019 20:49:11 -0500 Message-Id: <20191113015025.9685-135-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191113015025.9685-1-sashal@kernel.org> References: <20191113015025.9685-1-sashal@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Björn Töpel [ Upstream commit 541d7fdd7694560404c502f64298a90ffe017e6b ] The AF_XDP socket struct can exist in three different, implicit states: setup, bound and released. Setup is prior the socket has been bound to a device. Bound is when the socket is active for receive and send. Released is when the process/userspace side of the socket is released, but the sock object is still lingering, e.g. when there is a reference to the socket in an XSKMAP after process termination. The Rx fast-path code uses the "dev" member of struct xdp_sock to check whether a socket is bound or relased, and the Tx code uses the struct xdp_umem "xsk_list" member in conjunction with "dev" to determine the state of a socket. However, the transition from bound to released did not tear the socket down in correct order. On the Rx side "dev" was cleared after synchronize_net() making the synchronization useless. On the Tx side, the internal queues were destroyed prior removing them from the "xsk_list". This commit corrects the cleanup order, and by doing so xdp_del_sk_umem() can be simplified and one synchronize_net() can be removed. Fixes: 965a99098443 ("xsk: add support for bind for Rx") Fixes: ac98d8aab61b ("xsk: wire upp Tx zero-copy functions") Reported-by: Jesper Dangaard Brouer Signed-off-by: Björn Töpel Acked-by: Song Liu Signed-off-by: Daniel Borkmann Signed-off-by: Sasha Levin --- net/xdp/xdp_umem.c | 11 +++-------- net/xdp/xsk.c | 13 ++++++++----- 2 files changed, 11 insertions(+), 13 deletions(-) diff --git a/net/xdp/xdp_umem.c b/net/xdp/xdp_umem.c index 8cab91c482ff5..d9117ab035f7c 100644 --- a/net/xdp/xdp_umem.c +++ b/net/xdp/xdp_umem.c @@ -32,14 +32,9 @@ void xdp_del_sk_umem(struct xdp_umem *umem, struct xdp_sock *xs) { unsigned long flags; - if (xs->dev) { - spin_lock_irqsave(&umem->xsk_list_lock, flags); - list_del_rcu(&xs->list); - spin_unlock_irqrestore(&umem->xsk_list_lock, flags); - - if (umem->zc) - synchronize_net(); - } + spin_lock_irqsave(&umem->xsk_list_lock, flags); + list_del_rcu(&xs->list); + spin_unlock_irqrestore(&umem->xsk_list_lock, flags); } int xdp_umem_query(struct net_device *dev, u16 queue_id) diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c index 661504042d304..ff15207036dc5 100644 --- a/net/xdp/xsk.c +++ b/net/xdp/xsk.c @@ -343,12 +343,18 @@ static int xsk_release(struct socket *sock) local_bh_enable(); if (xs->dev) { + struct net_device *dev = xs->dev; + /* Wait for driver to stop using the xdp socket. */ - synchronize_net(); - dev_put(xs->dev); + xdp_del_sk_umem(xs->umem, xs); xs->dev = NULL; + synchronize_net(); + dev_put(dev); } + xskq_destroy(xs->rx); + xskq_destroy(xs->tx); + sock_orphan(sk); sock->sk = NULL; @@ -707,9 +713,6 @@ static void xsk_destruct(struct sock *sk) if (!sock_flag(sk, SOCK_DEAD)) return; - xskq_destroy(xs->rx); - xskq_destroy(xs->tx); - xdp_del_sk_umem(xs->umem, xs); xdp_put_umem(xs->umem); sk_refcnt_debug_dec(sk); -- 2.20.1