From patchwork Thu Aug 27 22:32:50 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jakub Kicinski X-Patchwork-Id: 261823 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=-14.1 required=3.0 tests=BAYES_00,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 CB08FC433E2 for ; Thu, 27 Aug 2020 22:33:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9EC5120872 for ; Thu, 27 Aug 2020 22:33:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598567598; bh=D/YPsAYRAGpzuQZHWDZnyq/tJC1zikV3r+8kkiFiJQs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=lhCmANuarRr8X16w1Lu6FyGDjWISLRs574mYZF82hSQ6cbBGSLc3qCOCX4sOtvuAT maHbVhMW+1Fpx6vDSN8vpqNF4BaY+/Dvwh5fI8QQe5gbz8bjxEbYCzgD6tOCiY5x+Q P/VWLY2SbzldOdnA9d4o4m5LLLSMSR+Mn2nmaStQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727950AbgH0WdQ (ORCPT ); Thu, 27 Aug 2020 18:33:16 -0400 Received: from mail.kernel.org ([198.145.29.99]:49542 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726953AbgH0WdO (ORCPT ); Thu, 27 Aug 2020 18:33:14 -0400 Received: from kicinski-fedora-PC1C0HJN.thefacebook.com (unknown [163.114.132.6]) (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 33D7420B80; Thu, 27 Aug 2020 22:33:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598567594; bh=D/YPsAYRAGpzuQZHWDZnyq/tJC1zikV3r+8kkiFiJQs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Ws6HLszuTrqMO20mHwy9jPqzLPbS0pqzNcv04MhbJ60+0JB4qG0LZusKVGJjaLB/7 E6U68E4RPIhyDwmf/4bNj0R4l6MxPFcvfLp7lZIVeAg5VcFyqRqksvMMO40bNlqzWu VUof3bpWVFyBDlUavwr0BwxgT+3Jsm+z9Z4km3o0= From: Jakub Kicinski To: eric.dumazet@gmail.com Cc: davem@davemloft.net, netdev@vger.kernel.org, kernel-team@fb.com, Jakub Kicinski Subject: [RFC -next 3/3] net: make sure napi_list is safe for RCU traversal Date: Thu, 27 Aug 2020 15:32:50 -0700 Message-Id: <20200827223250.2045503-4-kuba@kernel.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200827223250.2045503-1-kuba@kernel.org> References: <20200827104753.29d836bb@kicinski-fedora-PC1C0HJN> <20200827223250.2045503-1-kuba@kernel.org> MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org netpoll needs to traverse dev->napi_list under RCU, make sure it uses the right iterator and that removal from this list is handled safely. Signed-off-by: Jakub Kicinski --- net/core/dev.c | 2 +- net/core/netpoll.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/net/core/dev.c b/net/core/dev.c index 623060907132..dfb4a4137eea 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -6656,7 +6656,7 @@ void __netif_napi_del(struct napi_struct *napi) return; napi_hash_del(napi); - list_del_init(&napi->dev_list); + list_del_rcu(&napi->dev_list); napi_free_frags(napi); flush_gro_hash(napi); diff --git a/net/core/netpoll.c b/net/core/netpoll.c index 2338753e936b..c310c7c1cef7 100644 --- a/net/core/netpoll.c +++ b/net/core/netpoll.c @@ -297,7 +297,7 @@ static int netpoll_owner_active(struct net_device *dev) { struct napi_struct *napi; - list_for_each_entry(napi, &dev->napi_list, dev_list) { + list_for_each_entry_rcu(napi, &dev->napi_list, dev_list) { if (napi->poll_owner == smp_processor_id()) return 1; }