From patchwork Tue Aug 30 00:56:38 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: shaozhengchao X-Patchwork-Id: 12958560 X-Patchwork-Delegate: kuba@kernel.org Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 38E90ECAAD4 for ; Tue, 30 Aug 2022 00:54:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229504AbiH3AyP (ORCPT ); Mon, 29 Aug 2022 20:54:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51262 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229449AbiH3AyN (ORCPT ); Mon, 29 Aug 2022 20:54:13 -0400 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8184981B2D; Mon, 29 Aug 2022 17:54:12 -0700 (PDT) Received: from dggpeml500026.china.huawei.com (unknown [172.30.72.53]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4MGpfT6JDVznTnY; Tue, 30 Aug 2022 08:51:45 +0800 (CST) Received: from huawei.com (10.175.101.6) by dggpeml500026.china.huawei.com (7.185.36.106) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Tue, 30 Aug 2022 08:54:10 +0800 From: Zhengchao Shao To: , , , , , , , , CC: , , Subject: [PATCH net-next 2/2] net: sched: htb: remove redundant resource cleanup in htb_init() Date: Tue, 30 Aug 2022 08:56:38 +0800 Message-ID: <20220830005638.276584-3-shaozhengchao@huawei.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20220830005638.276584-1-shaozhengchao@huawei.com> References: <20220830005638.276584-1-shaozhengchao@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.101.6] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To dggpeml500026.china.huawei.com (7.185.36.106) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org If htb_init() fails, qdisc_create() invokes htb_destroy() to clear resources. Therefore, remove redundant resource cleanup in htb_init(). Signed-off-by: Zhengchao Shao --- net/sched/sch_htb.c | 36 +++++++++--------------------------- 1 file changed, 9 insertions(+), 27 deletions(-) diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c index cb5872d22ecf..da75885bbffd 100644 --- a/net/sched/sch_htb.c +++ b/net/sched/sch_htb.c @@ -1102,7 +1102,7 @@ static int htb_init(struct Qdisc *sch, struct nlattr *opt, err = qdisc_class_hash_init(&q->clhash); if (err < 0) - goto err_free_direct_qdiscs; + return err; qdisc_skb_head_init(&q->direct_queue); @@ -1125,8 +1125,7 @@ static int htb_init(struct Qdisc *sch, struct nlattr *opt, qdisc = qdisc_create_dflt(dev_queue, &pfifo_qdisc_ops, TC_H_MAKE(sch->handle, 0), extack); if (!qdisc) { - err = -ENOMEM; - goto err_free_qdiscs; + return -ENOMEM; } htb_set_lockdep_class_child(qdisc); @@ -1144,7 +1143,7 @@ static int htb_init(struct Qdisc *sch, struct nlattr *opt, }; err = htb_offload(dev, &offload_opt); if (err) - goto err_free_qdiscs; + return err; /* Defer this assignment, so that htb_destroy skips offload-related * parts (especially calling ndo_setup_tc) on errors. @@ -1152,22 +1151,6 @@ static int htb_init(struct Qdisc *sch, struct nlattr *opt, q->offload = true; return 0; - -err_free_qdiscs: - for (ntx = 0; ntx < q->num_direct_qdiscs && q->direct_qdiscs[ntx]; - ntx++) - qdisc_put(q->direct_qdiscs[ntx]); - - qdisc_class_hash_destroy(&q->clhash); - /* Prevent use-after-free and double-free when htb_destroy gets called. - */ - q->clhash.hash = NULL; - q->clhash.hashsize = 0; - -err_free_direct_qdiscs: - kfree(q->direct_qdiscs); - q->direct_qdiscs = NULL; - return err; } static void htb_attach_offload(struct Qdisc *sch) @@ -1690,13 +1673,12 @@ static void htb_destroy(struct Qdisc *sch) qdisc_class_hash_destroy(&q->clhash); __qdisc_reset_queue(&q->direct_queue); - if (!q->offload) - return; - - offload_opt = (struct tc_htb_qopt_offload) { - .command = TC_HTB_DESTROY, - }; - htb_offload(dev, &offload_opt); + if (q->offload) { + offload_opt = (struct tc_htb_qopt_offload) { + .command = TC_HTB_DESTROY, + }; + htb_offload(dev, &offload_opt); + } if (!q->direct_qdiscs) return;