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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 9B2AAC433DF for ; Thu, 2 Jul 2020 21:25:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7B5DB20772 for ; Thu, 2 Jul 2020 21:25:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726112AbgGBVZG (ORCPT ); Thu, 2 Jul 2020 17:25:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55256 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725937AbgGBVZG (ORCPT ); Thu, 2 Jul 2020 17:25:06 -0400 Received: from shards.monkeyblade.net (shards.monkeyblade.net [IPv6:2620:137:e000::1:9]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5182FC08C5C1 for ; Thu, 2 Jul 2020 14:25:06 -0700 (PDT) Received: from localhost (unknown [IPv6:2601:601:9f00:477::3d5]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id 1B1C21282F6F9; Thu, 2 Jul 2020 14:25:06 -0700 (PDT) Date: Thu, 02 Jul 2020 14:25:05 -0700 (PDT) Message-Id: <20200702.142505.302089629790561856.davem@davemloft.net> To: wenxu@ucloud.cn Cc: netdev@vger.kernel.org Subject: Re: [PATCH net 1/2] net/sched: act_ct: fix restore the qdisc_skb_cb after defrag From: David Miller In-Reply-To: <89404b82-71b8-c94d-1e0b-11e3755da0b3@ucloud.cn> References: <1593422178-26949-1-git-send-email-wenxu@ucloud.cn> <20200701.152116.1519098438346883237.davem@davemloft.net> <89404b82-71b8-c94d-1e0b-11e3755da0b3@ucloud.cn> X-Mailer: Mew version 6.8 on Emacs 26.3 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Thu, 02 Jul 2020 14:25:06 -0700 (PDT) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: wenxu Date: Thu, 2 Jul 2020 17:17:47 +0800 > On 7/2/2020 6:21 AM, David Miller wrote: >> From: wenxu@ucloud.cn >> Date: Mon, 29 Jun 2020 17:16:17 +0800 >> >> Nothing can clobber the qdisc_skb_cb like this in these packet flows >> otherwise we will have serious crashes and problems. Some packet >> schedulers store pointers in the qdisc CB private area, for example. > Why store all the cb private and restore it can't total fix this? Parallel accesses to the SKB.