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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 21B52C677FC for ; Thu, 11 Oct 2018 17:26:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DF42120645 for ; Thu, 11 Oct 2018 17:26:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DF42120645 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=davemloft.net Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729018AbeJLAyP (ORCPT ); Thu, 11 Oct 2018 20:54:15 -0400 Received: from shards.monkeyblade.net ([23.128.96.9]:59242 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726168AbeJLAyP (ORCPT ); Thu, 11 Oct 2018 20:54:15 -0400 Received: from localhost (c-67-183-145-105.hsd1.wa.comcast.net [67.183.145.105]) (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 44AB912DE580E; Thu, 11 Oct 2018 10:26:04 -0700 (PDT) Date: Thu, 11 Oct 2018 10:26:03 -0700 (PDT) Message-Id: <20181011.102603.2088827315896221671.davem@davemloft.net> To: ying.xue@windriver.com Cc: jon.maloy@ericsson.com, dvyukov@google.com, parthasarathy.bhuvaragan@ericsson.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, tipc-discussion@lists.sourceforge.net Subject: Re: [PATCH net] tipc: eliminate possible recursive locking detected by LOCKDEP From: David Miller In-Reply-To: <1539259076-8562-1-git-send-email-ying.xue@windriver.com> References: <1539259076-8562-1-git-send-email-ying.xue@windriver.com> X-Mailer: Mew version 6.7 on Emacs 26 / Mule 6.0 (HANACHIRUSATO) 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, 11 Oct 2018 10:26:04 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Ying Xue Date: Thu, 11 Oct 2018 19:57:56 +0800 > When booting kernel with LOCKDEP option, below warning info was found: > > WARNING: possible recursive locking detected > 4.19.0-rc7+ #14 Not tainted ... > The reason why the noise above was complained by LOCKDEP is because we > nested to hold l->wakeupq.lock and l->inputq->lock in tipc_link_reset > function. In fact it's unnecessary to move skb buffer from l->wakeupq > queue to l->inputq queue while holding the two locks at the same time. > Instead, we can move skb buffers in l->wakeupq queue to a temporary > list first and then move the buffers of the temporary list to l->inputq > queue, which is also safe for us. > > Fixes: 3f32d0be6c16 ("tipc: lock wakeup & inputq at tipc_link_reset()") > Reported-by: Dmitry Vyukov > Signed-off-by: Ying Xue Applied.