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=-3.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 8C6FDC4727D for ; Thu, 24 Sep 2020 07:30:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D18822395C for ; Thu, 24 Sep 2020 07:30:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="S1BVR9KR" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727095AbgIXHaW (ORCPT ); Thu, 24 Sep 2020 03:30:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49474 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726655AbgIXHaV (ORCPT ); Thu, 24 Sep 2020 03:30:21 -0400 Received: from merlin.infradead.org (merlin.infradead.org [IPv6:2001:8b0:10b:1231::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 98ABAC0613CE; Thu, 24 Sep 2020 00:30:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=XgcGJ4sjIBTMAlJ2aTWqRW+QA3vpY8W+uIP1Muzktyc=; b=S1BVR9KRk5gwMpGsS4TSkkHnYV GDdeP+4hzqnOLjmkgTQF3vDuegYsLCixunemrnJ8KmIxgsRHnP6pob4AX3L/eUO6stS//0ww54+he 2hpf9yMmqGDJwm8+OnURJ8c8auXCyRm99AOuuUnnsxtlsEoOsFiJyjBLqFZpO36BK8CqjmZMK9Tlx dZqKOsjIwjGlyvpyLH0+gZhlhpAWGbdMIMAURyV8BGEHMk6c+1ExazZEo0eooHv4MUcfj1iqUSxcO u0jL061DHP2DkQXaofjA1MUvSXt8c0zPc4LpbLUKBiXf/EPDqGD0Qm1Pf70N9PNSwEQYHTZXQhJtm fudIAkVA==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1kLLhe-00064O-Bp; Thu, 24 Sep 2020 07:30:06 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id EB37D300455; Thu, 24 Sep 2020 09:30:03 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id AA1F82BC0B6AD; Thu, 24 Sep 2020 09:30:03 +0200 (CEST) Date: Thu, 24 Sep 2020 09:30:03 +0200 From: peterz@infradead.org To: Dmitry Vyukov Cc: Herbert Xu , syzbot , David Miller , Jakub Kicinski , LKML , netdev , Steffen Klassert , syzkaller-bugs , Ingo Molnar , Will Deacon Subject: Re: possible deadlock in xfrm_policy_delete Message-ID: <20200924073003.GZ1362448@hirez.programming.kicks-ass.net> References: <00000000000056c1dc05afc47ddb@google.com> <20200924043554.GA9443@gondor.apana.org.au> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Thu, Sep 24, 2020 at 06:44:12AM +0200, Dmitry Vyukov wrote: > On Thu, Sep 24, 2020 at 6:36 AM Herbert Xu wrote: > > > (k-slock-AF_INET6){+.-.}-{2:2} That's a seqlock. > > What's going on with all these bogus lockdep reports? > > > > These are two completely different locks, one is for TCP and the > > other is for SCTP. Why is lockdep suddenly beoming confused about > > this? > > > > FWIW this flood of bogus reports started on 16/Sep. > > > FWIW one of the dups of this issue was bisected to: > > commit 1909760f5fc3f123e47b4e24e0ccdc0fc8f3f106 > Author: Ahmed S. Darwish > Date: Fri Sep 4 15:32:31 2020 +0000 > > seqlock: PREEMPT_RT: Do not starve seqlock_t writers > > Can it be related? Did that tree you're testing include 267580db047e ("seqlock: Unbreak lockdep") ?