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 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 2A965C388F2 for ; Thu, 22 Oct 2020 11:17:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 92046222E9 for ; Thu, 22 Oct 2020 11:17:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="dM9SNk4z" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2897127AbgJVLRF (ORCPT ); Thu, 22 Oct 2020 07:17:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59954 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2502527AbgJVLRD (ORCPT ); Thu, 22 Oct 2020 07:17:03 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 27999C0613CE; Thu, 22 Oct 2020 04:17:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.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=LtnWOsuhrFn7+oVdVMoCVndSGLt50TxPAs4a8rGonYE=; b=dM9SNk4zcle/PDQ1qASd5oGeZD 15OTWVsGJmAwDJbMWe3Ej6eMLj3ozlRrmd93px6u2Pf16reezDP0o7RNDLBS8s8TqfQoKipM1fRTu ffh0hX+0SCxzP9gyK6AIjY1VOkKICSYPTNV006ltNaaqX2/xwl/W2oLqbKE6Q0owHKAUJXWT3w4Gu sBkQuOW5J4AYILe2395k1EnRX+SLoGepwPACg24NVWITWhyG2l/2VoRSfI0j9wlgl3tmmQigEI4BD RpmtCqDULdVvhePJvaPp5ciZXBUBqbzxWrIs4J2u/D6G1e1o2gqdORCIxbnC7YEFqibZU5sBXn7zF T+Nk1Lbg==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1kVYaa-0004im-SV; Thu, 22 Oct 2020 11:17:01 +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 48B7F304D28; Thu, 22 Oct 2020 13:17:00 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 32D6A203D0810; Thu, 22 Oct 2020 13:17:00 +0200 (CEST) Date: Thu, 22 Oct 2020 13:17:00 +0200 From: Peter Zijlstra To: Anatoly Pugachev Cc: Linux Kernel list , Sparc kernel list , Ingo Molnar Subject: Re: [sparc64] lockdep: Fix lockdep recursion - call trace Message-ID: <20201022111700.GZ2651@hirez.programming.kicks-ass.net> References: <20201022110015.GJ2594@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201022110015.GJ2594@hirez.programming.kicks-ass.net> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 22, 2020 at 01:00:16PM +0200, Peter Zijlstra wrote: > On Thu, Oct 22, 2020 at 12:21:55PM +0300, Anatoly Pugachev wrote: > > Hello! > > > > Bisected the following linux calltrace after v5.9 : > > > > [ 8.650198] systemd[1]: Started Journal Service. > > [ 9.028125] ------------[ cut here ]------------ > > [ 9.028171] WARNING: CPU: 11 PID: 499 at > > net/netfilter/nf_tables_api.c:622 nft_chain_parse_hook+0x7c/0x360 > > [nf_tables] > > [ 9.028185] Modules linked in: nf_tables nfnetlink sunrpc ip_tables > > x_tables ipv6 crc_ccitt autofs4 ext4 crc16 mbcache jbd2 raid10 raid456 > > async_raid6_recov async_mem > > cpy async_pq async_xor xor async_tx raid6_pq raid1 raid0 multipath > > linear md_mod crc32c_sparc64 > > [ 9.028243] CPU: 11 PID: 499 Comm: nft Tainted: G W > > 5.9.0-rc8-00209-gbaffd723e44d #111 > > [ 9.028255] Call Trace: > > [ 9.028269] [<00000000004727e8>] __warn+0xa8/0x120 > > [ 9.028278] [<0000000000472c20>] warn_slowpath_fmt+0x34/0x74 > > [ 9.028291] [<00000000100c19fc>] nft_chain_parse_hook+0x7c/0x360 [nf_tables] > > > commit 4d004099a668c41522242aa146a38cc4eb59cb1e > > What's unexpected.. while I just queued a another fix for that commit: > > https://lkml.kernel.org/r/20201022103028.GC2611@hirez.programming.kicks-ass.net > > I don't think that explains this WARN. Let me go prod at it. This looks like lockdep_is_held() encounters an incremented recursion count and returns 1, which in this case will trigger the WARN. But that would mean we're leaking a recursion count somewhere... do you have CONFIG_DEBUG_PREEMPT enabled?