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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F1FF7C433F5 for ; Sun, 26 Sep 2021 15:10:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D55D760F44 for ; Sun, 26 Sep 2021 15:10:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232011AbhIZPM2 (ORCPT ); Sun, 26 Sep 2021 11:12:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58194 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232107AbhIZPMY (ORCPT ); Sun, 26 Sep 2021 11:12:24 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2C712C061575 for ; Sun, 26 Sep 2021 08:10:47 -0700 (PDT) From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1632669045; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=FnplyvWyxnR6F++laozuRCz3CoQ3kHJFgDmxVAQUv+s=; b=jeXE+aNLl3dc9EsQAqNJ3C309fSiERMnlPRqr4CKuE09tCojfmZQ3rEf2eZ3GjQNT6tLfE vC7Sd8/2MbWyaWxTuh62UPmV9ieSSyb6PbFvynY68x74xjKi6D/CinmhcM0QAb2VI/JeAR FFXLg1RYV0pP0O7PeUJy4OSGD9iO/3ICrDAeptKiRlWCFf1xEP4as3J1vz9VJ//fSAE8l/ 7Sz+AkcvldBezbOBoDcsD2ml1P7Ji1W6ntknQ1cMG5jCvjB13S5cu6rJMa6RBFyMBex/1O xc1pZN0zHR70ZUdWoLYBEsxMfNPJKT9hJAxval9xM/lG2wgHWd8NSSEPWw/2kw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1632669045; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=FnplyvWyxnR6F++laozuRCz3CoQ3kHJFgDmxVAQUv+s=; b=uKo8a3DtKQHOfzL5SKdS50Tm9w1Md6wdCikPLiWUMpUPN4NIKSOKlayqbXhk0eiIor2AHl dCEjYO5cPufyQwCw== To: Mike Galbraith , RT Cc: Sebastian Andrzej Siewior Subject: Re: [patch] Re: v5.15-rc2-rt3: WARNING: CPU: 0 PID: 12 at ./include/linux/seqlock.h:271 In-Reply-To: References: <20210922210006.rmfpkps6hguyo5ll@linutronix.de> Date: Sun, 26 Sep 2021 17:10:45 +0200 Message-ID: <87zgrzbcei.ffs@tglx> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-rt-users@vger.kernel.org On Sun, Sep 26 2021 at 06:05, Mike Galbraith wrote: > On Fri, 2021-09-24 at 07:22 +0200, Mike Galbraith wrote: > --- a/net/bridge/br_multicast.c > +++ b/net/bridge/br_multicast.c > @@ -1679,10 +1679,14 @@ static void br_multicast_update_querier( > { > lockdep_assert_held_once(&brmctx->br->multicast_lock); > > + if (IS_ENABLED(CONFIG_PREEMPT_RT)) > + preempt_disable(); That sequence count is protected by brmctx->br->multicast_lock, but seqcount_init() does not associate the lock. Untested below should cure it properly. Thanks, tglx --- --- a/net/bridge/br_multicast.c +++ b/net/bridge/br_multicast.c @@ -1677,8 +1677,6 @@ static void br_multicast_update_querier( int ifindex, struct br_ip *saddr) { - lockdep_assert_held_once(&brmctx->br->multicast_lock); - write_seqcount_begin(&querier->seq); querier->port_ifidx = ifindex; memcpy(&querier->addr, saddr, sizeof(*saddr)); @@ -3867,13 +3865,13 @@ void br_multicast_ctx_init(struct net_br brmctx->ip4_other_query.delay_time = 0; brmctx->ip4_querier.port_ifidx = 0; - seqcount_init(&brmctx->ip4_querier.seq); + seqcount_spinlock_init(&brmctx->ip4_querier.seq, &br->multicast_lock); brmctx->multicast_igmp_version = 2; #if IS_ENABLED(CONFIG_IPV6) brmctx->multicast_mld_version = 1; brmctx->ip6_other_query.delay_time = 0; brmctx->ip6_querier.port_ifidx = 0; - seqcount_init(&brmctx->ip6_querier.seq); + seqcount_spinlock_init(&brmctx->ip6_querier.seq, &br->multicast_lock); #endif timer_setup(&brmctx->ip4_mc_router_timer, --- a/net/bridge/br_private.h +++ b/net/bridge/br_private.h @@ -82,7 +82,7 @@ struct bridge_mcast_other_query { struct bridge_mcast_querier { struct br_ip addr; int port_ifidx; - seqcount_t seq; + seqcount_spinlock_t seq; }; /* IGMP/MLD statistics */