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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 A8B00C56201 for ; Thu, 19 Nov 2020 15:35:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5222924695 for ; Thu, 19 Nov 2020 15:35:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728451AbgKSPfG (ORCPT ); Thu, 19 Nov 2020 10:35:06 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45816 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726691AbgKSPfG (ORCPT ); Thu, 19 Nov 2020 10:35:06 -0500 Received: from Chamillionaire.breakpoint.cc (Chamillionaire.breakpoint.cc [IPv6:2a0a:51c0:0:12e:520::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B4577C0613CF for ; Thu, 19 Nov 2020 07:35:05 -0800 (PST) Received: from fw by Chamillionaire.breakpoint.cc with local (Exim 4.92) (envelope-from ) id 1kflxe-000311-9E; Thu, 19 Nov 2020 16:35:02 +0100 From: Florian Westphal To: Cc: Florian Westphal , Naresh Kamboju Subject: [PATCH nf] netfilter: nf_tables: avoid false-postive lockdep splat Date: Thu, 19 Nov 2020 16:34:54 +0100 Message-Id: <20201119153454.28089-1-fw@strlen.de> X-Mailer: git-send-email 2.26.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org There are reports wrt lockdep splat in nftables, e.g.: ------------[ cut here ]------------ WARNING: CPU: 2 PID: 31416 at net/netfilter/nf_tables_api.c:622 lockdep_nfnl_nft_mutex_not_held+0x28/0x38 [nf_tables] ... These are caused by an earlier, unrelated bug such as a n ABBA deadlock in a different subsystem. In such an event, lockdep is disabled and lockdep_is_held returns true unconditionally. This then causes the WARN() in nf_tables. Make the WARN conditional on lockdep still active to avoid this. Fixes: f102d66b335a417 ("netfilter: nf_tables: use dedicated mutex to guard transactions") Reported-by: Naresh Kamboju Link: https://lore.kernel.org/linux-kselftest/CA+G9fYvFUpODs+NkSYcnwKnXm62tmP=ksLeBPmB+KFrB2rvCtQ@mail.gmail.com/ Signed-off-by: Florian Westphal --- net/netfilter/nf_tables_api.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 0f58e98542be..23abf1578594 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -619,7 +619,8 @@ static int nft_request_module(struct net *net, const char *fmt, ...) static void lockdep_nfnl_nft_mutex_not_held(void) { #ifdef CONFIG_PROVE_LOCKING - WARN_ON_ONCE(lockdep_nfnl_is_held(NFNL_SUBSYS_NFTABLES)); + if (debug_locks) + WARN_ON_ONCE(lockdep_nfnl_is_held(NFNL_SUBSYS_NFTABLES)); #endif } -- 2.26.2