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=-8.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=unavailable 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 EFB54C433E9 for ; Mon, 15 Feb 2021 13:14:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C0ECB64E5A for ; Mon, 15 Feb 2021 13:14:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230026AbhBONN6 (ORCPT ); Mon, 15 Feb 2021 08:13:58 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37444 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230233AbhBONNu (ORCPT ); Mon, 15 Feb 2021 08:13:50 -0500 Received: from sipsolutions.net (s3.sipsolutions.net [IPv6:2a01:4f8:191:4433::2]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3A9CDC061574; Mon, 15 Feb 2021 05:13:07 -0800 (PST) Received: by sipsolutions.net with esmtpsa (TLS1.3:ECDHE_SECP256R1__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.94) (envelope-from ) id 1lBdgE-003Frr-1U; Mon, 15 Feb 2021 14:12:46 +0100 Message-ID: <79aeb83a288051bd3a2a3f15e5ac42e06f154d48.camel@sipsolutions.net> Subject: Re: [PATCH 1/2] lockdep: add lockdep_assert_not_held() From: Johannes Berg To: Peter Zijlstra , Shuah Khan Cc: mingo@redhat.com, will@kernel.org, kvalo@codeaurora.org, davem@davemloft.net, kuba@kernel.org, ath10k@lists.infradead.org, linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Date: Mon, 15 Feb 2021 14:12:30 +0100 In-Reply-To: <20210215104402.GC4507@worktop.programming.kicks-ass.net> (sfid-20210215_114645_090502_64B4A89D) References: <37a29c383bff2fb1605241ee6c7c9be3784fb3c6.1613171185.git.skhan@linuxfoundation.org> <20210215104402.GC4507@worktop.programming.kicks-ass.net> (sfid-20210215_114645_090502_64B4A89D) Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.36.5 (3.36.5-2.fc32) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-malware-bazaar: not-scanned Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Mon, 2021-02-15 at 11:44 +0100, Peter Zijlstra wrote: > > I think something like so will work, but please double check. Yeah, that looks better. > +++ b/include/linux/lockdep.h > @@ -294,11 +294,15 @@ extern void lock_unpin_lock(struct lockdep_map *lock, struct pin_cookie); > > #define lockdep_depth(tsk) (debug_locks ? (tsk)->lockdep_depth : 0) > > -#define lockdep_assert_held(l) do { \ > - WARN_ON(debug_locks && !lockdep_is_held(l)); \ > +#define lockdep_assert_held(l) do { \ > + WARN_ON(debug_locks && lockdep_is_held(l) == 0)); \ > } while (0) That doesn't really need to change? It's the same. > -#define lockdep_assert_held_write(l) do { \ > +#define lockdep_assert_not_held(l) do { \ > + WARN_ON(debug_locks && lockdep_is_held(l) == 1)); \ > + } while (0) > + > +#define lockdep_assert_held_write(l) do { \ > WARN_ON(debug_locks && !lockdep_is_held_type(l, 0)); \ > } while (0) > > diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c > index c1418b47f625..983ba206f7b2 100644 > --- a/kernel/locking/lockdep. > +++ b/kernel/locking/lockdep.c > @@ -5467,7 +5467,7 @@ noinstr int lock_is_held_type(const struct lockdep_map *lock, int read) > int ret = 0; > > if (unlikely(!lockdep_enabled())) > - return 1; /* avoid false negative lockdep_assert_held() */ > + return -1; /* avoid false negative lockdep_assert_held() */ Maybe add lockdep_assert_not_held() to the comment, to explain the -1 (vs non-zero)? johannes