From nobody Sun Sep 14 10:12:44 2025 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 923C8C54E94 for ; Wed, 25 Jan 2023 16:20:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235852AbjAYQUU (ORCPT ); Wed, 25 Jan 2023 11:20:20 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52282 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235646AbjAYQUO (ORCPT ); Wed, 25 Jan 2023 11:20:14 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CFA6C5618F for ; Wed, 25 Jan 2023 08:20:12 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 665D56144C for ; Wed, 25 Jan 2023 16:20:12 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D323FC433AA; Wed, 25 Jan 2023 16:20:11 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.96) (envelope-from ) id 1pKiVO-004MsU-2b; Wed, 25 Jan 2023 11:20:10 -0500 Message-ID: <20230125162010.631776115@goodmis.org> User-Agent: quilt/0.66 Date: Wed, 25 Jan 2023 11:18:29 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Masami Hiramatsu , Andrew Morton , Daniel Bristot de Oliveira , Chuang Wang Subject: [for-linus][PATCH 05/11] tracing/osnoise: Use built-in RCU list checking References: <20230125161824.332648375@goodmis.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Chuang Wang list_for_each_entry_rcu() has built-in RCU and lock checking. Pass cond argument to list_for_each_entry_rcu() to silence false lockdep warning when CONFIG_PROVE_RCU_LIST is enabled. Execute as follow: [tracing]# echo osnoise > current_tracer [tracing]# echo 1 > tracing_on [tracing]# echo 0 > tracing_on The trace_types_lock is held when osnoise_tracer_stop() or timerlat_tracer_stop() are called in the non-RCU read side section. So, pass lockdep_is_held(&trace_types_lock) to silence false lockdep warning. Link: https://lkml.kernel.org/r/20221227023036.784337-1-nashuiliang@gmail.c= om Cc: Masami Hiramatsu Fixes: dae181349f1e ("tracing/osnoise: Support a list of trace_array *tr") Acked-by: Daniel Bristot de Oliveira Signed-off-by: Chuang Wang Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace_osnoise.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/kernel/trace/trace_osnoise.c b/kernel/trace/trace_osnoise.c index 94c1b5eb1dc0..210e1f168392 100644 --- a/kernel/trace/trace_osnoise.c +++ b/kernel/trace/trace_osnoise.c @@ -147,9 +147,8 @@ static void osnoise_unregister_instance(struct trace_ar= ray *tr) * register/unregister serialization is provided by trace's * trace_types_lock. */ - lockdep_assert_held(&trace_types_lock); - - list_for_each_entry_rcu(inst, &osnoise_instances, list) { + list_for_each_entry_rcu(inst, &osnoise_instances, list, + lockdep_is_held(&trace_types_lock)) { if (inst->tr =3D=3D tr) { list_del_rcu(&inst->list); found =3D 1; --=20 2.39.0