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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4B958C433F5 for ; Wed, 27 Apr 2022 19:38:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229585AbiD0Tlt (ORCPT ); Wed, 27 Apr 2022 15:41:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45800 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233552AbiD0Tj5 (ORCPT ); Wed, 27 Apr 2022 15:39:57 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7819510D9 for ; Wed, 27 Apr 2022 12:36:44 -0700 (PDT) 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 5991B61B72 for ; Wed, 27 Apr 2022 19:36:44 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 35D51C385AF; Wed, 27 Apr 2022 19:36:44 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.95) (envelope-from ) id 1njnSt-002IzN-AN; Wed, 27 Apr 2022 15:36:43 -0400 Message-ID: <20220427193643.160375389@goodmis.org> User-Agent: quilt/0.66 Date: Wed, 27 Apr 2022 15:36:43 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , kernel test robot , Mark-PK Tsai Subject: [for-next][PATCH 20/21] tracing: Avoid adding tracer option before update_tracer_options References: <20220427193623.529296556@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Mark-PK Tsai To prepare for support asynchronous tracer_init_tracefs initcall, avoid calling create_trace_option_files before __update_tracer_options. Otherwise, create_trace_option_files will show warning because some tracers in trace_types list are already in tr->topts. For example, hwlat_tracer call register_tracer in late_initcall, and global_trace.dir is already created in tracing_init_dentry, hwlat_tracer will be put into tr->topts. Then if the __update_tracer_options is executed after hwlat_tracer registered, create_trace_option_files find that hwlat_tracer is already in tr->topts. Link: https://lkml.kernel.org/r/20220426122407.17042-2-mark-pk.tsai@mediatek.com Link: https://lore.kernel.org/lkml/20220322133339.GA32582@xsang-OptiPlex-9020/ Reported-by: kernel test robot Signed-off-by: Mark-PK Tsai Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 27bb486c3f97..7275173c55d0 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -6332,12 +6332,18 @@ static void tracing_set_nop(struct trace_array *tr) tr->current_trace = &nop_trace; } +static bool tracer_options_updated; + static void add_tracer_options(struct trace_array *tr, struct tracer *t) { /* Only enable if the directory has been created already. */ if (!tr->dir) return; + /* Only create trace option files after update_tracer_options finish */ + if (!tracer_options_updated) + return; + create_trace_option_files(tr, t); } @@ -9176,6 +9182,7 @@ static void __update_tracer_options(struct trace_array *tr) static void update_tracer_options(struct trace_array *tr) { mutex_lock(&trace_types_lock); + tracer_options_updated = true; __update_tracer_options(tr); mutex_unlock(&trace_types_lock); } -- 2.35.1