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[2620:137:e000::1:20]) by mx.google.com with ESMTP id 206-20020a6307d7000000b0046f59be9bebsi16457835pgh.102.2022.12.14.06.06.17; Wed, 14 Dec 2022 06:06:35 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238563AbiLNOCZ (ORCPT + 99 others); Wed, 14 Dec 2022 09:02:25 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32848 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238524AbiLNOCL (ORCPT ); Wed, 14 Dec 2022 09:02:11 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3897320BC4 for ; Wed, 14 Dec 2022 06:02:11 -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 D189661A69 for ; Wed, 14 Dec 2022 14:02:10 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3D0BDC4339E; Wed, 14 Dec 2022 14:02:10 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.96) (envelope-from ) id 1p5SKn-000gun-13; Wed, 14 Dec 2022 09:02:09 -0500 Message-ID: <20221214140209.194205837@goodmis.org> User-Agent: quilt/0.66 Date: Wed, 14 Dec 2022 09:01:38 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Masami Hiramatsu , Andrew Morton Subject: [for-next][PATCH 5/8] tracing: Do not synchronize freeing of trigger filter on boot up References: <20221214140133.608431204@goodmis.org> MIME-Version: 1.0 X-Spam-Status: No, score=-6.7 required=5.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,RCVD_IN_DNSWL_HI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1752198592826897749?= X-GMAIL-MSGID: =?utf-8?q?1752198592826897749?= From: "Steven Rostedt (Google)" If a trigger filter on the kernel command line fails to apply (due to syntax error), it will be freed. The freeing will call tracepoint_synchronize_unregister(), but this is not needed during early boot up, and will even trigger a lockdep splat. Avoid calling the synchronization function when system_state is SYSTEM_BOOTING. Link: https://lore.kernel.org/linux-trace-kernel/20221213172429.7774f4ba@gandalf.local.home Cc: Andrew Morton Acked-by: Masami Hiramatsu (Google) Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace_events_trigger.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c index 19ce9d22bfd7..e535959939d3 100644 --- a/kernel/trace/trace_events_trigger.c +++ b/kernel/trace/trace_events_trigger.c @@ -1085,8 +1085,14 @@ int set_trigger_filter(char *filter_str, rcu_assign_pointer(data->filter, filter); if (tmp) { - /* Make sure the call is done with the filter */ - tracepoint_synchronize_unregister(); + /* + * Make sure the call is done with the filter. + * It is possible that a filter could fail at boot up, + * and then this path will be called. Avoid the synchronization + * in that case. + */ + if (system_state != SYSTEM_BOOTING) + tracepoint_synchronize_unregister(); free_event_filter(tmp); }