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 83131EB64D7 for ; Mon, 26 Jun 2023 18:38:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232421AbjFZSiS (ORCPT ); Mon, 26 Jun 2023 14:38:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51526 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232425AbjFZSiQ (ORCPT ); Mon, 26 Jun 2023 14:38:16 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 29D13CC for ; Mon, 26 Jun 2023 11:38:15 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 5764C60EFC for ; Mon, 26 Jun 2023 18:38:13 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5E8E3C433C9; Mon, 26 Jun 2023 18:38:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1687804692; bh=vGBISMZizqVWCSLZ3DBlN0KgWbw9O0nLAye5pXvIv9Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0RfMpFfitesDpw4qtrVRLrJCnAzKPq1N+4T+yCm6T3KW5CnCYEZNzHS61abkhISu6 vZGG/biGxobo4MaPd6JFdg0IMjvHWcAtDIWwCcaCf/6iF7SwUGQIBvAWah9ZJiGSBy Dm2yXWdpJ8TzjcigetTcZFs1+f3eYtOsN2SEOcxs= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Masami Hiramatsu , Andrew Morton , Zheng Yejian , "Steven Rostedt (Google)" Subject: [PATCH 5.15 02/96] tracing: Add tracing_reset_all_online_cpus_unlocked() function Date: Mon, 26 Jun 2023 20:11:17 +0200 Message-ID: <20230626180747.034910095@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230626180746.943455203@linuxfoundation.org> References: <20230626180746.943455203@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Steven Rostedt (Google) commit e18eb8783ec4949adebc7d7b0fdb65f65bfeefd9 upstream. Currently the tracing_reset_all_online_cpus() requires the trace_types_lock held. But only one caller of this function actually has that lock held before calling it, and the other just takes the lock so that it can call it. More users of this function is needed where the lock is not held. Add a tracing_reset_all_online_cpus_unlocked() function for the one use case that calls it without being held, and also add a lockdep_assert to make sure it is held when called. Then have tracing_reset_all_online_cpus() take the lock internally, such that callers do not need to worry about taking it. Link: https://lkml.kernel.org/r/20221123192741.658273220@goodmis.org Cc: Masami Hiramatsu Cc: Andrew Morton Cc: Zheng Yejian Signed-off-by: Steven Rostedt (Google) Signed-off-by: Zheng Yejian Signed-off-by: Greg Kroah-Hartman --- kernel/trace/trace.c | 11 ++++++++++- kernel/trace/trace.h | 1 + kernel/trace/trace_events.c | 2 +- kernel/trace/trace_events_synth.c | 2 -- 4 files changed, 12 insertions(+), 4 deletions(-) --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -2175,10 +2175,12 @@ void tracing_reset_online_cpus(struct ar } /* Must have trace_types_lock held */ -void tracing_reset_all_online_cpus(void) +void tracing_reset_all_online_cpus_unlocked(void) { struct trace_array *tr; + lockdep_assert_held(&trace_types_lock); + list_for_each_entry(tr, &ftrace_trace_arrays, list) { if (!tr->clear_trace) continue; @@ -2190,6 +2192,13 @@ void tracing_reset_all_online_cpus(void) } } +void tracing_reset_all_online_cpus(void) +{ + mutex_lock(&trace_types_lock); + tracing_reset_all_online_cpus_unlocked(); + mutex_unlock(&trace_types_lock); +} + /* * The tgid_map array maps from pid to tgid; i.e. the value stored at index i * is the tgid last observed corresponding to pid=i. --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -580,6 +580,7 @@ int tracing_is_enabled(void); void tracing_reset_online_cpus(struct array_buffer *buf); void tracing_reset_current(int cpu); void tracing_reset_all_online_cpus(void); +void tracing_reset_all_online_cpus_unlocked(void); int tracing_open_generic(struct inode *inode, struct file *filp); int tracing_open_generic_tr(struct inode *inode, struct file *filp); bool tracing_is_disabled(void); --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -2974,7 +2974,7 @@ static void trace_module_remove_events(s * over from this module may be passed to the new module events and * unexpected results may occur. */ - tracing_reset_all_online_cpus(); + tracing_reset_all_online_cpus_unlocked(); } static int trace_module_notify(struct notifier_block *self, --- a/kernel/trace/trace_events_synth.c +++ b/kernel/trace/trace_events_synth.c @@ -1416,7 +1416,6 @@ int synth_event_delete(const char *event mutex_unlock(&event_mutex); if (mod) { - mutex_lock(&trace_types_lock); /* * It is safest to reset the ring buffer if the module * being unloaded registered any events that were @@ -1428,7 +1427,6 @@ int synth_event_delete(const char *event * occur. */ tracing_reset_all_online_cpus(); - mutex_unlock(&trace_types_lock); } return ret;