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 D4503C433F5 for ; Thu, 28 Apr 2022 21:52:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347549AbiD1VzY (ORCPT ); Thu, 28 Apr 2022 17:55:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55324 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1352598AbiD1Vy7 (ORCPT ); Thu, 28 Apr 2022 17:54:59 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 775E8340FA for ; Thu, 28 Apr 2022 14:51:44 -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 ams.source.kernel.org (Postfix) with ESMTPS id 28BEDB83079 for ; Thu, 28 Apr 2022 21:51:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D32C7C385BB; Thu, 28 Apr 2022 21:51:41 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.95) (envelope-from ) id 1nkC32-003MbM-VP; Thu, 28 Apr 2022 17:51:40 -0400 Message-ID: <20220428215140.807739542@goodmis.org> User-Agent: quilt/0.66 Date: Thu, 28 Apr 2022 17:51:08 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Ingo Molnar , Jakob Koschel Subject: [for-next][PATCH 6/8] tracing: Remove usage of list iterator variable after the loop References: <20220428215102.260147624@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: Jakob Koschel In preparation to limit the scope of a list iterator to the list traversal loop, use a dedicated pointer to point to the found element [1]. Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1] Link: https://lkml.kernel.org/r/20220427170734.819891-3-jakobkoschel@gmail.com Cc: Ingo Molnar Signed-off-by: Jakob Koschel Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace_events.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index e11e167b7809..e4a442060707 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -1723,9 +1723,9 @@ static LIST_HEAD(event_subsystems); static int subsystem_open(struct inode *inode, struct file *filp) { + struct trace_subsystem_dir *dir = NULL, *iter_dir; + struct trace_array *tr = NULL, *iter_tr; struct event_subsystem *system = NULL; - struct trace_subsystem_dir *dir = NULL; /* Initialize for gcc */ - struct trace_array *tr; int ret; if (tracing_is_disabled()) @@ -1734,10 +1734,12 @@ static int subsystem_open(struct inode *inode, struct file *filp) /* Make sure the system still exists */ mutex_lock(&event_mutex); mutex_lock(&trace_types_lock); - list_for_each_entry(tr, &ftrace_trace_arrays, list) { - list_for_each_entry(dir, &tr->systems, list) { - if (dir == inode->i_private) { + list_for_each_entry(iter_tr, &ftrace_trace_arrays, list) { + list_for_each_entry(iter_dir, &iter_tr->systems, list) { + if (iter_dir == inode->i_private) { /* Don't open systems with no events */ + tr = iter_tr; + dir = iter_dir; if (dir->nr_events) { __get_system_dir(dir); system = dir->subsystem; @@ -1753,9 +1755,6 @@ static int subsystem_open(struct inode *inode, struct file *filp) if (!system) return -ENODEV; - /* Some versions of gcc think dir can be uninitialized here */ - WARN_ON(!dir); - /* Still need to increment the ref count of the system */ if (trace_array_get(tr) < 0) { put_system(dir); -- 2.35.1