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 X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CAFE8C35254 for ; Wed, 5 Feb 2020 10:51:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A6D3D218AC for ; Wed, 5 Feb 2020 10:51:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728332AbgBEKvP (ORCPT ); Wed, 5 Feb 2020 05:51:15 -0500 Received: from mail.kernel.org ([198.145.29.99]:59470 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728034AbgBEKvO (ORCPT ); Wed, 5 Feb 2020 05:51:14 -0500 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 313F021741; Wed, 5 Feb 2020 10:51:14 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.93) (envelope-from ) id 1izIH3-001NsT-3x; Wed, 05 Feb 2020 05:51:13 -0500 Message-Id: <20200205105113.004907028@goodmis.org> User-Agent: quilt/0.65 Date: Wed, 05 Feb 2020 05:49:31 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Amol Grover Subject: [for-next][PATCH 2/4] tracing: Annotate ftrace_graph_hash pointer with __rcu References: <20200205104929.313040579@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Amol Grover Fix following instances of sparse error kernel/trace/ftrace.c:5664:29: error: incompatible types in comparison kernel/trace/ftrace.c:5785:21: error: incompatible types in comparison kernel/trace/ftrace.c:5864:36: error: incompatible types in comparison kernel/trace/ftrace.c:5866:25: error: incompatible types in comparison Use rcu_dereference_protected to access the __rcu annotated pointer. Link: http://lkml.kernel.org/r/20200201072703.17330-1-frextrite@gmail.com Signed-off-by: Amol Grover Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/ftrace.c | 2 +- kernel/trace/trace.h | 9 ++++++--- 2 files changed, 7 insertions(+), 4 deletions(-) diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 0e9612c30995..01d2ecd66161 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -5591,7 +5591,7 @@ static const struct file_operations ftrace_notrace_fops = { static DEFINE_MUTEX(graph_lock); -struct ftrace_hash *ftrace_graph_hash = EMPTY_HASH; +struct ftrace_hash __rcu *ftrace_graph_hash = EMPTY_HASH; struct ftrace_hash *ftrace_graph_notrace_hash = EMPTY_HASH; enum graph_filter_type { diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index f5480a2aa334..18ceab59a5ba 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -964,22 +964,25 @@ extern void __trace_graph_return(struct trace_array *tr, unsigned long flags, int pc); #ifdef CONFIG_DYNAMIC_FTRACE -extern struct ftrace_hash *ftrace_graph_hash; +extern struct ftrace_hash __rcu *ftrace_graph_hash; extern struct ftrace_hash *ftrace_graph_notrace_hash; static inline int ftrace_graph_addr(struct ftrace_graph_ent *trace) { unsigned long addr = trace->func; int ret = 0; + struct ftrace_hash *hash; preempt_disable_notrace(); - if (ftrace_hash_empty(ftrace_graph_hash)) { + hash = rcu_dereference_protected(ftrace_graph_hash, !preemptible()); + + if (ftrace_hash_empty(hash)) { ret = 1; goto out; } - if (ftrace_lookup_ip(ftrace_graph_hash, addr)) { + if (ftrace_lookup_ip(hash, addr)) { /* * This needs to be cleared on the return functions -- 2.24.1