Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932600AbcCNSIf (ORCPT ); Mon, 14 Mar 2016 14:08:35 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:44143 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754151AbcCNRy1 (ORCPT ); Mon, 14 Mar 2016 13:54:27 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Sudeep Holla , Steven Rostedt Subject: [PATCH 3.14 03/19] tracing: Fix check for cpu online when event is disabled Date: Mon, 14 Mar 2016 10:52:43 -0700 Message-Id: <20160314175029.656934809@linuxfoundation.org> X-Mailer: git-send-email 2.7.2 In-Reply-To: <20160314175029.541742468@linuxfoundation.org> References: <20160314175029.541742468@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2800 Lines: 72 3.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Steven Rostedt (Red Hat) commit dc17147de328a74bbdee67c1bf37d2f1992de756 upstream. Commit f37755490fe9b ("tracepoints: Do not trace when cpu is offline") added a check to make sure that tracepoints only get called when the cpu is online, as it uses rcu_read_lock_sched() for protection. Commit 3a630178fd5f3 ("tracing: generate RCU warnings even when tracepoints are disabled") added lockdep checks (including rcu checks) for events that are not enabled to catch possible RCU issues that would only be triggered if a trace event was enabled. Commit f37755490fe9b only stopped the warnings when the trace event was enabled but did not prevent warnings if the trace event was called when disabled. To fix this, the cpu online check is moved to where the condition is added to the trace event. This will place the cpu online check in all places that it may be used now and in the future. Fixes: f37755490fe9b ("tracepoints: Do not trace when cpu is offline") Fixes: 3a630178fd5f3 ("tracing: generate RCU warnings even when tracepoints are disabled") Reported-by: Sudeep Holla Tested-by: Sudeep Holla Signed-off-by: Steven Rostedt Signed-off-by: Greg Kroah-Hartman --- include/linux/tracepoint.h | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) --- a/include/linux/tracepoint.h +++ b/include/linux/tracepoint.h @@ -129,9 +129,6 @@ static inline void tracepoint_synchroniz void *it_func; \ void *__data; \ \ - if (!cpu_online(raw_smp_processor_id())) \ - return; \ - \ if (!(cond)) \ return; \ prercu; \ @@ -265,15 +262,19 @@ static inline void tracepoint_synchroniz * "void *__data, proto" as the callback prototype. */ #define DECLARE_TRACE_NOARGS(name) \ - __DECLARE_TRACE(name, void, , 1, void *__data, __data) + __DECLARE_TRACE(name, void, , \ + cpu_online(raw_smp_processor_id()), \ + void *__data, __data) #define DECLARE_TRACE(name, proto, args) \ - __DECLARE_TRACE(name, PARAMS(proto), PARAMS(args), 1, \ - PARAMS(void *__data, proto), \ - PARAMS(__data, args)) + __DECLARE_TRACE(name, PARAMS(proto), PARAMS(args), \ + cpu_online(raw_smp_processor_id()), \ + PARAMS(void *__data, proto), \ + PARAMS(__data, args)) #define DECLARE_TRACE_CONDITION(name, proto, args, cond) \ - __DECLARE_TRACE(name, PARAMS(proto), PARAMS(args), PARAMS(cond), \ + __DECLARE_TRACE(name, PARAMS(proto), PARAMS(args), \ + cpu_online(raw_smp_processor_id()) && (PARAMS(cond)), \ PARAMS(void *__data, proto), \ PARAMS(__data, args))