Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966792AbcCPLHF (ORCPT ); Wed, 16 Mar 2016 07:07:05 -0400 Received: from mx2.suse.de ([195.135.220.15]:47387 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966622AbcCPLAB (ORCPT ); Wed, 16 Mar 2016 07:00:01 -0400 X-Amavis-Alert: BAD HEADER SECTION, Duplicate header field: "References" From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, "Steven Rostedt (Red Hat)" , Greg Kroah-Hartman Subject: [PATCH 3.12 38/58] tracing: Fix check for cpu online when event is disabled Date: Wed, 16 Mar 2016 11:59:23 +0100 Message-Id: X-Mailer: git-send-email 2.7.3 In-Reply-To: <377b71e18f20d69b0df301ce7040554f40ba9651.1458125909.git.jslaby@suse.cz> References: <377b71e18f20d69b0df301ce7040554f40ba9651.1458125909.git.jslaby@suse.cz> In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2950 Lines: 74 From: "Steven Rostedt (Red Hat)" 3.12-stable review patch. If anyone has any objections, please let me know. =============== 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(-) diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h index c1248996006f..9ff9ca22cfb7 100644 --- a/include/linux/tracepoint.h +++ b/include/linux/tracepoint.h @@ -129,9 +129,6 @@ static inline void tracepoint_synchronize_unregister(void) 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_synchronize_unregister(void) * "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)) -- 2.7.3