From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755841Ab0CDQdl (ORCPT ); Thu, 4 Mar 2010 11:33:41 -0500 Received: from hera.kernel.org ([140.211.167.34]:46393 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755460Ab0CDQdi (ORCPT ); Thu, 4 Mar 2010 11:33:38 -0500 Date: Thu, 4 Mar 2010 16:33:07 GMT From: "tip-bot for Paul E. McKenney" Cc: linux-kernel@vger.kernel.org, paulmck@linux.vnet.ibm.com, hpa@zytor.com, mingo@redhat.com, fweisbec@gmail.com, rostedt@goodmis.org, tglx@linutronix.de, mingo@elte.hu Reply-To: mingo@redhat.com, hpa@zytor.com, paulmck@linux.vnet.ibm.com, linux-kernel@vger.kernel.org, fweisbec@gmail.com, rostedt@goodmis.org, tglx@linutronix.de, mingo@elte.hu In-Reply-To: <1267667418-32233-3-git-send-email-paulmck@linux.vnet.ibm.com> References: <1267667418-32233-3-git-send-email-paulmck@linux.vnet.ibm.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:core/urgent] rcu, ftrace: Fix RCU lockdep splat in ftrace_perf_buf_prepare() Message-ID: Git-Commit-ID: 8d53dd546f36073e0d29b0cfc24c665db301e3e7 X-Mailer: tip-git-log-daemon MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.3 (hera.kernel.org [127.0.0.1]); Thu, 04 Mar 2010 16:33:07 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 8d53dd546f36073e0d29b0cfc24c665db301e3e7 Gitweb: http://git.kernel.org/tip/8d53dd546f36073e0d29b0cfc24c665db301e3e7 Author: Paul E. McKenney AuthorDate: Wed, 3 Mar 2010 17:50:18 -0800 Committer: Ingo Molnar CommitDate: Thu, 4 Mar 2010 12:07:35 +0100 rcu, ftrace: Fix RCU lockdep splat in ftrace_perf_buf_prepare() Change the pair of rcu_dereference() calls in ftrace_perf_buf_prepare() to rcu_dereference_sched(). Signed-off-by: Paul E. McKenney Acked-by: Frederic Weisbecker Cc: Steven Rostedt Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com Cc: Frederic Weisbecker LKML-Reference: <1267667418-32233-3-git-send-email-paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar --- include/trace/ftrace.h | 4 ++-- kernel/trace/trace_event_profile.c | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h index 0804cd5..601ad77 100644 --- a/include/trace/ftrace.h +++ b/include/trace/ftrace.h @@ -699,9 +699,9 @@ __attribute__((section("_ftrace_events"))) event_##call = { \ * __cpu = smp_processor_id(); * * if (in_nmi()) - * trace_buf = rcu_dereference(perf_trace_buf_nmi); + * trace_buf = rcu_dereference_sched(perf_trace_buf_nmi); * else - * trace_buf = rcu_dereference(perf_trace_buf); + * trace_buf = rcu_dereference_sched(perf_trace_buf); * * if (!trace_buf) * goto end; diff --git a/kernel/trace/trace_event_profile.c b/kernel/trace/trace_event_profile.c index f0d6930..c1cc3ab 100644 --- a/kernel/trace/trace_event_profile.c +++ b/kernel/trace/trace_event_profile.c @@ -138,9 +138,9 @@ __kprobes void *ftrace_perf_buf_prepare(int size, unsigned short type, cpu = smp_processor_id(); if (in_nmi()) - trace_buf = rcu_dereference(perf_trace_buf_nmi); + trace_buf = rcu_dereference_sched(perf_trace_buf_nmi); else - trace_buf = rcu_dereference(perf_trace_buf); + trace_buf = rcu_dereference_sched(perf_trace_buf); if (!trace_buf) goto err;