From bfc533a9c7eeacbc884f2ce3c84bc711237dfd6a Mon Sep 17 00:00:00 2001
From: Steven Rostedt <rostedt@goodmis.org>
Date: Thu, 1 Mar 2012 13:55:32 -0500
Subject: [PATCH 253/290] ring-buffer/rt: Check for irqs disabled before
 grabbing reader lock

In RT the reader lock is a mutex and we can not grab it when preemption is
disabled. The in_atomic() check that is there does not check if irqs are
disabled. Add that check as well.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Carsten Emde <C.Emde@osadl.org>
Cc: John Kacur <jkacur@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Clark Williams <clark.williams@gmail.com>
Cc: stable-rt@vger.kernel.org
Link: http://lkml.kernel.org/r/20120301190345.786365803@goodmis.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 kernel/trace/ring_buffer.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 354017f..c060f04 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -1054,7 +1054,7 @@ static inline int ok_to_lock(void)
 	if (in_nmi())
 		return 0;
 #ifdef CONFIG_PREEMPT_RT_FULL
-	if (in_atomic())
+	if (in_atomic() || irqs_disabled())
 		return 0;
 #endif
 	return 1;