[PATCH RT 21/25][RFC 3.0.23-rt39-rc1] ring-buffer/rt: Check for irqs disabled before grabbing reader lock

[Steven Rostedt]

From: Steven Rostedt <rostedt@xxxxxxxxxxx>

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@xxxxxxxxxxx>
Cc: Carsten Emde <C.Emde@xxxxxxxxx>
Cc: John Kacur <jkacur@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Clark Williams <clark.williams@xxxxxxxxx>
Cc: stable-rt@xxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/20120301190345.786365803@xxxxxxxxxxx
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
 kernel/trace/ring_buffer.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 2467714..2ffbb9d 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -1045,7 +1045,7 @@ 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;
-- 
1.7.8.3


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