tracing: fix recursive test level calculation

The recursive tests to detect same level recursion in the ring buffers
did not account for the hard/softirq_counts to be shifted. Thus the
numbers could be larger than then mask to be tested.

This patch includes the shift for the calculation of the irq depth.

[ Impact: stop false positives in trace recursion detection ]

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index e145969a8edab596fd8d2b7d4411718d5692caf2..aa40ae92233b33f7e8d312edcdb10f4914e80dbf 100644 (file)
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -1483,7 +1483,9 @@ rb_reserve_next_event(struct ring_buffer_per_cpu *cpu_buffer,
 
 static int trace_irq_level(void)
 {
-       return hardirq_count() + softirq_count() + in_nmi();
+       return (hardirq_count() >> HARDIRQ_SHIFT) +
+               (softirq_count() >> + SOFTIRQ_SHIFT) +
+               !!in_nmi();
 }
 
 static int trace_recursive_lock(void)