ftrace: debug smp_processor_id, use notrace preempt disable
The debug smp_processor_id caused a recursive fault in debugging
the irqsoff tracer. The tracer used a smp_processor_id in the
ftrace callback, and this function called preempt_disable which
also is traced. This caused a recursive fault (stack overload).
Since using smp_processor_id without debugging on does not cause
faults with the tracer (even when the tracer is wrong), the
debug version should not cause a system reboot.
This changes the debug_smp_processor_id to use the notrace versions
of preempt_disable and enable.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/lib/smp_processor_id.c b/lib/smp_processor_id.c
index e555ab6..3b4dc09 100644
--- a/lib/smp_processor_id.c
+++ b/lib/smp_processor_id.c
@@ -37,7 +37,7 @@
/*
* Avoid recursion:
*/
- preempt_disable();
+ preempt_disable_notrace();
if (!printk_ratelimit())
goto out_enable;
@@ -49,7 +49,7 @@
dump_stack();
out_enable:
- preempt_enable_no_resched();
+ preempt_enable_no_resched_notrace();
out:
return this_cpu;
}