The syscall tracepoints need tracepoint_iter_lock for the tp_printk work.

Signed-off-by: Jeff Xie <xiehuan09@gmail.com>
---
 kernel/trace/trace.c | 2 +-
 kernel/trace/trace.h | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index eaf7d30ca6f1..867f00473f9f 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2833,7 +2833,7 @@ trace_event_buffer_lock_reserve(struct trace_buffer **current_rb,
 }
 EXPORT_SYMBOL_GPL(trace_event_buffer_lock_reserve);
 
-static DEFINE_SPINLOCK(tracepoint_iter_lock);
+DEFINE_SPINLOCK(tracepoint_iter_lock);
 static DEFINE_MUTEX(tracepoint_printk_mutex);
 
 static void output_printk(struct trace_event_buffer *fbuffer)
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 0f5e22238cd2..7ce345699ac2 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -1523,6 +1523,7 @@ static inline void *event_file_data(struct file *filp)
 
 extern struct mutex event_mutex;
 extern struct list_head ftrace_events;
+extern spinlock_t tracepoint_iter_lock;
 
 extern const struct file_operations event_trigger_fops;
 extern const struct file_operations event_hist_fops;
-- 
2.25.1