tracepoints: samples, fix teardown

Impact: fix a bug in sample tracepoints

Need a tracepoint_synchronize_unregister() before the end of exit() to
make sure every probe callers have exited the non preemptible section
and thus are not executing the probe code anymore.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

2 files changed, 2 insertions, 0 deletions

diff --git a/samples/tracepoints/tracepoint-probe-sample.c b/samples/tracepoints/tracepoint-probe-sample.c
index 55abfdda4bd4..e3a964889dc7 100644
--- a/samples/tracepoints/tracepoint-probe-sample.c
+++ b/samples/tracepoints/tracepoint-probe-sample.c
@@ -46,6 +46,7 @@ void __exit tp_sample_trace_exit(void)
 {
         unregister_trace_subsys_eventb(probe_subsys_eventb);
         unregister_trace_subsys_event(probe_subsys_event);
+        tracepoint_synchronize_unregister();
 }
 
 module_exit(tp_sample_trace_exit);
diff --git a/samples/tracepoints/tracepoint-probe-sample2.c b/samples/tracepoints/tracepoint-probe-sample2.c
index 5e9fcf4afffe..685a5acb4562 100644
--- a/samples/tracepoints/tracepoint-probe-sample2.c
+++ b/samples/tracepoints/tracepoint-probe-sample2.c
@@ -33,6 +33,7 @@ module_init(tp_sample_trace_init);
 void __exit tp_sample_trace_exit(void)
 {
         unregister_trace_subsys_event(probe_subsys_event);
+        tracepoint_synchronize_unregister();
 }
 
 module_exit(tp_sample_trace_exit);