rcu: Add failure tracing to rcutorture

Trace the rcutorture RCU accesses and dump the trace buffer when the
first failure is detected.

Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>

1 files changed, 8 insertions, 0 deletions

diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index cd1ad4b04c6d..8d315b013e37 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -51,6 +51,8 @@ extern int rcutorture_runnable; /* for sysctl */
 #if defined(CONFIG_TREE_RCU) || defined(CONFIG_TREE_PREEMPT_RCU)
 extern void rcutorture_record_test_transition(void);
 extern void rcutorture_record_progress(unsigned long vernum);
+extern void do_trace_rcu_torture_read(char *rcutorturename,
+                                      struct rcu_head *rhp);
 #else
 static inline void rcutorture_record_test_transition(void)
 {
@@ -58,6 +60,12 @@ static inline void rcutorture_record_test_transition(void)
 static inline void rcutorture_record_progress(unsigned long vernum)
 {
 }
+#ifdef CONFIG_RCU_TRACE
+extern void do_trace_rcu_torture_read(char *rcutorturename,
+                                      struct rcu_head *rhp);
+#else
+#define do_trace_rcu_torture_read(rcutorturename, rhp) do { } while (0)
+#endif
 #endif
 
 #define UINT_CMP_GE(a, b)       (UINT_MAX / 2 >= (a) - (b))