Merge tag 'trace-v6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace...

[linux-block.git] / include / linux / tracepoint.h

diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
index e299f29375bb7f1e55789adca45b45e31bebde84..6811e43c1b5c2afed0bad0a2e7469e8573916eb9 100644 (file)
--- a/include/linux/tracepoint.h
+++ b/include/linux/tracepoint.h
@@ -242,12 +242,11 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
  * not add unwanted padding between the beginning of the section and the
  * structure. Force alignment to the same alignment as the section start.
  *
- * When lockdep is enabled, we make sure to always do the RCU portions of
- * the tracepoint code, regardless of whether tracing is on. However,
- * don't check if the condition is false, due to interaction with idle
- * instrumentation. This lets us find RCU issues triggered with tracepoints
- * even when this tracepoint is off. This code has no purpose other than
- * poking RCU a bit.
+ * When lockdep is enabled, we make sure to always test if RCU is
+ * "watching" regardless if the tracepoint is enabled or not. Tracepoints
+ * require RCU to be active, and it should always warn at the tracepoint
+ * site if it is not watching, as it will need to be active when the
+ * tracepoint is enabled.
  */
 #define __DECLARE_TRACE(name, proto, args, cond, data_proto)           \
        extern int __traceiter_##name(data_proto);                      \
@@ -260,9 +259,7 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
                                TP_ARGS(args),                          \
                                TP_CONDITION(cond), 0);                 \
                if (IS_ENABLED(CONFIG_LOCKDEP) && (cond)) {             \
-                       rcu_read_lock_sched_notrace();                  \
-                       rcu_dereference_sched(__tracepoint_##name.funcs);\
-                       rcu_read_unlock_sched_notrace();                \
+                       WARN_ON_ONCE(!rcu_is_watching());               \
                }                                                       \
        }                                                               \
        __DECLARE_TRACE_RCU(name, PARAMS(proto), PARAMS(args),          \