Subject: [PATCH net-next 2/7] rcu: un-hide lockdep maps for !LOCKDEP

From: Jakub Kicinski <[email-masked]>
Date: Wed, 16 Sep 2020 11:45:23 -0700

We're trying to make LOCKDEP-related forward declarations
visible to the compiler and depend on dead code elimination
to remove them.

Expose RCU lock maps.

Signed-off-by: Jakub Kicinski <[email-masked]>
---
CC: [email-masked]
CC: [email-masked]
CC: [email-masked]
CC: [email-masked]
CC: [email-masked]
CC: [email-masked]
---
 include/linux/rcupdate.h       | 9 +++++----
 include/linux/rcupdate_trace.h | 4 ++--
 2 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index d15d46db61f7..53f9648cb982 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -234,6 +234,11 @@ bool rcu_lockdep_current_cpu_online(void);
 static inline bool rcu_lockdep_current_cpu_online(void) { return true; }
 #endif /* #else #if defined(CONFIG_HOTPLUG_CPU) && defined(CONFIG_PROVE_RCU) */
 
+extern struct lockdep_map rcu_lock_map;
+extern struct lockdep_map rcu_bh_lock_map;
+extern struct lockdep_map rcu_sched_lock_map;
+extern struct lockdep_map rcu_callback_map;
+
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 
 static inline void rcu_lock_acquire(struct lockdep_map *map)
@@ -246,10 +251,6 @@ static inline void rcu_lock_release(struct lockdep_map *map)
 	lock_release(map, _THIS_IP_);
 }
 
-extern struct lockdep_map rcu_lock_map;
-extern struct lockdep_map rcu_bh_lock_map;
-extern struct lockdep_map rcu_sched_lock_map;
-extern struct lockdep_map rcu_callback_map;
 int debug_lockdep_rcu_enabled(void);
 int rcu_read_lock_held(void);
 int rcu_read_lock_bh_held(void);
diff --git a/include/linux/rcupdate_trace.h b/include/linux/rcupdate_trace.h
index aaaac8ac927c..25cdef506cae 100644
--- a/include/linux/rcupdate_trace.h
+++ b/include/linux/rcupdate_trace.h
@@ -11,10 +11,10 @@
 #include <linux/sched.h>
 #include <linux/rcupdate.h>
 
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
-
 extern struct lockdep_map rcu_trace_lock_map;
 
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+
 static inline int rcu_read_lock_trace_held(void)
 {
 	return lock_is_held(&rcu_trace_lock_map);
-- 
2.26.2