6 files changed, 16 insertions, 10 deletions
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 2f05e9128201..4b5fd3da5fe8 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -536,6 +536,7 @@ extern int panic_on_warn;
 extern unsigned long panic_on_taint;
 extern bool panic_on_taint_nousertaint;
 extern int sysctl_panic_on_rcu_stall;
+extern int sysctl_max_rcu_stall_to_panic;
 extern int sysctl_panic_on_stackoverflow;
 
 extern bool crash_kexec_post_notifiers;
diff --git a/include/linux/list.h b/include/linux/list.h
index a18c87b63376..89bdc92e75c3 100644
--- a/include/linux/list.h
+++ b/include/linux/list.h
@@ -9,7 +9,7 @@
 #include <linux/kernel.h>
 
 /*
- * Simple doubly linked list implementation.
+ * Circular doubly linked list implementation.
  *
  * Some of the internal functions ("__xxx") are useful when
  * manipulating whole lists rather than single entries, as
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index f5594879175a..ccc3ce66c7e0 100644
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -375,6 +375,12 @@ static inline void lockdep_unregister_key(struct lock_class_key *key)
 
 #define lockdep_depth(tsk)	(0)
 
+/*
+ * Dummy forward declarations, allow users to write less ifdef-y code
+ * and depend on dead code elimination.
+ */
+extern int lock_is_held(const void *);
+extern int lockdep_is_held(const void *);
 #define lockdep_is_held_type(l, r)		(1)
 
 #define lockdep_assert_held(l)			do { (void)(l); } while (0)
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index 6cdd0152c253..de0826411311 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -241,6 +241,11 @@ 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)
@@ -253,10 +258,6 @@ 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);
@@ -327,7 +328,7 @@ static inline void rcu_preempt_sleep_check(void) { }
 
 #else /* #ifdef CONFIG_PROVE_RCU */
 
-#define RCU_LOCKDEP_WARN(c, s) do { } while (0)
+#define RCU_LOCKDEP_WARN(c, s) do { } while (0 && (c))
 #define rcu_sleep_check() do { } while (0)
 
 #endif /* #else #ifdef CONFIG_PROVE_RCU */
diff --git a/include/linux/rcupdate_trace.h b/include/linux/rcupdate_trace.h
index 3e7919fc5f34..86c8f6c98412 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);
diff --git a/include/linux/sched/task.h b/include/linux/sched/task.h
index 85fb2f34c59b..c0f71f2e7160 100644
--- a/include/linux/sched/task.h
+++ b/include/linux/sched/task.h
@@ -47,9 +47,7 @@ extern spinlock_t mmlist_lock;
 extern union thread_union init_thread_union;
 extern struct task_struct init_task;
 
-#ifdef CONFIG_PROVE_RCU
 extern int lockdep_tasklist_lock_is_held(void);
-#endif /* #ifdef CONFIG_PROVE_RCU */
 
 extern asmlinkage void schedule_tail(struct task_struct *prev);
 extern void init_idle(struct task_struct *idle, int cpu);