1 files changed, 11 insertions, 4 deletions

diff --git a/include/linux/srcu.h b/include/linux/srcu.h
index e1b005918bbb..d3d5fa54f25e 100644
--- a/include/linux/srcu.h
+++ b/include/linux/srcu.h
@@ -99,15 +99,18 @@ long srcu_batches_completed(struct srcu_struct *sp);
  * power mode. This way we can notice an extended quiescent state to
  * other CPUs that started a grace period. Otherwise we would delay any
  * grace period as long as we run in the idle task.
+ *
+ * Similarly, we avoid claiming an SRCU read lock held if the current
+ * CPU is offline.
  */
 static inline int srcu_read_lock_held(struct srcu_struct *sp)
 {
-        if (rcu_is_cpu_idle())
-                return 0;
-
         if (!debug_lockdep_rcu_enabled())
                 return 1;
-
+        if (rcu_is_cpu_idle())
+                return 0;
+        if (!rcu_lockdep_current_cpu_online())
+                return 0;
         return lock_is_held(&sp->dep_map);
 }
 
@@ -169,6 +172,8 @@ static inline int srcu_read_lock(struct srcu_struct *sp) __acquires(sp)
         int retval = __srcu_read_lock(sp);
 
         rcu_lock_acquire(&(sp)->dep_map);
+        rcu_lockdep_assert(!rcu_is_cpu_idle(),
+                           "srcu_read_lock() used illegally while idle");
         return retval;
 }
 
@@ -182,6 +187,8 @@ static inline int srcu_read_lock(struct srcu_struct *sp) __acquires(sp)
 static inline void srcu_read_unlock(struct srcu_struct *sp, int idx)
         __releases(sp)
 {
+        rcu_lockdep_assert(!rcu_is_cpu_idle(),
+                           "srcu_read_unlock() used illegally while idle");
         rcu_lock_release(&(sp)->dep_map);
         __srcu_read_unlock(sp, idx);
 }