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-rw-r--r--include/linux/srcu.h15
1 files changed, 11 insertions, 4 deletions
diff --git a/include/linux/srcu.h b/include/linux/srcu.h
index e1b005918bb..d3d5fa54f25 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);
}