srcu: Make Tiny synchronize_srcu() check for readers

[linux-2.6-microblaze.git] / kernel / rcu / srcutiny.c

diff --git a/kernel/rcu/srcutiny.c b/kernel/rcu/srcutiny.c
index 33adafd..b12fb0c 100644 (file)
--- a/kernel/rcu/srcutiny.c
+++ b/kernel/rcu/srcutiny.c
@@ -197,6 +197,16 @@ void synchronize_srcu(struct srcu_struct *ssp)
 {
        struct rcu_synchronize rs;
 
+       RCU_LOCKDEP_WARN(lockdep_is_held(ssp) ||
+                       lock_is_held(&rcu_bh_lock_map) ||
+                       lock_is_held(&rcu_lock_map) ||
+                       lock_is_held(&rcu_sched_lock_map),
+                       "Illegal synchronize_srcu() in same-type SRCU (or in RCU) read-side critical section");
+
+       if (rcu_scheduler_active == RCU_SCHEDULER_INACTIVE)
+               return;
+
+       might_sleep();
        init_rcu_head_on_stack(&rs.head);
        init_completion(&rs.completion);
        call_srcu(ssp, &rs.head, wakeme_after_rcu);