3 files changed, 53 insertions, 19 deletions

diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c
index 9b7fd4723878..033cb55c26df 100644
--- a/kernel/rcupdate.c
+++ b/kernel/rcupdate.c
@@ -50,6 +50,16 @@ static struct lock_class_key rcu_lock_key;
 struct lockdep_map rcu_lock_map =
         STATIC_LOCKDEP_MAP_INIT("rcu_read_lock", &rcu_lock_key);
 EXPORT_SYMBOL_GPL(rcu_lock_map);
+
+static struct lock_class_key rcu_bh_lock_key;
+struct lockdep_map rcu_bh_lock_map =
+        STATIC_LOCKDEP_MAP_INIT("rcu_read_lock_bh", &rcu_bh_lock_key);
+EXPORT_SYMBOL_GPL(rcu_bh_lock_map);
+
+static struct lock_class_key rcu_sched_lock_key;
+struct lockdep_map rcu_sched_lock_map =
+        STATIC_LOCKDEP_MAP_INIT("rcu_read_lock_sched", &rcu_sched_lock_key);
+EXPORT_SYMBOL_GPL(rcu_sched_lock_map);
 #endif
 
 /*
diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c
index adda92bfafac..5f43f30fcd1d 100644
--- a/kernel/rcutorture.c
+++ b/kernel/rcutorture.c
@@ -796,7 +796,11 @@ static void rcu_torture_timer(unsigned long unused)
 
         idx = cur_ops->readlock();
         completed = cur_ops->completed();
-        p = rcu_dereference(rcu_torture_current);
+        p = rcu_dereference_check(rcu_torture_current,
+                                  rcu_read_lock_held() ||
+                                  rcu_read_lock_bh_held() ||
+                                  rcu_read_lock_sched_held() ||
+                                  srcu_read_lock_held(&srcu_ctl));
         if (p == NULL) {
                 /* Leave because rcu_torture_writer is not yet underway */
                 cur_ops->readunlock(idx);
@@ -853,7 +857,11 @@ rcu_torture_reader(void *arg)
                 }
                 idx = cur_ops->readlock();
                 completed = cur_ops->completed();
-                p = rcu_dereference(rcu_torture_current);
+                p = rcu_dereference_check(rcu_torture_current,
+                                          rcu_read_lock_held() ||
+                                          rcu_read_lock_bh_held() ||
+                                          rcu_read_lock_sched_held() ||
+                                          srcu_read_lock_held(&srcu_ctl));
                 if (p == NULL) {
                         /* Wait for rcu_torture_writer to get underway */
                         cur_ops->readunlock(idx);
diff --git a/kernel/srcu.c b/kernel/srcu.c
index 31b275b9c112..bde4295774c8 100644
--- a/kernel/srcu.c
+++ b/kernel/srcu.c
@@ -34,6 +34,30 @@
 #include <linux/smp.h>
 #include <linux/srcu.h>
 
+static int init_srcu_struct_fields(struct srcu_struct *sp)
+{
+        sp->completed = 0;
+        mutex_init(&sp->mutex);
+        sp->per_cpu_ref = alloc_percpu(struct srcu_struct_array);
+        return sp->per_cpu_ref ? 0 : -ENOMEM;
+}
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+
+int __init_srcu_struct(struct srcu_struct *sp, const char *name,
+                       struct lock_class_key *key)
+{
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+        /* Don't re-initialize a lock while it is held. */
+        debug_check_no_locks_freed((void *)sp, sizeof(*sp));
+        lockdep_init_map(&sp->dep_map, name, key, 0);
+#endif /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */
+        return init_srcu_struct_fields(sp);
+}
+EXPORT_SYMBOL_GPL(__init_srcu_struct);
+
+#else /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */
+
 /**
  * init_srcu_struct - initialize a sleep-RCU structure
  * @sp: structure to initialize.
@@ -44,13 +68,12 @@
  */
 int init_srcu_struct(struct srcu_struct *sp)
 {
-        sp->completed = 0;
-        mutex_init(&sp->mutex);
-        sp->per_cpu_ref = alloc_percpu(struct srcu_struct_array);
-        return (sp->per_cpu_ref ? 0 : -ENOMEM);
+        return init_srcu_struct_fields(sp);
 }
 EXPORT_SYMBOL_GPL(init_srcu_struct);
 
+#endif /* #else #ifdef CONFIG_DEBUG_LOCK_ALLOC */
+
 /*
  * srcu_readers_active_idx -- returns approximate number of readers
  *      active on the specified rank of per-CPU counters.
@@ -100,15 +123,12 @@ void cleanup_srcu_struct(struct srcu_struct *sp)
 }
 EXPORT_SYMBOL_GPL(cleanup_srcu_struct);
 
-/**
- * srcu_read_lock - register a new reader for an SRCU-protected structure.
- * @sp: srcu_struct in which to register the new reader.
- *
+/*
  * Counts the new reader in the appropriate per-CPU element of the
  * srcu_struct.  Must be called from process context.
  * Returns an index that must be passed to the matching srcu_read_unlock().
  */
-int srcu_read_lock(struct srcu_struct *sp)
+int __srcu_read_lock(struct srcu_struct *sp)
 {
         int idx;
 
@@ -120,26 +140,22 @@ int srcu_read_lock(struct srcu_struct *sp)
         preempt_enable();
         return idx;
 }
-EXPORT_SYMBOL_GPL(srcu_read_lock);
+EXPORT_SYMBOL_GPL(__srcu_read_lock);
 
-/**
- * srcu_read_unlock - unregister a old reader from an SRCU-protected structure.
- * @sp: srcu_struct in which to unregister the old reader.
- * @idx: return value from corresponding srcu_read_lock().
- *
+/*
  * Removes the count for the old reader from the appropriate per-CPU
  * element of the srcu_struct.  Note that this may well be a different
  * CPU than that which was incremented by the corresponding srcu_read_lock().
  * Must be called from process context.
  */
-void srcu_read_unlock(struct srcu_struct *sp, int idx)
+void __srcu_read_unlock(struct srcu_struct *sp, int idx)
 {
         preempt_disable();
         srcu_barrier();  /* ensure compiler won't misorder critical section. */
         per_cpu_ptr(sp->per_cpu_ref, smp_processor_id())->c[idx]--;
         preempt_enable();
 }
-EXPORT_SYMBOL_GPL(srcu_read_unlock);
+EXPORT_SYMBOL_GPL(__srcu_read_unlock);
 
 /*
  * Helper function for synchronize_srcu() and synchronize_srcu_expedited().