1 files changed, 30 insertions, 8 deletions

diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c
index f19271dce0a9..4f6db7e6a117 100644
--- a/kernel/rcu/update.c
+++ b/kernel/rcu/update.c
@@ -121,11 +121,14 @@ EXPORT_SYMBOL(rcu_read_lock_sched_held);
  * Should expedited grace-period primitives always fall back to their
  * non-expedited counterparts?  Intended for use within RCU.  Note
  * that if the user specifies both rcu_expedited and rcu_normal, then
- * rcu_normal wins.
+ * rcu_normal wins.  (Except during the time period during boot from
+ * when the first task is spawned until the rcu_exp_runtime_mode()
+ * core_initcall() is invoked, at which point everything is expedited.)
  */
 bool rcu_gp_is_normal(void)
 {
-	return READ_ONCE(rcu_normal);
+	return READ_ONCE(rcu_normal) &&
+	       rcu_scheduler_active != RCU_SCHEDULER_INIT;
 }
 EXPORT_SYMBOL_GPL(rcu_gp_is_normal);
 
@@ -135,13 +138,14 @@ static atomic_t rcu_expedited_nesting =
 /*
  * Should normal grace-period primitives be expedited?  Intended for
  * use within RCU.  Note that this function takes the rcu_expedited
- * sysfs/boot variable into account as well as the rcu_expedite_gp()
- * nesting.  So looping on rcu_unexpedite_gp() until rcu_gp_is_expedited()
- * returns false is a -really- bad idea.
+ * sysfs/boot variable and rcu_scheduler_active into account as well
+ * as the rcu_expedite_gp() nesting.  So looping on rcu_unexpedite_gp()
+ * until rcu_gp_is_expedited() returns false is a -really- bad idea.
  */
 bool rcu_gp_is_expedited(void)
 {
-	return rcu_expedited || atomic_read(&rcu_expedited_nesting);
+	return rcu_expedited || atomic_read(&rcu_expedited_nesting) ||
+	       rcu_scheduler_active == RCU_SCHEDULER_INIT;
 }
 EXPORT_SYMBOL_GPL(rcu_gp_is_expedited);
 
@@ -257,7 +261,7 @@ EXPORT_SYMBOL_GPL(rcu_callback_map);
 
 int notrace debug_lockdep_rcu_enabled(void)
 {
-	return rcu_scheduler_active && debug_locks &&
+	return rcu_scheduler_active != RCU_SCHEDULER_INACTIVE && debug_locks &&
 	       current->lockdep_recursion == 0;
 }
 EXPORT_SYMBOL_GPL(debug_lockdep_rcu_enabled);
@@ -591,7 +595,7 @@ EXPORT_SYMBOL_GPL(call_rcu_tasks);
 void synchronize_rcu_tasks(void)
 {
 	/* Complain if the scheduler has not started.  */
-	RCU_LOCKDEP_WARN(!rcu_scheduler_active,
+	RCU_LOCKDEP_WARN(rcu_scheduler_active == RCU_SCHEDULER_INACTIVE,
 			 "synchronize_rcu_tasks called too soon");
 
 	/* Wait for the grace period. */
@@ -813,6 +817,23 @@ static void rcu_spawn_tasks_kthread(void)
 
 #endif /* #ifdef CONFIG_TASKS_RCU */
 
+/*
+ * Test each non-SRCU synchronous grace-period wait API.  This is
+ * useful just after a change in mode for these primitives, and
+ * during early boot.
+ */
+void rcu_test_sync_prims(void)
+{
+	if (!IS_ENABLED(CONFIG_PROVE_RCU))
+		return;
+	synchronize_rcu();
+	synchronize_rcu_bh();
+	synchronize_sched();
+	synchronize_rcu_expedited();
+	synchronize_rcu_bh_expedited();
+	synchronize_sched_expedited();
+}
+
 #ifdef CONFIG_PROVE_RCU
 
 /*
@@ -865,6 +886,7 @@ void rcu_early_boot_tests(void)
 		early_boot_test_call_rcu_bh();
 	if (rcu_self_test_sched)
 		early_boot_test_call_rcu_sched();
+	rcu_test_sync_prims();
 }
 
 static int rcu_verify_early_boot_tests(void)