1 files changed, 28 insertions, 0 deletions

diff --git a/kernel/cpu.c b/kernel/cpu.c
index 0097acec1c71..be4859f07153 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -315,6 +315,16 @@ void lockdep_assert_cpus_held(void)
         percpu_rwsem_assert_held(&cpu_hotplug_lock);
 }
 
+static void lockdep_acquire_cpus_lock(void)
+{
+        rwsem_acquire(&cpu_hotplug_lock.rw_sem.dep_map, 0, 0, _THIS_IP_);
+}
+
+static void lockdep_release_cpus_lock(void)
+{
+        rwsem_release(&cpu_hotplug_lock.rw_sem.dep_map, 1, _THIS_IP_);
+}
+
 /*
  * Wait for currently running CPU hotplug operations to complete (if any) and
  * disable future CPU hotplug (from sysfs). The 'cpu_add_remove_lock' protects
@@ -344,6 +354,17 @@ void cpu_hotplug_enable(void)
         cpu_maps_update_done();
 }
 EXPORT_SYMBOL_GPL(cpu_hotplug_enable);
+
+#else
+
+static void lockdep_acquire_cpus_lock(void)
+{
+}
+
+static void lockdep_release_cpus_lock(void)
+{
+}
+
 #endif  /* CONFIG_HOTPLUG_CPU */
 
 #ifdef CONFIG_HOTPLUG_SMT
@@ -616,6 +637,12 @@ static void cpuhp_thread_fun(unsigned int cpu)
          */
         smp_mb();
 
+        /*
+         * The BP holds the hotplug lock, but we're now running on the AP,
+         * ensure that anybody asserting the lock is held, will actually find
+         * it so.
+         */
+        lockdep_acquire_cpus_lock();
         cpuhp_lock_acquire(bringup);
 
         if (st->single) {
@@ -661,6 +688,7 @@ static void cpuhp_thread_fun(unsigned int cpu)
         }
 
         cpuhp_lock_release(bringup);
+        lockdep_release_cpus_lock();
 
         if (!st->should_run)
                 complete_ap_thread(st, bringup);