Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

1 files changed, 11 insertions, 0 deletions

diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
index b746399ab59c..8abf1ba18085 100644
--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -85,9 +85,19 @@ check_stack(unsigned long ip, unsigned long *stack)
         if (!object_is_on_stack(stack))
                 return;
 
+        /* Can't do this from NMI context (can cause deadlocks) */
+        if (in_nmi())
+                return;
+
         local_irq_save(flags);
         arch_spin_lock(&max_stack_lock);
 
+        /*
+         * RCU may not be watching, make it see us.
+         * The stack trace code uses rcu_sched.
+         */
+        rcu_irq_enter();
+
         /* In case another CPU set the tracer_frame on us */
         if (unlikely(!frame_size))
                 this_size -= tracer_frame;
@@ -169,6 +179,7 @@ check_stack(unsigned long ip, unsigned long *stack)
         }
 
  out:
+        rcu_irq_exit();
         arch_spin_unlock(&max_stack_lock);
         local_irq_restore(flags);
 }