1 files changed, 30 insertions, 4 deletions

diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
index 5aa9a5b9b6e2..8a4e5cb66a4c 100644
--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -51,11 +51,33 @@ static DEFINE_MUTEX(stack_sysctl_mutex);
 int stack_tracer_enabled;
 static int last_stack_tracer_enabled;
 
+static inline void print_max_stack(void)
+{
+        long i;
+        int size;
+
+        pr_emerg("        Depth    Size   Location    (%d entries)\n"
+                           "        -----    ----   --------\n",
+                           max_stack_trace.nr_entries - 1);
+
+        for (i = 0; i < max_stack_trace.nr_entries; i++) {
+                if (stack_dump_trace[i] == ULONG_MAX)
+                        break;
+                if (i+1 == max_stack_trace.nr_entries ||
+                                stack_dump_trace[i+1] == ULONG_MAX)
+                        size = stack_dump_index[i];
+                else
+                        size = stack_dump_index[i] - stack_dump_index[i+1];
+
+                pr_emerg("%3ld) %8d   %5d   %pS\n", i, stack_dump_index[i],
+                                size, (void *)stack_dump_trace[i]);
+        }
+}
+
 static inline void
 check_stack(unsigned long ip, unsigned long *stack)
 {
-        unsigned long this_size, flags;
-        unsigned long *p, *top, *start;
+        unsigned long this_size, flags; unsigned long *p, *top, *start;
         static int tracer_frame;
         int frame_size = ACCESS_ONCE(tracer_frame);
         int i;
@@ -149,8 +171,12 @@ check_stack(unsigned long ip, unsigned long *stack)
                         i++;
         }
 
-        BUG_ON(current != &init_task &&
-                *(end_of_stack(current)) != STACK_END_MAGIC);
+        if ((current != &init_task &&
+                *(end_of_stack(current)) != STACK_END_MAGIC)) {
+                print_max_stack();
+                BUG();
+        }
+
  out:
         arch_spin_unlock(&max_stack_lock);
         local_irq_restore(flags);