tracing: Add stack dump to trace_printk if stacktrace option is set

If the ftrace stacktrace option is set, then add the stack dumps to
trace_printk.

Requested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 6 insertions, 2 deletions

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index abdd333a0825..5314c90bbc83 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1392,8 +1392,10 @@ int trace_vbprintk(unsigned long ip, const char *fmt, va_list args)
         entry->fmt                      = fmt;
 
         memcpy(entry->buf, trace_buf, sizeof(u32) * len);
-        if (!filter_check_discard(call, entry, buffer, event))
+        if (!filter_check_discard(call, entry, buffer, event)) {
                 ring_buffer_unlock_commit(buffer, event);
+                ftrace_trace_stack(buffer, flags, 6, pc);
+        }
 
 out_unlock:
         arch_spin_unlock(&trace_buf_lock);
@@ -1466,8 +1468,10 @@ int trace_array_vprintk(struct trace_array *tr,
 
         memcpy(&entry->buf, trace_buf, len);
         entry->buf[len] = '\0';
-        if (!filter_check_discard(call, entry, buffer, event))
+        if (!filter_check_discard(call, entry, buffer, event)) {
                 ring_buffer_unlock_commit(buffer, event);
+                ftrace_trace_stack(buffer, irq_flags, 6, pc);
+        }
 
  out_unlock:
         arch_spin_unlock(&trace_buf_lock);