ftrace: reset selftests

The tests may leave stuff in the buffers. This resets the buffers
after each test is run. If a test fails, it does not reset the
buffer to avoid touching a buffer that is corrupted.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 7 insertions, 0 deletions

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 8755a4370484..6580e7ed04be 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -289,6 +289,13 @@ int register_tracer(struct tracer *type)
                         printk(KERN_CONT "FAILED!\n");
                         goto out;
                 }
+                /* Only reset on passing, to avoid touching corrupted buffers */
+                for_each_possible_cpu(i) {
+                        data = tr->data[i];
+                        if (!head_page(data))
+                                continue;
+                        tracing_reset(data);
+                }
                 printk(KERN_CONT "PASSED\n");
         }
 #endif