ftracetest: Clear trace buffer after running kprobe testcases

The kprobe testcases create, use and delete dynamic events during the
test but didn't clear the trace buffer so it'll leave the result after
it finishes.

  # ./ftracetest
  ...

  # cat trace
  # tracer: nop
  #
  # entries-in-buffer/entries-written: 2/2   #P:12
  #
  #                              _-----=> irqs-off
  #                             / _----=> need-resched
  #                            | / _---=> hardirq/softirq
  #                            || / _--=> preempt-depth
  #                            ||| /     delay
  #           TASK-PID   CPU#  ||||    TIMESTAMP  FUNCTION
  #              | |       |   ||||       |         |
        ftracetest-26474 [009] d..1 79417.143782: Unknown type 1099
        ftracetest-26498 [009] d..1 79417.208034: Unknown type 1101

Link: http://lkml.kernel.org/r/1415239470-28705-2-git-send-email-namhyung@kernel.org

Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

4 files changed, 4 insertions, 0 deletions

diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/add_and_remove.tc b/tools/testing/selftests/ftrace/test.d/kprobe/add_and_remove.tc
index 1b8b665ab2b3..a5a426211129 100644
--- a/tools/testing/selftests/ftrace/test.d/kprobe/add_and_remove.tc
+++ b/tools/testing/selftests/ftrace/test.d/kprobe/add_and_remove.tc
@@ -9,3 +9,4 @@ echo p:myevent do_fork > kprobe_events
 grep myevent kprobe_events
 test -d events/kprobes/myevent
 echo > kprobe_events
+clear_trace
diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/busy_check.tc b/tools/testing/selftests/ftrace/test.d/kprobe/busy_check.tc
index b55c84003587..d8c7bb6581fe 100644
--- a/tools/testing/selftests/ftrace/test.d/kprobe/busy_check.tc
+++ b/tools/testing/selftests/ftrace/test.d/kprobe/busy_check.tc
@@ -11,3 +11,4 @@ echo 1 > events/kprobes/myevent/enable
 echo > kprobe_events && exit 1 # this must fail
 echo 0 > events/kprobes/myevent/enable
 echo > kprobe_events # this must succeed
+clear_trace
diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args.tc
index a603d3f8db7b..c45ee2761354 100644
--- a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args.tc
+++ b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args.tc
@@ -12,5 +12,6 @@ echo 1 > events/kprobes/testprobe/enable
 ( echo "forked")
 echo 0 > events/kprobes/testprobe/enable
 echo "-:testprobe" >> kprobe_events
+clear_trace
 test -d events/kprobes/testprobe && exit 1 || exit 0
 
diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kretprobe_args.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kretprobe_args.tc
index 283c29e7f7c4..31717985acc7 100644
--- a/tools/testing/selftests/ftrace/test.d/kprobe/kretprobe_args.tc
+++ b/tools/testing/selftests/ftrace/test.d/kprobe/kretprobe_args.tc
@@ -12,4 +12,5 @@ echo 1 > events/kprobes/testprobe2/enable
 ( echo "forked")
 echo 0 > events/kprobes/testprobe2/enable
 echo '-:testprobe2' >> kprobe_events
+clear_trace
 test -d events/kprobes/testprobe2 && exit 1 || exit 0