[PATCH -tip v3 2/9] selftests: ftrace: Initialize ftrace before each test

From: Masami Hiramatsu
Date: Wed Nov 16 2016 - 03:13:22 EST


Reset ftrace to initial state before running each test.
This fixes some test cases to enable tracing before starting
trace test. This can avoid false-positive failure when
previous testcase fails while disabling tracing.

Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Suggested-by: Steven Rostedt <rostedt@xxxxxxxxxxx>

---
Changes in v3:
- Fix to avoid initializing error by checking all optional features
---
tools/testing/selftests/ftrace/ftracetest | 2 +-
tools/testing/selftests/ftrace/test.d/functions | 28 +++++++++++++++++++++++
2 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/ftrace/ftracetest b/tools/testing/selftests/ftrace/ftracetest
index 4c6a0bf..a03d366 100755
--- a/tools/testing/selftests/ftrace/ftracetest
+++ b/tools/testing/selftests/ftrace/ftracetest
@@ -228,7 +228,7 @@ trap 'SIG_RESULT=$XFAIL' $SIG_XFAIL

__run_test() { # testfile
# setup PID and PPID, $$ is not updated.
- (cd $TRACING_DIR; read PID _ < /proc/self/stat ; set -e; set -x; . $1)
+ (cd $TRACING_DIR; read PID _ < /proc/self/stat; set -e; set -x; initialize_ftrace; . $1)
[ $? -ne 0 ] && kill -s $SIG_FAIL $SIG_PID
}

diff --git a/tools/testing/selftests/ftrace/test.d/functions b/tools/testing/selftests/ftrace/test.d/functions
index c37262f..91de1a8 100644
--- a/tools/testing/selftests/ftrace/test.d/functions
+++ b/tools/testing/selftests/ftrace/test.d/functions
@@ -23,3 +23,31 @@ reset_trigger() { # reset all current setting triggers
done
}

+reset_events_filter() { # reset all current setting filters
+ grep -v ^none events/*/*/filter |
+ while read line; do
+ echo 0 > `echo $line | cut -f1 -d:`
+ done
+}
+
+disable_events() {
+ echo 0 > events/enable
+}
+
+initialize_ftrace() { # Reset ftrace to initial-state
+# As the initial state, ftrace will be set to nop tracer,
+# no events, no triggers, no filters, no function filters,
+# no probes, and tracing on.
+ disable_tracing
+ reset_tracer
+ reset_trigger
+ reset_events_filter
+ disable_events
+ echo > set_event_pid # event tracer is always on
+ [ -f set_ftrace_filter ] && echo | tee set_ftrace_*
+ [ -f set_graph_function ] && echo | tee set_graph_*
+ [ -f stack_trace_filter ] && echo > stack_trace_filter
+ [ -f kprobe_events ] && echo > kprobe_events
+ [ -f uprobe_events ] && echo > uprobe_events
+ enable_tracing
+}