selftests: ftrace: Check whether snapshot trigger is supported correctly

If "snapshot" special file doesn't exist, that kernel does
not support snapshot and snapshot trigger too. In that case
snapshot trigger test results to unsupported instead of fail.

Link: http://lkml.kernel.org/r/147928401215.22982.10411665829041109794.stgit@devbox
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

diff --git a/tools/testing/selftests/ftrace/test.d/trigger/trigger-snapshot.tc b/tools/testing/selftests/ftrace/test.d/trigger/trigger-snapshot.tc
index f84b80d551a2804bc44c29f4392453dd4690bac8..ed94f0c4e0e4610b01025d71c1b0b2d41b7fcc44 100644 (file)
--- a/tools/testing/selftests/ftrace/test.d/trigger/trigger-snapshot.tc
+++ b/tools/testing/selftests/ftrace/test.d/trigger/trigger-snapshot.tc
@@ -23,6 +23,11 @@ if [ ! -f events/sched/sched_process_fork/trigger ]; then
     exit_unsupported
 fi
 
+if [ ! -f snapshot ]; then
+    echo "snapshot is not supported"
+    exit_unsupported
+fi
+
 reset_tracer
 do_reset