[BUGFIX PATCH v2 2/3] selftests/ftrace: Fix ftrace test cases to check unsupported

[Masami Hiramatsu <mhiramat@kernel.org>]

Since dynamic function tracer can be disabled, set_ftrace_filter
can be disappeared. Test cases which depends on it, must check
whether the set_ftrace_filter exists or not before testing
and if not, return as unsupported.

Also, if the function tracer itself is disabled, we can not
set "function" to current_tracer. Test cases must check it
before testing, and return as unsupported.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
---
 .../ftrace/test.d/ftrace/func-filter-stacktrace.tc |    2 ++
 .../selftests/ftrace/test.d/ftrace/func_cpumask.tc |    5 +++++
 2 files changed, 7 insertions(+)

diff --git a/tools/testing/selftests/ftrace/test.d/ftrace/func-filter-stacktrace.tc b/tools/testing/selftests/ftrace/test.d/ftrace/func-filter-stacktrace.tc
index 36fb59f886ea..1a52f2883fe0 100644
--- a/tools/testing/selftests/ftrace/test.d/ftrace/func-filter-stacktrace.tc
+++ b/tools/testing/selftests/ftrace/test.d/ftrace/func-filter-stacktrace.tc
@@ -3,6 +3,8 @@
 # description: ftrace - stacktrace filter command
 # flags: instance
 
+[ ! -f set_ftrace_filter ] && exit_unsupported
+
 echo _do_fork:stacktrace >> set_ftrace_filter
 
 grep -q "_do_fork:stacktrace:unlimited" set_ftrace_filter
diff --git a/tools/testing/selftests/ftrace/test.d/ftrace/func_cpumask.tc b/tools/testing/selftests/ftrace/test.d/ftrace/func_cpumask.tc
index 86a1f07ef2ca..7757b549f0b6 100644
--- a/tools/testing/selftests/ftrace/test.d/ftrace/func_cpumask.tc
+++ b/tools/testing/selftests/ftrace/test.d/ftrace/func_cpumask.tc
@@ -15,6 +15,11 @@ if [ $NP -eq 1 ] ;then
   exit_unresolved
 fi
 
+if ! grep -q function available_tracers ; then
+  echo "Function trace is not enabled"
+  exit_unsupported
+fi
+
 ORIG_CPUMASK=`cat tracing_cpumask`
 
 do_reset() {