tracing: Move setting of tracing_selftest_running out of register_tracer()

The variables tracing_selftest_running and tracing_selftest_disabled are
only used for when CONFIG_FTRACE_STARTUP_TEST is enabled. Make them only
visible within the selftest code. The setting of those variables are in
the register_tracer() call, and set in a location where they do not need
to be. Create a wrapper around run_tracer_selftest() called
do_run_tracer_selftest() which sets those variables, and have
register_tracer() call that instead.

Having those variables only set within the CONFIG_FTRACE_STARTUP_TEST
scope gets rid of them (and also the ability to remove testing against
them) when the startup tests are not enabled (most cases).

Link: https://lkml.kernel.org/r/20230528051742.1325503-2-rostedt@goodmis.orgSigned-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

kernel/trace/trace.c

@@ -2041,6 +2041,17 @@ static int run_tracer_selftest(struct tracer *type)
 	return 0;
 }
 
+static int do_run_tracer_selftest(struct tracer *type)
+{
+	int ret;
+
+	tracing_selftest_running = true;
+	ret = run_tracer_selftest(type);
+	tracing_selftest_running = false;
+
+	return ret;
+}
+
 static __init int init_trace_selftests(void)
 {
 	struct trace_selftests *p, *n;
@@ -2092,6 +2103,10 @@ static inline int run_tracer_selftest(struct tracer *type)
 {
 	return 0;
 }
+static inline int do_run_tracer_selftest(struct tracer *type)
+{
+	return 0;
+}
 #endif /* CONFIG_FTRACE_STARTUP_TEST */
 
 static void add_tracer_options(struct trace_array *tr, struct tracer *t);
@@ -2127,8 +2142,6 @@ int __init register_tracer(struct tracer *type)
 
 	mutex_lock(&trace_types_lock);
 
-	tracing_selftest_running = true;
-
 	for (t = trace_types; t; t = t->next) {
 		if (strcmp(type->name, t->name) == 0) {
 			/* already found */
@@ -2157,7 +2170,7 @@ int __init register_tracer(struct tracer *type)
 	/* store the tracer for __set_tracer_option */
 	type->flags->trace = type;
 
-	ret = run_tracer_selftest(type);
+	ret = do_run_tracer_selftest(type);
 	if (ret < 0)
 		goto out;
 
@@ -2166,7 +2179,6 @@ int __init register_tracer(struct tracer *type)
 	add_tracer_options(&global_trace, type);
 
  out:
-	tracing_selftest_running = false;
 	mutex_unlock(&trace_types_lock);
 
 	if (ret || !default_bootup_tracer)