Commit f4e781c0 authored by Steven Rostedt (Red Hat)'s avatar Steven Rostedt (Red Hat) Committed by Steven Rostedt
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tracing: Move the tracing selftest code into its own function 



Move the tracing startup selftest code into its own function and
when not enabled, always have that function succeed.

This makes the register_tracer() function much more readable.

Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent f5eb5588

kernel/trace/trace.c

+69 −55
Original line number Diff line number Diff line
@@ -818,56 +818,15 @@ static void default_wait_pipe(struct trace_iterator *iter) 
	ring_buffer_wait(iter->trace_buffer->buffer, iter->cpu_file);

}



/**

 * register_tracer - register a tracer with the ftrace system.

 * @type - the plugin for the tracer

 *

 * Register a new plugin tracer.

 */

int register_tracer(struct tracer *type)

{

	struct tracer *t;

	int ret = 0;



	if (!type->name) {

		pr_info("Tracer must have a name\n");

		return -1;

	}



	if (strlen(type->name) >= MAX_TRACER_SIZE) {

		pr_info("Tracer has a name longer than %d\n", MAX_TRACER_SIZE);

		return -1;

	}



	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 */

			pr_info("Tracer %s already registered\n",

				type->name);

			ret = -1;

			goto out;

		}

	}



	if (!type->set_flag)

		type->set_flag = &dummy_set_flag;

	if (!type->flags)

		type->flags = &dummy_tracer_flags;

	else

		if (!type->flags->opts)

			type->flags->opts = dummy_tracer_opt;

	if (!type->wait_pipe)

		type->wait_pipe = default_wait_pipe;





#ifdef CONFIG_FTRACE_STARTUP_TEST

	if (type->selftest && !tracing_selftest_disabled) {

static int run_tracer_selftest(struct tracer *type)

{

	struct trace_array *tr = &global_trace;

	struct tracer *saved_tracer = tr->current_trace;

	int ret;



	if (!type->selftest || tracing_selftest_disabled)

		return 0;



	/*

	 * Run a selftest on this tracer.
@@ -899,7 +858,7 @@ int register_tracer(struct tracer *type) 
		printk(KERN_CONT "FAILED!\n");

		/* Add the warning after printing 'FAILED' */

		WARN_ON(1);

			goto out;

		return -1;

	}

	/* Only reset on passing, to avoid touching corrupted buffers */

	tracing_reset_online_cpus(&tr->trace_buffer);
@@ -916,8 +875,63 @@ int register_tracer(struct tracer *type) 
#endif



	printk(KERN_CONT "PASSED\n");

	return 0;

}

#endif

#else

static inline int run_tracer_selftest(struct tracer *type)

{

	return 0;

}

#endif /* CONFIG_FTRACE_STARTUP_TEST */



/**

 * register_tracer - register a tracer with the ftrace system.

 * @type - the plugin for the tracer

 *

 * Register a new plugin tracer.

 */

int register_tracer(struct tracer *type)

{

	struct tracer *t;

	int ret = 0;



	if (!type->name) {

		pr_info("Tracer must have a name\n");

		return -1;

	}



	if (strlen(type->name) >= MAX_TRACER_SIZE) {

		pr_info("Tracer has a name longer than %d\n", MAX_TRACER_SIZE);

		return -1;

	}



	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 */

			pr_info("Tracer %s already registered\n",

				type->name);

			ret = -1;

			goto out;

		}

	}



	if (!type->set_flag)

		type->set_flag = &dummy_set_flag;

	if (!type->flags)

		type->flags = &dummy_tracer_flags;

	else

		if (!type->flags->opts)

			type->flags->opts = dummy_tracer_opt;

	if (!type->wait_pipe)

		type->wait_pipe = default_wait_pipe;



	ret = run_tracer_selftest(type);

	if (ret < 0)

		goto out;



	type->next = trace_types;

	trace_types = type;