Commit 95950c2e authored by Steven Rostedt's avatar Steven Rostedt Committed by Steven Rostedt
Browse files

ftrace: Add self-tests for multiple function trace users 



Add some basic sanity tests for multiple users of the function
tracer at startup.

Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent 936e074b

kernel/trace/trace.h

+2 −0
Original line number Diff line number Diff line
@@ -419,6 +419,8 @@ extern void trace_find_cmdline(int pid, char comm[]); 
extern unsigned long ftrace_update_tot_cnt;

#define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func

extern int DYN_FTRACE_TEST_NAME(void);

#define DYN_FTRACE_TEST_NAME2 trace_selftest_dynamic_test_func2

extern int DYN_FTRACE_TEST_NAME2(void);

#endif



extern int ring_buffer_expanded;

kernel/trace/trace_selftest.c

+209 −1
Original line number Diff line number Diff line
@@ -101,6 +101,206 @@ static inline void warn_failed_init_tracer(struct tracer *trace, int init_ret) 


#ifdef CONFIG_DYNAMIC_FTRACE



static int trace_selftest_test_probe1_cnt;

static void trace_selftest_test_probe1_func(unsigned long ip,

					    unsigned long pip)

{

	trace_selftest_test_probe1_cnt++;

}



static int trace_selftest_test_probe2_cnt;

static void trace_selftest_test_probe2_func(unsigned long ip,

					    unsigned long pip)

{

	trace_selftest_test_probe2_cnt++;

}



static int trace_selftest_test_probe3_cnt;

static void trace_selftest_test_probe3_func(unsigned long ip,

					    unsigned long pip)

{

	trace_selftest_test_probe3_cnt++;

}



static int trace_selftest_test_global_cnt;

static void trace_selftest_test_global_func(unsigned long ip,

					    unsigned long pip)

{

	trace_selftest_test_global_cnt++;

}



static int trace_selftest_test_dyn_cnt;

static void trace_selftest_test_dyn_func(unsigned long ip,

					 unsigned long pip)

{

	trace_selftest_test_dyn_cnt++;

}



static struct ftrace_ops test_probe1 = {

	.func			= trace_selftest_test_probe1_func,

};



static struct ftrace_ops test_probe2 = {

	.func			= trace_selftest_test_probe2_func,

};



static struct ftrace_ops test_probe3 = {

	.func			= trace_selftest_test_probe3_func,

};



static struct ftrace_ops test_global = {

	.func			= trace_selftest_test_global_func,

	.flags			= FTRACE_OPS_FL_GLOBAL,

};



static void print_counts(void)

{

	printk("(%d %d %d %d %d) ",

	       trace_selftest_test_probe1_cnt,

	       trace_selftest_test_probe2_cnt,

	       trace_selftest_test_probe3_cnt,

	       trace_selftest_test_global_cnt,

	       trace_selftest_test_dyn_cnt);

}



static void reset_counts(void)

{

	trace_selftest_test_probe1_cnt = 0;

	trace_selftest_test_probe2_cnt = 0;

	trace_selftest_test_probe3_cnt = 0;

	trace_selftest_test_global_cnt = 0;

	trace_selftest_test_dyn_cnt = 0;

}



static int trace_selftest_ops(int cnt)

{

	int save_ftrace_enabled = ftrace_enabled;

	struct ftrace_ops *dyn_ops;

	char *func1_name;

	char *func2_name;

	int len1;

	int len2;

	int ret = -1;



	printk(KERN_CONT "PASSED\n");

	pr_info("Testing dynamic ftrace ops #%d: ", cnt);



	ftrace_enabled = 1;

	reset_counts();



	/* Handle PPC64 '.' name */

	func1_name = "*" __stringify(DYN_FTRACE_TEST_NAME);

	func2_name = "*" __stringify(DYN_FTRACE_TEST_NAME2);

	len1 = strlen(func1_name);

	len2 = strlen(func2_name);



	/*

	 * Probe 1 will trace function 1.

	 * Probe 2 will trace function 2.

	 * Probe 3 will trace functions 1 and 2.

	 */

	ftrace_set_filter(&test_probe1, func1_name, len1, 1);

	ftrace_set_filter(&test_probe2, func2_name, len2, 1);

	ftrace_set_filter(&test_probe3, func1_name, len1, 1);

	ftrace_set_filter(&test_probe3, func2_name, len2, 0);



	register_ftrace_function(&test_probe1);

	register_ftrace_function(&test_probe2);

	register_ftrace_function(&test_probe3);

	register_ftrace_function(&test_global);



	DYN_FTRACE_TEST_NAME();



	print_counts();



	if (trace_selftest_test_probe1_cnt != 1)

		goto out;

	if (trace_selftest_test_probe2_cnt != 0)

		goto out;

	if (trace_selftest_test_probe3_cnt != 1)

		goto out;

	if (trace_selftest_test_global_cnt == 0)

		goto out;



	DYN_FTRACE_TEST_NAME2();



	print_counts();



	if (trace_selftest_test_probe1_cnt != 1)

		goto out;

	if (trace_selftest_test_probe2_cnt != 1)

		goto out;

	if (trace_selftest_test_probe3_cnt != 2)

		goto out;



	/* Add a dynamic probe */

	dyn_ops = kzalloc(sizeof(*dyn_ops), GFP_KERNEL);

	if (!dyn_ops) {

		printk("MEMORY ERROR ");

		goto out;

	}



	dyn_ops->func = trace_selftest_test_dyn_func;



	register_ftrace_function(dyn_ops);



	trace_selftest_test_global_cnt = 0;



	DYN_FTRACE_TEST_NAME();



	print_counts();



	if (trace_selftest_test_probe1_cnt != 2)

		goto out_free;

	if (trace_selftest_test_probe2_cnt != 1)

		goto out_free;

	if (trace_selftest_test_probe3_cnt != 3)

		goto out_free;

	if (trace_selftest_test_global_cnt == 0)

		goto out;

	if (trace_selftest_test_dyn_cnt == 0)

		goto out_free;



	DYN_FTRACE_TEST_NAME2();



	print_counts();



	if (trace_selftest_test_probe1_cnt != 2)

		goto out_free;

	if (trace_selftest_test_probe2_cnt != 2)

		goto out_free;

	if (trace_selftest_test_probe3_cnt != 4)

		goto out_free;



	ret = 0;

 out_free:

	unregister_ftrace_function(dyn_ops);

	kfree(dyn_ops);



 out:

	/* Purposely unregister in the same order */

	unregister_ftrace_function(&test_probe1);

	unregister_ftrace_function(&test_probe2);

	unregister_ftrace_function(&test_probe3);

	unregister_ftrace_function(&test_global);



	/* Make sure everything is off */

	reset_counts();

	DYN_FTRACE_TEST_NAME();

	DYN_FTRACE_TEST_NAME();



	if (trace_selftest_test_probe1_cnt ||

	    trace_selftest_test_probe2_cnt ||

	    trace_selftest_test_probe3_cnt ||

	    trace_selftest_test_global_cnt ||

	    trace_selftest_test_dyn_cnt)

		ret = -1;



	ftrace_enabled = save_ftrace_enabled;



	return ret;

}



/* Test dynamic code modification and ftrace filters */

int trace_selftest_startup_dynamic_tracing(struct tracer *trace,

					   struct trace_array *tr,
@@ -166,16 +366,20 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace, 


	/* check the trace buffer */

	ret = trace_test_buffer(tr, &count);

	trace->reset(tr);

	tracing_start();



	/* we should only have one item */

	if (!ret && count != 1) {

		trace->reset(tr);

		printk(KERN_CONT ".. filter failed count=%ld ..", count);

		ret = -1;

		goto out;

	}



	/* Test the ops with global tracing running */

	ret = trace_selftest_ops(1);

	trace->reset(tr);



 out:

	ftrace_enabled = save_ftrace_enabled;

	tracer_enabled = save_tracer_enabled;
@@ -183,6 +387,10 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace, 
	/* Enable tracing on all functions again */

	ftrace_set_global_filter(NULL, 0, 1);



	/* Test the ops with global tracing off */

	if (!ret)

		ret = trace_selftest_ops(2);



	return ret;

}

#else

kernel/trace/trace_selftest_dynamic.c

+6 −0
Original line number Diff line number Diff line
@@ -5,3 +5,9 @@ int DYN_FTRACE_TEST_NAME(void) 
	/* used to call mcount */

	return 0;

}



int DYN_FTRACE_TEST_NAME2(void)

{

	/* used to call mcount */

	return 0;

}