1// SPDX-License-Identifier: GPL-2.0-only
  2#include <linux/module.h>
  3#include <linux/kthread.h>
  4
  5/*
  6 * Any file that uses trace points, must include the header.
  7 * But only one file, must include the header by defining
  8 * CREATE_TRACE_POINTS first.  This will make the C code that
  9 * creates the handles for the trace points.
 10 */
 11#define CREATE_TRACE_POINTS
 12#include "trace-events-sample.h"
 13
 14static const char *random_strings[] = {
 15	"Mother Goose",
 16	"Snoopy",
 17	"Gandalf",
 18	"Frodo",
 19	"One ring to rule them all"
 20};
 21
 22static void do_simple_thread_func(int cnt, const char *fmt, ...)
 23{
 24	unsigned long bitmask[1] = {0xdeadbeefUL};
 25	va_list va;
 26	int array[6];
 27	int len = cnt % 5;
 28	int i;
 29
 30	set_current_state(TASK_INTERRUPTIBLE);
 31	schedule_timeout(HZ);
 32
 33	for (i = 0; i < len; i++)
 34		array[i] = i + 1;
 35	array[i] = 0;
 36
 37	va_start(va, fmt);
 38
 39	/* Silly tracepoints */
 40	trace_foo_bar("hello", cnt, array, random_strings[len],
 41		      current->cpus_ptr, fmt, &va);
 42
 43	va_end(va);
 44
 45	trace_foo_with_template_simple("HELLO", cnt);
 46
 47	trace_foo_bar_with_cond("Some times print", cnt);
 48
 49	trace_foo_with_template_cond("prints other times", cnt);
 50
 51	trace_foo_with_template_print("I have to be different", cnt);
 52
 53	trace_foo_rel_loc("Hello __rel_loc", cnt, bitmask, current->cpus_ptr);
 54}
 55
 56static void simple_thread_func(int cnt)
 57{
 58	do_simple_thread_func(cnt, "iter=%d", cnt);
 59}
 60
 61static int simple_thread(void *arg)
 62{
 63	int cnt = 0;
 64
 65	while (!kthread_should_stop())
 66		simple_thread_func(cnt++);
 67
 68	return 0;
 69}
 70
 71static struct task_struct *simple_tsk;
 72static struct task_struct *simple_tsk_fn;
 73
 74static void simple_thread_func_fn(int cnt)
 75{
 76	set_current_state(TASK_INTERRUPTIBLE);
 77	schedule_timeout(HZ);
 78
 79	/* More silly tracepoints */
 80	trace_foo_bar_with_fn("Look at me", cnt);
 81	trace_foo_with_template_fn("Look at me too", cnt);
 82}
 83
 84static int simple_thread_fn(void *arg)
 85{
 86	int cnt = 0;
 87
 88	while (!kthread_should_stop())
 89		simple_thread_func_fn(cnt++);
 90
 91	return 0;
 92}
 93
 94static DEFINE_MUTEX(thread_mutex);
 95static int simple_thread_cnt;
 96
 97int foo_bar_reg(void)
 98{
 99	mutex_lock(&thread_mutex);
100	if (simple_thread_cnt++)
101		goto out;
102
103	pr_info("Starting thread for foo_bar_fn\n");
104	/*
105	 * We shouldn't be able to start a trace when the module is
106	 * unloading (there's other locks to prevent that). But
107	 * for consistency sake, we still take the thread_mutex.
108	 */
109	simple_tsk_fn = kthread_run(simple_thread_fn, NULL, "event-sample-fn");
110 out:
111	mutex_unlock(&thread_mutex);
112	return 0;
113}
114
115void foo_bar_unreg(void)
116{
117	mutex_lock(&thread_mutex);
118	if (--simple_thread_cnt)
119		goto out;
120
121	pr_info("Killing thread for foo_bar_fn\n");
122	if (simple_tsk_fn)
123		kthread_stop(simple_tsk_fn);
124	simple_tsk_fn = NULL;
125 out:
126	mutex_unlock(&thread_mutex);
127}
128
129static int __init trace_event_init(void)
130{
131	simple_tsk = kthread_run(simple_thread, NULL, "event-sample");
132	if (IS_ERR(simple_tsk))
133		return -1;
134
135	return 0;
136}
137
138static void __exit trace_event_exit(void)
139{
140	kthread_stop(simple_tsk);
141	mutex_lock(&thread_mutex);
142	if (simple_tsk_fn)
143		kthread_stop(simple_tsk_fn);
144	simple_tsk_fn = NULL;
145	mutex_unlock(&thread_mutex);
146}
147
148module_init(trace_event_init);
149module_exit(trace_event_exit);
150
151MODULE_AUTHOR("Steven Rostedt");
152MODULE_DESCRIPTION("trace-events-sample");
153MODULE_LICENSE("GPL");

 
  1#include <linux/module.h>
  2#include <linux/kthread.h>
  3
  4/*
  5 * Any file that uses trace points, must include the header.
  6 * But only one file, must include the header by defining
  7 * CREATE_TRACE_POINTS first.  This will make the C code that
  8 * creates the handles for the trace points.
  9 */
 10#define CREATE_TRACE_POINTS
 11#include "trace-events-sample.h"
 12
 13static const char *random_strings[] = {
 14	"Mother Goose",
 15	"Snoopy",
 16	"Gandalf",
 17	"Frodo",
 18	"One ring to rule them all"
 19};
 20
 21static void simple_thread_func(int cnt)
 22{
 
 
 23	int array[6];
 24	int len = cnt % 5;
 25	int i;
 26
 27	set_current_state(TASK_INTERRUPTIBLE);
 28	schedule_timeout(HZ);
 29
 30	for (i = 0; i < len; i++)
 31		array[i] = i + 1;
 32	array[i] = 0;
 33
 
 
 34	/* Silly tracepoints */
 35	trace_foo_bar("hello", cnt, array, random_strings[len],
 36		      &current->cpus_allowed);
 
 
 37
 38	trace_foo_with_template_simple("HELLO", cnt);
 39
 40	trace_foo_bar_with_cond("Some times print", cnt);
 41
 42	trace_foo_with_template_cond("prints other times", cnt);
 43
 44	trace_foo_with_template_print("I have to be different", cnt);
 
 
 
 
 
 
 
 45}
 46
 47static int simple_thread(void *arg)
 48{
 49	int cnt = 0;
 50
 51	while (!kthread_should_stop())
 52		simple_thread_func(cnt++);
 53
 54	return 0;
 55}
 56
 57static struct task_struct *simple_tsk;
 58static struct task_struct *simple_tsk_fn;
 59
 60static void simple_thread_func_fn(int cnt)
 61{
 62	set_current_state(TASK_INTERRUPTIBLE);
 63	schedule_timeout(HZ);
 64
 65	/* More silly tracepoints */
 66	trace_foo_bar_with_fn("Look at me", cnt);
 67	trace_foo_with_template_fn("Look at me too", cnt);
 68}
 69
 70static int simple_thread_fn(void *arg)
 71{
 72	int cnt = 0;
 73
 74	while (!kthread_should_stop())
 75		simple_thread_func_fn(cnt++);
 76
 77	return 0;
 78}
 79
 80static DEFINE_MUTEX(thread_mutex);
 81static int simple_thread_cnt;
 82
 83int foo_bar_reg(void)
 84{
 85	mutex_lock(&thread_mutex);
 86	if (simple_thread_cnt++)
 87		goto out;
 88
 89	pr_info("Starting thread for foo_bar_fn\n");
 90	/*
 91	 * We shouldn't be able to start a trace when the module is
 92	 * unloading (there's other locks to prevent that). But
 93	 * for consistency sake, we still take the thread_mutex.
 94	 */
 95	simple_tsk_fn = kthread_run(simple_thread_fn, NULL, "event-sample-fn");
 96 out:
 97	mutex_unlock(&thread_mutex);
 98	return 0;
 99}
100
101void foo_bar_unreg(void)
102{
103	mutex_lock(&thread_mutex);
104	if (--simple_thread_cnt)
105		goto out;
106
107	pr_info("Killing thread for foo_bar_fn\n");
108	if (simple_tsk_fn)
109		kthread_stop(simple_tsk_fn);
110	simple_tsk_fn = NULL;
111 out:
112	mutex_unlock(&thread_mutex);
113}
114
115static int __init trace_event_init(void)
116{
117	simple_tsk = kthread_run(simple_thread, NULL, "event-sample");
118	if (IS_ERR(simple_tsk))
119		return -1;
120
121	return 0;
122}
123
124static void __exit trace_event_exit(void)
125{
126	kthread_stop(simple_tsk);
127	mutex_lock(&thread_mutex);
128	if (simple_tsk_fn)
129		kthread_stop(simple_tsk_fn);
130	simple_tsk_fn = NULL;
131	mutex_unlock(&thread_mutex);
132}
133
134module_init(trace_event_init);
135module_exit(trace_event_exit);
136
137MODULE_AUTHOR("Steven Rostedt");
138MODULE_DESCRIPTION("trace-events-sample");
139MODULE_LICENSE("GPL");