1 /* tracepoint-sample.c
2  *
3  * Executes a tracepoint when /proc/tracepoint-sample is opened.
4  *
5  * (C) Copyright 2007 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
6  *
7  * This file is released under the GPLv2.
8  * See the file COPYING for more details.
9  */
10 
11 #include <linux/module.h>
12 #include <linux/sched.h>
13 #include <linux/proc_fs.h>
14 #include "tp-samples-trace.h"
15 
16 DEFINE_TRACE(subsys_event);
17 DEFINE_TRACE(subsys_eventb);
18 
19 struct proc_dir_entry *pentry_sample;
20 
my_open(struct inode * inode,struct file * file)21 static int my_open(struct inode *inode, struct file *file)
22 {
23 	int i;
24 
25 	trace_subsys_event(inode, file);
26 	for (i = 0; i < 10; i++)
27 		trace_subsys_eventb();
28 	return -EPERM;
29 }
30 
31 static const struct file_operations mark_ops = {
32 	.open = my_open,
33 	.llseek = noop_llseek,
34 };
35 
sample_init(void)36 static int __init sample_init(void)
37 {
38 	printk(KERN_ALERT "sample init\n");
39 	pentry_sample = proc_create("tracepoint-sample", 0444, NULL,
40 		&mark_ops);
41 	if (!pentry_sample)
42 		return -EPERM;
43 	return 0;
44 }
45 
sample_exit(void)46 static void __exit sample_exit(void)
47 {
48 	printk(KERN_ALERT "sample exit\n");
49 	remove_proc_entry("tracepoint-sample", NULL);
50 }
51 
52 module_init(sample_init)
53 module_exit(sample_exit)
54 
55 MODULE_LICENSE("GPL");
56 MODULE_AUTHOR("Mathieu Desnoyers");
57 MODULE_DESCRIPTION("Tracepoint sample");
58