1 /*
2  * tracepoint-probe-sample2.c
3  *
4  * 2nd sample tracepoint probes.
5  */
6 
7 #include <linux/module.h>
8 #include <linux/fs.h>
9 #include "tp-samples-trace.h"
10 
11 /*
12  * Here the caller only guarantees locking for struct file and struct inode.
13  * Locking must therefore be done in the probe to use the dentry.
14  */
probe_subsys_event(void * ignore,struct inode * inode,struct file * file)15 static void probe_subsys_event(void *ignore,
16 			       struct inode *inode, struct file *file)
17 {
18 	printk(KERN_INFO "Event is encountered with inode number %lu\n",
19 		inode->i_ino);
20 }
21 
tp_sample_trace_init(void)22 static int __init tp_sample_trace_init(void)
23 {
24 	int ret;
25 
26 	ret = register_trace_subsys_event(probe_subsys_event, NULL);
27 	WARN_ON(ret);
28 
29 	return 0;
30 }
31 
32 module_init(tp_sample_trace_init);
33 
tp_sample_trace_exit(void)34 static void __exit tp_sample_trace_exit(void)
35 {
36 	unregister_trace_subsys_event(probe_subsys_event, NULL);
37 	tracepoint_synchronize_unregister();
38 }
39 
40 module_exit(tp_sample_trace_exit);
41 
42 MODULE_LICENSE("GPL");
43 MODULE_AUTHOR("Mathieu Desnoyers");
44 MODULE_DESCRIPTION("Tracepoint Probes Samples");
45