/*
   * tracepoint-probe-sample.c
   *
   * sample tracepoint probes.
   */
  
  #include <linux/module.h>
  #include <linux/file.h>
  #include <linux/dcache.h>
  #include "tp-samples-trace.h"
  
  /*
   * Here the caller only guarantees locking for struct file and struct inode.
   * Locking must therefore be done in the probe to use the dentry.
   */

  static void probe_subsys_event(void *ignore,
  			       struct inode *inode, struct file *file)

  {
  	path_get(&file->f_path);
  	dget(file->f_path.dentry);
  	printk(KERN_INFO "Event is encountered with filename %s
  ",
  		file->f_path.dentry->d_name.name);
  	dput(file->f_path.dentry);
  	path_put(&file->f_path);
  }

  static void probe_subsys_eventb(void *ignore)

  {
  	printk(KERN_INFO "Event B is encountered
  ");
  }

  static int __init tp_sample_trace_init(void)

  {
  	int ret;

  	ret = register_trace_subsys_event(probe_subsys_event, NULL);

  	WARN_ON(ret);

  	ret = register_trace_subsys_eventb(probe_subsys_eventb, NULL);

  	WARN_ON(ret);
  
  	return 0;
  }
  
  module_init(tp_sample_trace_init);

  static void __exit tp_sample_trace_exit(void)

  {

  	unregister_trace_subsys_eventb(probe_subsys_eventb, NULL);
  	unregister_trace_subsys_event(probe_subsys_event, NULL);

  	tracepoint_synchronize_unregister();

  }
  
  module_exit(tp_sample_trace_exit);
  
  MODULE_LICENSE("GPL");
  MODULE_AUTHOR("Mathieu Desnoyers");
  MODULE_DESCRIPTION("Tracepoint Probes Samples");