LXR linux/samples/tracepoints/tracepoint-probe-sample2.c

   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 */
  15static 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
  22static 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
  32module_init(tp_sample_trace_init);
  33
  34static void __exit tp_sample_trace_exit(void)
  35{
  36        unregister_trace_subsys_event(probe_subsys_event, NULL);
  37        tracepoint_synchronize_unregister();
  38}
  39
  40module_exit(tp_sample_trace_exit);
  41
  42MODULE_LICENSE("GPL");
  43MODULE_AUTHOR("Mathieu Desnoyers");
  44MODULE_DESCRIPTION("Tracepoint Probes Samples");
  45