OpenCloudOS-Kernel/samples/tracepoints/tracepoint-probe-sample.c

57 lines
1.2 KiB
C

/*
* 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(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\n",
file->f_path.dentry->d_name.name);
dput(file->f_path.dentry);
path_put(&file->f_path);
}
static void probe_subsys_eventb(void)
{
printk(KERN_INFO "Event B is encountered\n");
}
int __init tp_sample_trace_init(void)
{
int ret;
ret = register_trace_subsys_event(probe_subsys_event);
WARN_ON(ret);
ret = register_trace_subsys_eventb(probe_subsys_eventb);
WARN_ON(ret);
return 0;
}
module_init(tp_sample_trace_init);
void __exit tp_sample_trace_exit(void)
{
unregister_trace_subsys_eventb(probe_subsys_eventb);
unregister_trace_subsys_event(probe_subsys_event);
tracepoint_synchronize_unregister();
}
module_exit(tp_sample_trace_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Mathieu Desnoyers");
MODULE_DESCRIPTION("Tracepoint Probes Samples");