aboutsummaryrefslogtreecommitdiffstats
path: root/samples/tracepoints/tracepoint-probe-sample.c
diff options
context:
space:
mode:
Diffstat (limited to 'samples/tracepoints/tracepoint-probe-sample.c')
-rw-r--r--samples/tracepoints/tracepoint-probe-sample.c55
1 files changed, 55 insertions, 0 deletions
diff --git a/samples/tracepoints/tracepoint-probe-sample.c b/samples/tracepoints/tracepoint-probe-sample.c
new file mode 100644
index 000000000000..55abfdda4bd4
--- /dev/null
+++ b/samples/tracepoints/tracepoint-probe-sample.c
@@ -0,0 +1,55 @@
1/*
2 * tracepoint-probe-sample.c
3 *
4 * sample tracepoint probes.
5 */
6
7#include <linux/module.h>
8#include <linux/file.h>
9#include <linux/dcache.h>
10#include "tp-samples-trace.h"
11
12/*
13 * Here the caller only guarantees locking for struct file and struct inode.
14 * Locking must therefore be done in the probe to use the dentry.
15 */
16static void probe_subsys_event(struct inode *inode, struct file *file)
17{
18 path_get(&file->f_path);
19 dget(file->f_path.dentry);
20 printk(KERN_INFO "Event is encountered with filename %s\n",
21 file->f_path.dentry->d_name.name);
22 dput(file->f_path.dentry);
23 path_put(&file->f_path);
24}
25
26static void probe_subsys_eventb(void)
27{
28 printk(KERN_INFO "Event B is encountered\n");
29}
30
31int __init tp_sample_trace_init(void)
32{
33 int ret;
34
35 ret = register_trace_subsys_event(probe_subsys_event);
36 WARN_ON(ret);
37 ret = register_trace_subsys_eventb(probe_subsys_eventb);
38 WARN_ON(ret);
39
40 return 0;
41}
42
43module_init(tp_sample_trace_init);
44
45void __exit tp_sample_trace_exit(void)
46{
47 unregister_trace_subsys_eventb(probe_subsys_eventb);
48 unregister_trace_subsys_event(probe_subsys_event);
49}
50
51module_exit(tp_sample_trace_exit);
52
53MODULE_LICENSE("GPL");
54MODULE_AUTHOR("Mathieu Desnoyers");
55MODULE_DESCRIPTION("Tracepoint Probes Samples");