mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-21 16:29:59 +00:00
2504ea5edf
Impact: fix a bug in sample tracepoints Need a tracepoint_synchronize_unregister() before the end of exit() to make sure every probe callers have exited the non preemptible section and thus are not executing the probe code anymore. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Signed-off-by: Ingo Molnar <mingo@elte.hu>
56 lines
1.2 KiB
C
56 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");
|