mirror of
https://github.com/torvalds/linux
synced 2024-11-05 18:23:50 +00:00
531d297569
Need a marker_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>
92 lines
2.1 KiB
C
92 lines
2.1 KiB
C
/* probe-example.c
|
|
*
|
|
* Connects two functions to marker call sites.
|
|
*
|
|
* (C) Copyright 2007 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
|
|
*
|
|
* This file is released under the GPLv2.
|
|
* See the file COPYING for more details.
|
|
*/
|
|
|
|
#include <linux/sched.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/marker.h>
|
|
#include <asm/atomic.h>
|
|
|
|
struct probe_data {
|
|
const char *name;
|
|
const char *format;
|
|
marker_probe_func *probe_func;
|
|
};
|
|
|
|
void probe_subsystem_event(void *probe_data, void *call_data,
|
|
const char *format, va_list *args)
|
|
{
|
|
/* Declare args */
|
|
unsigned int value;
|
|
const char *mystr;
|
|
|
|
/* Assign args */
|
|
value = va_arg(*args, typeof(value));
|
|
mystr = va_arg(*args, typeof(mystr));
|
|
|
|
/* Call printk */
|
|
printk(KERN_INFO "Value %u, string %s\n", value, mystr);
|
|
|
|
/* or count, check rights, serialize data in a buffer */
|
|
}
|
|
|
|
atomic_t eventb_count = ATOMIC_INIT(0);
|
|
|
|
void probe_subsystem_eventb(void *probe_data, void *call_data,
|
|
const char *format, va_list *args)
|
|
{
|
|
/* Increment counter */
|
|
atomic_inc(&eventb_count);
|
|
}
|
|
|
|
static struct probe_data probe_array[] =
|
|
{
|
|
{ .name = "subsystem_event",
|
|
.format = "integer %d string %s",
|
|
.probe_func = probe_subsystem_event },
|
|
{ .name = "subsystem_eventb",
|
|
.format = MARK_NOARGS,
|
|
.probe_func = probe_subsystem_eventb },
|
|
};
|
|
|
|
static int __init probe_init(void)
|
|
{
|
|
int result;
|
|
int i;
|
|
|
|
for (i = 0; i < ARRAY_SIZE(probe_array); i++) {
|
|
result = marker_probe_register(probe_array[i].name,
|
|
probe_array[i].format,
|
|
probe_array[i].probe_func, &probe_array[i]);
|
|
if (result)
|
|
printk(KERN_INFO "Unable to register probe %s\n",
|
|
probe_array[i].name);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static void __exit probe_fini(void)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < ARRAY_SIZE(probe_array); i++)
|
|
marker_probe_unregister(probe_array[i].name,
|
|
probe_array[i].probe_func, &probe_array[i]);
|
|
printk(KERN_INFO "Number of event b : %u\n",
|
|
atomic_read(&eventb_count));
|
|
marker_synchronize_unregister();
|
|
}
|
|
|
|
module_init(probe_init);
|
|
module_exit(probe_fini);
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_AUTHOR("Mathieu Desnoyers");
|
|
MODULE_DESCRIPTION("SUBSYSTEM Probe");
|