tracepoint-sample.c

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/* tracepoint-sample.c
 *
 * Executes a tracepoint when /proc/tracepoint-sample is opened.
 *
 * (C) Copyright 2007 Mathieu Desnoyers <[email protected]>
 *
 * This file is released under the GPLv2.
 * See the file COPYING for more details.
 */

#include <linux/module.h>
#include <linux/sched.h>
#include <linux/proc_fs.h>
#include "tp-samples-trace.h"

DEFINE_TRACE(subsys_event);
DEFINE_TRACE(subsys_eventb);

struct proc_dir_entry *pentry_sample;

static int my_open(struct inode *inode, struct file *file)
{
    int i;

    trace_subsys_event(inode, file);
    for (i = 0; i < 10; i++)
        trace_subsys_eventb();
    return -EPERM;
}

static const struct file_operations mark_ops = {
    .open = my_open,
    .llseek = noop_llseek,
};

static int __init sample_init(void)
{
    printk(KERN_ALERT "sample init\n");
    pentry_sample = proc_create("tracepoint-sample", 0444, NULL,
        &mark_ops);
    if (!pentry_sample)
        return -EPERM;
    return 0;
}

static void __exit sample_exit(void)
{
    printk(KERN_ALERT "sample exit\n");
    remove_proc_entry("tracepoint-sample", NULL);
}

module_init(sample_init)
module_exit(sample_exit)

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Mathieu Desnoyers");
MODULE_DESCRIPTION("Tracepoint sample");