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/* -*- linux-c -*-
* Systemtap Test Module 1
* Copyright (C) 2007 Red Hat Inc.
*
* This file is part of systemtap, and is free software. You can
* redistribute it and/or modify it under the terms of the GNU General
* Public License (GPL); either version 2, or (at your option) any
* later version.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/proc_fs.h>
#include <linux/compiler.h>
#include <linux/sched.h>
#include <linux/uaccess.h>
/*
* The purpose of this module is to provide a function that can be
* triggered from user context via a /proc file. Systemtap scripts
* set probes on the function and run tests to see if the expected
* output is received. This is better than using the kernel's modules
* because kernel internals frequently change.
*/
/************ Below are the functions to create this module ************/
static struct proc_dir_entry *stm_ctl = NULL;
static int last_cmd = -1;
static ssize_t stm_write_cmd (struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
char type;
if (get_user(type, (char __user *)buf))
return -EFAULT;
switch (type) {
case '0':
last_cmd = 0;
break;
case '1':
last_cmd = 1;
break;
case '2':
last_cmd = 2;
break;
default:
printk ("stap_kmodule: invalid command type %d\n", (int)type);
return -EINVAL;
}
return count;
}
static struct file_operations stm_fops_cmd = {
.owner = THIS_MODULE,
.write = stm_write_cmd,
};
int init_module(void)
{
stm_ctl = proc_create ("stap_kmodule_cmd", 0666, NULL, &stm_fops_cmd);
if (stm_ctl == NULL)
return -1;
return 0;
}
void cleanup_module(void)
{
if (stm_ctl)
remove_proc_entry ("stap_kmodule_cmd", NULL);
}
MODULE_DESCRIPTION("systemtap test module");
MODULE_LICENSE("GPL");
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