模块编程简单实例<3>

   今天编了一个简单的模块，用来遍历给定进程的父进程，子进程，以及兄弟进程:

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/proc_fs.h>
#include <linux/pid_namespace.h>
#include <linux/sched.h>
#include <linux/pid.h>
#include <linux/rculist.h>
#include <linux/init_task.h>
#include <linux/syscalls.h>
#include <linux/slab.h>
#include <linux/bootmem.h>
#include <linux/pid_namespace.h>
#include <linux/list.h>

static pid_t pid;


module_param(pid,int,S_IRUGO);


static int __init hello_init(void)
{
    struct task_struct *cur_task;
    cur_task=pid_task(find_get_pid(pid),PIDTYPE_PID); //获取pid进程块

    struct task_struct *task=NULL;
    struct list_head *list;

   


    task = cur_task;
    printk("遍历进程号为%d的父进程如下:\n",pid);
    while(task->parent->pid) {
        task = task->parent;
        if (task) {
             printk(KERN_ALERT"comm=%s\tpid=%u\tstate=%ld\n",task->comm,task->pid,task->state);    
        }
    }

    printk("遍历进程号为%d的子进程如下:\n",pid);
    list_for_each(list, &(cur_task->children)) {
        task = list_entry(list, struct task_struct,children);
        printk(KERN_ALERT"comm=%s\tpid=%u\tstate=%ld\n",task->comm,task->pid,task->state);
    }

    printk("遍历进程号为%d的兄弟进程如下:\n",pid);
    list_for_each(list, &(cur_task->sibling)) {
        task = list_entry(list, struct task_struct,sibling);
        printk(KERN_ALERT"comm=%s\tpid=%u\tstate=%ld\n",task->comm,task->pid,task->state);
    }
    printk("测试进程cur_task的pid :%u\n",cur_task -> pid);
    return 0;
}

static void __exit hello_exit(void)
{
    printk(KERN_INFO "Leaving the kernel!Byebye!\n");
}

MODULE_LICENSE("GPL");//Check if the code support the protocol

module_init(hello_init);
module_exit(hello_exit);
MODULE_AUTHOR("email:[e-mail]");


Makefile 文件如下:

#
# Copyleft (C) 2010 caojiangfeng
#
# Makefile
#
# DATE: 27.04.2010
#
# REV:1.0.A
#
# PLATFROM: Linux/Unix
#
# REV LIST:
#     DATE: 27.04.2010
#     BY: caojiangfeng
#     MODIFICATION: standard more
#

# target

TARGET=travel_proc

# variable

obj-m := $(TARGET).o
all:
    make -C /usr/src/linux-headers-2.6.31-17-generic M=$(PWD) modules
install:
    sudo insmod $(TARGET).ko
uninstall:
    sudo rmmod $(TARGET)
clean:
    make -C /lib/modules/$(shell uname -r)/build M=$(PWD) clean

测试过程如下：
make
sudo insmod travel_proc.ko pid = 8
dmesg//查看打印信息
make uninstall//卸载