Files
LDD-LinuxDeviceDrivers/study/process/find/find_task.c
T

105 lines
2.3 KiB
C

/*************************************************************************
> File Name: process.c
> Author: GatieMe
> Mail: gatieme@163.com
> Created Time: 2016年04月01日 星期五 21时09分29秒
************************************************************************/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/sched.h>
/*
* find_task_by_pid maybe not supported
* O(n) is fine :)
*/
struct task_struct * findTaskByPid(pid_t pid)
{
struct task_struct *task = NULL;
return NULL;
}
/*
* show the task info
*/
void getTaskinfo(struct task_struct *task)
{
}
//#define METHOD 2
static unsigned int METHOD = 1;
module_param(METHOD, uint,0400);
static unsigned int PID = 1;
module_param(PID, uint,0400);
static int find_task_init(void)
{
struct task_struct *task = NULL, *pTask = NULL;
struct list_head *pos = NULL;
char *method = NULL;
task = &init_task;
printk(KERN_ALERT"PID\tCOMM\tADDR\n");
switch(METHOD)
{
case 1 :
method = "list_for_each";
list_for_each(pos, &task->tasks)
{
pTask = list_entry(pos, struct task_struct, tasks );
if(pTask->pid == (pid_t)PID)
{
printk(KERN_ALERT "%d\t%s\t%p\n", pTask->pid, pTask->comm, pTask);
break;
}
}
break;
case 2 :
method = "for_each_process";
for_each_process(task)
{
if(task->pid == PID)
{
printk(KERN_ALERT "%d\t%s\t%p\n", task->pid, task->comm, task);
break;
}
}
break;
case 3 :
method = "list_for_each_entry";
list_for_each_entry(pTask, &task->tasks, tasks)
{
if(pTask->pid == PID)
{
printk(KERN_ALERT "%d\t%s\t%p\n", pTask->pid, pTask->comm, pTask);
}
}
}
printk("the method is %s", method);
return 0;
}
static void find_task_exit(void)
{
printk(KERN_ALERT "GOOD BYE:find_task!!\n");
}
module_init(find_task_init);
module_exit(find_task_exit);
MODULE_AUTHOR("gatieme");
MODULE_LICENSE("GPL");