proc_module.c~

动态加载模块

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/proc_fs.h>
#include <linux/sched.h>
#include <asm/uaccess.h>

#define MODULE_NAME "proc"

#define FOOBAR_LEN 255

static struct proc_dir_entry *example_dir,*jiffies_file;

static int proc_read_jiffies(char *page, char **start,off_t off,int count,int *eof, void *data){
	int len;
	try_module_get(THIS_MODULE);
	struct timespec aa;
	aa=current_kernel_time();
	len=sprintf(page,"%ld\t%ld\n",(long)aa.tv_sec,aa.tv_nsec);
	module_put(THIS_MODULE);
	return len;
}

static int proc_init(void){
	int rv = 0;
	example_dir = proc_mkdir(MODULE_NAME,NULL);
	if(example_dir == NULL){
		rv = -ENOMEM;
		goto out;
	}

	example_dir->owner = THIS_MODULE;
	jiffies_file = create_proc_read_entry("xtime",0444,example_dir,proc_read_jiffies,NULL);
	if(jiffies_file == NULL){
		rv = -ENOMEM;
		goto no_jiffies;
	}

	jiffies_file->owner = THIS_MODULE;

	return 0;
	no_jiffies:
		remove_proc_entry(MODULE_NAME,NULL);
	out:
		return rv;
}

static void proc_exit(void){
	remove_proc_entry("xtime",example_dir);
	remove_proc_entry(MODULE_NAME,NULL);
	printk("%s removed\n",MODULE_NAME);
}

module_init(proc_init);
module_exit(proc_exit);

MODULE_LICENSE("Dual BSD/GPL");
MODULE_DESCRIPTION("PROC");