Unknown symbol copy_from user出错问题

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谋先
帖子: 12
注册时间: 2008-07-05 11:12

Unknown symbol copy_from user出错问题

#1

帖子 谋先 » 2008-11-22 20:53

我的Linux内核树是2.6.9,我的机子是RedFlag 5,gcc版本是3.4.2
我写了一个简单的驱动程序,如下:
#include <linux/module.h>
#include <linux/types.h>
#include <linux/fs.h>
#include <linux/errno.h>
#include <linux/mm.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/cdev.h>
#include <asm/io.h>
#include <asm/system.h>
#include <asm/uaccess.h>

#define GLOBALMEM_SIZE 0x1000 /*全局内存最大4K字节*/
#define MEM_CLEAR 0x1 /*清0全局内存*/
#define GLOBALMEM_MAJOR 254 /*预设的globalmem的主设备号*/

static int globalmem_major = GLOBALMEM_MAJOR;
/*globalmem设备结构体*/
struct globalmem_dev
{
struct cdev cdev; /*cdev结构体*/
unsigned char mem[GLOBALMEM_SIZE]; /*全局内存*/
};

struct globalmem_dev *globalmem_devp; /*设备结构体指针*/
/*文件打开函数*/
int globalmem_open(struct inode *inode, struct file *filp)
{
/*将设备结构体指针赋值给文件私有数据指针*/
filp->private_data = globalmem_devp;
return 0;
}
/*文件释放函数*/
int globalmem_release(struct inode *inode, struct file *filp)
{
return 0;
}

/* ioctl设备控制函数 */
static int globalmem_ioctl(struct inode *inodep, struct file *filp, unsigned
int cmd, unsigned long arg)
{
struct globalmem_dev *dev = filp->private_data;/*获得设备结构体指针*/

switch (cmd)
{
case MEM_CLEAR:
memset(dev->mem, 0, GLOBALMEM_SIZE);
printk(KERN_INFO "globalmem is set to zero\n");
break;

default:
return - EINVAL;
}
return 0;
}

/*读函数*/
static ssize_t globalmem_read(struct file *filp, char __user *buf, size_t size,
loff_t *ppos)
{
unsigned long p = *ppos;
unsigned int count = size;
int ret = 0;
struct globalmem_dev *dev = filp->private_data; /*获得设备结构体指针*/

/*分析和获取有效的写长度*/
if (p >= GLOBALMEM_SIZE)
return count ? - ENXIO: 0;
if (count > GLOBALMEM_SIZE - p)
count = GLOBALMEM_SIZE - p;

/*内核空间->用户空间*/
if (copy_to_user(buf, (void*)(dev->mem + p), count))
{
ret = - EFAULT;
}
else
{
*ppos += count;
ret = count;

printk(KERN_INFO "read %d bytes(s) from %d\n", count, p);
}

return ret;
}

/*写函数*/
static ssize_t globalmem_write(struct file *filp, const char __user *buf,
size_t size, loff_t *ppos)
{
unsigned long p = *ppos;
unsigned int count = size;
int ret = 0;
struct globalmem_dev *dev = filp->private_data; /*获得设备结构体指针*/

/*分析和获取有效的写长度*/
if (p >= GLOBALMEM_SIZE)
return count ? - ENXIO: 0;
if (count > GLOBALMEM_SIZE - p)
count = GLOBALMEM_SIZE - p;

/*用户空间->内核空间*/
if (copy_from_user(dev->mem + p, buf, count))
ret = - EFAULT;
else
{
*ppos += count;
ret = count;

printk(KERN_INFO "written %d bytes(s) from %d\n", count, p);
}

return ret;
}

/* seek文件定位函数 */
static loff_t globalmem_llseek(struct file *filp, loff_t offset, int orig)
{
loff_t ret = 0;
switch (orig)
{
case 0: /*相对文件开始位置偏移*/
if (offset < 0)
{
ret = - EINVAL;
break;
}
if ((unsigned int)offset > GLOBALMEM_SIZE)
{
ret = - EINVAL;
break;
}
filp->f_pos = (unsigned int)offset;
ret = filp->f_pos;
break;
case 1: /*相对文件当前位置偏移*/
if ((filp->f_pos + offset) > GLOBALMEM_SIZE)
{
ret = - EINVAL;
break;
}
if ((filp->f_pos + offset) < 0)
{
ret = - EINVAL;
break;
}
filp->f_pos += offset;
ret = filp->f_pos;
break;
default:
ret = - EINVAL;
break;
}
return ret;
}

/*文件操作结构体*/
static const struct file_operations globalmem_fops =
{
.owner = THIS_MODULE,
.llseek = globalmem_llseek,
.read = globalmem_read,
.write = globalmem_write,
.ioctl = globalmem_ioctl,
.open = globalmem_open,
.release = globalmem_release,
};

/*初始化并注册cdev*/
static void globalmem_setup_cdev(struct globalmem_dev *dev, int index)
{
int err, devno = MKDEV(globalmem_major, index);

cdev_init(&dev->cdev, &globalmem_fops);
dev->cdev.owner = THIS_MODULE;
dev->cdev.ops = &globalmem_fops;
err = cdev_add(&dev->cdev, devno, 1);
if (err)
printk(KERN_NOTICE "Error %d adding LED%d", err, index);
}

/*设备驱动模块加载函数*/
int globalmem_init(void)
{
int result;
dev_t devno = MKDEV(globalmem_major, 0);

/* 申请设备号*/
if (globalmem_major)
result = register_chrdev_region(devno, 1, "globalmem");
else /* 动态申请设备号 */
{
result = alloc_chrdev_region(&devno, 0, 1, "globalmem");
globalmem_major = MAJOR(devno);
}
if (result < 0)
return result;

/* 动态申请设备结构体的内存*/
globalmem_devp = kmalloc(sizeof(struct globalmem_dev), GFP_KERNEL);
if (!globalmem_devp) /*申请失败*/
{
result = - ENOMEM;
goto fail_malloc;
}
memset(globalmem_devp, 0, sizeof(struct globalmem_dev));

globalmem_setup_cdev(globalmem_devp, 0);
return 0;

fail_malloc: unregister_chrdev_region(devno, 1);
return result;
}

/*模块卸载函数*/
void globalmem_exit(void)
{
cdev_del(&globalmem_devp->cdev); /*注销cdev*/
kfree(globalmem_devp); /*释放设备结构体内存*/
unregister_chrdev_region(MKDEV(globalmem_major, 0), 1); /*释放设备号*/
}

MODULE_AUTHOR("MouXian");
MODULE_LICENSE("Dual BSD/GPL");

module_param(globalmem_major, int, S_IRUGO);

module_init(globalmem_init);
module_exit(globalmem_exit);


出现的问题是:
编译通过了,但是当我要挂载的时候出现如下:
insmod: error inserting 'globalmem.ko': -1 Unknown symbol in module

我用命令dmesg查看了一下打印信息,出现如下:
globalmem: Unknown symbol copy_from_user
globalmem: Unknown symbol copy_to_user

请问到底是什么原因?
lianxi1999
帖子: 1
注册时间: 2008-04-08 17:13

Re: Unknown symbol copy_from user出错问题

#2

帖子 lianxi1999 » 2008-12-05 11:06

我也遇到了相似的问题
你解决了吗?能不能提供点帮助?
http://linux.chinaunix.net/bbs/thread-1050394-1-1.html
这是我发的帖子~~谢谢拉~
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