简单的字符设备驱动程序居然出错!大家帮忙看看哈^_^__inode_file_static_struct_length_

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简单的字符设备驱动程序居然出错!大家帮忙看看哈^_^

来源: 互联网发布时间：2015-10-11

本文导语: //chardev.c #include #include #include #include #define SUCCESS 0 #define DEVICE_NAME "char_dev" #define BUF_LEN 80 static int Device_Open=0; static char Message[BUF_LEN]; static char *Message_Ptr; static i...

//chardev.c
#include
#include
#include
#include

#define SUCCESS 0
#define DEVICE_NAME "char_dev"
#define BUF_LEN 80
static int Device_Open=0;
static char Message[BUF_LEN];
static char *Message_Ptr;

static int device_open(struct inode *inode,struct file *file)
{
    static int counter=0;
#ifdef DEBUG
    printk("device_open(%p,%p)n",inode,file);
#endif
    if(Device_Open)
        return -EBUSY;
    Device_Open++;
    sprintf(Message,"If I told you once, I told you %d times-Hello,world!n",counter++);
    Message_Ptr=Message;
    MOD_INC_USE_COUNT;
    return SUCCESS;
}
static void device_release(struct inode *inode,struct file *file)
{
#ifdef DEBUG
    printk("device_release(%p,%p)n",inode,file);
#endif
    Device_Open--;
    MOD_DEC_USE_COUNT;
}

static int device_read(struct inode *inode,
                       struct file *file,
                       char *buffer,
                       int length)
{
    int bytes_read=0;
#ifdef DEBUG
    printk("device_read(%p,%p,%p,%d)n",inode,file,buffer,length);
#endif
    if(*Message_Ptr==0)
        return 0;
    while(length && *Message_Ptr)
    {
        put_user(*(Message_Ptr++),buffer++);
        length--;
        bytes_read++;
    }
#ifdef DEBUG
    printk("Read %d bytes,%d leftn",bytes_read,length);
#endif
    return bytes_read;
}
static int device_write(struct inode *inode,
                        struct file *file,
                        const char *buffer,
                        int length)
{
#ifdef DEBUG
    printk("device_write(%p,%p,%s,%d)n",inode,file,buffer,length);
#endif
    return -EINVAL;
}
static int Major;
struct file_operations Fops={
    NULL,
    device_read,
    device_write,
    NULL,
    NULL,
    NULL,
    NULL,
    device_open,
    device_release
};
int init_module()
{
    Major=module_register_chrdev(0,
        DEVICE_NAME,
        &Fops);
    if(Major