驱动程序函数不会在c中执行,但其他函数会执行

在dmesg中,我得到“内部读取”,但没有“内部查找”,也没有错误。在终端或编译过程中也没有错误。我也不太了解c。

主要的

int file = open("/dev/simple_char_driver", O_RDWR);

//read example, this works fine
printf("Enter how many bytes you want to read: \n");
int len[10];
scanf("%d", len);
char *ptr = malloc(*len * sizeof(char));

read(file, ptr, *len);

//llseek example, doesn't enter
int offset [10];
int whence [10];
scanf("%d",offset);
printf("Enter a value for whence: \n");
scanf("%d",whence);

llseek(file, offset, whence); 

在我的设备驱动程序中:

loff_t simple_char_driver_seek (struct file *pfile, loff_t offset, int whence)
{
    printk(KERN_ALERT "Inside SEEK");
    return 0;
}

ssize_t simple_char_driver_read (struct file *pfile, char __user *buffer, size_t length, loff_t *offset)
{
    printk(KERN_ALERT "Inside READ");
    return 0;
}

struct file_operations simple_char_driver_file_operations = {

    .owner   = THIS_MODULE,
    .open    = simple_char_driver_open,
    .release = simple_char_driver_close,
    .read    = simple_char_driver_read,
    .write   = simple_char_driver_write,
    .llseek  = simple_char_driver_seek,
};