字符设备中的权限被拒绝

时间:2014-01-08 20:00:33

标签: c terminal kernel debian linux-device-driver

我正在为debian 6内核编程设备的驱动程序模块,该内核充当FIFO设备,编译非常正确,我使用以下代码创建它:

Major = register_chrdev(0, DEVICE_NAME, &fops); //Major is an integer value
if (Major < 0) {
  printk(KERN_ALERT "Registering char device failed with %d\n", Major);
  return -Major;
}
/*
 * Creation of buffer;
 */
if( (buf = create_cbuffer_t(MAX_BUFFER_SIZE)) == NULL){
    printk(KERN_ALERT "Error when creating the FIFO device.");
    return -EINVAL;
}
    printk(KERN_INFO "Buffer created without error.\n");

签名的主号码是251,我用它创建了它的文件:

sudo mknod /dev/fifodev c 251 0

它工作正常,但当我尝试在终端访问时,这是结果

dsouser@debian:~/Escritorio/Prac3/ParteB$ echo whatever > /dev/fifodev 
bash: /dev/fifodev: Permiso denegado **This means:Permission denied**

这也会发生:

dsouser@debian:~/Escritorio/Prac3/ParteB$ cat /dev/fifodev
cat: /dev/fifodev: Argumento inválido

它内部的问题或使其运行的正确方法是什么?

非常感谢

1 个答案:

答案 0 :(得分:4)

更改/dev/fifodev

的权限
 sudo chmod 666 /dev/fifodev