Linux内核编程（持续整理）

1. 如何给模块传一个数组性参数

   #include 
   static int arr_var[10];
   static int num=0;
   module_param_array(arr_var, int, &num, 0644);//最后一个数字是访问权限
   

2. /proc编程

   1. 创建entry: struct proc_dir_entry * entry = proc_create("name", 0444, NULL, &file_ops);

      其中parent为NULL即直接创建在/proc目录下, file_ops是文件操作

   2. file_operations

   file_operations的的结构体定义如下，

        struct file_operations {  
           struct module *owner;  
           loff_t (*llseek) (struct file *, loff_t, int);  
           ssize_t (*read) (struct file *, char *, size_t, loff_t *);  
           ssize_t (*write) (struct file *, const char *, size_t, loff_t *);  
           int (*readdir) (struct file *, void *, filldir_t);  
           unsigned int (*poll) (struct file *, struct poll_table_struct *);  
           int (*ioctl) (struct inode *, struct file *, unsigned int, unsigned long);  
           int (*mmap) (struct file *, struct vm_area_struct *);  
           int (*open) (struct inode *, struct file *);  
           int (*flush) (struct file *);  
           int (*release) (struct inode *, struct file *);  
           int (*fsync) (struct file *, struct dentry *, int datasync);  
           int (*fasync) (int, struct file *, int);  
           int (*lock) (struct file *, int, struct file_lock *);  
           ssize_t (*readv) (struct file *, const struct iovec *, unsigned long,  
             loff_t *);  
          ssize_t (*writev) (struct file *, const struct iovec *, unsigned long,  
              loff_t *);  
       };
   

   当我们需要定义自己的文件操作的时候，

   static const struct file_operations proc_read_only_fops = {
       .open = my_open,
       .read = my_read
   };