Энциклопедия разработчика модулей ядра Linux

static struct inode_operations Inode_Ops_4_Our_Proc_File = {

 &File_Ops_4_Our_Proc_File,

 NULL, /* create */

 NULL, /* lookup */

 NULL, /* link */

 NULL, /* unlink */

 NULL, /* symlink */

 NULL, /* mkdir */

 NULL, /* rmdir */

 NULL, /* mknod */

 NULL, /* rename */

 NULL, /* readlink */

 NULL, /* follow_link */

 NULL, /* readpage */

 NULL, /* writepage */

 NULL, /* bmap */

 NULL, /* truncate */

 module_permission /* check for permissions */

};

/* Directory entry */

static struct proc_dir_entry Our_Proc_File = {

 0, /* Inode number - ignore, it will be filled by proc_register[_dynamic] */

 5, /* Length of the file name */

 "sleep", /* The file name */

 S_IFREG | S_IRUGO | S_IWUSR,

  /* File mode - this is a regular file which

  * can be read by its owner, its group, and everybody

  * else. Also, its owner can write to it.

  *

  * Actually, this field is just for reference, it's

  * module_permission that does the actual check. It

  * could use this field, but in our implementation it

  * doesn't, for simplicity. */

 1, /* Number of links (directories where the file is referenced) */

 0, 0, /* The uid and gid for the file - we give it to root */

 80, /* The size of the file reported by ls. */

 &Inode_Ops_4_Our_Proc_File,

  /* A pointer to the inode structure for

  * the file, if we need it. In our case we

  * do, because we need a write function. */

 NULL

  /* The read function for the file.

  * Irrelevant, because we put it

  * in the inode structure above */

};

 /* Module initialization and cleanup **************** */

/* Initialize the module - register the proc file */

int init_module() {

 /* Success if proc_register_dynamic is a success,

 * failure otherwise */

#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,2,0)

 return proc_register(&proc_root, &Our_Proc_File);

#else

 return proc_register_dynamic(&proc_root, &Our_Proc_File);

#endif

 /* proc_root is the root directory for the proc

 * fs (/proc). This is where we want our file to be

 * located. */

}

/* Cleanup - unregister our file from /proc. This could

* get dangerous if there are still processes waiting in

* WaitQ, because they are inside our open function,

* which will get unloaded. I'll explain how to avoid

* removal of a kernel module in such a case in chapter 10. */

void cleanup_module() {

 proc_unregister(&proc_root, Our_Proc_File.low_ino);

}

Замена для printk

В начале (глава1), я сказал, что X и программирование модулей ядра не совместимы. Это истинно при разработке модуля, но в фактическом использовании, Вы должны быть способны послать сообщениям любому tty[10]. Это важно для идентификации ошибок после того, как модуль выпущен, потому что он будет использоваться через любой из терминалов.