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| #include <linux/module.h>
#include <linux/fs.h> #include <linux/errno.h> #include <linux/miscdevice.h> #include <linux/kernel.h> #include <linux/major.h> #include <linux/mutex.h> #include <linux/proc_fs.h> #include <linux/seq_file.h> #include <linux/stat.h> #include <linux/init.h> #include <linux/device.h> #include <linux/tty.h> #include <linux/kmod.h> #include <linux/gfp.h>
static int major = 0; static char kernel_buf[1024]; static struct class *hello_class;
#define MIN(a, b) (a < b ? a : b)
static ssize_t hello_drv_read (struct file *file, char __user *buf, size_t size, loff_t *offset) { int err; printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__); err = copy_to_user(buf, kernel_buf, MIN(1024, size)); return MIN(1024, size); }
static ssize_t hello_drv_write (struct file *file, const char __user *buf, size_t size, loff_t *offset) { int err; printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__); err = copy_from_user(kernel_buf, buf, MIN(1024, size)); return MIN(1024, size); }
static int hello_drv_open (struct inode *node, struct file *file) { printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__); return 0; }
static int hello_drv_close (struct inode *node, struct file *file) { printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__); return 0; }
static struct file_operations hello_drv = { .owner = THIS_MODULE, .open = hello_drv_open, .read = hello_drv_read, .write = hello_drv_write, .release = hello_drv_close, };
static int __init hello_init(void) { int err; printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__); major = register_chrdev(0, "hello", &hello_drv);
hello_class = class_create(THIS_MODULE, "hello_class"); err = PTR_ERR(hello_class); if (IS_ERR(hello_class)) { printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__); unregister_chrdev(major, "hello"); return -1; } device_create(hello_class, NULL, MKDEV(major, 0), NULL, "hello"); return 0; }
static void __exit hello_exit(void) { printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__); device_destroy(hello_class, MKDEV(major, 0)); class_destroy(hello_class); unregister_chrdev(major, "hello"); }
module_init(hello_init); module_exit(hello_exit);
MODULE_LICENSE("GPL");
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