insmod错误

Question

本帖最后由 createwindow 于 2011-05-12 09:30 编辑

以下为代码

1. #include <linux/module.h>
2. #include <linux/kernel.h>
3. #include <linux/init.h>
4. #include <linux/fs.h>
5. #include <linux/cdev.h>
6. #include <linux/device.h>
8. MODULE_LICENSE ("GPL");
10. int hello_major = 120;
11. int hello_minor = 0;
12. int number_of_devices = 1;
14. struct cdev cdev;
15. static dev_t dev;
17. struct file_operations hello_fops = {
18.       .owner = THIS_MODULE
19. };
21. static void char_reg_setup_cdev (void)
22. {
23.    int error;
24.    cdev_init (&cdev, &hello_fops);
25.    cdev.owner = THIS_MODULE;
26.    cdev.ops = &hello_fops;
27.    error = cdev_add (&cdev, dev, 1);
28.    if (error)
29.        printk (KERN_NOTICE "Error %d adding char_reg_setup_cdev", error);
31. }
33. struct class *my_class;
35. static int __init hello_2_init (void)
36. {
37.     int result;
38.     dev = MKDEV(hello_minor, hello_minor);
39.     result = register_chrdev_region (dev, number_of_devices, "hello");
40.     if (result<0) {
41.         printk (KERN_WARNING "hello: can't get major number %d\n", hello_major);
42.         return result;
43.      }
45.     char_reg_setup_cdev ();
47.     /* create your own class under /sysfs */
48.     my_class = class_create(THIS_MODULE, "my_class");
49.     if(IS_ERR(my_class))
50.     {
51.         printk("Err: failed in creating class.\n");
52.         return -1;
53.     }
55.     /* register your own device in sysfs, and this will cause udev to create corresponding device node */
56.     device_create( my_class, NULL, dev, "hello%d", 0 );
58.     printk (KERN_INFO "Registered character driver\n");
59.     return 0;
60. }
62. static void __exit hello_2_exit (void)
63. {
64.     cdev_del (&cdev);
65.     device_destroy(my_class, dev);   
66.     class_destroy(my_class);                              
67.     unregister_chrdev_region (dev, number_of_devices);
69.     printk (KERN_INFO "char driver cleaned up\n");
70. }
72. module_init (hello_2_init);
73. module_exit (hello_2_exit);

复制代码成功编译后，insmod hello.ko,只提示"killed".
若再次insmod hello.ko则会提示insmod error inserting 'hello.ko ':-1 file exists。运行lsmod |grep hello，显示
hello                   2849  1
如果rmmod hello.ko，则提示ERROR: Module hello is in use

内核版本为2.6.38.2

请大家指教。

Answer 1

有人帮忙吗

Answer 2

写个简单的调试一下吧，一个helloworld写这么多

Answer 3

建议先手动创建设备节点，OK后再自动创建，step by step。
建议用动态的方式分配dev_t
建议注意一些常用的内核编程习惯

Answer 4

回复 3# dreamice

试过简单的了，下面是改过的版本。问题依旧。但是删除device_create()后，结果是正常的。非常奇怪

1. #include <linux/module.h>
2. #include <linux/kernel.h>
3. #include <linux/init.h>
4. #include <linux/fs.h>
5. #include <linux/cdev.h>
6. #include <linux/slab.h>
7. #include <linux/device.h>
9. MODULE_LICENSE ("GPL");
11. static struct cdev ctest;
12. static dev_t devno;
14. struct file_operations hello_fops = {
15.       .owner = THIS_MODULE,
16. };
19. struct class *my_class;
21. int __init heiman_init (void)
22. {
23.     int error;
24.    
25.     if (alloc_chrdev_region(&devno, 0, 1, "heiman") < 0) {
26.         printk(KERN_DEBUG "CAN'T register a device\n");
27.         return -1;
28.     }
30.     my_class = class_create(THIS_MODULE, "heiman");
31.     cdev_init (&ctest, &hello_fops);
32.     ctest.owner = THIS_MODULE;
33.     error = cdev_add (&ctest, devno, 1);
34.     device_create( my_class, NULL, devno, "heiman%d", 0);
36.     printk (KERN_INFO "Registered character driver\n");
37.     return 0;
38. }
40. static void __exit heiman_exit (void)
41. {
42.     unregister_chrdev_region(devno, 1);
43.     device_destroy(my_class, devno);   
44.     cdev_del(&ctest);
45.     class_destroy(my_class);         
47.     printk (KERN_INFO "char driver cleaned up\n");
48.     return;
49. }
51. module_init(heiman_init);
52. module_exit(heiman_exit);

复制代码

Answer 5

device_create( my_class, NULL, dev, "hello%d", 0 );用错拉！
改成device_create( my_class, NULL, MKDEV(hello_major, 0), NULL ,"hello%d", 0);就可以了，你那个代码是从网上抄来的吧！

/**
* device_create - creates a device and registers it with sysfs
* @class: pointer to the struct class that this device should be registered to
* @parent: pointer to the parent struct device of this new device, if any
* @devt: the dev_t for the char device to be added
* @drvdata: the data to be added to the device for callbacks
* @fmt: string for the device's name
*
* This function can be used by char device classes.  A struct device
* will be created in sysfs, registered to the specified class.
*
* A "dev" file will be created, showing the dev_t for the device, if
* the dev_t is not 0,0.
* If a pointer to a parent struct device is passed in, the newly created
* struct device will be a child of that device in sysfs.
* The pointer to the struct device will be returned from the call.
* Any further sysfs files that might be required can be created using this
* pointer.
*
* Returns &struct device pointer on success, or ERR_PTR() on error.
*
* Note: the struct class passed to this function must have previously
* been created with a call to class_create().
*/
struct device *device_create(struct class *class, struct device *parent,
                             dev_t devt, void *drvdata, const char *fmt, ...)
{
        va_list vargs;
        struct device *dev;

        va_start(vargs, fmt);
        dev = device_create_vargs(class, parent, devt, drvdata, fmt, vargs);
        va_end(vargs);
        return dev;
}
EXPORT_SYMBOL_GPL(device_create);

Answer 6

实不相瞒，是你的device_create缺少一个参数。
device_create( my_class, NULL, devno, “hello0", "heiman%d", 0);

Answer 7

重启电脑就可以解决了。哈哈，