ldd3的complete简单例子问题--cat completion不知道怎么执行

zzban

最近在看ldd3, 看到complete的时候参考如下博客：
http://hi.baidu.com/phenix_yw/blog/item/4757f6243dcd83004c088dd9.html/cmtid/6ccf41df4bc1a01849540387
我的代码是complete.c：

1. #include <linux/module.h>
   
2. 
   
3. #include <linux/init.h>
   
4. 
   
5. 
   
6. 
   
7. #include <linux/sched.h>
   
8. 
   
9. #include <linux/kernel.h>
   
10. 
    
11. #include <linux/fs.h>
    
12. 
    
13. #include <linux/types.h>
    
14. 
    
15. #include <linux/completion.h>
    
16. 
    
17. 
    
18. 
    
19. MODULE_LICENSE("Dual BSD/GPL");
    
20. 
    
21. 
    
22. 
    
23. static int complete_major = 0;
    
24. 
    
25. 
    
26. 
    
27. struct completion comp;
    
28. 
    
29. DELCARE_COMPLETION(comp);
    
30. 
    
31. 
    
32. 
    
33. ssize_t complete_read (struct file *filp, char __user *buf, size_t count, loff_t *pos)
    
34. 
    
35. {
    
36. 
    
37.     printk(KERN_DEBUG "process %i (%s) going to sleep\n",
    
38. 
    
39.             current->pid, current->comm);
    
40. 
    
41.     wait_for_completion(&comp);
    
42. 
    
43.     printk(KERN_DEBUG "awoken %i (%s)\n", current->pid, current->comm);
    
44. 
    
45.     return 0;
    
46. 
    
47. }
    
48. 
    
49. 
    
50. 
    
51. ssize_t complete_write(struct file *filp, const char __user *buf, size_t count, loff_t *pos)
    
52. 
    
53. {
    
54. 
    
55.     printk(KERN_DEBUG "process %i (%s) awakening the readers...\n",
    
56. 
    
57.             current->pid, current->comm);
    
58. 
    
59.     complete(&comp);
    
60. 
    
61.     return count;
    
62. 
    
63. }
    
64. 
    
65. 
    
66. 
    
67. struct file_operations complete_fops = {
    
68. 
    
69.     .owner = THIS_MODULE,
    
70. 
    
71.     .read = complete_read,
    
72. 
    
73.     .write = complete_write,
    
74. 
    
75. };
    
76. 
    
77. 
    
78. 
    
79. int complete_init(void)
    
80. 
    
81. {
    
82. 
    
83.     int result;
    
84. 
    
85. 
    
86. 
    
87.     result = register_chrdev(complete_major, "complete", &complete_fops);
    
88. 
    
89.     if (result < 0)
    
90. 
    
91.     {
    
92. 
    
93.         return result;
    
94. 
    
95.     }
    
96. 
    
97.     if (complete_major == 0)
    
98. 
    
99.     {
    
100. 
     
101.         complete_major = result;
     
102. 
     
103.     }
     
104. 
     
105.     return 0;
     
106. 
     
107. }
     
108. 
     
109. 
     
110. 
     
111. void complete_cleanup(void)
     
112. 
     
113. {
     
114. 
     
115.     unregister_chrdev(complete_major, "complete");
     
116. 
     
117. }
     
118. 
     
119. 
     
120. 
     
121. module_init(complete_init);
     
122. 
     
123. module_exit(complete_cleanup);

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Makefile是bj-m :=complete.o

1. default:
   
2.     make -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules
   
3. clean:
   
4.     make -C /lib/modules/$(shell uname -r)/build M=$(PWD) clean

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编译成功后安装模块成功：

1. #cat /proc/modules |grep complete
   
2. complete 1936 0 - Live 0xf8202000

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但是再开一个终端尝试执行cat completion的时候却失败拉。。。说：

1. #cat completion
   
2. cat: completion: No such file or directory

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请问有人遇到过这种情况吗？谢谢

T-Bagwell

没有mknod吧？
参考一下ldd3

godbach

嗯，字符设备的话，需要mknod创建的

openspace

ldd3中有脚本帮你创建设备文件
lz可以看看