error: implicit declaration of the function 'copy_to_user [- Werror=implicit function - declaration] 
Copy_to_user (buf, drv_buf, size); 
Error: implicit declaration of "the copy_from_user function [- Werror=implicit function - declaration] 
The copy_from_user (drv_buf, buf, size); 

First check your header file, whether the lack of the
# include & lt; Linux/uaccess. H>

CodePudding user response:

General error: implicit declaration of the function of XXX, did not check the corresponding header file contains came in

CodePudding user response:

Compile a implicit specification error, there are generally two kinds of circumstances,
1, control the Linux kernel check header files for missing; 2, pay attention to the function declaration

CodePudding user response:

Did not include the header file