undefined reference to errno

[Innovator]

I am using errno (global variable) in my socket.c file of the kernel
and have also include <bits/errno.h> file and also define Extern int errno in the socket.c file. I have done this to check out the errors which are received when a client and server are running ....
To include the changes which i have made in the socket.c file i am compiling the kernel. But it is giving me error as
Undefined reference to errno

So, anyone please help me out..

[Rubberman]

As far as I know, the errno variable is NOT defined in the kernel. The errno.h files simply contain the error macro values, such as EBADF, etc. You will need to implement and set/read your own variable inside your kernel module(s). Some modules use error, and others use things like si_errno, etc. Also, some are ints and others are uint32 variables. Using an int is preferred, since there are times (not too common) when you may want to set a negative value for an error.