Unknown symbol in module

Question

I have a kernel module which was probably written for the 2.6xx kernel version. Now I currently want to plug that module onto kernel version 3.1x and above. I have tweaked and changed the code and apparently now there is compilation error except the below mentioned warnings.

WARNING: "do_mmap_pgoff" [/home/abdullah/Downloads/my_mod.ko] undefined!

WARNING: "putname" [/home/abdullah/Downloads/my_mod.ko] undefined!

WARNING: "get_task_cred" [/home/abdullah/Downloads/my_mod.ko] undefined!

Now when I checked my kernel Module.symvers I did not find all three of the functions in it for exports. Which results in a fatal error when inserting the module. Now my question: Does anybody know the alternative to these functions? Any help will be really appreciated. Below is a sample function which illustrates the scenario as the complete function is to long.

int function_1(const char *fname)
{
    struct cred *task_cred; 
    struct filename *filename  = NULL;

    filename = getname(__user(fname));
    task_cred = (struct cred *)get_task_cred(current);  
    putname(filename); 
    filename = NULL;

    return 1;
}

Answer 1

Well, there is another way also which is bit unsafe, any body who is not on a production system he can export these function in the kernel source file as I did