i followed the link and tried to add a system call in kernel-version 2.6.37
here is the code :

#include<linux/linkage.h>
#include<linux/kernel.h>
#include<linux/fs.h> //for getname
#include<linux/err.h> //for PTR_ERR
asmlinkage int sys_hariohm(const char __user *filename)
{
    char *tmp = getname(filename);
     int fd=PTR_ERR(tmp);
        if (!IS_ERR(tmp))
        {
        printk("filename %s \n",tmp);
        putname(tmp);
        return fd;
        }
        else
        {
        return 2;
        }
}

the compilation process was silent (without any error).
but when i try to boot into the kernel having this system call , i get the errors like :

do_exit() ,do_group_exit() , syscall_init() error lines with some addresses.

can someone help me understand what is wrong with this code?

thanks in advance :)

and also when i tried to boot into this kernel , it was showing some initrafs error.

--
........................
MOHIT VERMA