Adding a new system call in Linux kernel 3.3

How to add a new Linux kernel API in 3.3 version? -- for 64 bits OS

• get kernel codes from www.kernel.org.
  wget http://www.kernel.org/pub/linux/kernel/v3.0/linux-3.3.1.tar.bz2

• Upzip it with command ‘tar xvfj XXX” to a folder For example : /root/kernel tar xvfj linux-3.3.1.tar.bz2 
• Edit file “/root/kernel/linux-3.3.1/arch/x86/syscalls/syscall_64.tbl” Add new line
  312 64 husky1 sys_husky1 
• Eidt file “/root/kernel/linux-3.3.1/include/linux/syscalls.h” Add new function declaration
  asmlinkage long sys_husky1(int fd);
  before the line “#endif” 
• Add a new c file under “/root/kernel/linux-3.3.1/arch/x86/kernel”
  long sys_husky1(int fd) { ... }
• Edit “/root/kernel/linux-3.3.1/arch/x86/kernel/Makefile” Add a new line “obj-y += husky.o” 
• goto /root/kernel/linux-3.3.1 folder and run command “make –j8” 

User space code for calling the new system call:

int ret = syscall(312);

Due to standard kernel header doesn't know our new system call,
we need to use system call number here.

Ref: http://stackoverflow.com/questions/9977968/adding-a-new-system-call-in-linux-kernel-3-3