struct sigscratch {
  	unsigned long scratch_unat;	/* ar.unat for the general registers saved in pt */
  	unsigned long ar_pfs;		/* for syscalls, the user-level function-state  */
  	struct pt_regs pt;
  };
  
  struct sigframe {
  	/*
  	 * Place signal handler args where user-level unwinder can find them easily.
  	 * DO NOT MOVE THESE.  They are part of the IA-64 Linux ABI and there is
  	 * user-level code that depends on their presence!
  	 */
  	unsigned long arg0;		/* signum */
  	unsigned long arg1;		/* siginfo pointer */
  	unsigned long arg2;		/* sigcontext pointer */
  	/*
  	 * End of architected state.
  	 */
  
  	void __user *handler;		/* pointer to the plabel of the signal handler */
  	struct siginfo info;
  	struct sigcontext sc;
  };
  
  extern void ia64_do_signal (struct sigscratch *, long);