unsigned long p4, unsigned long p5, unsigned long p6,
struct pt_regs *regs);
int sys_pipe(int __user *fildes);
-int sys_ptrace(long request, long pid, long addr, long data);
struct sigaction;
long sys_rt_sigaction(int sig, const struct sigaction __user *act,
struct sigaction __user *oact, size_t sigsetsize);