sys_ptrace
int sys_ptrace(struct lwp *, const struct sys_ptrace_args *, register_t *);
.sy_call = (sy_call_t *)sys_ptrace
if (sys_ptrace == sys_nosys)
return sys_ptrace(l, &pa, retval);
if (sys_ptrace == sys_nosys)
{ SYS_ptrace, 0, (sy_call_t *)sys_ptrace },
check_syscall_args(sys_ptrace)
int sys_ptrace(struct lwp *, const struct sys_ptrace_args *, register_t *);