linux_sys_arch_prctl_args
const struct linux_sys_arch_prctl_args *uap, register_t *retval)
int linux_sys_arch_prctl(struct lwp *, const struct linux_sys_arch_prctl_args *, register_t *);
ns(struct linux_sys_arch_prctl_args),
const struct linux_sys_arch_prctl_args *p = params;