compat_ustat
COMPAT_SYSCALL_DEFINE2(ustat, unsigned, dev, struct compat_ustat __user *, u)
struct compat_ustat tmp;
memset(&tmp, 0, sizeof(struct compat_ustat));
if (copy_to_user(u, &tmp, sizeof(struct compat_ustat)))
asmlinkage long compat_sys_ustat(unsigned dev, struct compat_ustat __user *u32);