rem: rc = user_strncpy(newpath, unewpath, SYS_MAX_PATH_LEN); if (rc < 0) return rc; newpath[SYS_MAX_PATH_LEN] = 0;  return common_rename(oldpath, newpath, false);
add: return common_rename(oldPath, newPath, false);
context: user_rename(const char *uoldpath, const char *unewpath){	char oldpath[SYS_MAX_PATH_LEN + 1];	char newpath[SYS_MAX_PATH_LEN + 1];	int rc;	if ((addr)uoldpath >= KERNEL_BASE && (addr)uoldpath <= KERNEL_TOP)		return ERR_VM_BAD_USER_MEMORY;	if ((addr)unewpath >= KERNEL_BASE && (addr)unewpath <= KERNEL_TOP)		return ERR_VM_BAD_USER_MEMORY;	rc = user_strncpy(oldpath, uoldpath, SYS_MAX_PATH_LEN);	if (rc < 0)		return rc;	oldpath[SYS_MAX_PATH_LEN] = 0;	rc = user_strncpy(newpath, unewpath, SYS_MAX_PATH_LEN);	if (rc < 0)		return rc;	newpath[SYS_MAX_PATH_LEN] = 0;	return common_rename(oldpath, newpath, false);}