system/kernel/port.cpp

1870 _user_read_port_etc(port_id port, int32 *userCode, void *userBuffer,
1878 	if (userBuffer == NULL && bufferSize != 0)
1881 		|| (userBuffer != NULL && !IS_USER_ADDRESS(userBuffer)))
1884 	bytesRead = read_port_etc(port, &messageCode, userBuffer, bufferSize,
1896 _user_write_port_etc(port_id port, int32 messageCode, const void *userBuffer,
1899 	iovec vec = { (void *)userBuffer, bufferSize };
1903 	if (userBuffer == NULL && bufferSize != 0)
1905 	if (userBuffer != NULL && !IS_USER_ADDRESS(userBuffer))