如何找到虚拟地址的偏移量和页码？

Question

使用具有4K页面的x86_64 Linux，虚拟地址0xeas17e57的页面偏移是多少？以0x开头的十六进制给出答案。有人可以指导我如何做吗？

Answer 1

除以页面大小可获取页码，可使用模数获取偏移量。在C语言中，这将是：

const screen2Config = {
  duration: 300,
  easing: Easing.out(Easing.poly(4)),
  timing: Animated.timing,
};

export const ScreenStack = createStackNavigator({
  Screen1: {
    screen: Screen1,
    navigationOptions: ({ navigation }) => ({
      headerTitle: 'Screen1',
      headerTitleAllowFontScaling: false,
    }),
  },
  Screen2: {
    screen: Screen2,
    navigationOptions: ({ navigation }) => ({
      headerTitle: 'Screen2',
      headerTitleAllowFontScaling: false,
      tabBarVisible: false,
    }),
  },
  Screen3: {
    screen: Screen3,
    navigationOptions: ({ navigation }) => ({
      headerTitle: 'Screen3',
      headerTitleAllowFontScaling: false,
    }),
  },
  Screen4: {
    screen: Screen4,
    navigationOptions: ({ navigation }) => ({
      headerTitle: 'Screen4',
      headerTitleAllowFontScaling: false,
    }),
  },
}, {
  headerMode: 'float',
  mode: 'modal',
  transitionConfig: sceneProps => ({
    transitionSpec: sceneProps.scene.route.routeName === 'Screen2' ? screen2Config : {},
    screenInterpolator: (sceneProps) => {
      if (sceneProps.scene.route.routeName === 'Screen2') {
        const { layout, position, scene } = sceneProps;
        const { index } = scene;

        const width = layout.initWidth;
        const translateX = position.interpolate({
          inputRange: [index - 1, index, index + 1],
          outputRange: [width, 0, 0],
        });

        const opacity = position.interpolate({
          inputRange: [index - 1, index - 0.99, index],
          outputRange: [0, 1, 1],
        });

        return { opacity, transform: [{ translateX }] };
      }
    },
  }),
});