openharmony_ci
fa4115e1c6
fix(buffer_handle): validate deserialized BufferHandle fields in ReadBufferHandle
Created-by: Felix-fangyang
Commit-by: fangxiang
Merged-by: openharmony_ci
Description: **Description:**
**Issue number:**
**Test & Result:**
**CodeCheck:**
<table>
<tr>
<th>类型</th><th>自检项</th><th>自检结果</th>
</tr>
<tr>
<td rowspan="2">多线程相关</td><td>在类的成员变量中定义了vector/map/list等容器类型，且在多个成员函数中有操作时，需要加锁保护</td><td>自检结果：不涉及</td>
</tr>
<tr>
<td>定义全局变量，在多个函数中都有操作时，需要加锁保护</td><td>自检结果：不涉及</td>
</tr>
<tr>
<td rowspan="4">内存相关</td><td>调用外部接口时，确认是否对返回值做了判断，尤其外部接口返回了nullptr的情况，避免进程崩溃</td><td>自检结果：不涉及</td>
</tr>
<tr>
<td>调用安全函数时，如memcpy_s等，是否检查其返回值</td><td>自检结果：不涉及</td>
</tr>
<tr>
<td>检查函数中是否涉及了内存或资源申请（如文件句柄），注意每个异常退出流程，是否都已经将资源释放（推荐使用RAII）</td><td>自检结果：不涉及</td>
</tr>
</tr>
<tr>
<td>隐式内存分配场景：realpath、ReadParcelable序列化、cJSON相关函数时等，需主动释放或使用智能指针</td><td>自检结果：不涉及</td>
</tr>
<tr>
<td rowspan="4">校验外部输入</td><td>使用nlohmann:json解析外部输入时，需判断参数类型是否符合预期</td><td>自检结果：不涉及</td>
</tr>
<tr>
<td>所有外部输入均不可信，需判断外部输入是否直接作为内存分配的大小，数组下标、循环条件、SQL查询等</td><td>自检结果：不涉及</td>
</tr>
<tr>
<td>外部输入的路径不可信，需使用realpath做标准化处理，并判断路径的合法性</td><td>自检结果：不涉及</td>
</tr>
<tr>
<td>外部输入包括对外提供的接口，IPC的proxy/stub接口，序列化/反序列化接口等</td><td>自检结果：不涉及</td>
</tr>
</tr>
<tr>
<td rowspan="2">数学运算</td><td>代码中是否混合了加减乘除等运算，需检查是否可能导致整数溢出或符号翻转</td><td>自检结果：不涉及</td>
</tr>
<tr>
<td>需检查代码是否有高精度数字转换为低精度的操作，如果必须，建议使用C++安全类型转换接口</td><td>自检结果：不涉及</td>
</tr>
</tr>
<tr>
<td rowspan="1">秘钥相关</td><td>如变量临时保存了口令、秘钥等，需要在使用完成后及时清空（内存memset掉）</td><td>自检结果：不涉及</td>
</tr>
<tr>
<td rowspan="2">权限相关</td><td>作为系统服务对外提供了接口，是否做了权限保护和校验（如需要），只允许申请了权限的应用访问</td><td>自检结果：不涉及</td>
</tr>
<tr>
<td>内核对外提供了设备节点，是否做了权限保护，只允许特定的系统服务访问</td><td>自检结果：不涉及</td>
</tr>
</tr>
<tr>
<td rowspan="3">内核操作</td><td>如有mmap操作，并使用remap_pfn_range进行地址映射时，校验起始地址是否是用户态输入且没有做合法性校验</td><td>自检结果：不涉及</td>
</tr>
<tr>
<td>是否有copy_from_user，并对外部输入的数据做了长度校验，以防止缓冲区溢出</td><td>自检结果：不涉及</td>
</tr>
<tr>
<td>是否有使用copy_to_user，并在返回到用户态时，对数据做了完整初始化，或使用memset清空后再赋值</td><td>自检结果：不涉及</td>
</tr>
</tr>
</table>
See merge request: openharmony/graphic_graphic_surface!1416
Surface
Introduction
A surface is used to manage and transfer the shared memory of graphics and media. Specific use cases include graphics display and composition, and media playback and recording.
A surface transfers data across processes through control structures such as Inter-Process Communication (IPC) handles (with copies), and transfers graphics and media data (zero-copy) through shared memory. The following figure shows the position where a surface works in the system architecture. The elements in green blocks are surface buffers.
Figure 1 Position of a surface (known as Screen buffer in the following figure) in the system architecture
Directory Structure
/foundation/graphic/graphic_surface
├── surface # Framework code
│ ├── include # Header
│ ├── src # Source Code
│ └── test # Test code
│ ├── fuzztest # Fuzzing
│ └── unittest # Unit testing
├── interfaces # APIs
│ ├── innerkits # APIs between modules
│ └── kits # External APIs
├── buffer_handle # widget storage
└── scoped_bytrace # widget storage
Compilation and Building
# Generate the surface.so file in the out directory of the product folder through GN compilation.
hb build graphic_surface
Description
Process Description
Take the interaction between Window Manager Service (WMS) and UI as an example. UI works as a producer, and WMS works as a consumer.
The producer obtains a buffer from the free queue, draws the UI content into the buffer, and places the buffer in the dirty queue.
The consumer obtains the buffer from the dirty queue, synthesizes graphics data, and places the buffer in the free queue again.
Figure 2 Surface rotation process
NOTICE:
- A shared memory is used for data transfer, and the process of creating a surface of the first time should be responsible for task of managing the shared memory. If the process is abnormal and is not recycled, severe memory leakage occurs. Therefore, pay special attention to the process.
- Surfaces are generally used for cross-process transfers of large memory blocks (such as display data) in graphics or media. Especially, when continuous physical memory is used, the transfer rate can be greatly improved. It is not recommended that surfaces be used in small-memory transfer scenarios. Otherwise, memory fragmentation may occur, which affects the performance in typical scenarios.
Usage
For details, see lite WMS.