ReactOS系统中MmLocateMemoryAreaByAddress函数的实现：搜索目标地址所在的节点

ReactOS系统中MmLocateMemoryAreaByAddress函数的实现：搜索目标地址所在的节点

//搜索目标地址所在的节点MmLocateMemoryAreaByAddress

/* FUNCTIONS *****************************************************************/

PMEMORY_AREA NTAPI
MmLocateMemoryAreaByAddress(
    PMMSUPPORT AddressSpace,
    PVOID Address_)
{
    ULONG_PTR StartVpn = (ULONG_PTR)Address_ / PAGE_SIZE;
    PEPROCESS Process;
    PMM_AVL_TABLE Table;
    PMMADDRESS_NODE Node;
    PMEMORY_AREA MemoryArea;
    TABLE_SEARCH_RESULT Result;
    PMMVAD_LONG Vad;

	获取用户空间的AVL树
    Process = MmGetAddressSpaceOwner(AddressSpace);
    Table = (Process != NULL) ? &Process->VadRoot : &MiRosKernelVadRoot;

	//检测该AVL树是否存在问题
    Result = MiCheckForConflictingNode(StartVpn, StartVpn, Table, &Node);
    if (Result != TableFoundNode)
    {
        return NULL;
    }
  // 根据二叉搜索树的性质进行和遍历，小到其左子树遍历，大则到其右子树遍历
    Vad = (PMMVAD_LONG)Node;
    if (Vad->u.VadFlags.Spare == 0)
    {
        /* Check if this is VM VAD */
        if (Vad->ControlArea == NULL)
        {
            /* We store the reactos MEMORY_AREA here */
            MemoryArea = (PMEMORY_AREA)Vad->FirstPrototypePte;
        }
        else
        {
            /* This is a section VAD. Store the MAREA here for now */
            MemoryArea = (PMEMORY_AREA)Vad->u4.Banked;
        }
    }
    else
    {
        MemoryArea = (PMEMORY_AREA)Node;
    }

    return MemoryArea;
}