HvlpAcquireHypercallPage

VOID *__stdcall HvlpAcquireHypercallPage(
        PHYSICAL_ADDRESS *PageInfo,
        UINT64 Flags,
        VOID *StackBuffer,
        UINT64 ElementSize){
  PHYSICAL_ADDRESS *HypercallCachedPages; 
  LONG v7; 
  __int16 v9; 
  struct _KPRCB *v10; 
  VOID *result; 
  struct _KPRCB *CurrentPrcb; 
  PSLIST_ENTRY v13; 
  _QWORD *p_Next; 
  PHYSICAL_ADDRESS Next; 
  unsigned __int64 v16; 
  unsigned __int64 v17; 
  unsigned __int8 CurrentIrql; 
  __int16 v19; 
  struct _KPRCB *v20; 
  __int16 v21; 

  HypercallCachedPages = 0i64;
  v7 = Flags;
  if( (HvlpFlags & 8) != 0 )
  {
    CurrentPrcb = KeGetCurrentPrcb();
    v13 = RtlpInterlockedPopEntrySList(&CurrentPrcb->HypercallPageList);
    p_Next = &v13->Next;
    if( v13 )
    {
      PageInfo->anonymous_0.LowPart = 1;
      PageInfo[1].QuadPart = (LONGLONG)CurrentPrcb;
      PageInfo[2].QuadPart = (LONGLONG)v13;
      Next = (PHYSICAL_ADDRESS)v13[1].Next;
    }
    else
    {
      if( (v7 & 4) != 0 )
        return 0i64;
      if( StackBuffer )
      {
        v16 = ((unsigned __int64)StackBuffer + 7) & 0xFFFFFFFFFFFFFFF8ui64;
        v17 = v16 + ElementSize - 1;
        p_Next = (_QWORD *)(v17 & 0xFFFFFFFFFFFFF000ui64);
        if( ((v16 ^ v17) & 0xFFFFFFFFFFFFF000ui64) == 0 )
          p_Next = (_QWORD *)(((unsigned __int64)StackBuffer + 7) & 0xFFFFFFFFFFFFFFF8ui64);
        PageInfo->anonymous_0.LowPart = 2;
        CurrentIrql = KeGetCurrentIrql();
        LOBYTE(PageInfo[1].anonymous_0.LowPart) = CurrentIrql;
        if( CurrentIrql < 2u )
        {
          KeGetCurrentIrql();
          __writecr8(2ui64);
        }
        Next.anonymous_0.LowPart = MmGetPhysicalAddress((UINT64)p_Next);
      }
      else
      {
        v19 = v21;
        PageInfo->anonymous_0.LowPart = 4;
        _disable();
        PageInfo[1].anonymous_0.HighPart = v7;
        LOBYTE(PageInfo[1].anonymous_0.LowPart) = (v19 & 0x200) != 0;
        v20 = KeGetCurrentPrcb();
        if( (v7 & 1) != 0 )
        {
          p_Next = v20->HypercallCachedPages;
        }
        else if( (v7 & 2) != 0 )
        {
          p_Next = (char *)v20->HypercallCachedPages + 4096;
        }
        Next = (PHYSICAL_ADDRESS)p_Next[2];
      }
    }
    PageInfo[3] = Next;
    return p_Next;
  }
  else
  {
    v9 = v21;
    PageInfo->anonymous_0.LowPart = 4;
    _disable();
    PageInfo[1].anonymous_0.HighPart = Flags;
    LOBYTE(PageInfo[1].anonymous_0.LowPart) = (v9 & 0x200) != 0;
    v10 = KeGetCurrentPrcb();
    if( (Flags & 1) != 0 )
    {
      HypercallCachedPages = (PHYSICAL_ADDRESS *)v10->HypercallCachedPages;
    }
    else if( (Flags & 2) != 0 )
    {
      HypercallCachedPages = (PHYSICAL_ADDRESS *)((char *)v10->HypercallCachedPages + 4096);
    }
    result = HypercallCachedPages;
    PageInfo[3] = HypercallCachedPages[2];
  }
  return result;
}

Referenced by: