Question

我已经更新了我的XE5 Update1的几个应用程序。从那时起，ShowMessage经常触发访问冲突。这种情况发生在几个应用程如果我用一个简单的表单替换ShowMessage，那么AV就不见了。所以这显然是ShowMessage的罪魁祸首。

AV出现在函数TaskDialogIndirect的WinApi.CommCtrl.pas中（参见下面的标记行）：

function TaskDialogIndirect(const pTaskConfig: TTaskDialogConfig;
  pnButton: PInteger; pnRadioButton: PInteger; pfVerificationFlagChecked: PBOOL): HRESULT;
begin
  if Assigned(_TaskDialogIndirect) then
    Result := _TaskDialogIndirect(pTaskConfig, pnButton, pnRadioButton,
      pfVerificationFlagChecked)         // <====== HERE ==========
  else
  begin
    InitComCtl;
    Result := E_NOTIMPL;
    if ComCtl32DLL <> 0 then
    begin
      @_TaskDialogIndirect := GetProcAddress(ComCtl32DLL, 'TaskDialogIndirect');
      if Assigned(_TaskDialogIndirect) then
        Result := _TaskDialogIndirect(pTaskConfig, pnButton, pnRadioButton,
          pfVerificationFlagChecked)
    end;
  end;
end;

发生异常时的堆栈跟踪：

:671cab85 ; D:\Development\DelphiLibs\madCollection\madExcept\Dlls\madExcept32.dll
:671cabe2 ; D:\Development\DelphiLibs\madCollection\madExcept\Dlls\madExcept32.dll
:671ca755 madExcept32.ThisIsNoLeak + 0x29
:004aa9d7 ThisIsNoLeak + $F
:004a9412 HookedCreateThread + $82
:769613a2 msvcrt._beginthreadex + 0x74
:5f028473 ; C:\Windows\SysWOW64\DUser.dll
:5f028234 DUser.InitGadgets + 0xf5
:5f028177 DUser.InitGadgets + 0x38
:70e4da8d ; C:\Windows\WinSxS\x86_microsoft.windows.common-controls_6595b64144ccf1df_6.0.7601.17514_none_41e6975e2bd6f2b2\comctl32.dll
:70e5d492 ; C:\Windows\WinSxS\x86_microsoft.windows.common-controls_6595b64144ccf1df_6.0.7601.17514_none_41e6975e2bd6f2b2\comctl32.dll
Winapi.CommCtrl.TaskDialogIndirect(???,???,$18E974,$18E96C)
Vcl.Dialogs.TCustomTaskDialog.DoExecute(460578)
Vcl.Dialogs.TCustomTaskDialog.Execute(???)
Vcl.Dialogs.TTaskMessageDialog.Execute(???)
Vcl.Dialogs.TCustomTaskDialog.Execute
Vcl.Dialogs.DoTaskMessageDlgPosHelp('','Calibration failed Unknown error',mtCustom,[mbOK],0,-1,-1,'',mbOK)
Vcl.Dialogs.DoTaskMessageDlgPosHelp('',???,mtCustom,[mbOK],0,-1,-1,'')
Vcl.Dialogs.MessageDlgPosHelp('Calibration failed Unknown error',mtCustom,[mbOK],0,-1,-1,'')
Vcl.Dialogs.ShowMessagePos('',-1,-1)
Vcl.Dialogs.ShowMessage(???)
AutomationTechspCalibration.TCalibrationForm.StartCalibrationButtonClick($8C56D14)
Vcl.Controls.TControl.Click
Vcl.StdCtrls.TCustomButton.Click
Vcl.StdCtrls.TCustomButton.CNCommand(???)
Vcl.Controls.TControl.WndProc((48401, 1786, 526074, 0, 1786, 0, (), 1786, 8, (), 0, 0, ()))
Vcl.Controls.TWinControl.WndProc((48401, 1786, 526074, 0, 1786, 0, (), 1786, 8, (), 0, 0, ()))
Vcl.StdCtrls.TButtonControl.WndProc((48401, 1786, 526074, 0, 1786, 0, (), 1786, 8, (), 0, 0, ()))
Vcl.Controls.TControl.Perform(???,???,526074)
Vcl.Controls.DoControlMsg(???,(no value))
Vcl.Controls.TWinControl.WMCommand((273, (), 1786, 0, (), 526074, 0))
Vcl.Forms.TCustomForm.WMCommand((273, (), 1786, 0, (), 526074, 0))
Vcl.Controls.TControl.WndProc((273, 1786, 526074, 0, 1786, 0, (), 1786, 8, (), 0, 0, ()))
Vcl.Controls.TWinControl.WndProc((273, 1786, 526074, 0, 1786, 0, (), 1786, 8, (), 0, 0, ()))
Vcl.Forms.TCustomForm.WndProc((273, 1786, 526074, 0, 1786, 0, (), 1786, 8, (), 0, 0, ()))
Vcl.Controls.TWinControl.MainWndProc(???)
System.Classes.StdWndProc(460578,273,1786,526074)
:757462fa ; C:\Windows\syswow64\USER32.dll
:75746d3a USER32.GetThreadDesktop + 0xd7
:7574965e ; C:\Windows\syswow64\USER32.dll
:757496c5 USER32.SendMessageW + 0x4c
:70e84601 ; C:\Windows\WinSxS\x86_microsoft.windows.common-controls_6595b64144ccf1df_6.0.7601.17514_none_41e6975e2bd6f2b2\comctl32.dll
:70e84663 ; C:\Windows\WinSxS\x86_microsoft.windows.common-controls_6595b64144ccf1df_6.0.7601.17514_none_41e6975e2bd6f2b2\comctl32.dll
:70e844ed ; C:\Windows\WinSxS\x86_microsoft.windows.common-controls_6595b64144ccf1df_6.0.7601.17514_none_41e6975e2bd6f2b2\comctl32.dll
:757462fa ; C:\Windows\syswow64\USER32.dll
:75746d3a USER32.GetThreadDesktop + 0xd7
:75750d27 USER32.GetClientRect + 0xc5
:75750d4d USER32.CallWindowProcW + 0x1b
Vcl.Controls.TWinControl.DefaultHandler(???)
:005b92ef TWinControl.DefaultHandler + $EB
:005b91de TWinControl.WndProc + $5CA
:005d6599 TButtonControl.WndProc + $71
:0053ea12 StdWndProc + $16
:757462fa ; C:\Windows\syswow64\USER32.dll
:75746d3a USER32.GetThreadDesktop + 0xd7
:757477c4 ; C:\Windows\syswow64\USER32.dll
:7574788a USER32.DispatchMessageW + 0xf

任何帮助表示感谢。

Answer 1

我已经禁用了madExcept并使用了FastMM4（不是XE5附带的那个，而是来自Sourceforge的最新版本）。 FastMM立即向我展示了madExcept没有捕获的缓冲区溢出。

我解决了这个问题。我用FastMM工作了几个小时，然后我再次使用了madExcept，一切正常。没有AV。

我的结论是缓冲区溢出以导致ShowMessage AV的方式破坏了堆！ madExcept不是问题，ShowMessage也不是。这是我自己的代码（缓冲区溢出），它搞砸了一切。感谢FastMM几乎立即指向它（打开FastMM的FullDebugMode）。

Delphi XE5 Upd1 ShowMessage生成AV

1 个答案: