Symptoms
Consider the following scenario:
-
You run a 32-bit application on a computer that is running a 64-bit version of Windows 7 or of Windows Server 2008 R2.
-
An exception occurs when the direction flag is set to 1.
Note The direction flag should still be 0 inside the exception handler. -
The exception handler thread enters an alterable wait state, and an asynchronous procedure call (APC) occurs during the alterable wait.
In this scenario, the direction flag is incorrectly set to 1 after the alterable wait is finished. Therefore, all operations that rely on the direction flag bit write to a wrong location or read from the wrong data.
Cause
This issue occurs because the EFLAGS direction bit is restored after the APC. However, the related WOW64 function does not save or restore the EFLAGS direction bit. Instead, the function uses the data that is stored before the exception occurs. Therefore, the EFLAGS direction bit is set incorrectly after the APC.
Resolution
Hotfix information
A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing the problem described in this article. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.
If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, contact Microsoft Customer Service and Support to obtain the hotfix.
Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft Web site:
http://support.microsoft.com/contactus/?ws=supportNote The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.
Prerequisites
To apply this hotfix, you must be running Windows 7 or Windows Server 2008 R2.
Registry information
To use the hotfix in this package, you do not have to make any changes to the registry.
Restart requirement
You may have to restart the computer after you apply this hotfix.
Hotfix replacement information
This hotfix does not replace a previously released hotfix.
File information
The English (United States) version of this hotfix installs files that have the attributes that are listed in the following tables. The dates and the times for these files are listed in Coordinated Universal Time (UTC). The dates and the times for these files on your local computer are displayed in your local time together with your current daylight saving time (DST) bias. Additionally, the dates and the times may change when you perform certain operations on the files.
Windows 7 and Windows Server 2008 R2 file information notes
Important Windows 7 hotfixes and Windows Server 2008 R2 hotfixes are included in the same packages. However, hotfixes on the Hotfix Request page are listed under both operating systems. To request the hotfix package that applies to one or both operating systems, select the hotfix that is listed under "Windows 7/Windows Server 2008 R2" on the page. Always refer to the "Applies To" section in articles to determine the actual operating system that each hotfix applies to.
-
The MANIFEST files (.manifest) and the MUM files (.mum) that are installed for each environment are listed separately in the "Additional file information for Windows Server 2008 R2 and for Windows 7" section. MUM and MANIFEST files, and the associated security catalog (.cat) files, are extremely important to maintain the state of the updated components. The security catalog files, for which the attributes are not listed, are signed with a Microsoft digital signature.
For all supported x64-based versions of Windows 7 and of Windows Server 2008 R2
|
File name |
File version |
File size |
Date |
Time |
Platform |
|---|---|---|---|---|---|
|
Ntvdm64.dll |
6.1.7600.16385 |
16,384 |
14-Jul-2009 |
01:41 |
x64 |
|
Wow64.dll |
6.1.7600.20737 |
243,200 |
18-Jun-2010 |
09:42 |
x64 |
|
Wow64cpu.dll |
6.1.7600.20737 |
13,312 |
18-Jun-2010 |
09:42 |
x64 |
|
Wow64win.dll |
6.1.7600.16385 |
361,984 |
14-Jul-2009 |
01:41 |
x64 |
|
Acwow64.dll |
6.1.7600.20737 |
44,032 |
18-Jun-2010 |
09:06 |
x86 |
|
Instnm.exe |
6.1.7600.20737 |
7,680 |
18-Jun-2010 |
06:44 |
x86 |
|
Ntvdm64.dll |
6.1.7600.20737 |
14,336 |
18-Jun-2010 |
09:08 |
x86 |
|
Setup16.exe |
3.1.0.1918 |
25,600 |
18-Jun-2010 |
09:06 |
x86 |
|
User.exe |
6.1.7600.20737 |
2,048 |
18-Jun-2010 |
06:44 |
x86 |
|
Wow32.dll |
6.1.7600.20737 |
5,120 |
18-Jun-2010 |
09:04 |
x86 |
For all supported IA-64-based versions of Windows Server 2008 R2
|
File name |
File version |
File size |
Date |
Time |
Platform |
|---|---|---|---|---|---|
|
Ia32exec.bin |
6.8.6808.0 |
8,781,824 |
10-Jun-2009 |
21:15 |
Not Applicable |
|
Ntvdm64.dll |
6.1.7600.16385 |
27,648 |
14-Jul-2009 |
01:48 |
IA-64 |
|
Wow64.dll |
6.1.7600.20737 |
580,608 |
18-Jun-2010 |
08:44 |
IA-64 |
|
Wow64cpu.dll |
6.1.7600.20737 |
36,864 |
18-Jun-2010 |
08:44 |
IA-64 |
|
Wow64win.dll |
6.1.7600.16385 |
716,288 |
14-Jul-2009 |
01:50 |
IA-64 |
|
Wowia32x.dll |
6.8.6807.0 |
88,576 |
18-Jun-2010 |
08:44 |
IA-64 |
|
Acwow64.dll |
6.1.7600.20737 |
44,032 |
18-Jun-2010 |
09:06 |
x86 |
|
Instnm.exe |
6.1.7600.20737 |
7,680 |
18-Jun-2010 |
06:44 |
x86 |
|
Ntvdm64.dll |
6.1.7600.20737 |
14,336 |
18-Jun-2010 |
09:08 |
x86 |
|
Setup16.exe |
3.1.0.1918 |
25,600 |
18-Jun-2010 |
09:06 |
x86 |
|
User.exe |
6.1.7600.20737 |
2,048 |
18-Jun-2010 |
06:44 |
x86 |
|
Wow32.dll |
6.1.7600.20737 |
5,120 |
18-Jun-2010 |
09:04 |
x86 |
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
More Information
For more information about the direction flag, visit the following Microsoft website:
General information about the direction flagFor more information about APCs, visit the following Microsoft website:
General information about the APCsFor more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base:
824684 Description of the standard terminology that is used to describe Microsoft software updates
Additional file information
Additional file information for Windows 7 and for Windows Server 2008 R2
Additional files for all supported x64-based versions of Windows 7 and of Windows Server 2008 R2
|
File name |
Amd64_42e64950aa8c344092efd47996c9100b_31bf3856ad364e35_6.1.7600.20737_none_5efa25eb1e178b03.manifest |
|
File version |
Not Applicable |
|
File size |
697 |
|
Date (UTC) |
18-Jun-2010 |
|
Time (UTC) |
14:19 |
|
Platform |
Not Applicable |
|
File name |
Amd64_43deca60196c36280cbb942c1031e652_31bf3856ad364e35_6.1.7600.20737_none_cd8305fc204f6e00.manifest |
|
File version |
Not Applicable |
|
File size |
697 |
|
Date (UTC) |
18-Jun-2010 |
|
Time (UTC) |
14:19 |
|
Platform |
Not Applicable |
|
File name |
Amd64_b3a28370776bbf4aad6d698150c11dd2_31bf3856ad364e35_6.1.7600.20737_none_836155eece42accc.manifest |
|
File version |
Not Applicable |
|
File size |
1,036 |
|
Date (UTC) |
18-Jun-2010 |
|
Time (UTC) |
14:19 |
|
Platform |
Not Applicable |
|
File name |
Amd64_microsoft-windows-wow64_31bf3856ad364e35_6.1.7600.20737_none_c4dc6c5e09f376a8.manifest |
|
File version |
Not Applicable |
|
File size |
11,008 |
|
Date (UTC) |
18-Jun-2010 |
|
Time (UTC) |
14:21 |
|
Platform |
Not Applicable |
|
File name |
Wow64_microsoft-windows-wow64_31bf3856ad364e35_6.1.7600.20737_none_cf3116b03e5438a3.manifest |
|
File version |
Not Applicable |
|
File size |
12,084 |
|
Date (UTC) |
18-Jun-2010 |
|
Time (UTC) |
09:33 |
|
Platform |
Not Applicable |
Additional files for all supported IA-64-based versions of Windows Server 2008 R2
|
File name |
Ia64_42e64950aa8c344092efd47996c9100b_31bf3856ad364e35_6.1.7600.20737_none_02dd2e5d65b822c9.manifest |
|
File version |
Not Applicable |
|
File size |
696 |
|
Date (UTC) |
18-Jun-2010 |
|
Time (UTC) |
14:19 |
|
Platform |
Not Applicable |
|
File name |
Ia64_69282df8059fd83b40ea8cb870b6f290_31bf3856ad364e35_6.1.7600.20737_none_bd68a5b7233610e3.manifest |
|
File version |
Not Applicable |
|
File size |
695 |
|
Date (UTC) |
18-Jun-2010 |
|
Time (UTC) |
14:19 |
|
Platform |
Not Applicable |
|
File name |
Ia64_microsoft-windows-wow64_31bf3856ad364e35_6.1.7600.20737_none_68bf74d051940e6e.manifest |
|
File version |
Not Applicable |
|
File size |
12,845 |
|
Date (UTC) |
18-Jun-2010 |
|
Time (UTC) |
14:19 |
|
Platform |
Not Applicable |
|
File name |
Wow64_microsoft-windows-wow64_31bf3856ad364e35_6.1.7600.20737_none_cf3116b03e5438a3.manifest |
|
File version |
Not Applicable |
|
File size |
12,084 |
|
Date (UTC) |
18-Jun-2010 |
|
Time (UTC) |
09:33 |
|
Platform |
Not Applicable |
