Starting in User-Mode Driver Framework (UMDF) version 2, you can use a subset of the debugger extension commands implemented in Wdfkd.dll to debug a UMDF driver. This topic describes which commands you might start with to troubleshoot UMDF driver problems.
Determining Why a UMDF 2.0 Driver Crashed
If the driver host process is terminated, your driver might have a problem in a callback that results in the host timeout threshold being exceeded. In this case, the reflector terminates the driver host process.
To investigate, first set up a kernel-mode debugging session as described in How to Enable Debugging of a UMDF Driver.
If HostFailKdDebugBreak is set, the reflector breaks into the kernel-mode debugger when the timeout threshold is exceeded. In the debugger output, you will see several suggestions on how to begin, including links you can click on. For example:
**** Problem detected in UMDF driver "WUDFOsrUsbFx2". !process 0xFFFFE0000495B080 0x1f, !devstack 0xFFFFE000032BFA10, Problem code 3 **** **** Dump UMDF driver image name and stack: !wdfkd.wdfumdevstack 0x000000BEBB49AE20 **** Dump UM Irps for this stack: !wdfkd.wdfumirps 0x000000BEBB49AE20 **** Dump UMDF trace log: !wmitrace.logdump WUDFTrace **** Helpful UMDF debugger extension commands: !wdfkd.wdfhelp **** Note that driver host process may get terminated if you go past this break, making it difficult to debug the problem!
Use !analyze to display information about the failure, and additional UMDF extension commands you can try.
Use !process 0 0x1f wudfhost.exe to list all Wudfhost.exe driver host processes, including thread stack information.
You can also use !wdfkd.wdfldr to display all drivers that are currently bound to WDF. When you click on the image name of a UMDF driver, the debugger displays the address of the hosting process. You can then click on the process address to display information specific to that process.
If necessary, use .process /r /p *Process* to switch process context to that of the Wudfhost process that is hosting your driver. Use .cache forcedecodeuser and lmu to verify that your driver is hosted in the current process.
- Examine thread call stacks (!thread *Address*) to determine if a driver callback timed out. Look at the tick count for the threads. In Windows 8.1, the reflector times out after one minute.
- Use !wdfkd.wdfdriverinfo MyDriver.dll 0x10 to display the device tree in verbose form. Then click on !wdfdevice. This command displays detailed power, power policy, and Plug and Play (PnP) state information.
- Use !wdfkd.wdfumirps to look for pending IRPs.
- Use !wdfkd.wdfdevicequeues to check the status of the driver's queues.
- In a kernel-mode debugging session, you can use !wmitrace.logdump WudfTrace to display the trace log.
In a kernel-mode debugging session, you can use the !wdfkd.wdflogdump extension command to display the Windows Driver Frameworks (WDF) In-flight Recorder (IFR) log records, if available.
Finding Memory Dump Files
See Determining Why the Reflector Terminated the Host Process for information on finding user-mode dump files. See Using WPP Software Tracing in UMDF Drivers for information on how to set the LogMinidumpType registry value to specify the type of information stored in the minidump file.