keyboard filter

NTDEV
1

Hi,
I am new to device driver development.I was trying to load the DDK sample kbfltr.I included some DbgPrint messages in SERVICE CALL BACK ROUTINE.But my system started restarting…Whats the issue??

2

xxxxx@lantana.tenet.res.in wrote:

Hi,
I am new to device driver development.I was trying to load the DDK sample kbfltr.I included some DbgPrint messages in SERVICE CALL BACK ROUTINE.But my system started restarting…Whats the issue??

The issue is that you need to hook up a kernel debugger to figure out
what you did wrong.

–
Tim Roberts, xxxxx@probo.com
Providenza & Boekelheide, Inc.

3

First, get the wdk and install the WDF version of kbfiltr. It is a much more complete sample to start with. Second, learn how to connect windbg and debug a kernel mode driver. This way you can debug why the system is restarting. The first thing you will want to do once the machine bugchecks is to run !analyze -v in windbg. Also, it always helps to post the code that you have written.

My random guess is that you are specifying strings in your DbgPrint format string (e.g. “this %s got called”, “blah”). You cannot use strings in DbgPrint call at IRQL > passive and the service callback runs at dispatch level.

Now with that all said, why do you think you need a keyboard filter? What is your end goal?

d

-----Original Message-----
From: xxxxx@lists.osr.com [mailto:xxxxx@lists.osr.com] On Behalf Of xxxxx@lantana.tenet.res.in
Sent: Thursday, October 23, 2008 10:05 AM
To: Windows System Software Devs Interest List
Subject: [ntdev] keyboard filter

Hi,
I am new to device driver development.I was trying to load the DDK sample kbfltr.I included some DbgPrint messages in SERVICE CALL BACK ROUTINE.But my system started restarting…Whats the issue??

NTDEV is sponsored by OSR

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4

Isn’t that only true for UNICODE strings (otherwise <= DIRQL), Doron?

mm

Doron Holan wrote:

First, get the wdk and install the WDF version of kbfiltr. It is a much more complete sample to start with. Second, learn how to connect windbg and debug a kernel mode driver. This way you can debug why the system is restarting. The first thing you will want to do once the machine bugchecks is to run !analyze -v in windbg. Also, it always helps to post the code that you have written.

My random guess is that you are specifying strings in your DbgPrint format string (e.g. “this %s got called”, “blah”). You cannot use strings in DbgPrint call at IRQL > passive and the service callback runs at dispatch level.

Now with that all said, why do you think you need a keyboard filter? What is your end goal?

d

-----Original Message-----
From: xxxxx@lists.osr.com [mailto:xxxxx@lists.osr.com] On Behalf Of xxxxx@lantana.tenet.res.in
Sent: Thursday, October 23, 2008 10:05 AM
To: Windows System Software Devs Interest List
Subject: [ntdev] keyboard filter

Hi,
I am new to device driver development.I was trying to load the DDK sample kbfltr.I included some DbgPrint messages in SERVICE CALL BACK ROUTINE.But my system started restarting…Whats the issue??

NTDEV is sponsored by OSR

For our schedule of WDF, WDM, debugging and other seminars visit:
http://www.osr.com/seminars

To unsubscribe, visit the List Server section of OSR Online at http://www.osronline.com/page.cfm?name=ListServer

5

I think it is. I’d guess OP’s problem are wrong or missing parameters
which don’t correspond with format specification. It is quite easy to
make such a bug. I’m not sure if Prefast can check it; PC-lint can and
it is pretty useful thing.

Best regards,

Michal Vodicka
UPEK, Inc.
[xxxxx@upek.com, http://www.upek.com]

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Martin O’Brien
Sent: Thursday, October 23, 2008 9:18 PM
To: Windows System Software Devs Interest List
Subject: Re:[ntdev] keyboard filter

Isn’t that only true for UNICODE strings (otherwise <= DIRQL), Doron?

mm

Doron Holan wrote:
> First, get the wdk and install the WDF version of kbfiltr.
It is a much more complete sample to start with. Second,
learn how to connect windbg and debug a kernel mode driver.
This way you can debug why the system is restarting. The
first thing you will want to do once the machine bugchecks is
to run !analyze -v in windbg. Also, it always helps to post
the code that you have written.
>
> My random guess is that you are specifying strings in your
DbgPrint format string (e.g. “this %s got called”, “blah”).
You cannot use strings in DbgPrint call at IRQL > passive and
the service callback runs at dispatch level.
>
> Now with that all said, why do you think you need a
keyboard filter? What is your end goal?
>
> d
>
> -----Original Message-----
> From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of
xxxxx@lantana.tenet.res.in
> Sent: Thursday, October 23, 2008 10:05 AM
> To: Windows System Software Devs Interest List
> Subject: [ntdev] keyboard filter
>
> Hi,
> I am new to device driver development.I was trying to
load the DDK sample kbfltr.I included some DbgPrint messages
in SERVICE CALL BACK ROUTINE.But my system started
restarting…Whats the issue??
>
>
>
> —
> NTDEV is sponsored by OSR
>
> For our schedule of WDF, WDM, debugging and other seminars visit:
> http://www.osr.com/seminars
>
> To unsubscribe, visit the List Server section of OSR Online
at http://www.osronline.com/page.cfm?name=ListServer
>
>

NTDEV is sponsored by OSR

For our schedule of WDF, WDM, debugging and other seminars visit:
http://www.osr.com/seminars

To unsubscribe, visit the List Server section of OSR Online
at http://www.osronline.com/page.cfm?name=ListServer

6

Hi Ramya,

you can try using kdprint macro as a supplicant to dbgprint / dbgprintex routine.

sainath

7

Hi ,
I am in an educational institute and i have been given an assignment to write a keyboard upper filter driver.
I will try these suggestions and then get back
Thank You.

8

wrote in message news:xxxxx@ntdev…
> Hi ,
> I am in an educational institute and i have been given an assignment to
> write a keyboard upper filter driver.
> I will try these suggestions and then get back
> Thank You.

What your teachers/instructors are paid for? Why they don’t help ?
(sorry but I’m really curious … )

–PA