!wdfmemory question

WINDBG
1

I was trying to get some information about a WDFMEMORY object and used
the !wdfmemory extension. I passed is the value assigned to reqMemory
from the call WdfRequestRetrieveOutputMemory(Request, &reqMemory). When
I call !wdfmemory I get the following output:

kd> !wdfmemory 7e4fbc51
Matched: f74b04f4 Wdf01000!FxMemoryBuffer::vftable' = <no type>information&gt;<br>Matched: f74b0518 Wdf01000!FxMemoryBuffer::vftable’ = information>
Matched: f74b0c1c Wdf01000!FxMemoryBufferFromPool::vftable' = <no type>information&gt;<br>Matched: f74b0c38 Wdf01000!FxMemoryBufferFromPool::vftable’ = information>
Matched: f74b0bc0 Wdf01000!FxMemoryBufferFromLookaside::vftable' = <no>type information&gt;<br>Matched: f74b0be4 Wdf01000!FxMemoryBufferFromLookaside::vftable’ = type information>
Matched: f74b08d0 Wdf01000!FxMemoryBufferFromPoolLookaside::vftable' =<br><no type information><br>Matched: f74b0c00 Wdf01000!FxMemoryBufferFromPoolLookaside::vftable’ =

Matched: f74b0c38 Wdf01000!FxMemoryBufferPreallocated::vftable' = <no>type information&gt;<br>Matched: f74b098c Wdf01000!FxMemoryBufferPreallocated::vftable’ = type information>
uknown vtable a0000000

This doesn’t seem very helpful and isn’t displaying the buffer address
and length as stated by !wdfhelp. How can I get this information from a
WDFMEMORY object? Also is uknown supposed to be unknown?

Thanks,
- Steve -

2

I will look into it, but IIRC it is busted. The issue at hand is that
WDFMEMORY is really an abstract interface and the only way to figure out
the derived class is to look at the vtable itself. I am guessing that
the vtable info was not shipped as a part of public symbols.

d

– I can spell, I just can’t type.

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Whitman, Steve
Sent: Wednesday, February 22, 2006 9:50 AM
To: Kernel Debugging Interest List
Subject: [windbg] !wdfmemory question

I was trying to get some information about a WDFMEMORY object and used
the !wdfmemory extension. I passed is the value assigned to reqMemory
from the call WdfRequestRetrieveOutputMemory(Request, &reqMemory). When
I call !wdfmemory I get the following output:

kd> !wdfmemory 7e4fbc51
Matched: f74b04f4 Wdf01000!FxMemoryBuffer::vftable' = <no type>information&gt;<br>Matched: f74b0518 Wdf01000!FxMemoryBuffer::vftable’ = information>
Matched: f74b0c1c Wdf01000!FxMemoryBufferFromPool::vftable' = <no type>information&gt;<br>Matched: f74b0c38 Wdf01000!FxMemoryBufferFromPool::vftable’ = information>
Matched: f74b0bc0 Wdf01000!FxMemoryBufferFromLookaside::vftable' = <no>type information&gt;<br>Matched: f74b0be4 Wdf01000!FxMemoryBufferFromLookaside::vftable’ = type information>
Matched: f74b08d0 Wdf01000!FxMemoryBufferFromPoolLookaside::vftable' =<br><no type information><br>Matched: f74b0c00 Wdf01000!FxMemoryBufferFromPoolLookaside::vftable’ =

Matched: f74b0c38 Wdf01000!FxMemoryBufferPreallocated::vftable' = <no>type information&gt;<br>Matched: f74b098c Wdf01000!FxMemoryBufferPreallocated::vftable’ = type information> uknown vtable a0000000

This doesn’t seem very helpful and isn’t displaying the buffer address
and length as stated by !wdfhelp. How can I get this information from a
WDFMEMORY object? Also is uknown supposed to be unknown?

Thanks,
- Steve -

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3

Thanks Doron,

Many of the other !wdf* functions work fine and they have been very
useful. I especially like the fact that many of the outputs contain the
name of the extension command to call on the sub-objects displayed.

So far my foray into WDF has been very positive. The documentation is
still a bit weak and I wish that the build system had been updated to
VS.2005 standards (MSBuild) but overall WDF is getting the job done for
me.

  • Steve -

-----Original Message-----
From: xxxxx@lists.osr.com [mailto:bounce-241005-
xxxxx@lists.osr.com] On Behalf Of Doron Holan
Sent: Wednesday, February 22, 2006 2:08 PM
To: Kernel Debugging Interest List
Subject: RE: [windbg] !wdfmemory question

I will look into it, but IIRC it is busted. The issue at hand is that
WDFMEMORY is really an abstract interface and the only way to figure
out
the derived class is to look at the vtable itself. I am guessing that
the vtable info was not shipped as a part of public symbols.

d

– I can spell, I just can’t type.

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Whitman, Steve
Sent: Wednesday, February 22, 2006 9:50 AM
To: Kernel Debugging Interest List
Subject: [windbg] !wdfmemory question

I was trying to get some information about a WDFMEMORY object and used
the !wdfmemory extension. I passed is the value assigned to reqMemory
from the call WdfRequestRetrieveOutputMemory(Request, &reqMemory).
When
I call !wdfmemory I get the following output:

kd> !wdfmemory 7e4fbc51
Matched: f74b04f4 Wdf01000!FxMemoryBuffer::vftable' = <no type>&gt; information&gt;<br>&gt; Matched: f74b0518 Wdf01000!FxMemoryBuffer::vftable’ = > information>
> Matched: f74b0c1c Wdf01000!FxMemoryBufferFromPool::vftable' = <no>type<br>&gt; information&gt;<br>&gt; Matched: f74b0c38 Wdf01000!FxMemoryBufferFromPool::vftable’ = type
> information>
> Matched: f74b0bc0 Wdf01000!FxMemoryBufferFromLookaside::vftable' =<br><no>&gt; type information&gt;<br>&gt; Matched: f74b0be4 Wdf01000!FxMemoryBufferFromLookaside::vftable’ =
> type information>
> Matched: f74b08d0 Wdf01000!FxMemoryBufferFromPoolLookaside::vftable'<br>=<br>&gt; <no type information><br>&gt; Matched: f74b0c00 Wdf01000!FxMemoryBufferFromPoolLookaside::vftable’
=
>
> Matched: f74b0c38 Wdf01000!FxMemoryBufferPreallocated::vftable' = <no>&gt; type information&gt;<br>&gt; Matched: f74b098c Wdf01000!FxMemoryBufferPreallocated::vftable’ = > type information> uknown vtable a0000000
>
> This doesn’t seem very helpful and isn’t displaying the buffer address
> and length as stated by !wdfhelp. How can I get this information from
a
> WDFMEMORY object? Also is uknown supposed to be unknown?
>
> Thanks,
> - Steve -
>
>
>
> —
> You are currently subscribed to windbg as: unknown lmsubst tag
argument:
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>
>
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4

We are constantly working on the docs, please use the Send Feedback link
to suggest improvements (yes the email does get to real people ;)). We
are hopefully going to have preliminary preview docs on the debugger
extension up on WHDC within a few days.

d

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Whitman, Steve
Sent: Thursday, February 23, 2006 9:36 AM
To: Kernel Debugging Interest List
Subject: RE: [windbg] !wdfmemory question

Thanks Doron,

Many of the other !wdf* functions work fine and they have been very
useful. I especially like the fact that many of the outputs contain the
name of the extension command to call on the sub-objects displayed.

So far my foray into WDF has been very positive. The documentation is
still a bit weak and I wish that the build system had been updated to
VS.2005 standards (MSBuild) but overall WDF is getting the job done for
me.

  • Steve -

-----Original Message-----
From: xxxxx@lists.osr.com [mailto:bounce-241005-
xxxxx@lists.osr.com] On Behalf Of Doron Holan
Sent: Wednesday, February 22, 2006 2:08 PM
To: Kernel Debugging Interest List
Subject: RE: [windbg] !wdfmemory question

I will look into it, but IIRC it is busted. The issue at hand is that
WDFMEMORY is really an abstract interface and the only way to figure
out
the derived class is to look at the vtable itself. I am guessing that
the vtable info was not shipped as a part of public symbols.

d

– I can spell, I just can’t type.

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Whitman, Steve
Sent: Wednesday, February 22, 2006 9:50 AM
To: Kernel Debugging Interest List
Subject: [windbg] !wdfmemory question

I was trying to get some information about a WDFMEMORY object and used
the !wdfmemory extension. I passed is the value assigned to reqMemory
from the call WdfRequestRetrieveOutputMemory(Request, &reqMemory).
When
I call !wdfmemory I get the following output:

kd> !wdfmemory 7e4fbc51
Matched: f74b04f4 Wdf01000!FxMemoryBuffer::vftable' = <no type>&gt; information&gt;<br>&gt; Matched: f74b0518 Wdf01000!FxMemoryBuffer::vftable’ = > information>
> Matched: f74b0c1c Wdf01000!FxMemoryBufferFromPool::vftable' = <no>type<br>&gt; information&gt;<br>&gt; Matched: f74b0c38 Wdf01000!FxMemoryBufferFromPool::vftable’ = type
> information>
> Matched: f74b0bc0 Wdf01000!FxMemoryBufferFromLookaside::vftable' =<br><no>&gt; type information&gt;<br>&gt; Matched: f74b0be4 Wdf01000!FxMemoryBufferFromLookaside::vftable’ =
> type information>
> Matched: f74b08d0 Wdf01000!FxMemoryBufferFromPoolLookaside::vftable'<br>=<br>&gt; <no type information><br>&gt; Matched: f74b0c00 Wdf01000!FxMemoryBufferFromPoolLookaside::vftable’
=
>
> Matched: f74b0c38 Wdf01000!FxMemoryBufferPreallocated::vftable' = <no>&gt; type information&gt;<br>&gt; Matched: f74b098c Wdf01000!FxMemoryBufferPreallocated::vftable’ = > type information> uknown vtable a0000000
>
> This doesn’t seem very helpful and isn’t displaying the buffer address
> and length as stated by !wdfhelp. How can I get this information from
a
> WDFMEMORY object? Also is uknown supposed to be unknown?
>
> Thanks,
> - Steve -
>
>
>
> —
> You are currently subscribed to windbg as: unknown lmsubst tag
argument:
> ‘’
> To unsubscribe send a blank email to xxxxx@lists.osr.com
>
>
> —
> You are currently subscribed to windbg as: unknown lmsubst tag
argument:
> ‘’
> To unsubscribe send a blank email to xxxxx@lists.osr.com

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