MDL system space access.

NTFSD
1

Hi All,

I need a clarification regarding MDL buffer. I am calling,

datap = MmGetSystemAddressForMdl(pIrp->MdlAddress);

in the context of calling process. Can I use the system virtual address
(“datap”) in a different kernel thread context.

If I cannot use, please suggest me better way to get virtual address of MDL
data buffer in the context of different kernel thread.

Regards,
Prasanna Kumar V V.

2

What you get is an address into the system space, so it is safe to be used
into an arbitrary context.

----- Original Message -----
From: “Prasanna B R”
To: “File Systems Developers”
Cc: “Prasanna Kumar V V (E-mail)”
Sent: Thursday, June 27, 2002 2:12 PM
Subject: [ntfsd] MDL system space access.

> Hi All,
>
> I need a clarification regarding MDL buffer. I am calling,
>
> datap = MmGetSystemAddressForMdl(pIrp->MdlAddress);
>
> in the context of calling process. Can I use the system virtual address
> (“datap”) in a different kernel thread context.
>
> If I cannot use, please suggest me better way to get virtual address of
MDL
> data buffer in the context of different kernel thread.
>
> Regards,
> Prasanna Kumar V V.
>
>
> —
> You are currently subscribed to ntfsd as: xxxxx@rdsor.ro
> To unsubscribe send a blank email to %%email.unsub%%
>

3

> in the context of calling process. Can I use the system virtual
address

(“datap”) in a different kernel thread context.

Yes. Even in ISRs. In any kmode code in fact.

Max