Yes, I did know from Nagar’s book that using ObReferenceObjectByHandle, I
should be able to get the pointer to object which should be context
independent. Or I can use ObOpenObjectByPointer if I need a
context-independent handle.
I have not used both calls to see how they work though. Let’s see if I can
avoid them 
Jack
-----Original Message-----
From: Smith, Joel [SMTP:xxxxx@ntpsoftware.com]
Sent: Wednesday, March 01, 2000 1:42 PM
To: File Systems Developers Interest List
Subject: [ntfsd] RE: How to access named kernel object created by
use r mo de applicati on in kernel driver?Cool - sounds like a good approach, given that you’ll have many
user mode clients of these synch objects.As you probably know (I’m probably misinterpreting your last
paragraph) you would be able to use the synch objects from contexts other
than you user mode app (i.e. system process, other user mode processes) in
you device driver code (through kernel pointer to the dispatch objects).-Joel
Thanx, I may wind up in this route in the end. However, the reason that I
really want to use name is that the Filter driver is not the only client
of
these named kernel objects. There is also COM object that talk to this
user
mode application that create these kernel objects.Also the context that the filter driver access these kernel objects is
different from the user mode application. It will be preferrable if I can
access them by name.Jack
> -----Original Message-----
> From:Smith, Joel [SMTP:xxxxx@ntpsoftware.com]
> Sent:Wednesday, March 01, 2000 8:31 AM
> To: File Systems Developers Interest List
> Subject: [ntfsd] RE: How to access named kernel object created by
> user mo de applicati on in kernel driver?
>
> You could just pass the handles of the dispatch objects to the
> kernel mode driver from the user mode application via some IRP you
define.
> You will be in the same context as the user mode app, so the handles
will
> be valid. You could then reference the synch objects handles with
> ObReferenceObjectByHandle, hold onto there pointers in the driver, and
use
> the dispatch objects with normal kernel mode synchronization calls.
>
>
> Hi all,
>
> I have a user mode application that uses the SWMRG(single writer
multiple
> readers guard) as implemented in chap 10 of Advanced windows to protect
a
> named memory mapped file.
>
> In the kernel mode file filter driver, I need to access the memory
mapped
> file. In ZwOpenSection, we can pass an ObjectAttributes that
encapsulates
> the name. However, I did not know how to do that for Mutex, Event &
> Semaphore kernel objects.
>
> Any idea ?
>
> Thanks,
>
>
> Jack(Wei-Chi) Cheng
> Lexis-Nexis DCE Support Team
> email: xxxxx@lexis-nexis.com
> phone: 937-8656800 x 4028
>
>
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