Functionality of CSRSS.exe

Hi
I am trying to understand functionality of csrss.exe in windows.
In undocumented NT book:
“The DLLs USER32 and GDI32 contain stubs, which pass the function parameters
to the Win32 subsystem (CSRSS.EXE) and get the results back. The
communication between the client application and the Win32 subsystem is
achieved by using the local procedure call facility provided by the NT
executive.”
1-) Does csrss communicate user32 and gdi32 with win32k.sys?Is this mean
LPC?
2-) Or Lpc and csrss have different meaning or Lpc using instead of csrss?

Can you please explain me functionality of csrss.exe.
Thanks.

The Windows subsystem and the LPC mechanism have been documented pretty well
in Microsoft Windows Internals, Fourth Edition: Microsoft Windows Server™
2003, Windows XP, and Windows 2000. You may want to pick up a copy, it’s
very informative.

If you need more depth than what this book provides, I’d recommend a live
kernel debugging session.

From: serimc
>Reply-To: “Windows System Software Devs Interest List”
>
>To: “Windows System Software Devs Interest List”
>Subject: [ntdev] Functionality of CSRSS.exe
>Date: Sun, 24 Dec 2006 16:02:43 +0200
>
>Hi
>I am trying to understand functionality of csrss.exe in windows.
>In undocumented NT book:
>“The DLLs USER32 and GDI32 contain stubs, which pass the function
>parameters
>to the Win32 subsystem (CSRSS.EXE) and get the results back. The
>communication between the client application and the Win32 subsystem is
>achieved by using the local procedure call facility provided by the NT
>executive.”
>1-) Does csrss communicate user32 and gdi32 with win32k.sys?Is this mean
>LPC?
>2-) Or Lpc and csrss have different meaning or Lpc using instead of csrss?
>
>Can you please explain me functionality of csrss.exe.
>Thanks.
>
>—
>Questions? First check the Kernel Driver FAQ at
>http://www.osronline.com/article.cfm?id=256
>
>To unsubscribe, visit the List Server section of OSR Online at
>http://www.osronline.com/page.cfm?name=ListServer

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On Sun, Dec 24, 2006 at 04:02:43PM +0200, serimc wrote:

I am trying to understand functionality of csrss.exe in windows.
In undocumented NT book:
“The DLLs USER32 and GDI32 contain stubs, which pass the function parameters
to the Win32 subsystem (CSRSS.EXE) and get the results back. The
communication between the client application and the Win32 subsystem is
achieved by using the local procedure call facility provided by the NT
executive.”
1-) Does csrss communicate user32 and gdi32 with win32k.sys?Is this mean
LPC?
2-) Or Lpc and csrss have different meaning or Lpc using instead of csrss?

CSRSS handled the Win32 subsystem in Windows NT 3.x. In NT 4.0, that
functionality moved to the kernel in WIN32K.SYS, where it remains today.
CSRSS is no longer involved with GDI and USER calls.

Tim Roberts, xxxxx@probo.com
Providenza & Boeklheide, Inc.

> "The DLLs USER32 and GDI32 contain stubs, which pass the function

parameters
to the Win32 subsystem (CSRSS.EXE) and get the results back. The
communication between the client application and the Win32 subsystem is
achieved by using the local procedure call facility provided by the NT
executive."
1-) Does csrss communicate user32 and gdi32 with win32k.sys?Is this mean
LPC?
2-) Or Lpc and csrss have different meaning or Lpc using instead of csrss?

This is long ago obsolete, in NT4 already.

Since NT4, USER32 and GDI32 contain the syscalls to win32k.sys in the kernel.

CSRSS only remains for console window support.


Maxim Shatskih, Windows DDK MVP
StorageCraft Corporation
xxxxx@storagecraft.com
http://www.storagecraft.com

Hmm.
Ok.Thanks for answers.

Be aware that Max’s comment about “obsolete” was true when the book came
out, and is true about the book. Get the “Windows Internals” book by
Russinovich and Solomon and the “Windows NT/2000 Native API Reference” by
Nebbett and throw out the undocumented windows book, it is junk.


Don Burn (MVP, Windows DDK)
Windows 2k/XP/2k3 Filesystem and Driver Consulting
http://www.windrvr.com
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“serimc” wrote in message news:xxxxx@ntdev…
> Hmm.
> Ok.Thanks for answers.
>