windbg will not break in on hung system(kernel debugging)

The Justin Patterson

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Nov 11, 2009, 2:49:25 PM11/11/09

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I have a target system that is consistently hanging. After the hang I
get no response at all, I can't ping it, the NUM LOCK and CAPS LOCK
keys do not toggle the associated lights on the keyboard.

I am currently attached to the system using kernel mode debugging over
rs232. When the system hangs I am not able to break the debugger. Is
there another way for me investigate this hang?

Thanks,
Justin

David Craig

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Nov 11, 2009, 7:37:25 PM11/11/09

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Sure. An ICE should help. A PCIe bus analyzer may help if your device is a
card. If it is a software driver, try a code review.

"The Justin Patterson" <justinp...@gmail.com> wrote in message
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The Justin Patterson

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Nov 11, 2009, 10:48:15 PM11/11/09

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On Nov 11, 6:37 pm, "David Craig" <driv...@nospam.nospam> wrote:
> Sure. An ICE should help. A PCIe bus analyzer may help if your device is a
> card. If it is a software driver, try a code review.
>

> "The Justin Patterson" <justinpatter...@gmail.com> wrote in messagenews:5ca1b697-b099-4fc1...@v25g2000yqk.googlegroups.com...

>
>
>
> >I have a target system that is consistently hanging. After the hang I
> > get no response at all, I can't ping it, the NUM LOCK and CAPS LOCK
> > keys do not toggle the associated lights on the keyboard.
>
> > I am currently attached to the system using kernel mode debugging over
> > rs232. When the system hangs I am not able to break the debugger. Is
> > there another way for me investigate this hang?
>
> > Thanks,
> > Justin

All of our code is user mode. No drivers no hardware. can usermode
code even cause this kind of system hang?

David Craig

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Nov 11, 2009, 11:46:58 PM11/11/09

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It takes real skill to do it from usermode. Is your windbg connected via
serial, 1394a, or USB? Try running your application under Visual Studio and
see if it will catch the problem.

"The Justin Patterson" <justinp...@gmail.com> wrote in message

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The Justin Patterson

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Nov 12, 2009, 11:16:29 AM11/12/09

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David,

I am using a serial connection for kernel debugging. I have enabled
the crash on CTRL-Scroll Lock-Scroll Lock which does not work once the
system hangs (I verified that this does work while the system is OK).
My companies software is a suite of applications, not just one. This
issue is only happening on a specific set of hardware and only after
upgrading to Windows XP (It was 2000 until about a year ago). All
drivers have been updated.I have also setup a box without the software
running to see if it is just windows itself not meshing well with the
current hardware.

Thanks for your help!

On Nov 11, 10:46 pm, "David Craig" <driv...@nospam.nospam> wrote:
> It takes real skill to do it from usermode. Is your windbg connected via
> serial, 1394a, or USB? Try running your application under Visual Studio and
> see if it will catch the problem.
>

> "The Justin Patterson" <justinpatter...@gmail.com> wrote in messagenews:35d584b5-7bbf-47e4...@e23g2000yqd.googlegroups.com...

Giggle

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Nov 14, 2009, 11:03:51 AM11/14/09

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It seems that the CPU is running a higher IRQL than i8042prt needs, so
that you can't make the system crash by pressing the keys.
Have you enabled your system in debug mode? You need to modify the
boot config to enable it.

On Nov 13, 12:16 am, The Justin Patterson <justinpatter...@gmail.com>
wrote:

Pavel A.

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Nov 14, 2009, 4:17:25 PM11/14/09

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Do you have a PS/2 keyboard? The CTRL-Scroll Lock trick does not work on USB
keyboards.
Also, try a RAM test:
http://oca.microsoft.com/en/windiag.asp

--pa

"The Justin Patterson" <justinp...@gmail.com> wrote in message

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David Craig

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Nov 14, 2009, 5:03:31 PM11/14/09

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The Ctrl-Scroll Lock trick does work on USB keyboards with specific versions
of Windows. There is an article at Microsoft that shows the different setup
steps for both PS/2 and USB keyboards.

"Pavel A." <pav...@12fastmail34.fm> wrote in message
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Pavel A.

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Nov 14, 2009, 5:43:07 PM11/14/09

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David,

The OP wrote that they have XP. For USB, this works starting from win2003.

http://msdn.microsoft.com/en-us/library/cc266483.aspx

Regards,
--pa

"David Craig" <dri...@nospam.nospam> wrote in message
news:OTq6OZXZ...@TK2MSFTNGP02.phx.gbl...

The Justin Patterson

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Nov 16, 2009, 12:30:29 PM11/16/09

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@Giggle - I have enabled the system in debug mode, and I am able to
break in before the hang.

@Pavel A. - I am using a PS/2 keyboard and I am using windows XP.The
CrashOnCtrlScroll does work before the system hangs. I ran multiple
passes of the memory tests with no errors.

This hang is occurring on multiple machines, just all having the same
hardware.

I am downloading the Checked build of XP now, hopefully this will shed
some light on the issue.

Thanks for your help.

On Nov 14, 4:43 pm, "Pavel A." <pave...@12fastmail34.fm> wrote:
> David,
>
> The OP wrote that they have XP. For USB, this works starting from win2003.
>
> http://msdn.microsoft.com/en-us/library/cc266483.aspx
>
> Regards,
> --pa
>

> "David Craig" <driv...@nospam.nospam> wrote in message

>
> news:OTq6OZXZ...@TK2MSFTNGP02.phx.gbl...
>
>
>
> > The Ctrl-Scroll Lock trick does work on USB keyboards with specific
> > versions of Windows. There is an article at Microsoft that shows the
> > different setup steps for both PS/2 and USB keyboards.
>

> > "Pavel A." <pave...@12fastmail34.fm> wrote in message

> >news:30759265-B4F3-4467...@microsoft.com...
> >> Do you have a PS/2 keyboard? The CTRL-Scroll Lock trick does not work on
> >> USB keyboards.
> >> Also, try a RAM test:
> >>http://oca.microsoft.com/en/windiag.asp
>
> >> --pa
>

> >> "The Justin Patterson" <justinpatter...@gmail.com> wrote in message