Comment Feed for Channel 9 - Daniel Pearson: Debugging a Windows Blue Screen of Death

Re: Daniel Pearson: Debugging a Windows Blue Screen of Death

Chadk — Wed, 16 Jul 2008 21:02:21 GMT

This is awesome. I would love to see much more like this.

It was interesting how to see how you could find information from the memory dump.

posted by Chadk

Re: Daniel Pearson: Debugging a Windows Blue Screen of Death

stevo_ — Wed, 16 Jul 2008 22:08:33 GMT

I was just wondering today, what would happen if the 'code' that handles the bsod.. crashed? like, what if my processor was on last legs and caused an execution fault?

Let me guess, something really boring like everything going blank, or my computer restarting (or not)?

posted by stevo_

Re: Daniel Pearson: Debugging a Windows Blue Screen of Death

Charles — Wed, 16 Jul 2008 22:14:00 GMT

I've had something like this happen to my machine twice in the last two days. There's some sort of kernel crash that causes the system to reboot - with no telemetry whatsoever. Certainly a critical system failure, but the system is unable to record any data before restarting.

C

posted by Charles

Re: Daniel Pearson: Debugging a Windows Blue Screen of Death

PerfectPhase — Wed, 16 Jul 2008 23:16:50 GMT

If this sort of thing is of intreast to you, this is a must see Sysinternals Video Library

posted by PerfectPhase

Re: Daniel Pearson: Debugging a Windows Blue Screen of Death

karnokd — Thu, 17 Jul 2008 09:21:33 GMT

Nice video. However, I never understood why there aren't any minidump created in case the swap file is moved to a differend partition/hard disk in WinXP? (In my case, I play 3D games and the videocard driver sometimes crashes my system and I cannot hope to send that crash dump to its manufacturer.)

posted by karnokd

Re: Daniel Pearson: Debugging a Windows Blue Screen of Death

tomkirbygreen — Thu, 17 Jul 2008 09:45:28 GMT

Hardcore! Nice to see some close to the metal stuff in with all the managed goodness. Helps keep us honest as developers

posted by tomkirbygreen

Re: Daniel Pearson: Debugging a Windows Blue Screen of Death

stevo_ — Thu, 17 Jul 2008 18:49:59 GMT

That doesn't sound good charles .. I was interested because.. if theres no one "there" ie, the kernel itself doing its bugcheck code has crashed out due to a hardware fault.. does my system just sit there... I assume I'd still have display because the gpu would just be outputting the last buffer it was given?

But I've watched the video now, really cool, loved the idea of trapping a driver by putting it on a "known offenders" list, and luring into doing something it will get caught red handed for..

posted by stevo_

Re: Daniel Pearson: Debugging a Windows Blue Screen of Death

littleguru — Fri, 18 Jul 2008 12:17:54 GMT

Probably you get a freeze. A complete halt with the most current video buffer re-drawn over and over again.

posted by littleguru

Re: Daniel Pearson: Debugging a Windows Blue Screen of Death

Charles — Fri, 18 Jul 2008 18:08:26 GMT

Unhandled exceptions in kernel mode lead to reboot by policy (or if you're lucky a bluescreen with data capture for debugging purposes). Anytime something goes wrong in kernel world the system must commit temporary suicide (or start the reincarnation process, to be more positive in tone ). There's too much weird and invalid state to deal with when this happens and typically and it's not worth it (the insuing instability and total strangeness that user mode gets to experience as a result)...

This keeps happening on my machine and there's no way for me to debug given that no data on the fault is preserved (or even captured). Clearly, it's a device driver malfunction. I suspect it's a driver that's not Vista Ready...

What's one to do in this case, Daniel?
C

posted by Charles

Re: Daniel Pearson: Debugging a Windows Blue Screen of Death

ZXTT95 — Fri, 18 Jul 2008 20:41:18 GMT

karnokd:

It's simple really - boot device drivers have special requirements, which lead to the ability to save crash dumps.

A storage driver written any old way won't be able to do this. Windows loads an extra copy of the boot driver, kernel crash dump writing code, plus a bitmap of the page file on the boot drive, then checksums the lot. At blue screen time, the checksum is verified and if good, the crash dump is written directly to the sectors known to be used by the page file on the boot drive.

posted by ZXTT95

Re: Daniel Pearson: Debugging a Windows Blue Screen of Death

ZXTT95 — Fri, 18 Jul 2008 20:49:02 GMT

Can you save crash dumps in other cases? Make sure your page file on the boot drive (the one with the Windows directory) is large enough to save the kind of dump you've selected and turn off "Automatically restart" so you can see the blue screen (including the bugcheck code and parameters) and the results of the attempt to save the crash dump.

Then download notmyfault from here: http://technet.microsoft.com/en-us/sysinternals/bb963901.aspx

Use notmyfault to crash your system and verify that crash dumps can be saved.

posted by ZXTT95

Re: Daniel Pearson: Debugging a Windows Blue Screen of Death

Mark Russinovich — Fri, 18 Jul 2008 23:18:24 GMT

Daniel's video nicely complements a talk I've delivered on crash and hang analysis at various conferences. You can check out the on-demand web cast from TechEd a couple years ago here:

TechEd On-Demand Webcast: Windows Hang and Crash Dump Analysis

I answer some of the questions raised here in the comments, like how to debug a frozen system and why a dump file requires a paging file on the boot volum (the one with \Windows).

posted by Mark Russinovich

Re: Daniel Pearson: Debugging a Windows Blue Screen of Death

Daniel Pearson — Sat, 19 Jul 2008 12:17:35 GMT

Unfortunately your only real option is to attach a kernel debugger to the system and wait for it to crash again. If it's only just started happening and is rather frequent then I would suspect some sort of hardware error but get a debugger attached and we'll get some answers.

posted by Daniel Pearson

Re: Daniel Pearson: Debugging a Windows Blue Screen of Death

Daniel Pearson — Sat, 19 Jul 2008 12:34:29 GMT

Mark's video goes into more deal about the requirements for a successful dump but at a bare minimum you should create a 16 MB paging file on the same partition that Windows is installed and set the system to perform a small memory dump. That way once you triage the minidumps, you'll be able to determine if it's the same problem causing all of the bugchecks or if another action plan needs to be followed.

If you find it's your display driver causing the problem and it's not something the vendor has seen before, it's possible you'll need to provide them with a kernel memory dump. In that case you'll need to increase the size of the paging file on your boot partition and switch your options to kernel memory dump.

posted by Daniel Pearson

Re: Daniel Pearson: Debugging a Windows Blue Screen of Death

jasone — Sat, 09 Aug 2008 00:14:05 GMT

If you like debugging, check out http://blogs.msdn.com/ntdebugging/.

posted by jasone

Re: Daniel Pearson: Debugging a Windows Blue Screen of Death

jasone — Sat, 09 Aug 2008 00:14:34 GMT

If you like debugging, see http://blogs.msdn.com/ntdebugging/

posted by jasone