[Simon]

Yes, I'm serious about this. I'd like to know a simple way to induce a KP with software.

I remember there was a shell command in 10.2 that would cause a KP, but it was fixed in 10.3 IIRC. Does anybody know of such a command or an app that would allow me to induce KPs on a CD MB?

And before you post something like "<gasp>Why??? ", here's the deal. I'm trying to understand an issue with an iSight of one of our MBs here. Its iSight stops working every once in a while and all software repair attempts have failed. AHT reports no errors though. Interestingly enough we noticed the iSight started working again after a KP. We would like to reproduce this to see if it was just a coincidence.

[Madrag]

try this Month of Kernel Bugs (MoKB): Mac OS X Apple UDIF Disk Image Kernel Memory Corruption (1)
Download the .dmg file and mount it, you should experience a nice KP.

but I'm not sure that's the right way to sort your problem...

[Simon]

Unfortunately that didn't work.

One of the links was dead. The other one worked, but it didn't cause a KP.

[Madrag]

sorry about that, I didn't test it because I value my uptime
I'll give you another way today.

[TETENAL]

Boot from an external hard disk and then pull its plug.

[Big Mac]

Originally Posted by TETENAL 

Boot from an external hard disk and then pull its plug.

Ouch.

[Chuckit]

It would probably have to be the same kind of kernel panic. They all look the same, but the underlying events might be completely different.

[peeb]

Yeah - I can't recommend this as a diagnostic method. Many different things could cause a KP.

[kick52]

open up the computer, and hit unimportant parts with a hammer.

perhaps you could erase some virtual memory files while it is doing stuff?

[Simon]

Originally Posted by Chuckit 

It would probably have to be the same kind of kernel panic. They all look the same, but the underlying events might be completely different.

Definitely. But only once it's been demonstrated will the user know that a KP is not going to fix his iSight.

[Simon]

Originally Posted by kick52 

open up the computer, and hit unimportant parts with a hammer.

How witty! Is that your way of telling us you have no clue as to how to induce a KP?

perhaps you could erase some virtual memory files while it is doing stuff?

Now that's better! But have you actually tried that? You can delete the swap files and your Mac will still run. The thing is the files aren't actually deleted even though they appear to be gone. The OS is smart enough to not allow you to really remove the files.

cd /private/var/vm
ls -al
-rw------T 1 root wheel 67108864 Jan 3 10:13 swapfile0

It's all about that "T" up there - the sticky bit.

[Judge_Fire]

How about modifying a .kext file with gibberish?

Or would that just KP at startup, hmm? I was thinking something along the lines of a corrupt extension/driver that could by loaded by, for example, plugging in a related device or launching a piece of software that attempts to communicate with it.

(Conincidentally, I'm just sitting at a Mac I'm going to wipe clean in a few hours, so maybe I'll give this a shot after the backups are all done )

[Chuckit]

Just write a kernel extension that tries to divide by zero or memset NULL or something.

[CharlesS]

Moving a kernel extension out of Extensions while leaving it in the extensions cache and then rebooting used to do it for me.

Note that if you do this, you'll need to use single-user mode to fix it.

[proton]

Apple has a kernel extension to do this published here: http://developer.apple.com/technotes/tn2004/tn2118.html (at the bottom in the Downloadables section).

There's one problem though, it's PowerPC only. So if you head here: http://www.allocinit.net/files/InstantPanic.zip you'll be able to grab a version I updated with the latest Xcode and built as Intel native for you.

You should be able to use kextload (as root) to load this extension and get an immediate kernel panic.

- proton

[Madrag]

great find Proton!
Has anyone tested it with success?

[Simon]

Originally Posted by proton 

You should be able to use kextload (as root) to load this extension and get an immediate kernel panic.

That's looking like a real winner, proton. Unfortunately I wasn't able to load the kext.

sudo kextload ~/Desktop/InstantPanic/InstantPanic.kext
Password:
kextload: extension /Users/simon/Desktop/InstantPanic/InstantPanic.kext is not authentic (check ownership and permissions)



Any ideas what's going wrong there? I tried it as belonging to me and as root:admin. No dice. It's got 755 permissions so I guess that should be ok too.

[Chuckit]

I believe it's supposed to be owned by root:wheel.

[Simon]

Originally Posted by Chuckit 

I believe it's supposed to be owned by root:wheel.

Tried that too. Still no dice.