Linked by Thom Holwerda on Fri 10th Aug 2007 20:46 UTC, submitted by SReilly
Privacy, Security, Encryption An unpatched flaw in an ATI driver was at the center of the mysterious Purple Pill proof-of-concept tool that exposed a way to maliciously tamper with the Vista kernel. Purple Pill, a utility released by Alex Ionescu [yes, that Ionescu] and yanked an hour later after the kernel developer realized that the ATI driver flaw was not yet patched, provided an easy way to load unsigned drivers onto Vista - effectively defeating the new anti-rootkit/anti-DRM mechanism built into Microsoft's newest operating system.
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RE[6]: Microkernels
by Morin on Mon 13th Aug 2007 11:38 UTC in reply to "RE[5]: Microkernels"
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About the completely event-based OS: You would still want to isolate work into different "processes" such that bugs or malicious code won't hose the whole system (except for systems in which you can exclude both, but that would only be possible in embedded devices or similar custom systems). That means you get one event handler thread per process. Then some processes would want to do background work - this can be done on an event basis, but this is usually hard to implement since you'd fiddle around with events just to re-create the concept of a background thread. Soon you're back to the old model.

Singularity and JNode wil bring an interesting twist to the whole scene since they don't require context switches at all. But even JNode (don't know about singularity) is all the old model when it comes to concurrency and the likes. Making it completely event-based would bring up other questions, such as: what if an event handler locks up? May another handler be run concurrently, and if so, what about synch locks?

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RE[7]: Microkernels
by baadger on Mon 13th Aug 2007 16:05 in reply to "RE[6]: Microkernels"
baadger Member since:

> Singularity and JNode wil bring an interesting twist to the whole scene since they don't require context
> switches at all

That isn't quite right. From what I understand Singularity does away with virtual memory (Relying on code verification techniques and managed code to keep things tight) but doesn't regress away preemptive multitasking or get rid of the concept of a context switch.

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