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Hidden Debug Mode Found In AMD Processors
An anonymous reader writes "A hidden (and hardware password protected, by means of required special values in processor registers) debug mode has been found in AMD processors, and documented by a reverse engineer called Czernobyl on the RCE Forums community today. It enables powerful hardware debugging features long longed for by reverse engineers, such as hardware data-aware conditional breakpoints, and direct hardware 'page guard'-style breakpoints. And the best part is, it's sitting right there in your processor already, just read the details and off you go with the debugging ninja powers!"
Someone will find something similar in Intel chips as well.
Maybe Computers will never be as intelligent as Humans.
For sure they won't ever become so stupid. [VR-1988]
They did.
It's all documented there in the silicon.
It's not their fault you didn't read it.
Or that you don't have the tools necessary to read it.
Or that you're not intelligent enough to read it.
But once they document it in, e.g. human readable form, then they might be afraid that they'd have to support it in this and all future generations of their chips. Perhaps they don't want to be constrained to always supporting those particular features going forward.
It seems that the discovered functionality is about extending standard hardware watch feature with ability to match actual data being accessed, not only address.
It appears the site is now down so the details of the story aren't readily available. This has some major implications for those concerned about security as mentioned by many of the above. AMD is going to have to address this because they need to close that off or it could spell major trouble for AMD as a company and a vast majority of users.
don't they reveal this to the users?
Probably because then they'd have to fully document the features and test them thoroughly on each new chip, which would likely cost them quite a bit more than developing the features in the first place.
They would also be saddled with supporting backwards compatibility in future chips, since it becomes hard to remove publicly-accessible features in a CPU once they've been added.