Re: x86 architecture questions

From: David A. Caabeiro (me_at_privacy.net)
Date: 03/26/04 

Date: Fri, 26 Mar 2004 18:26:33 +0000 (UTC)

> The best way is if the kernel does not
> even reveal any of its code to the target (user) processes. Each
> run in their own virtual space. There is no "key" to protected space
> required, because such space is not mapped in common to user space
> unless the kernel wants that.

Latest SPARC uses something like this, which is exploited by Solaris..
Other plus is giving user processes the whole address space..
Unfortunately, current intel chips make this difficult (from performance
point of view)

> Whats really odd is (to my understanding) Windows uses do-it-yourself
> TSS and Linux uses the hardware supported TSS. You would think it
> would be the opposite.

Linux dropped support for TSS task switching, in favor of software based
approach (IIRC, this was since 2.4 kernel)

Regards,
David.-

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