Re: Rep:Re: [f-cpu] TLB right + resume

[Michael Riepe <michael@stud.uni-hannover.de>]

On Mon, Aug 19, 2002 at 09:11:59AM +0000, Nicolas Boulay wrote:
[...]
> >>> You can't prevent the mistake of all the future use of the F-cpu !
> Beleiving that the hardware will do all the job for you is a dream of
> progammer, but not a reality ! HW+SW are design to realise a task, the
> faster, the cheeper, the more flexible way they can. The RICS adventure
> said to use more the SW and speed up dumb thing in the HW and do the
> clever thing in SW. 

Since we're building a processor for general use, we must provide a
reasonable amount of functionality. Paging and fine-grained page level
protection *is* reasonable, IMHO.

[...]
> >>> I try to resume what we want to avoid :
> 1- give kernel page to kernel function call to access kernel page from
> user process.
> 2- execute user code in kernel mode 
> 3- execute librairy call to execute excve with /bin/sh to have a shell
> access.

That's a SW problem.

> 4- diseable any possiblity of buffer overflow.

Dto.

> 5- Protect part of the kernel (driver) from it-self

That's what you need fine-grained access rights for.

-- 
 Michael "Tired" Riepe <Michael.Riepe@stud.uni-hannover.de>
 "All I wanna do is have a little fun before I die"
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