RE: Reliability of RPC services

[Christopher Nelson]

> On 4/26/06, Jonathan S. Shapiro <address@hidden> wrote:
> > On Wed, 2006-04-26 at 10:00 +0200, Bas Wijnen wrote:
> >
> > > Obviously user-provided drivers cannot be allowed to do that 
> > > directly (but they may do it through calls to the framework).  
> > > However, for user-provided drivers I was thinking about 
> devices that 
> > > the users brings with him.  There it would be the bus 
> driver (usb, 
> > > firewire) which does the DMA calls, and the actual driver 
> just talks to the bus driver.
> >
> > This isn't how things work. The DMA chip isn't generally associated 
> > with the bus. It's generally on the card. USB may be something that 
> > could be handled as a special case.

> Devices connected to [PS]ATA, USB, FireWire, SCSI, parallel, etc.
> ports do not need trusted drivers. 

HUH?  So you have some random individual who want's to stick their own
DISK DRIVER into the system, and you think that it doesn't need to be
trusted?  *ESPECIALLY* in a persistent OS must disk drivers be trusted.
*EVERYTHING* you care about is on the disk, including the contents of
memory at any given time.  Anything that stores data needs to be a
trusted driver.  Otherwise they could read and/or overwrite your data at
any time.  Not to mention corrupting the bus and data integrity.

-={C}=-