lkml.org 
[lkml]   [1998]   [Feb]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: ANNOUNCE: /dev/bios - flash rom bios driver
Hi John,
if we would try to formulate requirements for the "flash rom bios
driver", then along with functional requirements, due to the possible
danger to the given computer, there will be some safety requirements as
well. One of the typical rules for the safety critical designs states
that no one single fault should be able to trigger safety critical
failure. However, in our case, the protection based on more then one
special dev does not satisfy given rule, because it would be very
simple to combine operations on those driver into one single operation.
However, if we would require that such driver will be allowed to run
only under special conditions, i.e. "single user mode", "flash_rom_bios
mode", or when special command line was entered during boot process,
then probability of occurrence will be reduced down to "weird" and
"intentional" cases.

Ark


John Labovitz wrote:
>
> > What does it change? How an additional dev adds more protection, and
> > from what?
>
> having something like /dev/biosguard that you have to open for writing
> first (and keep open until you're done writing to /dev/bios) simply
> ensures that you can't do something dangerous like:
>
> cat >/dev/bios
>
> ...and end up with a corrupted bios.
>
> chip's ioctl idea (open, ioctl to ask to write, then write) would
> work as well.
>
> john
>
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.rutgers.edu

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu

\
 
 \ /
  Last update: 2005-03-22 13:41    [W:0.031 / U:0.032 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site