On Tue, Dec 19, 2000 at 09:32:14PM +0100, Jes Sorensen wrote:
> >>>>> "ANK" == kuznet <kuznet@xxxxxxxxxxxxx> writes:
> ANK> Hello!
> >> The question is how much to copy.
> ANK> The answer is instant: MAC header only. 8)
> ANK> All the rest will be pulled out on demand.
> Thats where your suggestion fails, we then have to copy the entire
> packet then for the cards that disallow misaligned DMAs. My idea to
> add the misaligned word access would work.
Copying the header is identical to misaligned word accesses, except
that a small cache is put inbetween ;)
Doing it explicitely would be no replacement for kernel mode misalignment
though: when you make any mistake (and there are lots of places for that)
you have a remote exploitable kernel panic.
There is also probably other code in the kernel that has the same problem.