Re: [Patch 0/2] powerpc: avoid userspace poking to legacy ioports

On Mon, 18 Feb 2008 21:58:42 +0100
Jean Delvare [off-list ref] wrote:

On Tue, 19 Feb 2008 07:42:03 +1100, Benjamin Herrenschmidt wrote:

quoted

quoted

Maybe Christian's patch can be improved to not do the check on
these? As long as /dev/port exists, it seems reasonable that the
kernel should behave, no matter what I/O ports are accessed from
user-space.

nonsense.

 /dev/mem exists for example, but you are still not supposed to go
bang all over the place in it.

You should at least be able to read from it without crashing the
machine. Of course writing is a different story.

keep dreaming. This is not how /dev/mem works today, not on x86 and very likely not on ppc either.