Re: [patch 5/9] x86/ioport: Reduce ioperm impact for sane usage further

Linus Torvalds
2019-11-07T16:53:49Z

On Thu, Nov 7, 2019 at 8:45 AM Eric W. Biederman <ebiederm@xmission.com> wrote:
>
> Further a quick look shows that dosemu uses ioperm in a fine grained
> manner. From memory it would allow a handful of ports to allow directly
> accessing a device and depended on the rest of the port accesses to be
> disallowed so it could trap and emulate them.

Yes. Making ioperm() some all-or-nothing thing would be horribly bad,
and has no real advantages that I can see.

Linus