[PATCH v2 2/2] restrict /dev/mem to idle io memory ranges

[Dan Williams]

On Tue, Nov 24, 2015 at 4:47 PM, Andrew Morton
<akpm at linux-foundation.org> wrote:
> On Tue, 24 Nov 2015 16:34:19 -0800 Dan Williams <dan.j.williams at intel.com> wrote:
>
>> > IOW, a very good description of the problem-being-solved would help out
>> > a lot here...
>>
>> I'll fold the eventual result of this discussion into the changelog if
>> I can convince you it's worth moving forward.
>
> I'm easily convinced ;) Please let's get all the info into the right
> place, make sure it answers the thus-far-asked questions (at least) and
> we'll take it from there.
>
> And please do have a think about switching as much as possible over to
> runtime-configurability.  Because "please echo foo > /proc" is a heck
> of a lot nicer than "please reboot with iomem=" which is a heck of a lot
> nicer than "please ask vendor for a new kernel".

Actually, we already have runtime configuration.  For example, if you
want to muck with pmem via /dev/mem, just do this first:

    echo namespace0.0 > /sys/bus/nd/drivers/nd_pmem/unbind