Re: [PATCH] x86, powerpc : pkey-mprotect must allow pkey-0

[Dave Hansen]

On 03/09/2018 12:06 PM, Ram Pai wrote:
> On Fri, Mar 09, 2018 at 09:19:53PM +1100, Michael Ellerman wrote:
>> Ram Pai <linuxram@xxxxxxxxxx> writes:
>>
>>> Once an address range is associated with an allocated pkey, it cannot be
>>> reverted back to key-0. There is no valid reason for the above behavior.  On
>>> the contrary applications need the ability to do so.
>> Please explain this in much more detail. Is it an ABI change?
> Not necessarily an ABI change. older binary applications  will continue
> to work. It can be considered as a bug-fix.

Yeah, agreed.  I do not think this is an ABI change.