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Subject: Re: [PATCH] x86, powerpc : pkey-mprotect must allow pkey-0
To: Ram Pai <linuxram@us.ibm.com>, Michael Ellerman <mpe@ellerman.id.au>
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From: Dave Hansen <dave.hansen@intel.com>
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Date: Mon, 12 Mar 2018 08:46:04 -0700
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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@us.ibm.com> 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.