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

Ram Pai linuxram at us.ibm.com
Sat Mar 10 07:00:17 AEDT 2018


On Fri, Mar 09, 2018 at 12:04:49PM +0100, Florian Weimer wrote:
> On 03/09/2018 09:12 AM, Ram Pai wrote:
> >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.
> 
> mprotect without a key does not necessarily use key 0, e.g. if
> protection keys are used to emulate page protection flag combination
> which is not directly supported by the hardware.
> 
> Therefore, it seems to me that filtering out non-allocated keys is
> the right thing to do.

I am not sure, what you mean. Do you agree with the patch or otherwise?
RP



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