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Date: Tue, 24 Oct 2017 11:34:50 -0700
From: Ram Pai <linuxram@us.ibm.com>
To: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org, benh@kernel.crashing.org, paulus@samba.org,
 khandual@linux.vnet.ibm.com, aneesh.kumar@linux.vnet.ibm.com,
 bsingharora@gmail.com, hbabu@us.ibm.com, mhocko@kernel.org,
 bauerman@linux.vnet.ibm.com, ebiederm@xmission.com
Subject: Re: [PATCH 08/25] powerpc: sys_pkey_alloc() and sys_pkey_free()
 system calls
Reply-To: Ram Pai <linuxram@us.ibm.com>
References: <1504910713-7094-1-git-send-email-linuxram@us.ibm.com>
 <1504910713-7094-17-git-send-email-linuxram@us.ibm.com>
 <871sls4ke8.fsf@concordia.ellerman.id.au>
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On Tue, Oct 24, 2017 at 05:48:15PM +0200, Michael Ellerman wrote:
> Ram Pai <linuxram@us.ibm.com> writes:
> 
> > Finally this patch provides the ability for a process to
> > allocate and free a protection key.
> 
> This must be the last patch in the series.
> 
> We don't want to expose a half working interface to userspace.

The way the patch series is organized -- this patch; even-though
introduces the syscall, the syscall will fail because the pkey subsystem
is enabled only by the last patch. Till than the code exists , but does
a great job of failing with an appropriate return code.

Hope this helps,
RP