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Subject: Re: [PATCH v9 29/51] mm/mprotect, powerpc/mm/pkeys, x86/mm/pkeys:
 Add sysfs interface
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Ram Pai <linuxram@us.ibm.com>
Cc: Dave Hansen <dave.hansen@intel.com>, mpe@ellerman.id.au,
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Date: Thu, 21 Dec 2017 09:49:13 +1100
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On Wed, 2017-12-20 at 09:50 -0800, Ram Pai wrote:
> The argument against this patch is --  it should not be baked into
> the ABI as yet, since we do not have clarity on what applications need.
> 
> As it stands today the only way to figure out the information from
> userspace is by probing the kernel through calls to sys_pkey_alloc().
> 
> AT_HWCAP can be used, but that will certainly not be capable of
> providing all the information that userspace might expect.
> 
> Your thoughts?

Well, there's one well known application wanting that whole keys
business, so why not ask them what works for them ?

In the meantime, that shouldn't block the rest of the patches.

Cheers,
Ben.