Re: [PATCH 3.19 3/3] x86, mpx: Change the MPX enable/disable API to arch_prctl

[Andi Kleen]

Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> writes:

> On 12/29/2014 04:52 PM, Andy Lutomirski wrote:
>> This has the benefit the it avoids cluttering prctl with more
>> arch-specific functionality.  The down side is that arch_prctl will
>> need to be wired up as a 32-bit syscall to add 32-bit support for
>> MPX.
>
> There is existing userspace out there which depends on the existing
> prctl() setup.  There isn't a _lot_ and it might still be able to be
> changed easily, but this isn't a given.
>
> I'll check in with the folks doing the gcc (runtime) part of this next
> week and see what they think.

It'll be quite messy for 32bit because they would need to use syscall(),
as glibc won't have a arch_prctl stub.

-Andi

-- 
ak@xxxxxxxxxxxxxxx -- Speaking for myself only
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