PATCH: Add x32 arch_prctl support

[H.J. Lu]

On Mon, May 21, 2012 at 4:53 PM, Roland McGrath <roland@hack.frob.com> wrote:
>> The goes back to user uint32_t vs kernel uint64_t:
>>
>> http://sourceware.org/ml/libc-alpha/2012-05/msg01519.html
>>
>> The difference is movq vs movl.  There is no need for movq
>> since x32 will only pass unsigned 32-bit value to kernel.
>
> I see.  That one byte in a rarely-used call is not reason enough to
> make the code uglier.

Also since all inlined arguments will be casted to "long int",
using unsigned long long int or uint64_t is quite strange.

>> Thanks.  But since x32 kernel takes PTRACE_ARCH_PRCTL, I
>> still need x32 ptrace to either handle it properly or set EINVAL
>> when PTRACE_ARCH_PRCTL is passed.
>
> It was my proposal that the kernel be changed to refuse PTRACE_ARCH_PRCTL
> in a ptrace call made from an x32 task.
>

Adding Peter.  The x32 PTRACE_ARCH_PRCTL change is in kernel 3.4.
Peter, how hard to remove it from kernel?

-- 
H.J.