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Re: Problem with x32 pointer_guard
On Mon, May 21, 2012 at 11:43 AM, Roland McGrath <roland@hack.frob.com> wrote:
>> roland/x32-setjmp-mangle branch looks OK, except for that we
>> also need to make similar change in:
>>
>> ./sysdeps/unix/sysv/linux/x86_64/____longjmp_chk.S
>
> Ah. ?Done.
>
>> If we want to be clever, we can reorder sysdeps/x86_64/setjmp.S to
>> use misaligned store for upper 32 bits of RBP instead of
>> shift and 32-bit store. ?But I don't think it is really needed.
>
> It's not a misaligned store, it's just a partially-redundant store, right?
Yes.
> The does seem more clever, and it's fewer instructions. ?I'll take your
> word on whether the redundant store is better than two more register-only
> instructions for performance.
>
> Please verify the new version on the branch.
>
I verified that it works on Linux/x32.
Thanks.
--
H.J.