Re: siginfo & 32 bits compat, what is the story ?

[Andi Kleen <ak@muc.de>]

Benjamin Herrenschmidt <benh@kernel.crashing.org> writes:

>> I believe the x86_64 method is correct.
>> 
>> It might be worth moving this compatibility code to a
>> common place where all architectures could reference it.
>
> Hrm... I just heard the opposite: that is, the x86_64 code allows
> some cruft to communicate between 32 and 64 bits, but breaks anything
> that uses more than those 3 copied fields, even between 2 32 bits
> applications.

Note that there are several kinds of x86-64 codes: the original one
and Joe's rewritten version in recent kernels. I don't know where
you heard it is broken, but maybe they were describing the older
code.

If they were refering to the recent version I assume they 
would have reported it to the maintainer. But they didn't ...

Anyways - i guess it's hard to make such a decision on hearsay.  I
would suggest you start with the x86-64 version and when there are
really problems you tell us about them and we fix them.

BTW there was a merged version from some PA-RISC person (with yet
another rewritten siginfo copy function) discussed, but for some
reason he dropped the ball. 

-Andi