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

[Benjamin Herrenschmidt <benh@kernel.crashing.org>]

> 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.

Discussing with Stephen, looking at the current 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. 

So I suppose the decision to actually copy _and_ convert those 3 fields
when moving a userland siginfo around is based on an analysis of what
userland usually does ? What bothers me is that any app that uses a
different siginfo layout will be broken between 32 bits and 32 bits
with this scheme, but maybe that just never happens ?

Ben.